

BIOGEOCHIMICAL-CYCLE


                                                                         1 of 1  
TI: Bacterial contribution to sedimentary organic matter: A comparative study of lipid moieties in bacterial and Recent sediments.
AU: Goossens,-H.; Rijpstra,-W.I.C.; Duren,-R.R.; De-Leeuw,-J.W.; Schenck,-P.A.
SO: ORG.-GEOCHEM. 1986. vol. 10, no. 4-6, pp. 683-696
LA: English
ER: M (Marine)
AN: 1462297

                                                                       1 of 313  
TI: Comparison of the phytoplankton species composition and structure in the Climax Area (1973-1985) with that of Station ALOHA (1994)
AU: Venrick,-E.L.
AF: Mar. Life Res. Group, Scripps Inst. Oceanogr., Univ. California at San Diego, La Jolla, CA 92093-0227, USA
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 7, pp. 1643-1648
LA: English
ER: M (Marine)
AB: In August 1994, water samples were collected from seven depths on each of two casts at the Hawaiian Ocean Time-series station (ALOHA; 22 degree 45'N, 158 degree W). These samples allowed a comparison between the larger phytoplankton taxa at ALOHA and those in the Climax Area (near 28 degree N, 155 degree W) that were collected during summers between 1973 and 1985. Of the 142 species found at ALOHA, all but 6 have been seen in the Climax Area. The two-layered structure that is typical of the Climax Area was also found at station ALOHA, where the break between shallow and deep associations occurred between 100- and 135-m depth. However, abundances of the deep species at ALOHA were lower than in the Climax Area. The correlations between the rank order of abundances of phytoplankton from Sta. ALOHA and from the Climax Area fell within the spectrum of correlations between pairs of stations from the Climax Area. These results indicate that in August 1994 the phytoplankton at Sta. ALOHA was indistinguishable from that in the Climax Area between 1973 and 1985. Nevertheless, many additional studies are needed before results from the Climax Area or results from the Hawaiian Ocean Time-series program can be unconditionally generalized.
AN: 4364335

                                                                       2 of 313  
TI: Organic carbon isotope systematics of coastal marshes
AU: Middelburg,-J.J.; Nieuwenhuize,-J.; Lubberts,-R.K.; Van-de-Plassche,-O.
AF: Netherlands Inst. Ecol., Cent. for Estuarine and Coastal Ecol., Korringaweg 7, 4401 NT Yerseke, The Netherlands
SO: ESTUAR.-COAST.-SHELF-SCI. 1997 vol. 45, no. 5, pp. 681-687
LA: English
ER: M (Marine); B (Brackish)
AB: Measurements of nitrogen, organic carbon and  delta  super(13)C are presented for Spartina-dominated marsh sediments from a mineral marsh in SW Netherlands and from a peaty marsh in Massachusetts, U.S.A.  delta  super(13) C of organic carbon in the peaty marsh sediments is similar to that of Spartina material, whereas that in mineral marshes is depleted by 9-12 ppt. It is argued that this depletion in  delta  super(13)C of organic matter in marsh sediments is due to trapping of allochthonous organic matter which is depleted in  super(13)C. The isotopic composition and concentration of organic carbon are used in a simple mass balance to constrain the amount of plant material accumulating in marsh sediments, i.e. in terms of the so-called net ecosystem production. Net ecosystem production ( similar to 2-100 g C/m super(2) year) is a small fraction (1-5%) of plant production ( similar to 2000 g C/m super(2)/year). This small amount of plant material being preserved is nevertheless sufficient to support marsh-accretion rates similar to the rate of sea-level rise.
AN: 4353774

                                                                       3 of 313  
TI: Conclusions to special issue: water quality and biology of United Kingdom rivers entering the North Sea: the Land Ocean Interaction Study (LOIS) and associated work
AU: Neal,-C.; House,-W.A.; Whitton,-B.A.; Leeks,-G.J.L.
AF: Institute of Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxon OX10 8BB, UK
SO: Sci.-Total-Environ. 1998 vol. 210-211, no. 1-6, pp. 585-594
NT: Special issue: Land Ocean Interaction Study (LOIS).
LA: English
AB: This volume deals with the extensive information collected as part of one of the most ambitious environmental research programmes ever undertaken in the United Kingdom: the Land Ocean Interaction Study (LOIS). It concerns the water quality and biology of major British rivers draining into the North Sea and presents the newer findings in the context of an earlier special volume which dealt with the first 2 years of LOIS riverine research. The findings of the recently completed field programme at the core of the research is enhanced by specialist contributions on the key processes determining water quality and biological functioning within the LOIS rivers. The combination of an effective large-scale approach with standardised but comprehensive and high quality monitoring, highly structured databases and a full commitment to integrated research at all scales and across all the relevant disciplines, has led to new insights into how the riverine environment functions as an open system linked to atmospheric and marine processes and fluxes. The LOIS provides a valuable template for future national and international approaches to pollutant impacts on river systems, the shelf edge and the open ocean as well as a way forward for integrated environmental research approach in the United Kingdom and other developed as well as developing countries.
AN: 4342341

                                                                       4 of 313  
TI: Simulating carbon flux to the estuary: The first step
AU: Eatherall,-A.; Naden,-P.S.; Cooper,-D.M.
AF: Institute of Hydrology, Crowmarsh Gifford, Wallingford, Oxon OX10 6BB, UK
SO: Sci.-Total-Environ. 1998 vol. 210-211, no. 1-6, pp. 519-533
NT: Special issue: Land Ocean Interaction Study (LOIS).
LA: English
AB: The sources and sinks (point and non-point) of dissolved organic carbon (DOC), particulate organic carbon (POC) and dissolved inorganic carbon (DIC) are identified for the purposes of simulating carbon flux to the estuary. The sources and sinks are separated into three categories: allochthonous; anthropogenic; and autochthonous with each category examined in turn. Carbon loads to the Humber estuary are calculated and a mass balance calculation is performed for a section of the River Swale in Yorkshire showing decomposition rates of  similar to  3.8 t C/ha/year and a flux of  similar to  161 kt C/year. Finally, initial non-point source models are presented for DOC, POC and DIC. These algorithms are incorporated into a hydrological model that is used within the LOIS programme to simulate the flux of carbon to the river.
AN: 4342337

                                                                       5 of 313  
TI: Anomalies in coral reef community metabolism and their potential importance in the reef CO sub(2) source-sink debate
AU: Chisholm,-J.R.M.; Barnes,-D.J.
AF: Australian Institute of Marine Science, Private Mail Bag No. 3, Mail Centre, Townsville, Queensland 4810, Australia
SO: Proc.-Natl.-Acad.-Sci.-USA 1998 vol. 95, no. 11, pp. 6566-6569
LA: English
AB: It is not certain whether coral reefs are sources of or sinks for atmospheric CO sub(2). Air-sea exchange of CO sub(2) over reefs has been measured directly and inferred from changes in the seawater carbonate equilibrium. Such measurements have provided conflicting results. We provide community metabolic data that indicate that large changes in CO sub(2) concentration can occur in coral reef waters via biogeochemical processes not directly associated with photosynthesis, respiration, calcification, and CaCO sub(3) dissolution. These processes can significantly distort estimates of reef calcification and net productivity and obscure the contribution of coral reefs to global air-sea exchange of CO sub(2). They may, nonetheless, explain apparent anomalies in the metabolic performance of reefs close to land and reconcile the differing experimental findings that have given rise to the CO sub(2) debate.
AN: 4318417

                                                                       6 of 313  
TI: A synoptic study of nutrients in the north-west Irish Sea
AU: Gibson,-C.E.; Stewart,-B.M.; Gowen,-R.J.
AF: Agric. and Environ. Sci. Div., Dep. Agric. for Northern Ireland, Newforge Lane, Belfast BT9 5PX, Northern Ireland, UK
SO: ESTUAR.-COAST.-SHELF-SCI. 1997 vol. 45, no. 1, pp. 27-38
LA: English
ER: M (Marine)
AB: Concentrations of nitrate and nitrite (N), phosphorus (P) and silica (Si) were measured at a grid of stations in the north-west Irish Sea throughout 1992. The data were treated synoptically by mapping and graphical analysis to integrate data from 28 different stations. In spring, there was concurrent depletion of N, Si and P in the molar ratio 9 times 5:6 times 4:1, indicating that N was depleted before P and Si. Areal integrals were calculated for N and P at each station, which ranged in depth between 15 and 150 m. Over the summer, P integrals reduced pro rata with depth up to 60 m, but in stations deeper than 60 m, there was no further reduction in P. In contrast the areal N integral decreased in proportion to depth even in the deepest stations. It is suggested that loss of N in the deepwater stations may be due to denitrification in the bosom water. Over the winter N, P and Si concentrations returned to the winter maximum in more or less constant proportions. Mechanisms for the control of the nitrate concentration are discussed. A desk budget suggests that in situ regeneration of nitrate is the dominant process.
AN: 4353833

                                                                       7 of 313  
TI: The use of amides and other organic nitrogen sources by the phytoplankton Emiliania huxleyi
AU: Palenik,-B.; Henson,-S.E.
AF: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0202, USA
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 7, pp. 1544-1551
LA: English
ER: M (Marine)
AB: Although dissolved organic nitrogen (DON) is beginning to be seen as a potentially important nitrogen source for phytoplankton, much remains to be learned about its components and their utilization. Emiliania huxleyi, a cosmopolitan eukaryotic phytoplankton species abundant in oligotrophic oceans and during blooms in some coastal regions, was screened for use of various DON compounds. Hypoxanthine and other purines support the nickel-dependent growth of most E. huxleyi strains. Acetamide and formamide but not longer chain aliphatic amides were found to be excellent nitrogen sources for growth; other phytoplankton were also found to utilize acetamide but not formamide. In E. huxleyi, small amides are transported into the cell followed by degradation to ammonia, possibly by amide-specific enzymes. The related molecules hydroxyurea and thiourea were toxic to the cells and caused an increase in fluorescence consistent with blockage of photosystem II. This fluorescence increase was inhibited by urea and acetamide, suggesting transport of hydroxyurea, thiourea, urea, and acetamide by the same or closely related transporters.
AN: 4342604

                                                                       8 of 313  
TI: Nutrient biogeochemistry of the coastal zone
AU: Jickells,-T.D.
AF: Sch. Environ. Sci., Univ. East Anglia, Norwich NR4 7TJ, UK
SO: Science-Wash. 1998 vol. 281, no. 5374, pp. 217-222
LA: English
ER: M (Marine)
AB: The coastal seas are one of the most valuable and vulnerable of Earth's habitats. Significant inputs of nutrients to the coastal zone arrive via rivers, groundwater, and the atmosphere. Nutrient fluxes through these routes have been increased by human activity. In addition, the N:P:Si ratios of these inputs have been perturbed, and many coastal management practices exacerbate these perturbations. There is evidence of impacts arising from these changes (in phytoplankton numbers and relative species abundance, and deep-water oxygen declines) in areas of restricted water exchange. Elsewhere, the nutrient fluxes through the coastal zone appear to be still dominated by large inputs from the open ocean, and there is little evidence of anthropogenic perturbations.
AN: 4340262

                                                                       9 of 313  
TI: Biogeochemical controls and feedbacks on ocean primary production
AU: Falkowski,-P.G.; Barber,-R.T.; Smetacek,-V.
AF: Inst. Mar. and Coast. Sci., Rutgers Univ., New Brunswick, NJ 08901-8521, USA
SO: Science-Wash. 1998 vol. 281, no. 5374, pp. 200-206
LA: English
ER: M (Marine)
AB: Changes in oceanic primary production, linked to changes in the network of global biogeochemical cycles, have profoundly influenced the geochemistry of Earth for over 3 billion years. In the contemporary ocean, photosynthetic carbon fixation by marine phytoplankton leads to formation of  similar to 45 gigatons of organic carbon per annum, of which 16 gigatons are exported to the ocean interior. Changes in the magnitude of total and export production can strongly influence atmospheric CO sub(2) levels (and hence climate) on geological time scales, as well as set upper bounds for sustainable fisheries harvest. The two fluxes are critically dependent on gephysical processes that determine mixed-layer depth, nutrient fluxes to and within the ocean, and food-web structure. Because the average turnover time of phytoplankton carbon in the ocean is on the order of a week or less, total and export production are extremely sensitive to external forcing and consequently are seldom in steady state. Elucidating the biogeochemical controls and feedbacks on primary production is essential to understanding how oceanic biota responded to and affected natural climatic variability in the geological past, and will respond to anthropogenically influenced changes in coming decades. One of the most crucial feedbacks results from changes in radiative forcing on the hydrological cycle, which influences the aeolian iron flux and, in turn, affects nitrogen fixation and primary production in the oceans.
AN: 4340259

                                                                      10 of 313  
TI: Quantifying fluid flow, solute mixing, and biogeochemical turnover at cold vents of the eastern Aleutian subduction zone
AU: Wallmann,-K.; Linke,-P.; Suess,-E.; Bohrmann,-G.; Sahling,-H.; Schlueter,-M.; Daahlmann,-A.; Lammers,-S.; Greinert,-J.; Von-Mirbach,-N.
AF: GEOMAR Res. Cent., Wischhofstr. 1-3, D-24148 Kiel, Germany
SO: GEOCHIM.-COSMOCHIM.-ACTA 1997 vol. 61, no. 24, pp. 5209-5219
LA: English
ER: M (Marine)
AB: In situ oxygen fluxes were measured at vent sites in the Aleutian Trench at a water depth of almost 5000 m using a TV-guided benthic flux chamber. The flux was 2 orders of magnitude greater than benthic oxygen fluxes in areas unaffected by venting on the continental margin off Alaska. Porewater profiles taken from the surface sediment below a vent site showed high concentrations of sulfide, methane, and ammonia. The reduced carbon and nitrogen compounds are transported to the vent site by fluids expelled from deeper anoxic sediment layers by the forces of plate convergence. The tectonically driven fluid flow was determined from the biochemical turnover in vent communities and was found to be 3.4  plus or minus  0.5 m/yr. A model was used to quantify the transport of silica, Ca super(2+), and sulfate via diffusion, advection, and bioirrigation through the surface sediments of a vent site. A nonlocal mixing coefficient of 20-30/yr was determined by fitting the model curves to the measured porewater profiles showing that the transport of solutes within the near-surface sediments and across the sediment-water interface is dominated by the activity of the vent fauna. Sulfate-containing oceanic bottom water and methane-rich vent fluids were mixed below the clam colony to produce sulfide and a CaCO sub(3) precipitate. The vent biota shape their immediate environment and control the sediment-water exchange and the benthic fluxes at vent sites. The oxygen consumption at vent sites is a major sink for oxygen at the study area.
AN: 4340114

                                                                      11 of 313  
TI: Ecology of southeastern salt marshes
AU: Vernberg,-F.J.
AF: Belle W. Baruch Inst. for Mar. Biol. and Coastal Res., Univ. South Carolina, Columbia, SC 29208, USA
CO: Sustainable Development in the Southeastern Coastal Zone Symp., Myrtle Beach, SC (USA), 2-5 Mar 1993
SO: SUSTAINABLE-DEVELOPMENT-IN-THE-SOUTHEASTERN-COASTAL-ZONE. Vernberg,-F.J.;Vernberg,-W.B.;Siewicki,-T.-eds. SC-USA UNIVERSITY-OF-SOUTH-CAROLINA-PRESS 1996 no. 20 pp. 117-133
ST: BELLE-W.-BARUCH-LIBR.-MAR.-SCI. no. 20
LA: English
ER: M (Marine); B (Brackish)
AB: Saltwater marshes are a dominant feature of the southeastern coastal landscape. Not only is the areal extent of these marshes great, but they play a significant role in the ecology of estuaries and coastal waters. Due to the dominant vascular plant, Spartina, and the attendant other plants, salt marshes are one of the most productive habitats in the world. Associated with the richness and abundance of food found in marsh-estuarine system are the many animal species utilize this system on either a temporary or permanent basis. About 90% of the commercial fishery landings in the Southeast include species that spend a portion of their life cycle in estuaries. Salt marshes are exposed to marked fluctuations in biotic and abiotic factors since they are exposed alternately to aerial and aquatic conditions depending upon such factors as tides, winds, and rainfall. The biotic structure of this habitat fluctuates and represents a complex series of food webs and biogeochemical cycles.
AN: 4340049

                                                                      12 of 313  
TI: Influence of mesoscale eddies on new production in the Sargasso Sea
AU: McGillicuddy,-D.J.,Jr.; Robinson,-A.R.; Siegel,-D.A.; Jannasch,-H.W.; Johnson,-R.; Dickey,-T.D.; McNeil,-J.; Michaels,-A.F.; Knap,-A.H.
AF: Dep. Applied Ocean Phys. and Eng., Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: Nature 1998 vol. 394, no. 6690, pp. 263-266
LA: English
ER: M (Marine)
AB: It is problematic that geochemical estimates of new production--that fraction of total primary production in surface waters fuelled by externally supplied nutrients--in oligotrophic waters of the open ocean surpass that which can be sustained by the traditionally accepted mechanisms of nutrient supply. In the case of the Sargasso Sea, for example, these mechanisms account for less than half of the annual nutrient requirement indicated by new production estimates based on three independent transient-tracer techniques. Specifically, approximately one-quarter to one-third of the annual nutrient requirement can be supplied by entrainment into the mixed layer during wintertime convection, with minor contributions from mixing in the thermocline and wind-driven transport (the potentially important role of nitrogen fixation--for which estimates vary by an order of magnitude in this region--is excluded from this budget). Here we present four lines of evidence--eddy-resolving model simulations, high-resolution observations from moored instrumentation, shipboard surveys and satellite data--which suggest that the vertical flux of nutrients induced by the dynamics of mesoscale eddies is sufficient to balance the nutrient budget in the Sargasso Sea.
AN: 4338953

                                                                      13 of 313  
TI: [Study of decomposition of marine macrophytes]
OT: Estudio de descomposicion de macrofitos marinos
AU: Granado-Reyes,-I.; Caballero-Ortega,-P.
AF: Dpto. Biologia, Facultad Ciencias del Mar, ULPGC, Las Palmas de Gran Canaria, Canary Islands, Spain
CA: Instituto Canario de Ciencias Marinas, Las Palmas de Gran Canaria (Spain)
CO: 1. Congreso sobre Oceanografia y Recursos Marinos en el Atlantico Centro-Oriental, Gran Canaria (Spain), 28-30 Nov 1990
SO: Oceanography-and-marine-resources-in-the-eastern-Central-Atlantic.-OCEANOGRAFIA-Y-RECURSOS-MARINOS-EN-EL-ATLANTICO-CENTRO-ORIENTAL Llinas,-O.;Gonzalez,-J.A.;Rueda,-M.J.-eds. Las-Palmas-de-Gran-Canaria-Spain ICCM 1996 pp. 143-154
LA: Spanish
ER: M (Marine)
AB: Marine macrophyte litter degrades through a rapid leaching phase, a second phase in which decomposers degrade the litter, and a third very slow phase during which refractory compounds remain or are formed. The chemical composition of the litter is the major factor controlling the decay rates during the phases of decomposition. In order to investigate the decomposition rate, the leaching of soluble components and the chemical changes in the decomposing tissue of marine macrophytes, laboratory incubations were performed of 3 seaweeds (Enteromorpha compressa, Fucus spiralis, Gelidium canariensis) and a seagrass (Cymnodocea nodosa), under aerobic conditions.
AN: 4334026

                                                                      14 of 313  
TI: Release and bioavailability of C, N, P, Se, and Fe following viral lysis of a marine chrysophyte
AU: Gobler,-C.J.; Hutchins,-D.A.; Fisher,-N.S.; Cosper,-E.M.; Sanudo-Wilhelmy,-S.A.
AF: Mar. Sci. Res. Cent., State Univ. New York, Stony Brook, NY 11794-5000, USA
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 7, pp. 1492-1504
LA: English
ER: M (Marine)
AB: The potential importance of the viral lysis of phytoplankton for nutrient and carbon cycling has been acknowledged, but no quantitative assessments of this phenomenon exist. Radiotracer experiments examined the release and bioavailability of C, N, P, Fe, and Se following viral lysis of the "brown tide" chrysophyte Aureococcus anophagefferens. Photochemical effects on the dissolved-particulate partitioning and biological uptake of virally released elements were also investigated. Viral lysis of A. anophagefferens released 50% more C and Se than uninfected control cells to the dissolved phase, while N, P, and Fe remained in the particulate phase. There was a significant inverse correlation between A. anophagefferens and bacterial densities, as well as an increase in particulate organic nitrogen levels in cultures during viral lysis. These observations indicate that released dissolved organic matter supported bacterial growth and may be a pathway by which various elements are diverted in microbial food webs. Dissolved nutrients released by viral lysis were accumulated to varying degrees by natural assemblages of marine bacteria and cultured diatoms, and virally regenerated N and P relieved diatom nutrient limitation. During a 4-wk incubation, 80% of C and P within cell lysis debris was released to the dissolved phase, likely due to bacterial activity. Photochemical degradation of cell lysis debris enhanced dissolved levels of Se (100%) and Fe (50%) and reduced total dissolved C by 15%. Photochemistry doubled the bioavailability of virally released Se to diatoms, while decreasing the bioavailability of C to bacteria threefold. The viral lysis of an A. anophagefferens bloom in the field could release 40  mu M dissolved organic carbon and rapidly transfer other released elements to bacteria. Such occurrences may significantly affect water column chemistry, species composition, and succession within marine plankton communities.
AN: 4337203

                                                                      15 of 313  
TI: Mahoney Lake: A case study of the ecological significance of phototrophic sulfur bacteria
AU: Overmann,-J.
AF: Inst. fuer Chemie und Biologie des Meeres, Univ. Oldenburg, D-26111 Oldenburg, Germany
SO: ADV.-MICROB.-ECOL. 1997 vol. 15, pp. 251-284
LA: English
ER: F (Freshwater)
AN: 4337182

                                                                      16 of 313  
TI: Seasonal changes in the biochemistry of lake seston
AU: Kreeger,-D.A.; Goulden,-C.E.; Kilham,-S.S.; Lynn,-S.G.; Datta,-S.; Interlandi,-S.J.
AF: Patrick Center for Environmental Research, Academy of Natural Sciences, 19th and The Parkway, Philadelphia, PA 19103, USA
SO: Freshwat.-Biol. 1997 vol. 38, no. 3, pp. 539-554
NT: Special issue: The role of food quality for zooplankton. (Proceedings of a PEG workshop held at Nieuwersluis, the Netherlands, 17-21 March 1996).
LA: English
ER: F (Freshwater)
AB: The quantity of seston was measured and the elemental carbon, nitrogen and phosphorus (C, N, P) and biochemical composition (carbohydrates, proteins, lipids) of the <53  mu m size fraction in three temperate lakes, (lakes Giles, Lacawac and Waynewood), during one year were analysed. The lakes were characterized as oligotrophic, mesotrophic and eutrophic. Linear regression analyses defined associations between seston composition and either lake trophic status, depth or season. Concentrations of seston C, N and P were high in most cases in the spring and autumn and low in summer. Concentrations of P were particularly high during late summer and early autumn in the metalimnion, perhaps because of recovery of P from anaerobic sediments and hypolimnetic waters. Concentrations of protein, carbohydrate, polar lipid and triglyceride generally increased with lake type as expected (greatest in the eutrophic lake). As the year progressed, the concentration of polar lipid decreased. The biochemical composition of seston varied during the year and among lakes; for example, in Lake Waynewood the proportion of protein composing the seston (% protein by weight) varied from <10% to >40%. These seasonal biochemical changes in the seston food base were compared with biochemical changes known to occur in algae grown under N- or P-limited conditions in the laboratory, and the resultant quality of this algal food for suspension-feeding consumers (zooplankton). It was concluded that zooplankton were likely to be physiologically challenged by these distinct seasonal shifts in the quality of lake seston.
AN: 4334402

                                                                      17 of 313  
TI: Roles of submicron particles and colloids in microbial food webs and biogeochemical cycles within marine environments
AU: Nagata,-T.; Kirchman,-D.L.
AF: Ocean Res. Inst., Univ. Tokyo, Nakano, Tokyo 164, Japan
SO: ADV.-MICROB.-ECOL. 1997 vol. 15, pp. 81-103
LA: English
ER: M (Marine)
AB: This chapter presents recently emerging ideas on interactions of colloids and microorganisms and their implications for trophic dynamics and biogeochemical cycles in aquatic environments. We will emphasize interdisciplinary interactions between microbiology and geochemistry, where new perspectives are rapidly growing. Some challenging areas of future studies are also discussed.
AN: 4332607

                                                                      18 of 313  
TI: Geochemical constraints on chemolithoautotrophic metabolism by microorganisms in seafloor hydrothermal systems
AU: McCollom,-T.M.; Shock,-E.L.
AF: MS 4, Woods Hole Oceanographic Inst., Woods Hole, MA 02543, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA 1997 vol. 61, no. 20, pp. 4375-4391
LA: English
ER: M (Marine)
AB: Mixing of hydrothermal fluids and seawater at the ocean floor, combined with slow reaction kinetics for oxidation/reduction reactions, provides a source of metabolic energy for chemolithotrophic microorganisms which are the primary biomass producers for an extensive submarine ecosystem that is essentially independent of photosynthesis. Thermodynamic models are used to explore geochemical constraints on the amount of metabolic energy potentially available from chemosynthetic reactions involving S, C, Fe, and Mn compounds during mixing of hydrothermal fluids with seawater. For the vent fluid used in the calculations (EPR 21 degree N OBS), the model indicates that mixing environments are favorable for oxidation of H sub(2)S, CH sub(4), Fe super(2+) and Mn super(2+) only below  similar to 38 degree C, with methanogenesis and reduction of sulfate or S degree  favored at higher temperatures, suggesting that environments dominated by mixing provide habitats for mesophilic (but not thermophilic) aerobes and thermophilic (but not mesophilic) anaerobes. A maximum of  similar to 760 cal per kilogram vent fluid is available from sulfide oxidation while between 8 and 35 cal/kg vent fluid is available from methanotrophy, methanogenesis, oxidation of Fe or Mn, or sulfate reduction. The total potential for chemosynthetic primary production at deep-sea hydrothermal vents globally is estimated to be about 10 super(13) g biomass per year, which represents  similar to 0.02% of the global primary production by photosynthesis in the oceans. Thermophilic methanogens and sulfate- and S degree -reducers are likely to be the predominant organisms in the walls of vent chimneys and in the diffuse mixing zones beneath warm vents, where biological processes may contribute to the high methane concentrations of vent fluids and heavy  super(34)S/ super(32)S ratios of vent sulfide minerals. The metabolic processes taking place in these systems may be analogs of the first living systems to evolve on the Earth.
AN: 4332573

                                                                      19 of 313  
TI: Nitrogen elimination in two deep eutrophic lakes
AU: Mengis,-M.; Gaechter,-R.; Wehrli,-B.; Barnasconi,-S.
AF: Swiss Federal Inst. for Environ. Sci. and Technol. (EAWAG), Limnological Res. Cent., CH-6047 Kastanienbaum, Switzerland
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 7, pp. 1530-1543
LA: English
ER: F (Freshwater)
AB: Nitrogen elimination was investigated in two eutrophic Swiss lakes with different hypolimnetic oxygen conditions. Nitrogen burial was estimated from sediment-trap and sediment-core studies. Denitrification and NO sub(3) super(-)-ammonification rates were quantified with  super(15)NO sub(3) super(-) and acetylene incubation experiments and whole-lake mass balances. The study confirmed earlier reports that the acetylene-block technique yields denitrification rates that are systematically too low. Denitrification rates obtained from isotope tracer experiments were compatible with nitrogen consumption rates observed in flux chamber experiments and whole-lake mass balances. The NO sub(3) super(-)-ammonification contributed <5% to the NO sub(3) super(-) consumption rate in Lake Baldegg. Coupled nitrification-denitrification seemed to be insignificant at the deepest station of Lake Baldegg. The comparison of in situ denitrification rates measured at the deepest site (4.3 mmol m super(-2) d super(-1)) with the denitrification rate obtained from whole-lake mass balances (6.1 mmol m super(-2) d super(-1)) indicates that enhanced denitrification may be present in shallower sediments with a better supply of O sub(2). Mass transfer coefficients for NO sub(3) super(-) were similar in both lakes (21.7 and 21.4 m yr super(-1)). The NO sub(3) super(-) concentration seems to be a key parameter in determining denitrification rates.
AN: 4331990

                                                                      20 of 313  
TI: Iron-limited diatom growth and Si:N uptake ratios in a coastal upwelling regime
AU: Hutchins,-D.A.; Bruland,-K.W.
AF: Coll. Mar. Stud., Univ. Delaware, Lewes, DE 19958, USA
SO: Nature 1998 vol. 393, no. 6685, pp. 561-564
LA: English
ER: M (Marine)
AB: There is compelling evidence that phytoplankton growth is limited by iron availability in the subarctic Pacific, and equatorial Pacific and Southern oceans. A lack of iron prevents the complete biological utilization of the ambient nitrate and influences phytoplankton species composition in these open-ocean "high-nitrate, low-chlorophyll" (HNLC) regimes. But the effects of iron availability on coastal primary productivity and nutrient biogeochemistry are unknown. Here we present the results of shipboard seawater incubation experiments which demonstrate that phytoplankton are iron-limited in parts of the California coastal upwelling region. As in offshore HNLC regimes, the addition of iron to these nearshore HNLC waters promotes blooms of large chain-forming diatoms. The silicic acid:nitrate (Si:N) uptake ratios in control incubations are two to three times higher than those in iron incubations. Diatoms stressed by a lack of iron should therefore deplete surface waters of silicic acid before nitrate, leading to a secondary silicic acid limitation of the phytoplankton community. Higher Si:cell, Si:C and Si:pigment ratios in diatoms in the control incubations suggest that iron limitation leads to more silicited, faster-sinking diatom biomass. These results raise fundamental questions about the nature of nutrient-limitation interactions in marine ecosystems, paleoproductivity estimates based on the sedimentary accumulation of biogenic opal, and the controls on carbon export from some of the world's most productive surface waters.
AN: 4327200

                                                                      21 of 313  
TI: A modelling study of ecosystem dynamics and nutrient cycling in the Humber Plume, UK
AU: Allen,-J.I.
AF: Plymouth Mar. Lab., Prospect Place, West Hoe, Plymouth PL1 3DH, UK
SO: J.-SEA-RES. 1997 vol. 38, no. 3-4, pp. 333-359
NT: Special Issue: European Regional Seas Ecosystem Model II.
LA: English
ER: M (Marine)
AB: The European Regional Seas Ecosystem Model (ERSEM) has been coupled with a two-dimensional depth-averaged transport model of the Humber plume region and run to simulate 1988-1989. Simulations of the spatial and temporal variations in chlorophyll-a, nitrate, phosphate and suspended particulate matter distributions in winter, spring and summer show how the development of the spring bloom and subsequent maintenance of primary production is controlled by the physicochemical environment of the plume zone. Results are also shown for two stations, one characterised by the high nutrient and suspended matter concentrations of the plume and the other by the relatively low nutrient and sediment concentrations of the offshore waters. The modelled net primary production at the plume site was 105 g C/m super(2)/a and 127 g C/m super(2)/a offshore. Primary, production was controlled by light limitation between October and March and by the availability of nutrients during the rest of the year. The phytoplankton nutrient demand is met by in-situ recycling processes during the summer. The likely effect of increasing and decreasing anthropogenic riverine inputs of nitrate and phosphate upon ecosystem function was also investigated. Modelling experiments indicate that increasing the nitrogen to silicate ratio in freshwater inputs increased the production of non-siliceous phytoplankton in the plume. The results of this model have been used to calculate the annual and quarterly mass balances describing the usage of inorganic nitrogen, phosphate and silicate within the plume zone for the period of the NERC North Sea survey (September 1988 to October 1989). The modelled Humber plume retains 3.9% of the freshwater dissolved inorganic nitrogen, 2.2% of the freshwater phosphate and 1.3% of the freshwater silicate input over the simulated seasonal cycle. The remainder is transported into the southern North Sea in either dissolved or particulate form. The reliability of these results is discussed.
AN: 4321469

                                                                      22 of 313  
TI: Predictive models for phosphorus retention in wetlands
AU: Richardson,-C.J.; Qian,-S.; Craft,-C.B.; Qualls,-R.G.
AF: Duke Univ. Wetland Cent., Nicholas Sch. Environ., Durham, NC 27708, USA
CO: International Workshop "Nutrient Cycling and Retention in Wetlands and Their Use in Wastewater Treatment", Trebon (Czech Rep.), 5-9 Sep 1995
SO: WETLANDS-ECOL.-MANAGE. 1997 vol. 4, no. 3, pp. 159-175
LA: English
AB: The potential of wetlands to efficiently remove (i.e., act as a nutrient sink) or to transform nutrients like phosphorus under high nutrient loading has resulted in their consideration as a cost-effective means of treating wastewater on the landscape. Few predictive models exist which can accurately assess P retention capacity. An analysis of the north American data base (NADB) allowed us to develop a mass loading model that can be used to predict P storage and effluent concentrations from wetlands. Phosphorus storage in wetlands is proportional to P loadings but the output total phosphorus (TP) concentrations increase exponentially after a P loading threshold is reached. The threshold P assimilative capacity based on the NADB and a test site in the Everglades is approximately 1 g m super(-2) yr super(-1). We hypothesize that once loadings exceed 1 g m super(-2) yr super(-1) and short-term mechanisms are saturated, that the mechanisms controlling the uptake and storage of P in wetlands are exceeded and effluent concentrations of TP rise exponentially. We propose a "One Gram Rule" for freshwater wetlands and contend that this loading is near the assimilative capacity of wetlands. Our analysis further suggests that P loadings must be reduced to 1 g m super(-2) yr super(-1) or lower within the wetland if maintaining long-term low P output concentrations from the wetlands is the central goal.
AN: 4314866

                                                                      23 of 313  
TI: Colloid/solution partitioning of metal-selective organic ligands, and its relevance to Cu, Pb and Cd cycling in the Firth of Clyde
AU: Muller,-F.L.L.
AF: Department of Chemistry, University of Bergen, Allegaten 41, 5007 Bergen, Norway
SO: Estuar.-Coast.-Shelf-Sci. 1998 vol. 46, no. 3, pp. 419-437
LA: English
AB: The electrochemical lability of Cu, Pb and Cd and the complexation parameters (stability constants, ligand concentrations) of their organic ligands were determined by anodic stripping voltammetry (ASV) in 14 samples collected in April-May 1994 from the lower Clyde Estuary (S<30.0), through the surface estuarine plume (30.0<S<32.4), and into the Clyde Sea. The titrations were applied to 0.4  mu m-filtered and cross-flow filtered ( similar to  1 nm cut-off) fractions of each sample. In addition, the surface electrical properties of the colloidal matter (1 nm<size<0.4  mu m) were examined in 0.01 M NaCl medium as a function of pH by dynamic light scattering (DLS) electrophoresis. Copper was carried to the Clyde Sea by the plume largely in a dissolved form but subsequently reacted with - or formed - colloids. These colloids were either of marine origin or built up in situ from smaller sub-units such as organic macromolecules originating from the sediments. Overall, the degree of organic complexation for Cu (typically 76-96%) was less than that reported in other inshore marine systems. Biological production of strong ligands did take place in an adjoining loch, but their control on Cu speciation (up to 99.99% Cu in inert forms) remained localized. By contrast, organic complexation was sufficient to maintain pPb (pPb = - log [Pb super(2+)]) as high as 11.7-12.5. Lead in river runoff was extensively and strongly bound to organics. A unique class of ligands of in situ origin and belonging to the colloidal phase was detected at 40 m depth, i.e. under the plume. This colloidal material had limited affinity for Cd and no detectable affinity for Cu, and probably consisted of the remains of micro-organisms which must have been concentrated at this depth by the plume circulation. Despite some affinity for the above-mentioned colloidal ligands (resulting in 54-88% complexation) and for the dissolved ligands produced by phytoplankton (59-64% complexation), Cd was generally poorly bound (0-30% complexation) and the ligands responsible were mostly of marine origin. Although a fraction of the particulate Pb (associated with Mn-rich particles) was removed from the surface plume by sedimentation, the major modification in the seaward flux seemed to occur at the leading edge of the plume. There was a change in the speciation of Pb across this frontal zone, from a dominance by colloids and macroparticles in the plume to a situation where most of Pb found in the 0.4  mu m-filtered fraction was also present in the <1 nm permeate. In contrast, Cu became less extensively associated with the dissolved phase away from the plume. When interpreted in combination, the ASV and DLS results show that two bulk properties of organic coatings on colloids (electrophoretic mobility and second acidity constant), important in the context of colloid stability, can explain some of the variability in the colloid-solution partitioning of metal-complexing ligands. What is more, the surface electrical state of the colloids appears to have a different effect on the adsorption of Pb-binding ligands than on that of Cu-binding ligands, supporting the conclusion reached from the spatial distribution of ligands that they are metal-selective.
AN: 4308463

                                                                      24 of 313  
TI: Geoacoustic and physical properties of carbonate sediments of the Lower Florida Keys
AU: Richardson,-M.D.; Lavoie,-D.L.; Briggs,-K.B.
AF: Marine Geosciences Division, Naval Research Laboratory, Stennis Space Center, MS 39529-5004, USA
SO: Geo-Mar.-Lett. 1997 vol. 17, no. 4, pp. 316-324
NT: Special issue: Benthic boundary layer processes in the Lower Florida Keys.
LA: English
AB: Near-surface sediment geoacoustic and physical properties were measured from a variety of unconsolidated carbonate sediments in the Lower Florida Keys. Surficial values of compressional and shear speed correlate with sediment physical properties and near-surface acoustic reflectivity. Highest speeds (shear 125-150 m s super(-1); compressional 1670-1725 m s super(-1)) are from sandy sediments near Rebecca Shoal and lowest speeds (shear 40-65 m s super(-1); compressional 1520-1570 m s super(-1)) are found in soft, silty sediments which collect in sediment ponds in the Southeast Channel of the Dry Tortugas. High compressional wave attenuation is attributed to scattering of acoustic waves from heterogeneity caused by accumulation of abundant shell material and other impedance discontinuities rather than high intrinsic attenuation. Compared to siliciclastic sediments, carbonate sediment shear wave speed is high for comparable values of sediment physical properties. Sediment fabric, rather than changes due to the effects of biogeochemical processes, is responsible for these differences.
AN: 4269892

                                                                      25 of 313  
TI: Diffusion and reactions in the vicinity of plankton: A refined model for inorganic carbon transport
AU: Wolf-Gladrow,-D.; Riebesell,-U.
AF: Alfred-Wegener-Institute for Polar and Marine Research, Postfach 120161, D-27515 Bremerhaven, Germany
SO: MAR.-CHEM. 1997 vol. 59, no. 1-2, pp. 17-34
LA: English
ER: m
AB: Inorganic carbon uptake by phytoplankton depletes the immediate cell environment and disturbs the carbonate system equilibrium. Uptake is balanced by both diffusional transport across and chemical reactions within the depleted boundary layer. In this study, we have derived a model that simulates inorganic carbon diffusion and reactions in the vicinity of phytoplankton cells. To allow a general application of the model, the reaction kinetics of the carbonate system are reviewed and temperature- and salinity-dependence of the various rate constants are discussed. A consistency condition for some of the kinetic rates is derived. The effective thickness of the diffusive boundary layer in spherical and planar geometry is discussed. In addition, the effect of cell shape on diffusive transport to phytoplankton is examined and a simple means to account for this effect in model calculations is presented. In a second step, the complete description of the diffusion-reaction system is simplified to consider two special cases in which (1) algal production relies on CO2(aq) as the single source of inorganic carbon, and (2) CO2, HCO3-, or CO32- are utilized independently for organic matter production combined with calcite precipitation. In the size range typical for phytoplankton cells model predictions of these simplified versions are nearly identical to those of the complete model, indicating that the simplified models represent good approximations of the complete diffusion-reaction system.
AN: 4212144

                                                                      26 of 313  
TI: Factors controlling trophic conditions in the north-west Adriatic basin: seasonal variability
AU: Giordani,-P.; Miserocchi,-S.; Balboni,-V.; Malaguti,-A.; Lorenzelli,-R.; Honsell,-G.; Poniz,-P.
AF: Istituto per la Geologia Marina, CNR - Via Gobetti 101, 40129 Bologna, Italy
SO: MAR.-CHEM. 1997 vol. 58, no. 3-4, pp. 351-360
LA: English
ER: m
AB: The North-Adriatic basin shows typical shallow water mass characteristics which in a first approach, can be considered independent of the Middle and the Southern basins, being more affected by seasonal temperature and salinity variability. Primary production estimates represent the main quantitative assessments of the trophic conditions of a marine system, resulting from the combined effect of a large number of oceanographic factors. In this paper the results from three EUROMARGE AS (EEC-MAST II-MTP project) field trips carried out in 1994 are presented as a contribution to the better understanding of the factors controlling the trophic balance in the Northern Adriatic basin. These results include: depth profiles of salinity, nutrients and chlorophyll a concentrations, oxygen saturation, phytoplankton taxonomy and abundance, estimated biomass and primary production measurements by the 14C in-situ incubation method. The field trips were carried out in three seasons (February, July, September 1994) and the results reported belong to three stations in the northern basin, 5 miles off Ravenna, Cesenatico and Ancona, respectively. As expected, the physical situation of the water column was different in the three periods: the water was mixed in February and stratified in July and September. Nutrient concentrations were higher in winter, whilst the maximum of primary production was measured in September. The phytoplankton was composed predominantly of diatoms. The correlations between primary production and salinity reflect a difference in the factors controlling primary production. During February and September nutrients coming from rivers play an important role, although with a decreasing influence from station 1, nearest to the Po delta, towards station 3. Depth profiles of nutrient concentrations and O2 saturation measured during summer in the water column suggest that regeneration of nutrients in the water column down to the bottom boundary layer must play an important role in the nutrient cycling and dynamics in the basin.
AN: 4212139

                                                                      27 of 313  
TI: The effects of river input on the ecosystem dynamics in the continental coastal zone of the North Sea using ERSEM
AU: Lenhart,-H.J.; Radach,-G.; Ruardij,-P.
AF: Inst. fuer Meereskunde der Univ. Hamburg, Troplowitzstrasse 7, D-22529 Hamburg, Germany
SO: J.-SEA-RES. 1997 vol. 38, no. 3-4, pp. 249-274
NT: Special Issue: European Regional Seas Ecosystem Model II.
LA: English
ER: M (Marine)
AB: The general characteristics of the continental coastal zone, with nutrient concentrations, primary production and biomass high near the coast but decreasing with distance from the coast, are simulated by a box-refined version of the ecosystem model ERSEM. Aggregated model results compared to the literature as well as to two different three-dimensional models show a good agreement in the coastal region. The dynamical interactions as simulated by the ecosystem model are presented in the form of N/P ratios, the limitation by various nutrients and changes in the pathways of the flow of matter in the boxes; e.g. while the silicate limitation stops the spring bloom offshore, near the coast it is terminated by zooplankton grazing. When the river load was reduced by 50%, the largest effect was observed in the coastal boxes with 15% reduction of the net primary production. The discharges of the major rivers hardly affect the central North Sea, but lead to significant changes in nutrient limitations and mass flows in the coastal area. The realistic forcing, which was adopted for this setup, allows a higher net primary production in the southern North Sea in 1989 than in 1988, even though the nutrient river loads in 1989 were lower. The reason appears to be a higher solar energy input in 1989, by about 10 W/m super(2)/d, compared to 1988.
AN: 4314956

                                                                      28 of 313  
TI: Climatological annual cycles of nutrients and chlorophyll in the North Sea
AU: Radach,-G.; Paetsch,-J.
AF: Inst. fuer Meereskunde der Univ. Hamburg, Troplowitzstrasse 7, D-22529 Hamburg, Germany
SO: J.-SEA-RES. 1997 vol. 38, no. 3-4, pp. 231-248
NT: Special Issue: European Regional Seas Ecosystem Model II.
LA: English
ER: M (Marine)
AB: A large amount of nutrient and chlorophyll data from the North Sea were compiled and organised in a research data base to produce annual cycles on a relatively fine spatial resolution of 1 degree  in each horizontal direction. The data originate from many different sources and were partly provided by the ECOMOD data base of the Institut fuer Meereskunde in Hamburg and partly by ICES in Copenhagen to cover the time range from 1950 to 1994. While the annual cycles of nutrients and chlorophyll derived for the continental coastal zone are representative for the decade 1984-1993 only, those for the remaining parts of the North Sea may be considered climatological annual cycles based on data from more than four decades. The composite data set of climatological annual cycles of medians and their climatological ranges is well suited to serve for validational and forcing purposes for ecosystem models of the North Sea, which have a resolution larger than or equal to 1 degree  in both longitude and latitude. The annual cycles of the macronutrients and chlorophyll presented here for 1 degree  x 1 degree  squares in the North Sea show especially that sufficient observational data exist to provide initial, forcing and validational data for the simulations with the 130-box setup (ND130) of the ecosystem model ERSEM. The annual cycles presented give a clear picture for the whole of the North Sea. The highest concentrations occur at the continental coasts as a result of continued river input, which is added to the ongoing atmospheric input over the North Sea. Also, from the Atlantic Ocean water with relatively high nutrient concentrations enters the North Sea via the northern boundary. In the productive areas on and around the Dogger Bank nutrient concentrations are lower than in the other parts of the North Sea, even in winter. The areas with seasonal stratification have very different annual cycles in the upper (0-30 m) and lower layers (30 m-bottom). The shallow boxes are fully mixed and exhibit a relatively fast increase of nutrient concentrations caused by summer regeneration of nutrients.
AN: 4314955

                                                                      29 of 313  
TI: An analysis of benthic biological dynamics in a North Sea ecosystem model
AU: Blackford,-J.C.
AF: Plymouth Mar. Lab., Prospect Place, West Hoe, Plymouth PL1 3DH, UK
SO: J.-SEA-RES. 1997 vol. 38, no. 3-4, pp. 213-230
NT: Special Issue: European Regional Seas Ecosystem Model II.
LA: English
ER: M (Marine)
AB: This paper presents an overview and analysis of the benthic biological submodel of the European Regional Seas Ecosystem Model II (ERSEM II). This submodel consists of a detailed model description of the benthic system which is integrated with a marine ecosystem model which attempts to address the full range of pelagic and benthic biogeochemical and physical processes. The submodel simulates the seasonal dynamics of a number of functional groups, ranging from decomposers to predators and their interaction with detrital matter in the sediments. The improvements and extensions to the benthic biology submodel compared with the previous published version of the European Regional Seas Ecosystem Model are described. The improvements comprise: the reformulation of turbation and irrigation as functions of faunal activity, the inclusion of oxygen stress limitations and mortalities, a refinement of the description of detritus, additions to the diet of the filter feeders in line with the extensions to the primary production module and an extensive re-parameterisation. Using the 1 degree  x 1 degree  North Sea application, the submodel predictions are compared with data and the performance of the submodel assessed. Using the results of the submodel, the relation between benthic biological dynamics and its principal determinants, depth and overlying production is examined. The model is found to give qualitatively correct results. The transition in community type from anaerobe/deposit feeder in the south to a more mixed community in the north, involving aerobes and meiobenthos is also correctly predicted by the model. The biology is demonstrated to have a strong influence on nutrient efflux. The lack of resuspension/deposition processes is identified as the most significant omission from the current model.
AN: 4314954

                                                                      30 of 313  
TI: Carbon sources and cycle in the western Mediterranean - the use of molecular markers to determine the origin of organic matter
AU: Bouloubassi,-I.; Lipiatou,-E.; Saliot,-A.; Tolosa,-I.; Bayona,-J.M.; Albaiges,-J.
AF: Departement de Geologie et Oceanographie, URA CNRS 197, Univ. de Bordeaux I Nouvelle, Ave. des Facultes, 33405 Talence, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 781-799
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: A series of molecular organic markers were determined in surface sediment samples collected in the Rhone and Ebro prodeltas and the western Mediterranean Basin in order to map and estimate the flux of naturally-derived organic matter inputs to the area. Continental and marine inputs were characterized by the distributions of n-alkanes, n-fatty acids, sterols, and polycyclic aromatic hydrocarbons (PAHs) such as retene, perylene and tetrahydrochrysenes ( capital sigma THC). The distribution of terrestrial markers evidenced the influence of rivers as main vectors of continentally-derived inputs in the area. In the data set of the Rhone delta and slope, including stations from the Gulf of Lions, significant correlations were observed between the organic content of sediment and the  capital sigma THC and retene concentrations (R super(2) = 0.88 and 0.68, respectively) and between  capital sigma THC levels and the  delta  super(13)C of the organic matter (R super(2) = 0.89). The transport and settling of naturally-derived terrigenous material in the Ebro prodelta were reflected by the distribution of vascular plant n-alkanes. These refractory materials were preserved in the deep basin. Additionally, the distributions of fatty acids and sterols in the Ebro prodelta clearly evidenced algal signatures resulting from the enrichment of deltaic waters by nutrients transported by the river. Based on biomarker data a criterion is proposed to assess the percentage of terrestrial organic carbon in sediments, considering the river mouth sediment as the continental end-member. Fluxes of terrigenous organic inputs were calculated using sediment accumulation rates. Depositional flux estimates for the deltaic area off the Rhone River ( similar to 15 340 km super(2)) were as follows: 216 kg /year for  capital sigma THC, 104 kg/year for retene, 11 t/year for terrestrial n-alkanes. The accumulation rates in the area of influence of the Ebro River ( similar to 12 600 km super(2)) were 69 kg/year for retene and 6 t/year for terrestrial n-alkanes. Comparison of these data with estimates of riverine inputs suggests that the bulk inputs of terrestrial biomarkers are trapped within the terminal part of the river bed and in the narrow prodeltaic area in front of the river mouths to a depth of approximately 70 m. Atmospheric deposition may also contribute to the accumulation of terrigenous materials in the deep basin.
AN: 4314936

                                                                      31 of 313  
TI: Production of carbonate particles by phytobenthic communities on the Mallorca-Menorca shelf, Northwestern Mediterranean Sea
AU: Canals,-M.; Ballesteros,-E.
AF: Associated Unit on Mar. Geosciences CSIC-UB, Dep. de Geologia Dinamica, Geofisica i P., Univ. de Barcelona, Nucli Universitari de Pedralbes, E-08071 Barcelona, Spain
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 611-629
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: In this paper the carbonate content and production, both at the species level and at the community level, is quantified in four areas of the Mallorca-Menorca shelf, northwestern Mediterranean Sea. Eight benthic communities are identified, each living at specific depth ranges and preferentially colonising either rocky or sedimented soft bottoms: (1) Photophilic algae, (2) Hemisciaphilic algae, (3) Coralligenous algal-dominated, (4) Coralligenous animal-dominated, (5) Caulerpa-Cymodocea meadows, (6) Posidonia oceanica meadows, (7) maerl and free-Peyssonelia beds, and (8) sandy bottom communities. Encrusting and maerl species of Corallinales and of the red algal genus Peyssonelia and, to a lesser extent, the green alga Halimeda tuna, are the main carbonate producers. Most of the modern algal carbonate production in the Mallorca-Menorca shelf occurs at depths of less than 85-90 m, which is the lower limit of the coralligenous and maerl communities. Algal carbonate production in rocky areas is usually higher than that of soft bottoms, with the exception of the maerl beds in moderately deep waters (40-85 m). The highest algal carbonate production is found in coralligenous algal-dominated rock bottoms (464.6 g m super(-2) year super(-1)), photophilic algal communities (289.4 g m super(-2) year super(-1)) and maerl beds (210 g m super(-2) year super(-1)), while the lowest is displayed by seagrass meadows (60 to 70 g m super(-2) year super(-1)) and sandy bottoms (0.5 g m super(-2) year super(-1)). Nevertheless, the contribution of seagrass beds to benthic carbonate production in the Mallorca-Menorca shelf is outstanding due to the extent of the area occupied by these beds. The mean algal carbonate production rate over the upper 100 m water depth in the studied localities ranges from 90.60 to 123.89 g m super(-2) year super(-1), which correspond to the mostly sedimented Campos area and to the very rocky South Cabrera area, respectively. Overall mean carbonate production of the Mallorca-Menorca shelf is around 100 g CO sub(3)Ca m super(-2) year super(-1). These results may be viewed as a minimum estimate for total carbonate production on the Mallorca-Menorca shelf since they take into account only the phytobenthos.
AN: 4314934

                                                                      32 of 313  
TI: 1-D Coupled physical-biological model of the northwestern Mediterranean Sea
AU: Tusseau,-M.-H.; Lancelot,-C.; Martin,-J.-M.; Tassin,-B.
AF: Inst. de Biogeochimie Mar., URA CNRS No. 386, Ecole Normale Superieure, 1, Rue M. Arnoux, 92 120 Montrouge, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 851-880
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: A 1-D coupled physical-biological model of the ecosystem of the Ligurian Sea is described. The physical model has been adapted from a thermal dispersive lake model, and the biological model from the sub-models AQUAPHY and H.S.B. The biological model considers two types of phytoplankton, diatoms and nonsiliceous flagellates, to describe the response of the phytoplankton community and the related food-web to different types of fertilization (by river, atmospheric deposition or deep water upwelling) with different N:Si ratios. This distinction, and the detailed description of the microbial loop, helps to distinguish between new and regenerated primary production. The model has been calibrated on FRONTAL 1986 data, obtained monthly at a long-term station (43 degree 24'N, 07 degree 52'E). The quantitative biomass, its repartition between diatoms and flagellates, and its spatio-temporal variability are reasonably well reproduced by the model. From these simulations, an annual new production of 62 g C/m super(2) is computed, contributing 35% of total annual primary production (180 g C/m super(2)). This calculation reflects the oligotrophic state of the system, where regenerated production occurs most of the year while the biomass remains low. A Monte-Carlo sensitivity analysis performed on the parameters driving the model leads to a confidence interval for the simulation and also to a better understanding of how the model functions.
AN: 4314933

                                                                      33 of 313  
TI: Dynamics of nitrogen and phosphorus retention during wetland ecosystem succession
AU: Craft,-C.B.
AF: Dep. Biol., Univ. Louisville, Louisville, KY 40292, USA
CO: International Workshop "Nutrient Cycling and Retention in Wetlands and Their Use in Wastewater Treatment", Trebon (Czech Rep.), 5-9 Sep 1995
SO: WETLANDS-ECOL.-MANAGE. 1997 vol. 4, no. 3, pp. 177-187
LA: English
AB: We compared the mechanisms of nitrogen (N) and phosphorus (P) removal in four young (<15 years old) constructed estuarine marshes with paired mature natural marshes to determine how nutrient retention changes during wetland ecosystem succession. In constructed wetlands, N retention begins as soon as emergent vegetation becomes established and soil organic matter starts to accumulate, which is usually within the first 1-3 years. Accumulation of organic carbon in the soil sets the stage for denitrification which, after 5-10 years, removes approximately the same amount of N as accumulating organic matter, 5-10 g/m super(2)/yr each, under conditions of low N loadings. Under high N loadings, the amount of N stored in accumulating organic matter doubles while N removal from denitrification may increase by an order of magnitude or more. Both organic N accumulation and denitrification provide for long-term reliable N removal regardless of N loading rates. Phosphorus removal, on the other hand, is greatest during the first 1-3 years of succession when sediment deposition and sorption/ precipitation of P are greatest. During this time, constructed marshes may retain from 3 g P/m super(2)/yr under low P loadings to as much as 30 g P/m super(2) /yr under high loadings. However, as sedimentation decreases and sorption sites become saturated, P retention decreases to levels supported by organic P accumulation (1-2 g P/m super(2)/yr) and sorption/ precipitation with incoming aqueous and particulate Fe, Al and Ca. Phosphorus cycling in wetlands differs from forest and other terrestrial ecosystems in that conservation of P is greatest during the early years of succession, not during the middle or late stages. Conservation of P by wetlands is largely regulated by geochemical processes (sorption, precipitation) which operate independently of succession. In contrast, the conservation of N is controlled by biological processes (organic matter accumulation, denitrification) that change as succession proceeds.
AN: 4314867

                                                                      34 of 313  
TI: Marine biological processes in polar region and global climate change
AU: Wang,-Zipan
AF: 2nd Inst. Oceanogr., SOA, Hangzhou 310012, People's Rep. China
SO: Donghai-Mar.-Sci.-Donghai-Haiyang 1997 vol. 15, no. 3, pp. 29-36
LA: Chinese
AB: In this paper, the transfer and flux of carbon and other biogenic material in marine biological processes, and its importance to global climate changeare discussed. the interrelationship among sea water, sea ice and marine organismsis also illusrated. Thus it expresses the significance of biological products affecting marine ecosystem and climate change in polar regions.
AN: 4313313

                                                                      35 of 313  
TI: Particulate lipid composition in waters of the Ob' River estuary and the southeastern Kara Sea
OT: Sostav lipidov vzvesi v vodakh ehstuariya Obi i yugo-vostochnoj chasti Karskogo morya
AU: Aleksandrova,-O.A.; Shevchenko,-V.P.
AF: IORAN, Moscow, Russia
SO: Okeanologiya 1997 vol. 37, no. 5, pp. 715-722
LA: Russian
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Content and distribution of particulate lipids along the Ob' River-Kara Sea profile (Russia) were studied by thin-layer chromatography with flame ionization detection (Iatroscan TH-10). The content of lipids varied from 18.4 to 266  mu g/L and constituted 4.06 to 58.32% of the total particulate organic matter. Major constituents of particulate lipids were hydrocarbons (an average of 32.14% of the total lipids), polar compounds (29.85%), wax and sterol esters (13.04%), and mono- and diglycerides (12.52). Composition of particulate lipids along the Ob' River-Kara Sea section is greatly influenced by the river discharge and reflects differences in the processes of organic matter transformation between the marine parts of the section as well as species composition of Arctic marine communities.
AN: 4313154

                                                                      36 of 313  
TI: Accumulation of sedimentary lipid biomarkers in the Kara Sea sediments
OT: Zakonomernosti akkumulyatsii lipidov-biomarkerov v vodnykh osadkakh Karskogo morya
AU: Belyaeva,-A.N.; Ehglinton,-Dzh.
AF: IORAN, Moscow, Russia
SO: Okeanologiya 1997 vol. 37, no. 5, pp. 705-714
LA: Russian
ER: M (Marine)
AB: Distribution of terrigenous, planktogenous and bacterial sedimentary lipids was studied by analysis of the molecular lipid composition in bottom sediments along the section from the Ob' River mouth (Russia) to 76 degree N. Terrigenous compounds were found to be dominant in all major lipid fractions (fatty acids, alcohols, alkanes) but their distribution along the section was irregular and decreased in the northern part of the section due to increasing accumulation of planktogenous lipids in consequence of transport of primarily synthesized organic matter by zooplankton.
AN: 4313153

                                                                      37 of 313  
TI: Tetrazolium reduction in acidic Sphagnum-derived peat
AU: Wieder,-R.K.; Yavitt,-J.B.; Gasda,-C.E.; Starr,-S.T.; Williams,-C.J.
AF: Dep. Biol., Villanova Univ., Villanova, PA 19085, USA
SO: WETLANDS 1998 vol. 18, no. 1, pp. 79-83
LA: English
ER: F (Freshwater)
AB: Assessment of how carbon storage in peat and gas fluxes across the peatland/atmosphere interface may be affected by predicted climate changes requires an understanding of the controls on C mineralization in peat. Toward this end, our goal was to develop the INT[2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride] reduction procedure for use in the field as a rapid and reliable approach to estimating C mineralization (CO sub(2) and CH sub(4) production) in peat under near-natural conditions with considerable spatial and temporal replication. Sphagnum peat samples collected from three sites were divided and analyzed for INT reduction activity, as well as for production of CO sub(2) and CH sub(4), under both oxic and anoxic conditions. For peat from each site, we found no significant relationships between INT reduction and oxic or anoxic CO sub(2) or CH sub(4) production. Although INT is reduced in acidic Sphagnum peat, INT reduction rates do not provide a usable index of C mineralization.
AN: 4310185

                                                                      38 of 313  
TI: Variability of pCO sub(2) in the Tropical Atlantic in 1995
AU: Lefevre,-N.; Moore,-G.; Aiken,-J.; Watson,-A.; Cooper,-D.; Ling,-R.
AF: Plymouth Mar. Lab., Plymouth, UK
SO: J.-GEOPHYS.-RES.-C-OCEANS 1998 vol. 103, no. C3, pp. 5623-5634
LA: English
ER: M (Marine)
AB: Atmospheric and oceanic partial pressures of CO sub(2) (pCO sub(2)) have been recorded automatically along two Atlantic meridional transects in 1995. The Tropical Atlantic ocean (20 degree S-20 degree N) is generally a source of CO sub(2) for the atmosphere, but in the region of the North Equatorial Countercurrent an undersaturation of CO sub(2) has been observed. Undersaturations previously reported in the literature are explained by the decrease of salinity due to the high precipitations associated with the Intertropical Convergence Zone. In June 1995, strong CO sub(2) undersaturations ( Delta pCO sub(2) = -70  mu atm) were observed near 8 degree N, which suggests, in addition of the salinity effect, an uptake of CO sub(2) due to biological activity. This undersaturation, although weaker than in spring, also appeared at other periods of the year 1995.
AN: 4310068

                                                                      39 of 313  
TI: Methane production and methane consumption: A review of processes underlying wetland methane fluxes
AU: Segers,-R.
AF: Department of Theoretical Production Ecology, Wageningen Agricultural University, PO Box 430, 6700 AK Wageningen, The Netherlands
SO: BIOGEOCHEMISTRY 1998 vol. 41, no. 1, pp. 23-51
LA: English
ER: F (Freshwater)
AB: Potential rates of both methane production and methane consumption vary over three orders of magnitude and their distribution is skew. These rates are weakly correlated with ecosystem type, incubation temperature, in situ aeration, latitude, depth and distance to oxic /anoxic interface. Anaerobic carbon mineralisation is a major control of methane production. The large range in anaerobic CH sub(4):CO sub(2) production rates indicate that a large part of the anaerobically mineralised carbon is used for reduction of electron acceptors, and, hence, is not available for methanogenesis. Consequently, cycling of electron acceptors needs to be studied to understand methane production. Methane and oxygen half saturation constants for methane oxidation vary about one order of magnitude. Potential methane oxidation seems to be correlated with methanotrophic biomass. Therefore, variation in potential methane oxidation could be related to site characteristics with a model of methanotrophic biomass.
AN: 4309278

                                                                      40 of 313  
TI: Long-term study of litter decomposition on a Pennine peat bog: Which regression?
AU: Latter,-P.M.; Howson,-G.; Howard,-D.M.; Scott,-W.A.
AF: 74 Jutland Avenue, Flookburgh, Grange over Sands, Cumbria LA11 7LQ, UK
SO: OECOLOGIA 1997 vol. 113, no. 1, pp. 94-103
LA: English
ER: F (Freshwater)
AB: It is estimated that in the northern hemisphere one-third of the world pool of soil carbon is contained in peat resulting from an incomplete decomposition of plant remains. The time course for the decomposition of the predominant plant litters on a Pennine moorland in northern England is reported for a study extending over 23 years. Spatial variation of the weight remaining of decomposing litters increased with time. This experimental study gave an age for the upper layers of the bog and a curve for long-term decay based on direct observation rather than inferred from profile samples or from short-term observations. It showed that short-term observations can give misleading results in the long term, with a variety of litters with differing early decay rates ultimately making a similar contribution to accumulation. Spatial variation of the weight remaining of the decomposing litters increased with time, so that variation within micro-environments, or within apparantly uniform substrates, may contribute significantly to organic matter accumulation. An asymptotic curve best described the long-term course of decomposition leading to the accumulation of peat. The use of the model for the three litter types, Calluna vulgaris, Eriophorum vaginatum and Rubus chamaemorus, is described and the implication of the results for modelling of organic matter accumulation are then discussed.
AN: 4308814

                                                                      41 of 313  
TI: Modelling the signal transfer of seawater  delta  super(18)O to the  delta  super(18)O of atmospheric oxygen using a diagnostic box model for the terrestrial and marine biosphere
AU: Leuenberger,-M.C.
AF: Climate and Environ. Phys., Univ. Bern, Bern, Switzerland
SO: J.-GEOPHYS.-RES.-C-OCEANS 1997 vol. 102, no. C12, pp. 26,841-26,850
LA: English
ER: M (Marine)
AB: We make use of a simple diagnostic box model to determine the sensitivities of the influencing parameters for the isotopic signal transfer of seawater oxygen to atmospheric oxygen. We calculate the  delta  super(18)O of atmospheric oxygen from prescribed oxygen fluxes of the living and dead biomes on land and in the ocean, respectively. The model is driven by an assumed (experiment 1) or measured (experiments 2 and 3) temporal seawater  delta  super(18)O signal and a land biomass estimation. In experiment 1, we calculated the required changes of several model parameters in order to study fast variations of  delta  super(18)O of atmospheric oxygen as seen in the Greenland Ice Core Project (GRIP) ice at depths assigned to the Eemian time period. Our calculations support evidence of stratigraphic problems at these depths in the GRIP ice core. In experiment 2, we adjusted the model output, which was driven by the benthic seawater  delta  super(18)O record from V19-30, to the measured Greenland Ice Sheet Project 2  delta  super(18)O record of atmospheric oxygen for the last 110,000 years, by varying the model parameter. Single and multiparameter matchings were performed. The results for single-parameter runs exceed the uncertainty ranges for most of the parameters, while multiparameter variations are well within these ranges. The model calculations are most sensitive to the land respiration factor. Our results support the findings of Van de Water et al. [1994] that the fractionations associated with biomes activities were most probably lower during cold periods, which could point to a combination of fractionations with different temperature dependencies. The model results indicate periods of higher marine biological activity during the ice age than today. Temporal variations of the model parameters show a double peak around 10000 and 8000 years ago, which could be associated with meltwater pulses, as shown in experiment 3. However, they are hardly the well-known Fairbanks [Fairbanks et al., 1992] pulses since these occur 3000 to 4000 years earlier.
AN: 4296864

                                                                      42 of 313  
TI: Retention of NO sub(3) super(-) in an upland stream environment: A mass balance approach
AU: Burns,-D.A.
AF: U.S. Geol. Surv., 425 Jordan Rd., Troy, NY 12180, USA
SO: BIOGEOCHEMISTRY 1998 vol. 40, no. 1, pp. 73-96
LA: English
ER: F (Freshwater)
AB: Models of the effects of atmospheric N deposition in forested watersheds have not adequately accounted for the effects of aquatic and near-stream processes on the concentrations and loads of NO sub(3) super(-) in surface waters. This study compared the relative effects of aquatic and near-stream processes with those from the terrestrial ecosystem on the retention and transport of NO sub(3) super(-) in two contrasting stream reaches of the Neversink River, a forested watershed in the Catskill Mountains of New York that receives among the highest load of atmospheric N deposition in the northeastern United States. Results generally confirm that aquatic and near-stream processes cause significant losses of NO sub(3) super(-) in the Neversink River, and that the losses by these processes at downstream locations can exceed the NO sub(3) super(-) contributions to the stream from the terrestrial environment during summer and fall base-flow conditions. Failure to consider these aquatic and near-stream processes in models of watershed response to atmospheric N deposition could result in underestimates of the amount of NO sub(3) super(-) leaching from forested ecosystems and to an inability to unequivocally relate geographic differences in NO sub(3) super(-) concentrations of stream waters to corresponding differences in terrestrial processes.
AN: 4295551

                                                                      43 of 313  
TI: Net and gross sedimentation in relation to the phosphorus budget of Eau Galle Reservoir, Wisconsin
AU: James,-W.F.; Barko,-J.W.
AF: U.S. Army Engineer Waterways Experiment Stn., Eau Galle Aquatic Ecol. Lab., Spring Valley, WI 54767, USA
SO: HYDROBIOLOGIA 1997 vol. 345, no. pt. 1, pp. 15-20
NT: Special issue: Sediment-Water Interaction 7.
LA: English
ER: F (Freshwater)
AB: We compared P retention with direct measures of P sedimentation, estimated from sediment cores (annual P sedimentation) and sediment traps (daily P sedimentation), to quantify P sedimentation in Eau Galle Reservoir, Wisconsin. Mean annual P retention was similar to mean annual P sedimentation, as estimated from sediment core rates integrated over the entire lake basin, indicating that annual P mass balance approximated annual net P sedimentation in this reservoir. However, sediment trap P rates, measured over the summer stratified period, overestimated P retention rates determined over the same period, suggesting substantial deposition of internally-derived P. Inclusion of measured internal P loadings from a variety of sources in Eau Galle Reservoir in a P mass balance only accounted for an additional 24% of the summer sediment trap P rate, indicating substantial uncertainty in the overall P budget. Imbalances in the P budget may also suggest deposition of sediment from other as yet unquantified internal sources. Potential internal sources of P include sediment resuspension and chemical release and direct uptake of P from the sediment by phytoplankton.
AN: 4292773

                                                                      44 of 313  
TI: The types of aquatic ecosystems and their integral kinetic characteristics
AU: Gladyshev,-M.I.
AF: Inst. Biophys., Siberian Div., Russian Acad. Sci., Akademgorodok, Krasnoyarsk, 660036 Russia
SO: WATER-RESOUR.;VODNYE-RESURSY 1997 vol. 24, no. 5, pp. 484-489;vol. 24, no. 5, pp. 526-531
LA: English
ER: F (Freshwater)
AB: The hypothesis is proposed that a finite number of discrete types of ecosystems exist in time and space, and each type has its own definite integral functional (kinetic) characteristics. The notions of "general" and "specific" integral kinetic characteristics are considered. The hypothesis is substantiated based on the data on the kinetics of amino acid consumption by natural communities of microorganisms and on the kinetics of decay (self-purification) of phenols in natural water streams and bodies.
AN: 4291219

                                                                      45 of 313  
TI: Pyrite accumulation and sulfate depletion as affected by root distribution in a Juncus (needle rush) salt marsh
AU: Hsieh,-Y.P.; Yang,-C.H.
AF: Wetland Ecol. Prog., Florida A & M Univ., Tallahassee, FL 32307, USA
SO: ESTUARIES 1997 vol. 20, no. 3, pp. 640-645
LA: English
ER: M (Marine); B (Brackish)
AB: This study was undertaken to investigate patterns of pyrite accumulation found in a Juncus roemerianus tidal marsh of north Florida. We speculate that the pattern of pyrite accumulation was caused mainly by the distribution of roots. Sediment cores from living stands (LS), dead stands (DS), and recently killed stands (RKS) were collected and analyzed for dissolved organic carbon (DOC), sulfate, chloride, Cr(II)-reducible sulfide, and biomass of roots and rhizomes. Living roots were distributed mainly in the upper 16 cm and concentrated at 4-10 cm below the sediment surface. Pyrite accumulations were significantly different among the three types of sediment cores in the upper 16 cm sediment and follow the descending order of DS (615  mu mol cm super(-3)) > RKS (547  mu mol cm super(-3)) > LS (368  mu mol cm super(-3)). Between 20 cm and 30 cm, pyrite contents approached values of 40  mu mol cm super(-3) and 55  mu mol cm super(-3) in all sediment cores. The degree of pyritization approaches 92-94% between 14 cm and 20 cm where pyrite accumulation was probably limited by available iron. Root distribution also affected the redistribution of iron through iron sulfide formation. Sulfate depletion in the upper 16 cm was higher in RKS (79.3  mu mol cm super(-3)) than DS (49.1  mu mol cm super(-3)). No significant sulfate depletion was found in LS. Sulfate reduction under DS was likely limited by the readily available substrates. Root distribution had a major influence on pyrite accumulation and sulfate reduction of the marsh, and its effects need to be addressed in studies of wetland sulfur dynamics.
AN: 4290674

                                                                      46 of 313  
TI: Spatial distribution of acid-volatile sulfur in the sediments of Canadohta Lake, PA, [USA]
AU: Oehm,-N.J.; Luben,-T.J.; Ostrofsky,-M.L.
AF: Dep. Biol., Allegheny Coll., Meadville, PA 16335, USA
SO: HYDROBIOLOGIA 1997 vol. 345, no. pt. 1, pp. 79-85
NT: Special issue: Sediment-Water Interaction 7.
LA: English
ER: F (Freshwater)
AB: Lake sediments are an important source of dissolved substances and can be the site of processes important to the biogeochemical cycling of nutrients and metals. Most studies which examine these processes, however, are based on the analysis of a single or a very few sediment cores taken at or near the deepest area of the lake. The implicit assumption is that lake sediments are spatially homogeneous and that extrapolations from such limited samples are representative of the lake sediments throughout the lake basin. We examined this assumption with respect to concentrations of acid volatile sulfides (S super(2) super(-) sub(vol)) - sulfur species which have been implicated in eutrophication, acid-neutralization, and heavy-metal toxicity. S super(2) super(-) sub(vol) concentrations measured in the surficial sediments of Canadohta Lake, PA, a lake of very simple morphometry, ranged from 0.07 to 30.32  mu g g super(-1) sediment dry weight. Concentrations were directly correlated with depth and inversely correlated with organic matter. These results suggest that results extrapolated from a few deep-water cores can lead to a serious overestimation of S super(2) super(-) sub(vol) in the lake sediments.
AN: 4288846

                                                                      47 of 313  
TI: An autobiotic wetland phosphorus model
AU: Kadlec,-R.H.
AF: Wetland Manage. Serv., 6995 Westbourne Dr., Chelsea, MI 48118-9527, USA
SO: ECOL.-ENG. 1997 vol. 8, no. 2, pp. 145-172
LA: English
ER: F (Freshwater)
AB: Constructed and natural wetlands are capable of absorbing new phosphorus loadings, and in appropriate circumstances can provide a low cost alternative to chemical and biological treatment. Phosphorus (P) interacts strongly with wetland soils and biota, which provide both short term and sustainable long term storage of this nutrient. Soil sorption may provide initial removal, but this partly reversible storage eventually becomes saturated. Uptake by biota, including bacteria, algae, and duckweed, as well as macrophytes, forms an initial removal mechanism. Cycling through growth, death and decomposition returns most of the biotic uptake, but an important residual contributes to long term accretion in newly formed sediments and soils. Despite the apparent complexity of these several removal mechanisms, data analysis shows that relatively simple equations can describe the sustainable processes. Previous global first order removal rates characterize the sustainable removal, but do not incorporate any biotic features. This paper presents an autobiotic model, based upon cycling through the biomass compartments, and calibrates it to data from 17 years of operation of the Houghton Lake, MI treatment wetland. This model replaces a first order concentration-based rate with a first order biomass-based rate. When coupled with mass balances, it describes the spatial distribution of both biomass and P concentrations, as well as the evolution of the new standing crop.
AN: 4282512

                                                                      48 of 313  
TI: Effect of biogeochemical diagenesis on sediment fabric in shallow marine carbonate sediments near the Dry Tortugas, Florida
AU: Furukawa,-Y.; Lavoie,-D.; Stephens,-K.
AF: Institute of Marine Sciences, University of Southern Mississippi, Stennis Space Center, MS 39529, USA
SO: Geo-Mar.-Lett. 1997 vol. 17, no. 4, pp. 283-290
NT: Special issue: Benthic boundary layer processes in the Lower Florida Keys.
LA: English
AB: Shallow marine carbonate sediments near the Dry Tortugas undergo extensive biogeochemical diagenesis upon deposition, resulting in postdepositional fabric comprised of micritic aggregates of clay-sized particles, a matrix of peloidal mud, and intraparticular cementation. Freshly deposited primary skeletons, mostly Halimeda fragments, yield micritic aggregates of clay-sized particles, which then form peloidal mud fabric upon compaction. The cryptocrystalline particles produced by micritization are later replaced by high magnesian calcite. Cementation is observed in the intra-particular microenvironment. However, no inter-particular, grain-binding cement was detected throughout the gravity core samples investigated.
AN: 4269888

                                                                      49 of 313  
TI: Benthic boundary layer processes in the Lower Florida Keys
AU: Lavoie,-D.L.; Richardson,-M.D.; Holmes,-C.
AF: Marine Geosciences Division, Naval Research Laboratory, Stennis Space Center, MS 39529-5004, USA
SO: Geo-Mar.-Lett. 1997 vol. 17, no. 4, pp. 232-236
NT: Special issue: Benthic boundary layer processes in the Lower Florida Keys.
LA: English
AB: This special issue of Geo-Marine Letters, "Benthic Boundary Layer Processes in the Lower Florida Keys," includes 12 papers that present preliminary results from the Key West Campaign. The Dry Tortugas and Marquesas Keys test sites were selected by a group of 115 scientists and technicians to study benthic boundary layer processes in a carbonate environment controlled by bioturbation and biogeochemical processes. Major activities included remote sediment classification; high-frequency acoustic scattering experiments; sediment sampling for radiological, geotechnical, biological, biogeochemical, physical, and geoacoustic studies; and hydrodynamic studies using an instrumented tetrapod. All these data are being used to improve our understanding of the effects of environmental processes on sediment structure and behavior.
AN: 4269881

                                                                      50 of 313  
TI: Effects of dissolved organic carbon and salinity on bioavailability of mercury
AU: Barkay,-T.; Gillman,-M.; Turner,-R.R.
AF: Dep. Mol. Microbiol. and Biotechnol., Tel Aviv Univ., Ramat Aviv 69978, Israel
SO: APPL.-ENVIRON.-MICROBIOL. 1997 vol. 63, no. 11, pp. 4267-4271
LA: English
ER: F (Freshwater)
AB: Hypotheses that dissolved organic carbon (DOC) and electrochemical charge affect the rate of methylmercury [CH sub(3)Hg(I)] synthesis by modulating the availability of ionic mercury [Hg(II)] to bacteria were tested by using a mer-lux bioindicator (Escherichia coli). A decline in Hg(II)-dependent light production was observed in the presence of increasing concentrations of DOC, and this decline was more pronounced at pH 7 than at pH 5, suggesting that DOC is a factor controlling the bioavailability of Hg(II). A thermodynamic model (MINTEQA2) was used to select assay conditions that clearly distinguished among various Hg(II) species. By using this approach, it was shown that negatively charged forms of mercuric chloride (HgCl sub(3) super(-)/HgCl sub(4) super(2-)) induced less light production than the electrochemically neutral form (HgCl sub(2)), and no difference was observed between the two neutral forms, HgCl sub(2) and Hg(OH) sub(2). These results suggest that the negative charge of Hg(II) species reduces their availability to bacteria and may be one reason why accumulation of CH sub(3)Hg(I) is more often reported to occur in freshwater than in estuarine and marine biota.
AN: 4268223

                                                                      51 of 313  
TI: Spatial distribution and inhibition by ammonium of methane oxidation in intertidal freshwater marshes
AU: Van-der-Nat,-F.-J.W.A.; De-Brouwer,-J.F.C.; Middelburg,-J.J.; Laanbroek,-H.J.
AF: Cent. for Estuarine and Coastal Ecol., Netherlands Inst. Ecol., Yerseke, The Netherlands
SO: APPL.-ENVIRON.-MICROBIOL. 1997 vol. 63, no. 12, pp. 4734-4740
LA: English
ER: F (Freshwater)
AB: In two intertidal marshes, the vertical distribution in the sediment and inhibition by ammonium of methane oxidation were investigated by slurry incubation experiments. The two sites differ in their dominant vegetation type, i.e., reed and bulrush, and in their heights above sea level. The reed site was elevated with respect to the bulrush site, resulting in a lower frequency and duration of flooding and, consequently, a higher potential for methane oxidation. Methane oxidation decreased with depth in the bulrush and reed slurries, although methane oxidation associated with root material from the bulrush plants increased with depth. Reed root material had a limited capacity for methane oxidation and showed no significant increase with depth. Inhibition of methane oxidation by ammonium was observed in all samples and depended on methane and ammonium concentrations. Increasing ammonium concentrations resulted in greater inhibition, and increasing methane concentrations resulted in less. Ammonium concentrations had to exceed methane concentrations by at least 30-fold to become effective for inhibition. This ratio was found only in the surface layer of the sediment. Hence, the ecological relevance for ammonium inhibition of methane oxidation in intertidal marshes is rather limited and is restricted to the surface layer. Nitrate production was restricted to the 0- to 5-cm-depth slurries.
AN: 4266459

                                                                      52 of 313  
TI: Reconstructing the iron cycle from the horizontal distribution of metals in the sediment of Baldeggersee
AU: Schaller,-T.; Moor,-H.C.; Wehrli,-B.
AF: Limnological Res. Cent., Swiss Federal Inst. for Environ. Sci. and Technol. (EAWAG), CH-6047 Kastanienbaum, Switzerland
SO: AQUAT.-SCI. 1997 vol. 59, no. 4, pp. 326-344
NT: Special issue: High resolution varve studies in Baldeggersee.
LA: English
ER: F (Freshwater)
AB: In Baldeggersee, the distributions of solid phase Fe, Mn, V, Cr, As and Mo were determined in different sediment strata, deposited under various deep-water oxygen conditions. Iron concentrations are correlated with water depth when an anoxic sediment is in contact with an oxic water column. Benthic redox gradients trigger iron transport towards the deepest site (geochemical focusing) and loss of iron from the shallower parts through the outflow. Fe cycling in the lake is inhibited by oxygen penetration into the sediment. Vanadium and arsenic can be used as tracers for the internal Fe cycle. Their distribution patterns are highly correlated with iron. In case of a stable oxycline in the deep water, Mo is enriched in the sediment and correlates with Mn. The horizontal distribution patterns of Fe, V, As and the correlation of Fe and Mn with trace metals are promising proxy indicators for the reconstruction of deep-water oxygen conditions during deposition.
AN: 4265716

                                                                      53 of 313  
TI: Spatio-temporal variability of the thermohaline and biogeochemical properties and dissolved organic carbon in a coastal embayment affected by upwelling: the Ria de Vigo (NW Spain)
AU: Doval,-M.D.; Nogueira,-E.; Perez,-F.F.
AF: Inst. de Investigacions Marinas, CSIC, Eduardo Cabello, 6, 36208 Vigo, Spain
SO: J.-MAR.-SYST. 1998 vol. 14, no. 1-2, pp. 135-150
LA: English
ER: M (Marine)
AB: Hydrographic sampling was carried out along the main axis of the Ria de Vigo, from May 1994 to September 1995, to observe the spatio-temporal evolution of hydrographic and biogeochemical properties of the water column. Meteorology controls mainly the hydrography and biogeochemistry of the Ria. Two periods can be distinguished on a seasonal time-scale: the upwelling season, from March to October and the non-upwelling season, from November to February. A strong coupling was observed between meteorological, hydrographic and biogeochemical processes. The Ria behaves like an extension of the shelf during the upwelling season and like a partially mixed estuary during the non-upwelling season. Dissolved organic carbon was related to the thermohaline properties in the whole water column, and with oxygen and chlorophyll a in the surface layer. Extreme values were recorded during the upwelling season: the highest values (> 100  mu M), in the surface layer during upwelling relaxations and the lowest values (< 70  mu M), in the bottom layer in upwelled waters. Dissolved organic carbon maxima decrease shelfward thus suggesting export of dissolved organic carbon, in addition to particulate organic carbon, from the Ria to the shelf.
AN: 4265703

                                                                      54 of 313  
TI: Comparison of iron, manganese, and phosphorus retention in freshwater littoral sediment with growth of Littorella uniflora and benthic microalgae
AU: Christensen,-K.K.; Andersen,-F.O.; Jensen,-H.S.
AF: Odense University, Institute of Biology, Campusvej 55, DK-5230 Odense M, Denmark
SO: BIOGEOCHEMISTRY 1997 vol. 38, no. 2, pp. 149-171
LA: English
ER: F (Freshwater)
AB: Sediment columns from an oligotrophic lake were percolated with artificial porewater in two 46-day experiments to examine the effects of Littorella uniflora and benthic microalgae on retention of phosphorus (P) by either iron (Fe) or manganese (Mn). Cumulative retention of P, Fe, and Mn was 2-5 times higher in sediment with L. uniflora than in sediment with microalgae, because of higher P uptake and more efficient Fe and Mn oxidation by L. uniflora than by microalgae. Thus 34% and 21% of added P was retained in L. uniflora inhabited sediments as metal-oxide bound P compared to 11% and 2% in microalgae inhabited sediments, in experiments supplied with Fe and Mn, respectively. The atomic ratio of Fe/P precipitation was about 1 and for Mn/P precipitation it was about 5. These ratios indicate precipitation of Fe(III)-phosphate (strengite) and metastable Mn(IV)-compounds containing phosphate and hydroxide ions in variable amounts. In addition to metal-oxide P precipitation, increased P retention in the vegetated sediment was also caused by the presence of humic acid compounds, which accounted for about 26% of total retained P.
AN: 4264658

                                                                      55 of 313  
TI: Onset of a spring diatom bloom in the Ross Sea, November and December 1994: Timing and effects on nutrient and biogenic silica distributions
AU: Nelson,-D.M.; Gordon,-L.I.; Arrington,-J.M.; Ross,-A.A.
AF: College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
SO: Antarct.-J.-U.S. 1995 vol. 30, no. 5, pp. 207-209
LA: English
AB: We have carried out past collaborative studies of the cycling of biogenic silica and organic matter in the Ross Sea, for the purpose of understanding the processes that lead to the rich siliceous deposits in antarctic sediments (e.g., Nelson, Ahern, and Herlihy 1991; DeMaster et al. 1992; Nelson and Treguer 1992). A major goal of that work has been to obtain reliable estimates of the annual production of biogenic silica in surface waters, permitting the regional silica cycle to be evaluated quantitatively by comparison of production in the upper ocean with vertical transport.
AN: 4261103

                                                                      56 of 313  
TI: Agglutinated test morphogenesis in Astrammina rara, a giant foraminiferan protist from Explorers Cove, McMurdo Sound
AU: Bowser,-S.S.; Kinoshita,-R.K.; Bernhard,-J.M.; Hayden,-J.H.
AF: Wadsworth Center, Albany, NY 12201, USA
SO: Antarct.-J.-U.S. 1995 vol. 30, no. 5, pp. 161-162
LA: English
ER: M (Marine)
AB: Agglutinated foraminifera are protists that sculpt elegant tests (shells) by using their pseudopodia to collect mineral grains and secreting bioadhesives to hold the grains together. Agglutinated foraminifera are among the most abundant metazoans in deep-sea sediments, and evidence is accumulating that they may play important roles in nutrient cycling and community structure in the deep-sea benthos (reviewed in Gooday et al. 1992, pp. 63-91). For over a decade, Explorers Cove has served as an important site for conducting biological studies on agglutinated foraminifera because, uniquely, large numbers of deep-sea-like species can be collected and studied in situ by scuba divers (see, for example, DeLaca 1986; DeLaca, Lipps, and Hessler 1980; DeLaca, Karl, and Lipps 1981). Our current studies focus on agglutinated test morphogenesis in Astrammina rara, one of the most conspicuous members of the Explorers Cove foraminiferal assemblage. This species is highly selective for more than 500-micrometer sand grains and binds these grains together with a fibrous adhesive to form a spherical test (Bowser and Bernhard 1993). The goals of recent work are to determine how Astrammina's adhesive matrix is secreted and to characterize the mechanical properties of the matrix by performing finite element analysis of the intact shell. The results of these studies will provide insights into possible biotechnological uses for adhesives secreted by foraminifera.
AN: 4261079

                                                                      57 of 313  
TI: Photochemistry of antarctic waters during the 1994 austral summer
AU: Kieber,-D.J.; Mopper,-K.
AF: Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210, USA
SO: Antarct.-J.-U.S. 1995 vol. 30, no. 5, pp. 150-151
LA: English
AB: Solar radiation in natural waters initiates a wide variety of photochemical transformations, ranging from simple photolyses involving well-defined chromophores to complicated photoreactions involving ill-defined humic substances. The broad spectrum of photochemical transformations that have been documented attest to the importance of photochemistry in aquatic biogeochemical cycles. Perhaps the most interesting photochemical transformations are the formation of reactive species (e.g., the OH radical) and the production of substrates (e.g., pyruvate), since these processes represent a day-time stress and food source for plankton, respectively. The nature and extent of these photochemical-biological interactions in antarctic waters are not known, but it can be expected that they will be accelerated during an "ozone hole" because of an increase in the flux of ultraviolet-B (UV-B) radiation in the water column.
AN: 4261073

                                                                      58 of 313  
TI: Fluxes of copper-complexing ligands from estuarine sediments
AF: Department of Chemistry, University of North Carolina at Wilmington, Wilmington, NC 28403, USA
SO: Limnol.-Oceanogr. 1997 vol. 42, no. 5, pp. 992-996
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Most studies of the organic complexation of Cu in natural waters have focused on distributions and processes in the water column, where a significant fraction of Cu-complexing ligands may be biologically produced. We present direct evidence for a flux of Cu-complexing ligands from estuarine sediments, demonstrating that sediments are a significant, yet previously unrecognized source of the ligands. Fluxes of Cu-complexing ligands from Chesapeake Bay sediments range from 300 to 1,200 nmol m super(-2) d super(-1), exceeding fluxes of total dissolved Cu by 3->40-fold, suggesting that any Cu fluxing from the sediments is likely to be organically complexed. Our results indicate that benthic fluxes may supply from 10 to 50% of the standing stock of Cu-complexing ligands in Chesapeake Bay and suggest that such fluxes may strongly influence the biogeochemistry of Cu in shallow water environments and potentially in the ocean as a whole.
AN: 4258722

                                                                      59 of 313  
TI: The origin of sedimenting detrital matter in a coastal system
AF: Marine Biological Laboratory, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingor, Denmark
SO: Limnol.-Oceanogr. 1997 vol. 42, no. 5, pp. 1001-1005
LA: English
ER: M (Marine)
AB: Total sedimentation and the fraction due to copepod fecal pellets were measured during the growth season (March-October 1989) in the southern Kattegat, Denmark. In this period the sedimentation of detritus made up 52 g C m super(-2), equal to 82% of the sedimenting matter from the euphotic zone, but fecal pellets (11 g C m super(-2)) constituted only a minor fraction. The remaining detrital matter was produced by other heterotrophs than copepods. Published data on heterotrophic biomass and grazing obtained during the investigation in the Kattegat are reviewed in order to relate the sedimentation to processes in the pelagic system. Copepod defecation nearly equaled the sedimentation of fecal pellets, indicating that retention of this matter in the pelagic system was insignificant. A considerable fraction (10-24%) of the carbon flow processed by heterotrophic pico-, nano-, and microplankton was converted to detritus that was lost from the mixed system by sedimentation. The microbial food web is thus not an exclusively regenerating system.
AN: 4258718

                                                                      60 of 313  
TI: Evaluation of  super(32)Si as a tracer for measuring silica production rates in marine waters
AU: Brzezinski,-M.A.; Phillips,-D.R.
AF: Department of Ecology Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
SO: Limnol.-Oceanogr. 1997 vol. 42, no. 5, pp. 856-865
LA: English
ER: M (Marine)
AB: The radioisotope  super(32)Si was evaluated as a tracer for measuring silica production rates in marine waters.  super(32)Si is a weak  beta -emitter that decays to  super(32)P allowing the isotope to be used to determine simultaneously the production rate of biogenic silica and organic phosphorus. High specific activity  super(32)Si, 42,000-52,000 Bq ( mu g Si) super(-1), was produced by the proton spallation of KCl. Reasonable tracer additions result in only nanomolar increases in the ambient silicic acid and orthophosphate concentrations during production rate experiments. Protocols for quantifying the amount of  super(32)Si and  super(32)P in samples by liquid scintillation counting (LSC) and gas-flow proportional counting (GFPC) are presented. Both protocols eliminate the 4-month wait for secular equilibrium between  super(32)Si and  super(32)P required by earlier methods. GFPC is especially useful as the instrumentation is lightweight and portable allowing real-time analysis of samples at sea. Real-time analysis by GFPC at sea and postcruise analysis by LSC gave results that agreed to within 17 and 7% for  super(32)Si and  super(32)P, respectively. Subsequent intercalibrations of the LSC and GFPC methods indicated that agreement to within 0.1-4% for both isotopes can be achieved. Parallel incubations of samples from Monterey Bay, California, using the radioisotope  super(32)Si and the stable isotope  super(30)Si gave silica production rates that generally agreed to within 30%. No significant bias was observed between rates obtained with the two tracers. The greater sensitivity and ease of analysis of the radioisotope makes  super(32)Si the tracer of choice for future studies of silica production in the ocean.
AN: 4258703

                                                                      61 of 313  
TI: Transport and fate of dissolved organic carbon in the Lake Pontchartrain estuary, Louisiana, U.S.A.
AU: Argyrou,-M.E.; Bianchi,-T.S.; Lambert,-C.D.
AF: Dep. Ecol., Evolution and Organismal Biol., Tulane Univ., New Orleans, LA 70118, USA
SO: BIOGEOCHEMISTRY 1997 vol. 38, no. 2, pp. 207-226
LA: English
AB: Cycling dynamics of dissolved organic carbon (DOC) were examined in Lake Pontchartrain estuary, Louisiana, in relation to changes in freshwater inputs. DOC concentrations ranged from 5.3 to 8.5 mg C L super(-1) reaching their highest during high river inflow. The percentage of DOC represented by HMW DOC (or colloidal material) was greatest (ca. 11%) at stations where freshwater discharge from rivers and surrounding wetlands was most significant. Moreover, the lignin-phenol content of this material ( lambda  ranged from 0.09 to 0.33 and  Lambda  from 0.11 to 0.39) confirmed that a significant fraction of colloidal organic carbon was derived from terrestrial sources. Riverine and benthic fluxes represented the dominant sources of DOC to the estuary. On an annual basis, riverine and benthic DOC concentrations were estimated to be 2.8 x 10 super(10) g C yr super(-1) and 8.8 x 10 super(10) g C yr super(-1), respectively, while the total DOC pool in the estuary was 3.8 x 10 super(10) g C. Annual average concentrations of dissolved inorganic carbon (DIC) (1298  mu M) and pCO sub(2) (5774  mu atm) were comparable to those found in other freshwater systems that reached CO sub(2) saturation levels. Net losses of DOC in the Lake Pontchartrain estuary appeared to be primarily controlled by heterotrophic consumption (conversion of CO sub(2)) - which may have been amplified by the long residence time (approximately 120 days) of DOC in this system.
AN: 4256247

                                                                      62 of 313  
TI: Influence of sulfur-oxidizing bacteria on the budget of sulfate in Yugama crater lake, Kusatsu-Shirane volcano, Japan
AU: Takano,-B.; Koshida,-M.; Fujiwara,-Y.; Sugimori,-K.; Takayanagi,-S.
AF: Dep. Chem., Coll. Arts and Sci., Univ. Tokyo, Komaba, Meguro-ku, Tokyo 153, Japan
SO: BIOGEOCHEMISTRY 1997 vol. 38, no. 3, pp. 227-253
LA: English
ER: F (Freshwater)
AB: Sulfur-oxidizing bacteria, Thiobacillus thiooxidans, were found in a highly acidic (pH = 1 similar to 1.5) crater lake, Yugama, seasonally flowing streams and soil in the catchment area of the crater. Thiobacillus ferrooxidans was also found in some of the streams but not in the lake itself. The lake water contains aqueous carbon dioxide, hydrogen sulfide, polythionates and elemental sulfur in suspension which are the substrates for the growth of the sulfur-oxidizing bacteria as no organic compounds except for the microorganisms themselves were detected. The bacteria isolated from the Yugama water preferred polythionates in the following order: S sub(4)O sub(6) super(2-)>S sub(5)O sub(6) super(2-)>S sub(6)O sub(6) super(2-). On the other hand, H sub(2)S was more rapidly consumed by the bacteria than polythionates which were followed by elemental sulfur. In the case of test-tube incubation, the optimum pH of the solution for growth of the bacteria was between 1.0 and 1.5, and for cultivation in growth medium plates between 2.5 and 3.5. The bacteria hardly proliferated at pH 0.5 or below. In accordance with these characteristics of the bacteria, numbers of the bacteria in the surface Yugama crater lake water were at minimum (<a few cells/mL) in February and at maximum (10 super(6) cell/mL) in August. The bacterial activity changed in accordance with the surface lake water temperature, but not necessarily with the variations in H sub(2)S and polythionates concentrations of the lake water. Based on the variation in sulfur isotope ratios of sulfate and experimentally determined rate of oxidation of H sub(2)S in the lake water, the sulfate production rate by the bacteria in the catchment area and the lake were estimated to 9.5 and 8.4 g/m super(2)/day, respectively, during the period from 1988 to 1990 when the volcanic activity at Yugama was at minimum. Also stream, hydrothermal, H sub(2)S-oxidated SO sub(4) super(2-) inputs and outputs by seepage and precipitation have been calculated as 4.1, 32, 0.56, 36, and 1.2 ton/day, respectively.
AN: 4256167

                                                                      63 of 313  
TI: Quantification of organic matter degradation by microbial sulphate reduction for Quaternary sediments from the northern Arabian Sea
AU: Littke,-R.; Lueckge,-A.; Welte,-D.H.
AF: Inst. fuer Erdoel und Organische Geochemie (ICG-4), Forschungszentrum Juelich GmbH, D-52425 Juelich, Germany
SO: NATURWISSENSCHAFTEN 1997 vol. 84, no. 7, pp. 312-315
LA: English
ER: M (Marine)
AN: 4254168

                                                                      64 of 313  
TI: Annual cycle of heavy metals in a tropical lake- Lake Chapala, Mexico
AU: Shine,-J.P.; Ryan,-D.K.; Ford,-T.E.
AF: Harvard Sch. Public Health, Dep. Env. Health, 665 Huntington Ave., Boston, MA 02115, USA
SO: J.-Environ.-Sci.-Health,-Pt.-A:-Toxic-Hazard.-Subst.-Environ.-Eng. 1998 vol. A33, no. 1, pp. 23-43
LA: English
AB: Dissolved concentrations of seven metals (As, Pb, Cd, Zn, Ni, Cu, Cr) were determined monthly at six sampling stations in Lake Chapala, Mexico, between November 1990 and December, 1991. Lake Chapala is the largest lake in Mexico, and serves as a source of drinking water and an economically important fishery and center for tourism. Historically, Lake Chapala has received poorly characterized domestic, industrial, and agricultural wastes. As, Cd, Pb, Cr, and Zn displayed peaks in concentration during the period before the rainy season due, presumably, to evaporation. Comparison of inflow and outflow concentrations also indicated a direct source of As to the lake. During this period, the concentrations of both Cd and Pb were above the freshwater chronic criteria values recommended by the United States Environmental Protection Agency for protection of aquatic ecosystem health. The metals As, Cr, Zn, Ni, and Cu also showed concentrations peaks following the rainy season in August and September, perhaps due to increased input from the watershed or resuspension of metals in the lake driven by changes in water circulation patterns. Concentration data for the lake also suggested that a portion of the inflow water does not immediately mix with the lake as a whole, creating spatial gradients depending on the concentration of metals in the source water. Determination of metals in water hyacinth (Eichornia crassipes) plant tissue showed large partitioning of metals into root tissue, indicating that plants may be an important temporal sink for metals. In addition, copper and zinc accumulated to very high levels in Tilapia and Carp livers, indicating that some of the metal contaminants are entering the food chain.
AN: 4280575

                                                                      65 of 313  
TI: Methyl halides from Antarctic macroalgae
AU: Laturnus,-F.; Adams,-F.C.; Wiencke,-C.
AF: Plant Biol. and Biogeochemistry Dep., Riso Natl. Lab., Bldg. 124, PO Box 49, DK-4000 Roskilde, Denmark
SO: GEOPHYS.-RES.-LETT. 1998 vol. 25, no. 6, pp. 773-776
LA: English
ER: M (Marine)
AN: 4300582

                                                                      66 of 313  
TI: Dissolved dimethylsulphide, dimethylsulphoniopropionate and dimethylsulphoxide in western Mediterranean waters
AU: Simo,-R.; Grimalt,-J.O.; Albaiges,-J.
AF: Dep. Environ. Chem. (CID-CSIC), Jordi Girona, 18, 08034 Barcelona, Catalonia, Spain
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 929-950
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: Spring-summer concentrations of the three main dissolved dimethyl sulphur species (DMSS sub(d)), dimethylsulphide (DMS), dimethylsulphoniopropionate (DMSP sub(d)) and dimethylsulphoxide (DMSO), have been determined in western Mediterranean Sea water with some spatial and temporal resolution. Depth profiles showed that the three DMSS sub(d) were mostly confined to the euphotic layer. In surface waters, DMSO was generally the dominant DMSS sub(d) regardless of the site and the season. Concentration averages resulted in a DMS:DMSP sub(d):DMSO proportion of 1: 1: 6 (2.9: 3.0: 16.6 nM). DMSS sub(d) concentrations exhibited a great variability, but were higher on the continental shelf than in open seawaters, as were chlorophyll concentrations. Some hot spots with the highest levels were identified off the main continental outflows. None of the DMSS sub(d) correlated significantly with chlorophyll. In open seawaters (water column depth >200 m) DMS increased as chlorophyll declined between April and July. This was attributed to changes in the biological community from spring development to summer decay and ecological succession. The temporal variation of the three DMSS sub(d)s suggests that they are subject to a tight cycling of production and consumption where the composition of the entire planktonic community, as well as its physiological state, play a significant role. A similar conclusion was achieved from the study of the DMSS sub(d) concentrations in a transect between oligotrophic and eutrophic waters in the top NW area. Finally, the western Mediterranean has been assessed as a source of atmospheric sulphur. The moderate DMS emission flux estimates (mean: 5.4  mu mol/m super(2)/day) together with the moderate DMS surface concentrations, were consistent with the low productivity of the Mediterranean Sea.
AN: 4290948

                                                                      67 of 313  
TI: Dynamics of the vernal bloom in the marginal ice zone of the Barents Sea: Dimethyl sulfide and dimethylsulfoniopropionate budgets
AU: Matrai,-P.A.; Vernet,-M.
AF: Bigelow Lab. for Ocean Sci., West Boothbay Harbor, ME, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS 1997 vol. 102, no. C10, pp. 22,965-22,979
LA: English
ER: M (Marine)
AB: Phytoplankton is known to be a key element in the production and eventual oceanic efflux of dimethyl sulfide (DMS) to the atmosphere. We hypothesized that the alternation of Phaeocystis pouchetii and diatoms, the two major algal components of the spring bloom, would modulate the input of particulate organic sulfur (POS), dimethylsulfoniopropionate (DMSP), and DMS into the mixed layer of the marginal ice zone. A bloom of diatoms is expected to present similar pathways but to have very different rates of POS/DMSP/DMS production and POS/DMSP sinking and no or low DMS flux to the atmosphere as contrasted to the cycling occurring during the P. pouchetii phase of the bloom. Our initial hypothesis cannot be accepted based on our observations in the Barents Sea during the spring of 1993. The contribution of diatoms to the water column budgets of DMSP and DMS was significant and cannot be overlooked. We suggest that the physiological stage of the bloom is perhaps more important to biogeochemical cycling than its phytoplankton species composition in controlling DMSP and DMS fluxes in Arctic waters. Loss of particulate DMSP in the mixed layer was mainly by release into the dissolved pool and by sedimentation rather than by grazing, except in ice-free waters. Cycling of DMS in the mixed layer was predominantly biological in ice-free waters, while in Polar Front waters, ventilation was proportionally more important due to depressed microbiology.
AN: 4290535

                                                                      68 of 313  
TI: Biogeochemical significance of transport exopolymer particles in the Indian Ocean
AU: Dileep-Kumar,-M.; Sarma,-V.V.S.S.; Ramaiah,-N.; Gauns,-M.; De-Sousa,-S.N.
AF: Natl. Inst. Oceanogr., Dona Paula, Goa, India
SO: GEOPHYS.-RES.-LETT. 1998 vol. 25, no. 1, pp. 81-84
LA: English
ER: M (Marine)
AN: 4290501

                                                                      69 of 313  
TI: A one-dimensional physical-biological model study of the pelagic nitrogen cycling during the spring bloom in the northern North Sea (FLEX '76)
AU: Kuehn,-W.; Radach,-G.
AF: Inst. fuer Meereskunde, Univ. Hamburg, Troplowitzstr. 7, D-22529 Hamburg, Germany
SO: J.-MAR.-RES. 1997 vol. 55, no. 4, pp. 687-734
LA: English
ER: M (Marine)
AB: A one-dimensional model of the pelagic ecosystem was developed and applied to the spring bloom in the northern North Sea making use of the data set obtained during the Fladenground experiment FLEX '76. The physical submodel is the second-order turbulence closure model of level 2 type developed by Mellor and Yamada (1974, 1982). The biological submodel is a depth-resolved version of the nitrogen flux model of the lower trophic levels in the pelagic proposed by Fasham et al. (1990). The parameter set employed by Fasham et al. did not yield satisfying results. However, using a parameter set adapted to the North Sea ecosystem we obtained a realistic overall description of the development of the North Sea ecosystem during the spring bloom. We were able to hindcast successfully the onset, duration, magnitude and daily variability of the net primary production, the magnitude of the PON export flux to the sea bottom, of the bacterial production and of the nitrogen regeneration within the water column. From the results of the simulation a mass budget of nitrogen fluxes within the euphotic zone and the deeper water layers as well as between them was derived. The results of the simulation suggest that strong herbivorous grazing caused the decay of the bloom. The comparison with the grazing by mesozooplankton as estimated from the observations favors the hypothesis that herbivorous microzooplankton was mainly responsible for the breakdown. The depth dependence of the vertical particulate flux obtained from the simulation exhibits the hyperbolic character recently found in different oceanic regions. The vertical particulate nitrogen flux shows a stronger decrease than typically observed for the particulate carbon flux. This is in correspondence with the observation that there was a remarkable increase of the C /N ratio of POM with depth during FLEX '76.
AN: 4290440

                                                                      70 of 313  
TI: Effect of naturally occurring bromophenols on sulfate reduction and ammonia oxidation in intertidal sediments
AU: Giray,-C.; King,-G.M.
AF: Darling Mar. Cent., Univ. Maine, Walpole, ME 04573, USA
SO: AQUAT.-MICROB.-ECOL. 1997 vol. 13, no. 3, pp. 295-301
LA: English
ER: M (Marine)
AB: We examined the effect on ammonium oxidation and sulfate reduction of several brominated compounds [4-bromophenol, 2,4-dibromophenol (2,4-DBP), 2,6-dibromophenol and 2,4,6-tribromophenol] that occur naturally in enteropneusts. We compared rates of these processes with and without bromoorganics using bulk intertidal sediments and burrow wall sediments from 3 enteropneust species (2 containing 2,4-DBP and 1 containing 2,3,4-tribromopyrrole), a mollusc (Mya arenaria) and a polychaete (Nereis virens). Sulfate reduction in bulk sediment was unaffected by bromophenols at concentrations <100 nmol cm super(-3) sediment, but was inhibited temporarily at 1  mu mol cm super(-3). Sulfate reduction in burrow wall sediments differed from bulk sediments, but was not correlated with concentrations of naturally occurring bromophenols. Ammonium oxidation was inhibited in surface sediments by bromophenol concentrations as low as 1 nmol cm super(-3) sediment. Ammonium oxidation was enhanced in burrow wall sediments of N. virens, M. arenaria and the enteropneust Saccoglossus bromophenolosus relative to surface sediments, but was markedly lower and negatively correlated with ambient 2,4-DBP in burrow wall sediments of a second enteropneust, Protoglossus graveolens.
AN: 4282105

                                                                      71 of 313  
TI: Dissimilatory nitrate reduction in anaerobic sediments leading to river nitrite accumulation
AU: Kelso,-B.H.L.; Smith,-R.V.; Laughlin,-R.J.; Lennox,-S.D.
AF: Dep. Agric. and Environ. Sci., Queen's Univ. Belfast, Newforge Lane, Belfast BT9 5PX, UK
SO: APPL.-ENVIRON.-MICROBIOL. 1997 vol. 63, no. 12, pp. 4679-4685
LA: English
AB: Recent studies on Northern Ireland rivers have shown that summer nitrite (NO sub(2) super(-)) concentrations greatly exceed the European Union guideline of 3  mu g of N liter super(-1) for rivers supporting salmonid fisheries. In fast-flowing aerobic small streams, NO sub(2) super(-) is thought to originate from nitrification, due to the retardation of Nitrobacter strains by the presence of free ammonia. Multiple regression analyses of NO sub(2) super(-) concentrations against water quality variables of the six major rivers of the Lough Neagh catchment in Northern Ireland, however, suggested that the high NO sub(2) super(-) concentrations found in the summer under warm, slow-flow conditions may result from the reduction of NO sub(3) super(-). This hypothesis was supported by field observations of weekly changes in N species. Here, reduction of NO sub(3) super(-) was observed to occur simultaneously with elevation of NO sub(2) super(-) levels and subsequently NH sub(4) super(+) levels, indicating that dissimilatory NO sub(3) super(-) reduction to NH sub(4) super(+) (DNRA) performed by fermentative bacteria (e.g., Aeromonas and Vibrio spp.) is responsible for NO sub(2) super(-) accumulation in these large rivers. Mechanistic studies in which  super(15)N-labelled NO sub(3) super(-) in sediment extracts was used provided further support for this hypothesis. Maximal concentrations of NO sub(2) super(-) accumulation (up to 1.4 mg of N liter super(-1)) were found in sediments deeper than 6 cm associated with a high concentration of metabolizable carbon and anaerobic conditions. The  super(15)N enrichment of the NO sub(2) super(-) was comparable to that of the NO sub(3) super(-) pool, indicating that the NO sub(2) super(-) was predominantly NO sub(3) super(-) derived. There is evidence which suggests that the high NO sub(2) super(-) concentrations observed arose from the inhibition of the DNRA NO sub(2) super(-) reductase system by NO sub(3) super(-).
AN: 4268224

                                                                      72 of 313  
TI: Remote sensing of coccolithophore blooms in the western South Atlantic Ocean
AU: Brown,-C.W.; Podesta,-G.P.
AF: Satellite Res. Lab., NOAA/NESDIS E/RA13, Washington, DC 20233, USA
SO: REMOTE-SENS.-ENVIRON. 1997 vol. 60, no. 1, pp. 83-91
LA: English
ER: M (Marine)
AB: High-reflectance patches are regularly observed off the southeastern coast of South America during the late austral spring and summer in visible satellite imagery of the Coastal Zone Color Scanner (CZCS). Unfortunately, coincident in situ samples for identifying their cause are lacking. To ascertain the likelihood that these patches represent surface blooms of the coccolithophore Emiliania huxleyi, their distribution pattern was mapped and their spectral signature evaluated by classifying CZCS imagery with a supervised, multispectral classification scheme that had been developed to detect this phytoplankton species. On the basis of the similarity of these characteristics to those of documented cases, we conclude that the high-reflectance patches observed in surface waters of the shelf and beyond are E. huxleyi blooms. The blooms seasonally occupied an area as large as 550,000 km super(2). Standing stock estimates indicate that the detected blooms produced an average of 1.5-4.9 x 10 super(5) metric tons of calcite carbon and 4.0 x 10 super(3) t of dimethyl sulfide sulfur. The bloom's production of these climatically relevant compounds and their alteration of optical properties in the surface layer suggest that the blooms significantly affect the biogeochemistry and ecology of this region.
AN: 4265445

                                                                      73 of 313  
TI: In situ measurement of particulate organic matter removal rates by a tidal flat macrobenthic community
OT: Higata jo ni okeru makurobentosu gunshu ni yoru yuki kendakubutsu jokyosokudo no genba sokutei
AU: Aoyama,-Hiroaki; Suzuki,-Teruaki
AF: Aichi Prefect. Fish. Res. Inst., Miya-cho, Gamagori 443, Japan
SO: Bull.-Jap.-Soc.-Fish.-Oceanogr. 1997 vol. 61, no. 3, pp. 265-274
LA: Japanese
ER: M (Marine)
AB: Special transparent chambers were set at four stations on Isshiki tidal flat of Mikawa Bay to measure the in situ removal rates of particulate organic matter by the macrobenthic community. Concentrations of particulate organic nitrogen, carbon and chlorophyll pigment were measured and filtering rates was calculated with each chamber. The filtering rates per unit of macrobenthos biomass were almost equal in all chambers, with average value 21.7 l/g N/h which was 35 % less than the past data obtained under artificial laboratory condition. Characterstically, the filtering rate was proportional to the whole macrobenthos biomass rather than that of the suspension feeders. The removal rate of particulate organic nitrogen on Isshiki tidal flat was 227.4 mg N/m super(2)/day as calculated by the filter feeding rate and the average concentration of particulate organic nitrogen on the tidal flat. This rate was compared to the nitrogen budget ( 150 mg N/m super(2)/day) obtained by the BOX model analysis for the same period. Generally these values were in good agreement, assuming that about 60 % of the excrement of suspension feeding macrobenthos was resuspended and consumed again as food.
AN: 4281336

                                                                      74 of 313  
TI: Bacterial utilization of glucose in the water column from eutrophic to oligotrophic pelagic areas in the eastern North Atlantic Ocean
AU: Bianchi,-A.; Van-Wambeke,-F.; Garcin,-J.
AF: Microbiologie Mar. (C.N.R.S.-I.N.S.U., UPR 223), Univ. de la Mediterranee, Fac. des Sci. de Luminy, Case 907, 13288 Marseille Cedex 9, France
SO: J.-MAR.-SYST. 1998 vol. 14, no. 1-2, pp. 45-55
LA: English
ER: M (Marine)
AB: Vertical profiles of glucose utilization rates were compared at three sampling stations in the eastern part of the tropical North Atlantic Ocean. The investigation area was along 20-21 degree N and the three sampling sites, characterised by differences in their primary productivity, were located at 18 degree W, 21 degree W and 31 degree W. In the superficial waters, maximum (V sub(max)) glucose utilization (respiration plus incorporation) depended on the nutritional load being 20-fold higher in the eutrophic, compared to the oligotrophic zone. Due to these variations, natural turnover times for this labile compound were approximately 1 day in the eutrophic area, and up to 435 days in the oligotrophic area. Bacterial activity showed a steep decline immediately below the mixed layer in the mesotrophic and eutrophic areas and below the deep chlorophyll maximum in the oligotrophic area. Discrepancies between microbial activities in the three areas decreased with increasing depth: at depths below 250 m potential utilization rates of glucose were similar whatever the nutrient richness of the photic layer. Nevertheless, the distribution of microbial activities through the whole water column depended greatly on the productivity of superficial waters. In nutrient-rich areas 73% of glucose utilization activity was realized in the productive upper layer, whereas only 4% was metabolized at depths below 250 m. Conversely, in the oligotrophic area, more than 40% of the glucose utilized in the whole water column was processed in the intermediate and deep-water masses. Integration of V sub(max) values for the whole water column, suggested potential carbon fluxes due to bacterial utilization of glucose of 6 and 34 mg C m super(-2) d super(-1) in the oligotrophic and eutrophic areas, respectively. The fate of the metabolised carbon depended on the nutrient availability. In the mixed-water layer the glucose respiration percentage (%R) increased from 30% in nutrient-rich areas to 60% under oligotrophic conditions, moreover %R increased with depth. This infers that at lower nutritional loads, a greater proportion of highly labile compounds is used for energetic purposes, and therefore return to the inorganic carbon pool, but with very low turnover rates.
AN: 4282122

                                                                      75 of 313  
TI: Palmer LTER: Project SANTA CLA mu S: December 1994
AU: Karl,-D.M.
AF: School of Ocean and Earth Science and Technology, Department of Oceanography, University of Hawaii, Honolulu, HI 96822, USA
SO: Antarct.-J.-U.S. 1995 vol. 30, no. 5, pp. 252-254
LA: English
AB: Microorganisms, including unicellular algae, bacteria, viruses, protozoans, and small metazoans, are vital components of Southern Ocean habitats (Karl 1993). They are largely responsible for the production and decomposition of organic matter, for the primary uptake and regeneration of inorganic nutrients, and for export of carbon and energy to intermediate ocean depths. Furthermore, microbial growth and metabolism can have a profound effect on sea water pH and redox state and, therefore, can influence the distribution, speciation, and availability of certain elements and compounds. Consequently, field data both on individual groups of microorganisms and on the complex interactions among them are necessary for a complete assessment of the role of marine microorganisms on both local and global environments.
AN: 4261005

                                                                      76 of 313  
TI: The effects of sewage organic matter on biogeochemical processes within mid-shelf sediments offshore Sydney, Australia
AU: Bickford,-G.P.
AF: Dep. Geol. and Geophysics, Univ. Sydney, Sydney, NSW 2006, Australia
SO: MAR.-POLLUT.-BULL. 1997 vol. 33, no. 7-12, pp. 168-181
NT: Special issue: Ocean Outfalls - Sustainable Solution?
LA: English
ER: M (Marine)
AB: A laboratory incubation experiment was conducted using replicate cores collected from a muddy-sand sediment facies offshore Sydney, Australia to determine what components and processes would be affected by the addition of sewage organic matter. Sewage effluent has a solid phase composition of 40% carbon (35% organic carbon), 5% nitrogen, 1% phosphorus and 5% silicate. The molecular C:N:P ratio is 92:10:1, compared to the Redfield ratio of 106:16:1 in marine phytoplankton. Sediment cores were incubated at in situ temperature in a darkened room for periods up to 95 days. Sewage organic matter was added to the cores at three different loads equivalent to 0 (T0), 65 (T1) and 130 (T2) g m super(-2) of sediment. Following the addition of sewage organic matter, fluxes of oxygen (into the sediments), ammonia and phosphate (from the sediments) increased, reflecting an enhanced organic carbon supply to the sediments. Oxygen penetrated to a depth of 6 mm in the ambient cores, but the sediment oxygen content was severely depleted following the addition of the sewage-derived organic matter. Sediment porewater data, together with nutrient flux data indicate that oxygen reduction, nitrate reduction and sulphate reduction occurs within these sediments. Following the addition of sewage organic matter, increases in total nitrogen, total phosphate and total organic carbon were measured to depths of 5 cm in the sediments, suggesting that bioturbation influences nutrient and organic carbon distributions. Additionally, irrigation of the surficial sediments may play an important role in the metabolism of organic matter. These results indicate that oxygen penetration, oxygen fluxes, nitrate concentrations within porewaters, ammonia flux rates, and solid phase concentrations of total organic carbon and nutrients may be useful indicators of sediments affected by high rates of organic matter deposition onto Sydney's offshore sediments. The EPA has recently predicted maximum deposition rates of sewage particulate matter to be approximately 1 g m super(-2) day super(-1). Because of the similarities in CNP ratios of sewage organic matter and marine organic matter, the effects of sewage organic matter and marine organic matter inputs to coastal sediments may not be easily distinguishable.
AN: 4254038

                                                                      77 of 313  
TI: Phosphorus regeneration in continental margin sediments
AU: McManus,-J.; Berelson,-W.M.; Coale,-K.H.; Johnson,-K.S.; Kilgore,-T.E.
AF: Oregon State Univ., COAS, Ocean Admin. Bldg. 104, Corvallis, OR 97331-5503, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA 1997 vol. 61, no. 14, pp. 2891-2907
LA: English
ER: M (Marine)
AB: Benthic incubation chambers have been deployed in a variety of geochemical environments along the California Continental Margin. These include both high and low oxygen environments and sites where the rate of organic matter oxidation on the seafloor (C sub(ox)) ranges from <1 mmol m super(-2) day super(-1) to more than 7 mmol m super(-2) day super(-1) through a depth range of 100-3500 m. This range in the rate of organic matter oxidation along with variations in the concentration of bottom water oxygen allow us to elucidate the diagenetic conditions under which P regeneration may be decoupled from organic matter cycling. Under conditions where bottom water oxygen concentration is low (<50  mu M), and the rate of organic matter oxidation is also low (<1 mmol m super(-2) day super(-1)), P regeneration may be less than that expected from the decay of organic debris and, in some cases, there is a flux of phosphate into the sediments. At stations where bottom water oxygen is low, and the degradation rate of organic material is greater than 1 mmol m super(-2) day super(-1), phosphate may be released at a rate exceeding the production expected from the oxidation of organic matter. At stations having high bottom water oxygen concentrations, rates of organic matter decomposition <  similar to 7 mmol m super(-2) day super(-1), and where benthic irrigation is not significant, P regeneration is consistent with that expected from the decomposition of organic debris. In addition, our data indicate that high benthic iron fluxes are observed in regions exhibiting a decoupling between organic matter and phosphate, whereas low to zero iron fluxes are observed in regions where P regeneration is either consistent with or less than that expected from the decomposition of organic material. These results support previous work suggesting a coupling between iron cycling and phosphate cycling in suboxic environments. Data presented here show that this coupling may result in either preferential phosphate burial or release relative to organic material in suboxic environments.
AN: 4248919

                                                                      78 of 313  
TI: Acetate cycling in the water column and surface sediment of Long Island Sound following a bloom
AU: Wu,-Hanguo; Green,-M.; Scranton,-M.I.
AF: Mar. Sci. Res. Cent., State Univ. New York, Stony Brook, NY 11794-5000, USA
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 4, pp. 705-713
LA: English
ER: M (Marine)
AB: A number of workers have suggested that rates of acetate cycling in sediments may approximate the rates of anaerobic decomposition of organic matter. However, few studies have examined whether this relationship holds over very short time scales, such as those encountered during the deposition of the spring bloom into coastal sediments. In this study, we measured acetate concentrations and uptake rate constants in surface and bottom waters and in the top few centimeters of sediment in Long Island Sound. Samples were collected every 2-3 weeks from early spring to early summer of 1993. Acetate concentrations varied from 85 to 530 nM in the water column and from <2 to 29.8  mu M sub(sed) in pore water. Acetate concentrations in pore water showed a strong depth variation, with a concentration maximum in the surface few millimeters, as well as a strong temporal variation. The concentration of acetate averaged over the top 4 cm varied from about 5  mu M sub(sed) in the early spring to 14.3  mu M sub(sed) following the addition of spring bloom-derived organic carbon. Acetate uptake rate constants in the water column varied from 0.0012 to 0.037 h super(-1) (turnover time 33.4 to 1.13 d). The average uptake rate constants in the sediment over the top 4 cm varied from 0.07 to 0.59 h super(-1) (turnover time 0.59 to 0.07 d) and tended to increase over the course of the experiment in both the sediment and the water column. In the water column, acetate uptake rates (calculated as rate constant times concentration) varied from less than one nanomole per liter per hour in the early spring to tens of nanomoles per liter per hour in the early summer. In the sediment over the same period, acetate uptake rates averaged over the top 4 cm varied from 0.13 to 5.25  mu M sub(s) sub(e) sub(d) super(-1) h super(-1). Rates of acetate metabolism to CO sub(2) agreed within a factor of two to estimates of the  capital sigma CO sub(2) flux from the sediments, and both increased sharply following the deposition of the spring bloom. However, because temperatures were also increasing during this period, we are unable to separate unambiguously the effects of supply of labile carbon and of temperature on the acetate uptake rate.
AN: 4237657

                                                                      79 of 313  
TI: Dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) in relation to phytoplankton in the Gulf of Maine
AU: Townsend,-D.W.; Keller,-M.D.
AF: Department of Oceanography, 5741 Libby Hall, University of Maine, Orono, ME 04469, USA
SO: Mar.-Ecol.-Prog.-Ser. 1996 vol. 137, no. 1-3, pp. 229-241
LA: English
ER: M (Marine)
AB: Dimethylsulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP), in both particulate and dissolved forms, were surveyed during the early spring (March and April) and summer (July) of 1991 in coastal and offshore waters of the Gulf of Maine, USA, along with the hydrography, inorganic nutrients, phytoplankton chlorophyll, and phytoplankton taxonomic composition and abundance. Concentrations as high as 15 nM DMS (in April and July), 208 nM particulate DMSP (in April), and 101 nM dissolved DMSP (in July) were recorded. Total DMSP (dissolved plus particulate) reached 293 nM in a patch of the dinoflagellate Katodinium in April. This is the first report of high DMSP concentrations in temperate waters in early spring associated with any organism other than the prymnesiophyte Phaeocystis pouchetii. There were no correlations between phytoplankton biomass, as measured by chlorophyll a, and DMS, and there were only slight correlations between chlorophyll a and DMSP in either dissolved or particulate form. As previously demonstrated by others, concentrations of intracellular (particulate) DMSP were related more to the presence of specific phytoplankton species rather than to overall phytoplankton biomass. The occurrence of high DMSP and DMS levels in early spring, comparable with or higher than those seen in summer maxima, at a time when bacterial activity is minimal and wind speeds are typically high may result in enhanced air-sea-fluxes of DMS.
AN: 4213491

                                                                      80 of 313  
TI: Sulphate reduction in the root zone of the seagrass Zostera noltii on the intertidal flats of a coastal lagoon (Arcachon, France)
AU: Isaksen,-M.F.; Finster,-K.
AF: Institute of Biological Sciences, Department of Microbia, DK-8000 Aarhus, Denmark
SO: Mar.-Ecol.-Prog.-Ser. 1996 vol. 137, no. 1-3, pp. 187-194
LA: English
ER: M (Marine)
AB: Rates of sulphate reduction were determined in sediments from the eutrophic Bay of Arcachon, France. A comparison was made between sediment overgrown with the eelgrass Zostera noltii and unvegetated sediment. Rates of sulphate reduction were about twice as high in the root zone from 1 to 4 cm depth in the Z. noltii sediments (about 600 nmol/cm super(3)/d) as compared to the activity in the equivalent layer of the unvegetated sediment. The sulphate reduction in the root zone was not stimulated by light, which in other studies with other submersed macrophytes has been shown to promote sulphate reduction due to heightened excretion of organic molecules. Furthermore, in a field experiment, we were not able to detect any diurnal variation in the activity within the root zone. The stimulation of sulphate reduction by the presence of the Z. noltii was most likely due to degradation of leaf and root fragments which were found mixed into the sediment. Incubation times with radioactive sulphate had to be kept very short (preferably 15 min) to avoid a substantial reoxidation of sulphide and hence an underestimation of the rate of sulphate reduction.
AN: 4213487

                                                                      81 of 313  
TI: Denitrification in a coastal sediment measured n situ by the nitrogen isotope pairing technique applied to a benthic flux chamber
AU: Nielsen,-L.P.; Glud,-R.N.
AF: Institute of Biology, Department of Microbial Ecology, University of Aarhus, Ny Munkegade, bygn. 540, DK-8000 Arhus C, Denmark
SO: Mar.-Ecol.-Prog.-Ser. vol. 137, no. 1-3, pp. 181-186
LA: English
ER: M (Marine)
AB: A free operating benthic flux chamber lander (ELINOR) was used to measure in situ denitrification rates in the Aarhus Bight, Denmark (16 m depth). After insertion of the flux chamber into the sediment  super(15)NO sub(3)  super(-) was automatically injected into the enclosed water phase. After 3 to 4 h of incubation ELINOR was brought back to the surface with an intact water and sediment phase. Dinitrogen was extracted and later analyzed for  super(15)N enrichment by mass spectrometry. Parallel sediment cores were sampled for laboratory incubation under in situ conditions. In situ denitrification rates in June and November were 350 and 470  mu mol N/m super(2)/d respectively, and were not significantly different from the laboratory measured rates of 290 and 500  mu mol N /m super(2)/d, respectively. Oxygen uptake was 40% lower in the laboratory incubated cores compared to in situ measurements, apparently due to lowered activity of the dominating species of infauna, the bivalve Abra alba. Nitrate concentrations were low in the bottom water (<8  mu M) and most of the denitrification activity (65 to 100%) was coupled to nitrification in the sediment. A laboratory test showed that the addition of  super(15)NO sub(3)  super(-) did not significantly impede the reduction rate of the natural unlabelled NO sub(3)  super(-). The results support the validity of laboratory measurements for coastal waters and demonstrate the potential of combining benthic flux chamber landers and the isotope pairing technique for accurate measurements of denitrification in shelf, deep sea, and freshwater environments.
AN: 4213486

                                                                      82 of 313  
TI: PCBs in the Western Mediterranean. Temporal trends and mass balance assessment
AU: Tolosa,-I.; Readman,-J.W.; Fowler,-S.W.; Villeneuve,-J.P.; Dachs,-J.; Bayona,-J.M.; Albaiges,-J.
AF: IAEA Mar. Environ. Lab., BP 800, MC-98012, Monaco, Monaco
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 907-928
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: Comparison of data reported for polychlorinated biphenyl (PCB) concentrations in different environmental compartments of the western Mediterranean (dissolved and particulate phases of water, sediment and biota) over the last two decades shows a substantial decline in PCB concentrations, which coincides with legislated restrictions in the use of these compounds. Nevertheless, localised chronic ("hotspot") contamination continues, which underscores the importance of these compounds as environmental contaminants in certain specific areas of the region. Data on depositional fluxes are used to estimate and model transport processes to investigate the fate of these chemicals in the study area. A tentative mass balance of the compounds suggests that dry and wet deposition (12 t /year) account for most of the input. This compares with approximately 1 t/year discharged from rivers and sewage outfalls into coastal environments. Sedimentation is estimated to remove 5 t /year from the water column. Losses through volatilization are difficult to model owing to the critical dependance within calculations on atmospheric and dissolved seawater concentrations, for which very few data exist.
AN: 4273816

                                                                      83 of 313  
TI: Mass budget and dynamics of polycyclic aromatic hydrocarbons in the Mediterranean Sea
AU: Lipiatou,-E.; Tolosa,-I.; Simo,-R.; Bouloubassi,-I.; Dachs,-J.; Marti,-S.; Sicre,-M.-A.; Bayona,-J.M.; Grimalt,-J.O.; Saliot,-A.; Albaiges,-J.
AF: European Commission, Mar. Sci. and Technol. Programme (MAST), Directorate Gen. XII, 200 Rue de La Loi, 1040 Brussels, Belgium
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 881-905
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: A mass budget was constructed to examine the status and dynamics of polycyclic aromatic hydrocarbons (PAHs) in the western Mediterranean Sea. Using gas chromatography-mass spectrometry, 11 PAHs have been quantified in atmospheric aerosols, rivers and seawater, sediment cores and sediment trap samples. Total PAH concentrations in Mediterranean aerosols range from 0.2 to 2 ng /m super(3) with 50-70% associated with the sub-micron particles. Maximum PAH concentrations were observed in winter when the concentrations were double those recorded in the spring. Total PAH inputs from the atmosphere were estimated to be from 35 to 70 t/year with a mean value of 47.5 t/year (wet/dry mean ratio of  similar to 2-3). Atmospherically-deposited PAH are dominated by the benzofluoranthenes. The total PAH riverine inputs amount to about 5.3-33 t/year from the Rhone River and 1.3 t/year from the Ebro River. The difference in these riverine fluxes is due to differences in annual water discharges and upstream land use. The total PAH accumulation rate in surficial sediments in the whole basin is estimated at 182 t/year. Nearly 50% of the total PAHs accumulate in the 0-200 m water depth area supporting the importance of the coastal zone as a trap of terrigenous material and associated contaminants. Sediment trap experiments gave a mean residence time in the water column of total PAH (considering only particle settling) of 11 years, with higher residence times for high molecular weight PAHs. This supports the hypothesis that lower molecular weight PAHs are more efficiently removed from the water column. Water exchange resulted in a net outflow of 20 t/year and 2 t/year through the Gibraltar and Sicilian Straits, respectively. Atmospheric deposition and the Rhone River are the major contributors of PAH in the western Mediterranean. Sedimentation was identified as the major net output of PAH.
AN: 4273817

                                                                      84 of 313  
TI: The distribution and cycling of mercury species in the western Mediterranean
AU: Cossa,-D.; Martin,-J.-M.; Takayanagi,-K.; Sanjuan,-J.
AF: Inst. Francais de Recherches pour l'Exploitation de la Mer, BP 21105, F44311 Nantes Cedex 03, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 721-740
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: Total mercury concentrations were determined in water samples from ten vertical profiles in the western Mediterranean. Most Hg concentrations ranged from 0.5 to 4 pM, with a geometric mean of 2.26 pM. Such concentrations are in the same range as those measured in the North Atlantic and equatorial Pacific waters. There is no indication that the presence of geothermal activity or cinnabar deposits around the Mediterranean basin induces higher mercury concentrations in waters. Vertical concentration profiles were characterized by a maximum just below the thermocline, which is mainly developed in regions with relatively high primary production in the overlying waters. These observations support the remobilization model according to which, the mercury, associated with degradable organic matter, is solubilized from the particles accumulated in the thermocline layer. Additional measurements of certain mercury species, including reactive mercury (Hg sub(R)) and gaseous species [elemental mercury (Hg degree ) and dimethylmercury (DMHg)], were performed on three profiles in the Alboran Sea and the Strait of Gibraltar. While 50% of the total mercury consisted of unidentified organic association, a maximum of the three determined species were observed below the thermocline: up to 0.71 pM, 0.43 pM and 0.30 pM for Hg sub(R), Hg degree  and DMHg, respectively. DMHg and Hg degree  appear to be formed in the low oxygen zone. A specific methylation rate of 3 x 10 super(-9)/s can be estimated, which is six times higher than the values proposed for the North Atlantic waters. The mass balance budget in the western Mediterranean shows that, while the total mercury exchanges at the straits are not unbalanced, mercury enters the Mediterranean as inorganic mercury and is exported to the Atlantic Ocean partially as methylated species. Riverine input is mainly composed by particulate mercury which is readily accumulated in coastal sediments. The dissolved mercury flux from non-marine sources is largely dominated by atmospheric deposition, which is one order of magnitude higher than riverine input. The mercury accumulation rate in the sediments is quantitatively equivalent to the atmospheric inputs, but mainly constituted by terrestrial material deposited nearshore. On the basis of box-core analyses and the global model of Mason et al. (1994), and present results the pre-industrial Hg riverine, atmospheric and sedimentation fluxes are estimated to have been about one-third the current one.
AN: 4273818

                                                                      85 of 313  
TI: Biogeochemical behavior and mass balance of dissolved aluminum in the western Mediterranean Sea
AU: Chou,-Lei; Wollast,-R.
AF: Lab. d'Oceanographie Chimique, Univ. Libre de Bruxelles, Campus de la Plaine-C.P. 208, B-1050 Brussels, Belgium
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 741-768
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: The biogeochemical cycle of dissolved aluminum in the western Mediterranean has been thoroughly investigated during the EROS 2000 program. Measurements of the concentration of this element were carried out for 5 years both in the water column and in the pore waters of the sediment. Special attention was paid to the distribution of dissolved Al in the river plumes of the Rhone and Ebro. The vertical profiles of this element in the vicinity of the straits of Gibraltar and Sicily also were determined in order to quantify the exchange fluxes of Al at these two boundaries. Budget calculations indicate that the mass balance of the input and output fluxes is fairly well constrained. They also show that atmospheric dust of Saharan origin is by far the most important external source of dissolved Al for the western Mediterranean and thus is responsible for the anomalously high concentrations of this element observed in the water column. Data obtained in this study strongly support the hypothesis that the unusual nutrient-like vertical distribution is controlled mainly by biological activity. Calculations of renewal times of dissolved Al imply that its concentration and distribution can be affected significantly at time scales of a few decades if the atmospheric input is modified. Presently the net input flux of dissolved Al to the western Mediterranean is entirely exported to the Atlantic.
AN: 4273819

                                                                      86 of 313  
TI: EROS 2000 (European River Ocean System). The western Mediterranean: An introduction
AU: Martin,-J.-M.; Milliman,-J.D.
AF: Environ. Inst., Joint Res. Cent., European Commission, 21020 Ispra, Italy
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 521-529
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine); B (Brackish)
AB: The EROS 2000 project is an attempt to understand the biogeochemical processes and their alteration by human activity in the European coastal zone. More specifically, EROS 2000 addresses the following questions: What is the role of the estuarine and coastal environment in sequestering organic and inorganic carbon and in the exchange of carbon dioxide across the air-sea interface, and how do these processes affect the global carbon cycle? What is the role of the coastal ocean in the production of other greenhouse gases, such as compounds of nitrogen and sulphur? To what extent is the residence time of elements and compounds in the ocean controlled by the transformation and accumulation of organic and inorganic matter in the estuarine and coastal environment? What is the receiving capacity of the coastal ocean for pollutants of riverine and atmospheric origin? What are the socioeconomic consequences of environmental changes, particularly those induced by climatic modifications and by human impact on the coastal zone? The basic rationale of the EROS 2000 project was to carry out field investigations and modeling activities on estuary/shelf-sea systems representing the contrasting environmental characteristics of European waters that have different levels of pollution and eutrophication, and very different tidal regimes. First studies in 1988 in the northwestern Mediterranean revealed the paucity of systematic and reliable information for the majority of inorganic and organic constituents in the water column and sediments as well as for inputs from riverine and atmospheric sources.
AN: 4273823

                                                                      87 of 313  
TI: Transfer mechanisms and biogeochemical implications in the bottom nepheloid layer. A case study of the coastal zone off the Rhone River (France)
AU: Naudin,-J.J.; Cauwet,-G.
AF: GDR "Interactions Continent-Ocean", Lab. Arago, B.P. 44, F-66651 Banyuls sur mer Cedex, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 551-575
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: Particles supplied to the coastal zone are involved in numerous biogeochemical processes that rapidly modify particulate composition. The Bottom Nepheloid Layer (BNL) thus plays a significant role on the budget of elements transferred to the coastal zone. Although it should not be ignored in flux studies, little is known about the quantity and the quality of particles transported within it, mainly due to sampling difficulties. From field experiments in the coastal zone off the Rhone River, the physical mechanisms occurring within the BNL were delineated. Its temporal variability was then examined, regarding the influence of wind, river discharge and current velocity, in order to investigate the temporal scales that control the BNL's character and the processes occurring within it. In the BNL off the Rhone, particulate transfer can be as important, quantitatively, as in the river plume, and larger by far than within the water column.
AN: 4273825

                                                                      88 of 313  
TI: Hydrodynamic prevention of eutrophication in the Bay of Brest (France), a modelling approach
AU: Le-Pape,-O.; Menesguen,-A.
AF: Lab. DEL/CMCN, IFREMER, BP 70, 29280 Plouzane, France
CO: 27. Int. Liege Colloquium on Ocean Hydrodynamics, Liege (Belgium), 8-12 May 1995
SO: Journal-of-Marine-Systems 1997 vol. 12, no. 1-4, pp. 171-186
NT: Special Volume: Processes in Regions of Freshwater Influence (PROFILE)
LA: English
ER: M (Marine); B (Brackish)
AB: The Bay of Brest is a semi-enclosed coastal ecosystem where primary production is nutrient-limited, even if huge nutrients loading from tributaries are present. The most striking feature of the bay is the semi-diurnal tidal influence, resulting in large water exchange with the continental shelf. A historical study of the available data has shown the steadiness of this ecosystem during the two last decades in spite of increasing eutrophic conditions. This study has focused on hydrodynamic exchange which is one of the factors supposed to explain the resistance of this ecosystem to eutrophication: this stirring hinders the formation of a persistent upper mixed layer where phytoplankton would be in contact with nutrient-rich brackish waters and available light. Moreover, horizontal tidal currents lead to huge exchanges with the Iroise Sea and, then, to big losses of nutrients and living matter. To study this hydrodynamic influence thoroughly, a physical/biological model of this bay has been developed. This box model, based on the horizontal tidal circulation, has been developed thanks to "ELISE", an ecological modelling software and, then, tuned and validated on two data sets corresponding with the years 1977 and 1993. The model has allowed us to quantify the influence of hydrodynamics, climatic conditions and biological factors on biogeochemical processes in this ecosystem. It contributes to explain the good resistance of the Bay of Brest ecosystem to eutrophic conditions; both the hydrodynamic properties of this bay and the grazing pressure have prevented it from disturbances caused by high nitrogen loading from the watersheds and explain the steadiness of phytoplankton stocks in spite of increased loading. So, these results allow us to say that, even if nitrogen inputs increase continues, phytoplankton stocks will not increase in significant proportions. Nevertheless, changes in the phytoplanktonic populations may occur if such an enrichment continues.
AN: 4275121

                                                                      89 of 313  
TI: Role of zooplankton in the cycling and reminerallzation of chemical materials in the Southern California Bight: California Basin Study: DOE (Department of Energy) west coast basin program: Progress report 4, (June 1987-June 1988).
AU: Small,-L.F.; Huh,-C.A.
AF: Oregon State Univ., Corvallis, (USA). Coll. of Oceanography
SO: 1988 54 pp
NT: NTIS Order No.: DE89002260/GAR. Contract FG05-85ER60340. Portions of this document are illegible in microfiche. 33 refs.
RN: DOE/ER/60340-4 (DOEER603404)
LA: English
ER: M (Marine)
AB: The overall objective of our research, within the structure of the DOE CaBS (California Basin Study) program, is to understand the transport pathways and mass balances of selected metabolically active and inactive chemical species in the Santa Monica/San Pedro Basins. One focus of our study is to examine the role of zooplankton and micronekton in the cycling and remineralization of chemical materials in the Southern California Bight, with particular reference to C, N and certain radionuclides and trace metals. A second focus is to examine these same radionuclides and trace metals in other reservoirs besides the zooplankton (i.e., in seawater, sediment trap material and bottom sediments). Knowledge of the rates, routes and reservoirs of these nuclides and metals should lead to a cogent model for these elements in Santa Monica /San Pedro Basins. Our zooplankton C and N data, in conjunction with primary production, microbiological and sediment flux data from colleagues in the program, should also lead ultimately to a model of C and N cycling in the basins (DBO).
AN: 4275952

                                                                      90 of 313  
TI: [Modelling of biogeochemical cycles of elements limiting phytoplancton production in Brest Roadsted]
OT: Modelisation des cycles biogeochimiques des elements limitant la production phytoplanctonique en rade de Brest
AU: Le-Pape,-O.
CA: Ecole Natl. Superieure d'Agronomie ENSAR, Rennes (France)
SO: Rennes-France Ecole-Nationale-Superieure-d'-Agronomie 1996 195 pp
NT: Order number: 961 Serial number: H36.
LA: French
ER: M (Marine)
AB: This study has been planned in order to analyse the response of phytoplankton stocks to increasing eutrophic conditions. A survey of the annual cycle of hydrographic properties, nutrients and chlorophyll a concentrations, and carbon uptake rates was firstly performed at four stations in 1993. Compared to the seventies, a doubled nitrate loading is now entering this ecosystem, which is related to increased agricultural activities on the drainage basins, while the geographical origin of the nitrate input has been modified. As a result of these anthropogenie modifications, summer averaged Si/N stoichiometric balance has decreased during the two last decades but, phytoplankton stocks have not increased. This study of the available data on this ecosystem point out on several ecological factors which have hindered eutrophication: the high hydrodynamic mixing with adjacent marine waters, caused by the macrotidal regime, induces important nutrients losses, temperature and mostly light limit primary production while Si and P high recycling maintain nitrogen limitation in this ecosystem. Then, conjunction of non anthropogenic limiting factors seems to explain the global stability of phytoplankton stocks. A box model, based on the horizontal tidal circulation, has been developed thanks to "ELISE", an ecological modelling software. This model has allowed us to quantify the influence of hydrodynamism, climatic conditions and biological factors on biogeochemical processes in this ecosystem, contributing to explain the good resistance of the Bay of Brest ecosystem to eutrophic conditions. It demonstrates that, in the Bay of Brest, tide-induced water exchanges are important enough to export massive winter nutrients stocks before the first bloom occurrence. The increasing grazing pressure during summer, mostly by benthic feeders, explains the occurrence of low phytoplankton stocks during the summer period. Conjunction of abiotic factors in spring and biotic factors in summer then explains the low productivity of this ecosystem during the productive period in regard to nitrogen input. So, data analysis and modelling approach coupling leads to improve the knowledge on the bay of Brest ecosystem: both the physical (hydrodynamic and climatic) and the biological (mostly grazing pressure) properties of this bay have prevented it from disturbances caused by high nitrogen loading from the watersheds and explain the steadiness of phytoplankton stocks in spite of increasing loading. Then, these results and the hypothetical simulations performed with the model allow us to say that, even if nitrogen inputs increase goes on, phytoplankton stocks will not increase in important proportions. Nevertheless, changes in the phytoplanktonic populations may occur if such an enrichnient goes on.
AN: 4281608

                                                                      91 of 313  
TI: Upper ocean distribution of  super(234)Th in the Northeast Pacific: Temporal variation and the role of colloids
AU: Huh,-Chih-An
AF: Inst. Earth Sci., Acad. Sinica, Taipei, Taiwan, ROC
SO: J.-Oceanogr. 1997 vol. 53, no. 5, pp. 481-488
LA: English
ER: M (Marine)
AB: Temporal variation in upper ocean distribution of  super(234)Th between dissolved, colloidal, and particulate forms was observed at an open-ocean station in the Northeast Pacific. As a percentage of the total  super(234)Th in the euphotic zone (0-100m), dissolved, colloidal, and particulate  super(234)Th accounted for 78-91%, 5-12%, and 3-10%, respectively. The concentration of colloidal  super(234)Th correlated positively with chlorophyll a and negatively with dissolved  super(234)Th. A prominent feature of the water column profiles of colloidal and particulate  super(234)Th is that the former was always higher than the latter above the permanent pycnocline whereas the opposite was true below the permanent pycnocline. The observations support the perception that the bulk of colloids in the upper ocean are organic-rich macromolecules produced by phytoplankton and they are the immediate phase removing dissolved  super(234)Th from solution. The time integrated mean residence time in the euphotic zone is  reversible reaction  months for dissolved  super(234)Th and  similar to  days for colloidal and particulate  super(234)Th. The short residence time and organic nature of colloids suggest that, in addition to chemical scavenging of particle-reactive elements, colloids may also be responsible for a significant fraction of carbon export from the upper ocean.
AN: 4281362

                                                                      92 of 313  
TI: Response of benthic foraminifera to organic carbon accumulation rates in the Okinawa Trough
AU: Wahyudi; Minagawa,-Masao
AF: Grad. Sch. Environ. Earth Sci., Hokkaido Univ., Sapporo, Japan
SO: J.-Oceanogr. 1997 vol. 53, no. 5, pp. 411-420
LA: English
ER: M (Marine)
AB: The last glacial maximum in an Okinawa Trough sediment core is marked by high accumulation rate of organic carbon derived from surface water productivity. This coincides with increasing individual numbers of two benthic foraminifera, infaunal species Uvigerina peregrina and epifaunal Cibicidoides wuellerstorfi, and great  delta  super(13)C difference between both species. The increased abundances of U. peregrina and C. wuellerstorfi during the last glacial episode are interpreted as the result of a higher flux of organic matter (food) reaching the sediment surface as a consequence of increased surface water productivity. The good correlation between differences in  delta  super(13)C values of U. peregrina and C. wuellerstorfi and the organic carbon accumulation rates suggests that the greater the flux of organic matter reaching the sea floor, the more  super(13)C depleted CO sub(2) was released by organic matter decomposing within the sediment. On the other hand, when the flux of organic matter decreased, the  super(13)C depleted CO sub(2) within the sediment also decreased. We suggest that this  delta  super(13)C difference can be utilized as an indicator of organic matter flux changes. These findings provide new evidence for the paleoceanography of the Okinawa Trough in the East China Sea.
AN: 4281356

                                                                      93 of 313  
TI: Dissolved and particulate organic carbon in the western Mediterranean Sea
AU: Cauwet,-G.; Miller,-A.; Brasse,-S.; Fengler,-G.; Mantoura,-R.F.C.; Spitzy,-A.
AF: Cent. Natl. de la Recherche Scientifique, URA 117 and GDR 909, Observatoire Oceanologique, Lab. Arago, BP 44, 66651 Banyuls sur Mer, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 3-4, pp. 769-779
NT: Special issue: EROS 2000.
LA: English
ER: M (Marine)
AB: Particulate and dissolved organic carbon data, collected during five years in the western basin of the Mediterranean Sea, are presented and discussed. The influence of the river inputs is identified by higher surface DOC concentrations. Particulate carbon is mainly correlated with primary production in surface waters, and exhibits a seasonal variability. In surface waters, DOC is in higher concentration compared to deep water, in direct relation with particulate carbon, i.e. with production. Accumulation of DOC occurs during summer and disappears rapidly after September. Sections drawn along transects show that different water masses are identified, with characteristic DOC concentrations. Mechanisms of carbon cycling are identified, as are the general characteristics of the northwest Mediterranean Sea concerning organic carbon distribution.
AN: 4280131

                                                                      94 of 313  
TI: The relationship between ammonia excretion and GDH activity in marine zooplankton
AU: Hernandez-Leon,-S.; Torres,-S.
AF: Fac. de Cienc. del Mar, Univ. de Las Palmas de G.C., PO Box 550, Las Palmas de G.C., Canary Islands, Spain
SO: J.-PLANKTON-RES. 1997 vol. 19, no. 5, pp. 587-601
LA: English
ER: M (Marine)
AB: The relationship between the ammonia excretion rate and glutamate dehydrogenase (GDH) activity was studied in marine zooplankton over the course of a bloom and in different size classes (100-200, 200-500 and 500-1000  mu m). A weak correlation between GDH activity and ammonia excretion rate was observed when all data were pooled. Better relationships between the parameters were obtained by taking into account the substrate being metabolized, as deduced from the experimentally determined O/NH sub(4) ratio. There was also a positive correlation between the GDH/NH sub(4) and O/NH sub(4) ratios, suggesting that the former ratio was lower when the metabolic substrate being metabolized contained a high level of nitrogen. High GDH/NH sub(4) and high standard deviations were found when the in situ temperatures were low, while the ratio and standard deviations decreased at higher temperatures. Temperature probably had an indirect effect as a consequence of a better availability of nitrogen in the food when mixing took place in the water column. Differences in the GDH /ammonia ratio were also observed for different size fractions, largely because small animals had higher ammonia excretion rates. The composition of the metabolic substrate affected the observed GDH/NH sub(4) ratios because it led to variations in cellular glutamate concentrations, while enzyme activities were measured at maximal rates (V sub(max)). It is suggested that this methodological limitation is probably the most important factor in determining the relationship between enzymatic activities and metabolic rates.
AN: 4280115

                                                                      95 of 313  
TI: The need for mass balance and feedback in the geochemical carbon cycle
AU: Berner,-R.A.; Caldeira,-K.
AF: Dep. Geol. and Geophysics, Yale Univ., New Haven, CT 06520-8109, USA
SO: GEOLOGY 1997 vol. 25, no. 10, pp. 955-956
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: On a multimillion-year time scale, the level of atmospheric carbon dioxide, and consequently the atmospheric greenhouse effect, is affected largely by the geochemical, or long-term, carbon cycle. This cycle involves the exchange of carbon dioxide between rocks, on the one hand, and the surficial reservoir, consisting of the combined atmosphere, oceans, biosphere, plus soils, on the other. Carbon dioxide is exchanged with the surficial system via weathering of silicates and organic matter on the continents, the burial of carbonates (derived from silicate weathering) and organic matter in sediments, and the thermal breakdown of carbonates and organic matter at depth. It has been suggest that in the geochemical carbon cycle there is no necessity for a close balance between atmospheric inputs and outputs of CO sub(2), and therefore no need for a strongly coupled feedback to stabilize CO sub(2) level in the atmosphere. On the basis of their study of the chemistry of major rivers, Edmond et al. concluded that climate has little effect on global weathering rate and criticized the idea that long-term stabilization of CO sub(2) and climate comes about by increased chemical weathering rate that accompanies global greenhouse warming. In place of a climate-weathering feedback, Edmond et al. and Bickle assumed that increases in global degassing are eventually matched by increases in CO sub(2) uptake via enhanced weathering accompanying mountain uplift. We show here that in this case, atmospheric CO sub(2) would vary untenably as a result of large imbalances in the carbon cycle.
AN: 4279687

                                                                      96 of 313  
TI: Boundary flux measurements in the coastal ocean
AU: Brown,-W.S.
AF: Univ. New Hampshire, Durham, NH, USA
SO: The-Global-Coastal-Ocean:-Processes-and-Methods Brink,-K.H.;Robinson,-A.R.-eds. 605-Third-Avenue John-Wiley-and-Sons,-Inc. vol. 10 617 pp
ST: The-Sea:-Ideas-and-Observations-on-Progress-in-the-Study-of-the-Seas 1998 vol. 10
LA: English
ER: M (Marine)
AB: As we move rapidly toward operational use of regional data assimilation models for monitoring and prediction in the coastal ocean, appropriate observational systems will have to be implemented. Various combinations of measurements and models will be necessary to both force and constrain the models. There are two basic ways to approach the problem of combining observations and regional models of the coastal ocean. One is to apply "observed" boundary fluxes to the open boundaries of the model of choice. The other is to assimilate observations into the interior of the model using statistically and dynamically consistent methodology. The boundary fluxes then become part of the solution. In this chapter the former approach is emphasized while brief comment is made of the latter approach. In particular we review some of the methods presently used for providing various boundary fluxes through the surface, bottom and lateral boundaries of typical coastal ocean domains. Although any number of other coastal domains could serve our purposes here, we consider methods for measuring boundary fluxes as they apply to the Gulf of Maine region. Geographically, the Gulf of Maine is a marginal sea embedded in the northeast American continental shelf. Georges and Browns Banks effectively buffer the interior gulf from the deep ocean. This and adjacent regions contain a variety of coastal ocean environments, including wide shelves, narrow shelves, shallow banks, deep basins, and regions of both complex and smooth bathymetry.
AN: 4279512

                                                                      97 of 313  
TI: Evaluation and comparison of the global carbon cycle in the coastal zone and in the open ocean
AU: Wollast,-R.
AF: Univ. Brussels
SO: The-Global-Coastal-Ocean:-Processes-and-Methods Brink,-K.H.;Robinson,-A.R.-eds. 605-Third-Avenue John-Wiley-and-Sons,-Inc. vol. 10 617 pp
ST: The-Sea:-Ideas-and-Observations-on-Progress-in-the-Study-of-the-Seas 1998 vol. 10
LA: English
ER: M (Marine)
AB: Our knowledge of the carbon cycle on a global scale has improved greatly in the past decades. However, the role of the coastal zone in sequestering organic and inorganic carbon, as well as the importance of continental margins in the exchange of carbon with the open ocean, remain controversial. There are contrasting differences in the physical, chemical and biological properties between the coastal zone and the open ocean, leading to marked gradients that influence strongly the exchanges between the two systems. The fluxes at the ocean margins, linked to these horizontal gradients, may play a significant role in the elemental biogeochemical cycles in the oceans a local or global scale. Our knowledge is, however, presently insufficient for an understanding of the past, present and future behavior of these cycles. The aim of this chapter is to evaluate critically the existing data concerning the organic and inorganic carbon cycle in the marine system, with emphasis on the difference between the coastal zone and the open ocean.
AN: 4279374

                                                                      98 of 313  
TI: The importance of organic detritus in lotic ecosystems: Aspects of trophic interactions
AU: Chamier,-A.-C.
AF: Achandunie House, Ardoss by Alness, Ross and Cromarty IV17 OYB, UK
SO: Freshwat.-Forum 1997 vol. 9, pp. 14-24
LA: English
ER: F (Freshwater)
AB: Very little research has been carried out on detrital energetics and pathways in lotic ecosystems. Most investigations have concentrated on the degradation of allochthonous plant litter by fungi, with a glance at heterotrophic bacteria associated with decaying litter. In this short review, the author describes what is known of the detrition of plant litter in lotic waters, which results from the degradative activities of colonising saprophytic fungi and bacteria, and goes on to relate this process to those invertebrates that consume coarse and/or fine particulate detritus, or dissolved organic matter that aggregates into colloidal exopolymer particles. It is clear that many of the key processes involved in the relationships between the physical, chemical, biotic and biochemical elements present in running waters are very complex and poorly understood. Those few aspects for which there are reliable models with predictive power have resulted from data collections made over periods of 20 years or more. Comprehensive research of single catchments would provide a fine opportunity to collect data over a long period.
AN: 4271265

                                                                      99 of 313  
TI: A technique for the in situ assessment of the vertical nitrogen flux caused by the diel vertical migration of zooplankton
AU: Hays,-G.C.; Harris,-R.P.; Head,-R.N.; Kennedy,-H.
AF: Sch. Biol. Sci., Univ. Wales Swansea, Singleton Park, Swansea SA2 8PP, UK
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 6, pp. 1085-1089
LA: English
ER: M (Marine)
AB: It is argued that if herbivorous zooplankton exhibiting diel vertical migration generally feed only above the thermocline at night, but continue to excrete during the day when they are below the thermocline, then there should be a diel variation in their mean body nitrogen content. Thus measurement of the body nitrogen content of migrating zooplankton at different times of the day may provide a technique for the in situ assessment of the rate at which they remove nitrogen from the surface mixed layer. We show that if the inter-individual variation in body nitrogen content is high and sample size is low, then detection of the predicted diel change will tend to be obscured. However, in a simple laboratory experiment, a significant reduction in the mean body nitrogen content of the copepod Calanus helgolandicus was found between fed individuals (mean 12.91  mu g N, n = 42, SD = 1.63) and those starved for 18 h (11.89  mu g N, n = 30, SD = 1.29; t-test, t sub(69) = 2.92, P= 0.0047), suggesting that the technique may be applied in the field.
AN: 4266501

                                                                     100 of 313  
TI: Eddy-induced nutrient supply and new production in the Sargasso Sea
AU: McGillicuddy,-D.J.,Jr.; Robinson,-A.R.
AF: Dep. Applied Ocean Phys. and Eng., Woods Hole Oceanographic Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 8, pp. 1427-1450
LA: English
ER: M (Marine)
AB: A limited area, eddy resolving coupled physical and biological model is used to examine the role of mesoscale dynamical processes in nutrient cycling in the Sargasso Sea. Upwelling due to the formation of cyclonic eddies and their intensification caused by interaction with surrounding mesoscale features causes spatially and temporally intermittent fluxes of nitrate into the euphotic zone. The annual flux resulting from this eddy upwelling process is of the order of 0.5 mol N/m super(2)/year, which is sufficient to sustain a rate of new primary production that is consistent with estimates for this region derived from budgets of oxygen and other dissolved gases.
AN: 4260788

                                                                     101 of 313  
TI: Bacterial abundance and production in different water masses around South Island, New Zealand
AU: Smith,-R.; Hall,-J.
AF: Natl. Inst. Water & Atmos. Res. Ltd., P.O. Box 8602, Christchurch, New Zealand
SO: N.-Z.-J.-MAR.-FRESHWAT.-RES. 1997 vol. 31, no. 4, pp. 515-524
LA: English
ER: M (Marine)
AB: Bacterial numbers and production were measured in the upper water column in the winter and spring of 1993 in five water masses surrounding the South Island of New Zealand. Average bacterial numbers and production were found to be higher in spring (8.5 x 10 super(5) cells ml super(-1) and 0.20 mg m super(3) h super(-1), respectively) than winter (5.5 x 10 super(5) cells ml super(-1) and 0.05 mg C m super(3) h super(-1) respectively). Bacterial production was strongly correlated with chlorophyll a and primary production (P < 0.001) in spring but not in winter. Spring bacterial production and at 10 m depth averaged across 28 stations was 23% of primary production, and with a growth efficiency of 40%, may have consumed up to 57% of primary production. Bacterial biomass was greater than phytoplankton biomass for 75% of the 10 m depth comparisons during winter sampling and 44% during the spring sampling. The bacterial biomass was found to represent 24.6-33.5% of the nitrogen in particulate organic matter (<200  mu m) supporting the concept that in New Zealand oceanic water masses bacteria are of significant biogeochemical importance.
AN: 4260787

                                                                     102 of 313  
TI: The importance of microbial Mn oxidation in the upper ocean: A comparison of the Sargasso Sea and equatorial Pacific
AU: Moffett,-J.W.
AF: Dep. Mar. Chem. and Geochemistry, Woods Hole Oceanographic Inst., Woods Hole, MA 02543-1543, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 8, pp. 1277-1291
LA: English
ER: M (Marine)
AB: The processes responsible for Mn uptake onto suspended particles in the upper water column were studied in the equatorial Pacific and in the Sargasso Sea at the Bermuda Atlantic Time Series (BATS) Station. Oxidation was followed by incubating freshly collected seawater with  super(54)Mn and using a combination of procedures developed by others to distinguish oxidation from adsorption and biological from non-biological processes. Results in the Sargasso Sea indicate that oxidation is the principal pathway for the formation of particulate Mn throughout the year, in good agreement with the findings of earlier workers. These data, combined with earlier studies from diverse environments, suggest that microbial Mn oxidation is a ubiquitous process in oxygenated marine environments. However, in the equatorial Pacific we detected no microbial oxidation above 175 m. Formation of particulate  super(54)Mn occurred and was inhibited in the presence of azide, indicating a biological process, but the particulate Mn could not be dissolved by the addition of ascorbate, an important criterion, as Mn oxides are readily reduced at seawater pH by ascorbate. In the Pacific, the non-oxidative, biologically mediated uptake was enhanced by light, possibly because of uptake by phytoplankton, as Mn is an essential micronutrient. By contrast, oxidative biological uptake in the Sargasso Sea was inhibited by light, in agreement with earlier work. The results indicate that the geochemical cycling of Mn is different in the two environments, presumably reflecting aspects of the ecology of Mn oxidizing bacteria that are not understood. These findings suggest that it is premature to generalize about the relative importance of oxidative vs. non-oxidative scavenging of Mn from the euphotic zone in the open ocean without additional data.
AN: 4260772

                                                                     103 of 313  
TI: Phosphate mobilization in iron-rich anaerobic sediments: Microbial Fe(III) oxide reduction versus iron-sulfide formation
AU: Roden,-E.E.; Edmonds,-J.W.
AF: Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487-0206, USA
SO: Arch.-Hydrobiol. 1997 vol. 139, no. 3, pp. 347-378
NT: Inc. bibliogr.: 72 refs.
LA: English
ER: F (Freshwater)
AB: Mechanisms of phosphate (PO sub(4)  super(3-)) mobilization and retention were examined in iron-rich anaerobic freshwater wetland, lake, and coastal marine sediments. Direct microbial Fe(III) oxide reduction solubilized only 3-25% of initial solid-phase PO sub(4)  super(3-) during sulfate-free sediment incubation experiments. Experiments with reduced, non-sulfidic solid-phase Fe(II)-rich sediment demonstrated PO sub(4)  super(3-) sorption by the solid-phase, and chemical equilibrium calculations indicated that conditions were favorable for precipitation of Fe(II)-PO sub(4) minerals [e.g. Fe sub(3)(PO sub(4)) sub(2)] in such sediments. These results suggested that much of the PO sub(4)  super(3-) released from Fe(III) oxides during microbial Fe(III) reduction was captured by solid-phase reduced iron compounds (Fe(II) hydroxide-PO sub(4) complexes and/or Fe(II)-PO sub(4) minerals). Enhanced liberation of PO sub(4)  super(3-) to sediment porewaters (33-100 % of initial solid-phase PO sub(4)  super(3-)) occurred during anaerobic incubation in the presence of abundant sulfate and was directly corre- lated with sulfate reduction and iron-sulfide mineral formation. Incubation of PO sub(4)  super(3-)- amended sediment with different amounts of sulfate demonstrated a linear correlation between PO sub(4)  super(3-) release and sulfate reduction. Release of PO sub(4)  super(3-) to sediment porewaters during decomposition of fresh organic matter (freeze-dried cyanobacteria) was more extensive in sulfate-amended (67% of added organic P) than in sulfate-free sediment (17% of added organic P), and the ratio of dissolved PO sub(4)  super(3-) released to organic carbon oxidized was seven-fold higher in sulfate-amended sediment despite a common level of overall organic C and P mineralization in the two treatments. Our results demonstrate that iron-rich anaerobic sediments can immobilize substantial amounts of PO sub(4)  super(3-) under Fe(III) oxide-reducing conditions, but that extensive PO sub(4)  super(3-) release will take place if sediment Fe compounds are converted to iron-sulfides via bacterial sulfate reduction.
AN: 4257827

                                                                     104 of 313  
TI: Foraminiferal proxies: Constraints on their use in high latitude paleoceanography
OT: Zur Palaeoozeanographie hoher Breiten: Stellvertreterdaten aus Foraminiferen
AU: Mackensen,-A.
CA: Bremen Univ., Bremen (FRG), Fachber. Geowissenschaften
SO: Ber.-Polarforsch.-Rep.-Polar-Res. 1997 no. 243, 146 pp
NT: Incl. 18 pages refs.
LA: German
ER: M (Marine)
AB: This compilation on the reliability and trustworthiness of benthic foraminiferal proxies is based on Recent and Late Quaternary sample material from the polar oceans, collected during the last 15 years from the sea floors of the Arctic Ocean, the Norwegian/Greenland Seas and the North Atlantic Ocean, as well as from the Weddell Sea and the South Atlantic Ocean. In addition, Tertiary sample material from the Antarctic sites of the Ocean Drilling Program is considered. To check proxies against their Recent analogue foraminiferal faunas from surface sediment samples were investigated in relationship to their particular biogeochemical environment. First of all semi-quantitative and qualitative proxies for new production, seasonality, bottom water ventilation, current velocities, and water depth were discussed, all of which derived by paleontological methods from standing crop data, species composition and microhabitat preferences of benthic foraminiferal faunas. Then the author discusses proxies for nutrient content, temperature and salinity of water masses, all of which derived by geochemical methods from the stable isotopic composition and trace element contents of calcareous foraminiferal tests. As a conclusion, paleontological proxies can be quantitatively interpreted just in a broad way, i.e. only under consideration and with knowledge of ecologically limiting threshold values.
AN: 4257549

                                                                     105 of 313  
TI: Primary production, calcification, and air-sea CO sub(2) fluxes of a macroalgal-dominated coral reef community (Moorea, French Polynesia)
AU: Gattuso,-J.-P.; Payri,-C.E.; Pichon,-M.; Delesalle,-B.; Frankignoulle,-M.
AF: Observatoire Oceanologique Europeen, Ave. Saint-Martin, MC-98000 Monaco, Principality of Monaco
SO: J.-PHYCOL. 1997 vol. 33, no. 5, pp. 729-738
LA: English
ER: M (Marine)
AB: Community metabolism and air-sea carbon dioxide (CO sub(2)) fluxes were investigated in July 1992 on a fringing reef at Moorea (French Polynesia). The benthic community was dominated by macroalgae (85% substratum cover) and comprised of Phaeophyceae Padina tenuis (Bory), Turbinaria ornata (Turner) J. Agardh, and Hydroclathrus clathratus Bory (Howe); Chlorophyta Halimeda incrassata f. ovata J. Agardh (Howe); and Ventricaria ventricosa J. Agardh (Olsen et West), as well as several Rhodophyta (Actinotrichia fragilis Forskaal (Borgesen) and several species of encrusting coralline algae). Algal biomass was 171 g dry weight times m super(-2). Community gross production (P sub(g)), respiration (R), and net calcification (G) were measured in an open-top enclosure. P sub(g) and R were respectively 248 and 240 mmol CO sub(2)/m super(2)/d, and there was a slight net dissolution of CaCO sub(3) (0.8 mmol/m super(2)/d). This site was a sink for atmospheric CO sub(2) (10  plus or minus  4 mmol CO sub(2)/m super(2)/d), and the analysis of data from the literature suggests that this is a general feature of algal-dominated reefs. Measurement of air-sea CO sub(2) fluxes in open water close to the enclosure demonstrated that changes in small-scale hydrodynamics can lead to misleading conclusions. Net CO sub(2) evasion to the atmosphere was measured on the fringing reef due to changes in the current pattern that drove water from the barrier reef (a CO sub(2) source) to the study site.
AN: 4247872

                                                                     106 of 313  
TI: Methane and carbon dioxide dynamics in Typha latifolia (L.) wetlands in central New York state
AU: Yavitt,-J.B.
AF: Dep. Nat. Resour., Fernow Hall, Cornell Univ., Ithaca, NY 14853, USA
SO: WETLANDS 1997 vol. 17, no. 3, pp. 394-406
LA: English
ER: F (Freshwater)
AB: I examined differences in the biogeochemical cycles of CH sub(4) and CO sub(2) (fluxes, concentrations, production, CH sub(4) oxidation) in Typha latifolia wetlands on silty clay sediment versus organic peat soil in central New York state to determine whether variation in the amount of organic matter in sediment or soil, or plant production on sites with different organic matter content, affected variation in CH sub(4) and CO sub(2). I found very high temporal variation in CH sub(4) within each site, precluding the detection of variation in CH sub(4) as a function of sediment or soil organic matter content. In 1994, CH sub(4) efflux from two peat sites to the atmosphere averaged 7 and 87 nmol m super(-2) s super(-1) compared to 89 and 408 nmol m super(-2) s super(-1) for two sediment sites. Mean CO sub(2) efflux from the peat sites was 0.40 and 1.51  mu mol m super(-2) s super(-1) compared to 1.02 and 1.65  mu mol m super(-2) s super(-1) for the sediment sites. I assessed the role of plant production by experimentally removing T. latifolia shoots from small plots: this lowered CH sub(4) efflux from the sediment site by 85%, suggesting that plants foster CH sub(4) production in low organic matter sediment, but CH sub(4) efflux was 14-times greater following shoot removal on one peat site. Shoot removal had no effect on CO sub(2) efflux. Variations in temperature, dissolved organic carbon, and pCH sub(4) in sediment or soil porewater explained the variation in CH sub(4) efflux among the four study sites, whereas variation in net primary production explained the variation in CO sub(2) efflux.
AN: 4228923

                                                                     107 of 313  
TI: Seasonal variation of CDOM and DOC in the Middle Atlantic Bight: Terrestrial inputs and photooxidation
AU: Vodacek,-A.; Blough,-N.V.; DeGrandpre,-M.D.; Peltzer,-E.T.; Nelson,-R.K.
AF: Dep. Chem. and Biochem., Univ. Maryland, Coll. Park, MD 20742, USA
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 4, pp. 674-686
LA: English
ER: M (Marine)
AB: Extensive surveys of the fluorescence and absorption of chromophore-containing dissolved organic matter (CDOM), dissolved organic C (DOC) concentration, chlorophyll fluorescence, and salinity were performed during August and November 1993 and March and April 1994 along a cruise line extending from the mouth of Delaware Bay southeast to the Sargasso Sea. With shallow stratification in August, photobleaching dramatically altered the optical properties of the surface waters, with  similar to 70% of the CDOM absorption and fluorescence lost through photooxidation in the waters at the outer shelf. S, the slope of the log-linearized absorption spectrum of CDOM, increased offshore and seemed to increase with photodegradation. The increase in S combined with the seasonal variation in the relationship between Chl and CDOM underscores the difficulty in developing algorithms to predict Chl concentrations in turbid coastal waters with ocean color data. Despite the photooxidation of CDOM, the seasonal variation in the CDOM fluorescence-absorption relationship and fluorescence quantum yields was <15%. When using appropriate methods, the airborne lidar approach for remote determination of CDOM absorption coefficients seems to be a very robust technique. The photooxidation of CDOM in August also affected the relationship between CDOM and DOC concentration in the surface waters, although for the rest of the year the relationship was reasonably linear. The results of a simple model suggest  similar to 10% of the DOC in the mixed layer was directly converted photochemically to dissolved inorganic C (DIC).
AN: 4228354

                                                                     108 of 313  
TI: Microbial mineralization of organic carbon and dissolution of inorganic carbon from mussel shells (Mytilus edulis)
AU: Knauth-Koehler,-K.; Albers,-B.P.; Krumbein,-W.E.
AF: Carl von Ossietzky-Universitaet Oldenburg, Institut fuer Chemie und Biologie des Meeres (ICBM), Meeresstation, Schleusenstrasse 1, D-26382 Wilhelmshaven, FRG
SO: Senckenb.-Marit. 1996 vol. 26, no. 3-6, pp. 157-165
LA: English
ER: M (Marine)
AB: Bacteria in marine environments grow on living organisms as well as on surfaces of organic and inorganic detrital particles, where essential nutrients are concentrated. Using electron micrographs, this study of the influence of microorganisms on the decay of biogenic organic and inorganic carbon compounds has revealed a dense microflora adsorbing to mussel shells. Investigations of bacterial populations isolated from shells of Mytilus edulis demonstrated the use of organic matter from mussel shells as nutrient. This was also proved by changes in the  super(13)C/ super(12)C ratios of the mussel shells. It can be assumed that the decomposition of the periostracum impairs the crystallite structure of the mussel carbonate layers and thus initiates the microbial destruction of the biogenic carbonate. In laboratory experiments, it was shown that the bacterial populations produce organic acids under aerobic as well as under anaerobic conditions causing a shift in carbonate equilibrium which results in the dissolution of CaCO sub(3). The decomposition of organic mussel shell matrices and the high carbonate dissolution rates by bacterial populations isolated from mussel shells lead to the assumption that a specifically adapted epibiotic mussel microflora exists.
AN: 4212793

                                                                     109 of 313  
TI: Deep water particle flux in the Canary Island region: Seasonal trends in relation to long-term satellite derived pigment data and lateral sources
AU: Neuer,-S.; Ratmeyer,-V.; Davenport,-R.; Fischer,-G.; Wefer,-G.
AF: FB 5 Geosciences, Univ. Bremen, Klagenfurterstrasse, 28395 Bremen, Germany
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 8, pp. 1451-1466
LA: English
ER: M (Marine)
AB: We present a 3 year record of deep water particle flux at the recently initiated ESTOC (European Station for Time-series in the Ocean, Canary Islands) located in the eastern subtropical North Atlantic gyre. Particle flux was highly seasonal, with flux maxima occurring in late winter-early spring. A comparison with historic CZCS (Coastal Zone Colour Scanner) data shows that these flux maxima occurred about 1 month after maximum chlorophyll was observed in surface waters in a presumed primary source region 100 km x 100 km northeast of the trap location. The main components of the particles collected with the traps were mineral particles and carbonate, both correlating strongly with organic matter sedimentation. Mineral particles in the sinking matter are indicative of the high aeolian input from the African desert regions. Comparing particle fluxes at 1 km and 3 km depth, we find that particle sedimentation increased substantially with depth. Yearly organic carbon sedimentation was 0.6 g m super(-2) at 1 km depth compared with 0.8 g m super(-2) at 3 km. We hypothesize that higher phytoplankton biomass observed further north could be a source of laterally advecting particles that interact with fast sinking particles originating from the primary source region. This hypothesis is also supported by the differences in size distribution of lithogenic matter found at the two trap depths.
AN: 4241088

                                                                     110 of 313  
TI: Particle flux in deep seas: Regional characteristics and temporal variability
AU: Lampitt,-R.S.; Antia,-A.N.
AF: Southampton Oceanogr. Cent., Empress Dock, Southampton SO14 ZH, UK
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 8, pp. 1377-1403
LA: English
ER: M (Marine)
AB: Particle flux data have been collated from the literature representing most areas of the open ocean to determine regional trends in deep water flux and its seasonal variability. Organic carbon flux data normalised to a depth of 2000 m exhibits a range of an order of magnitude in areas outside the polar domains (0.38 to 4.2 g/m super(2) /y). In polar regions the range is wider (0.01-5.9 g/m super(2)/y). Latitudinal trends are not apparent for most components of the flux although calcite flux exhibits a poleward decrease. Limited data from polar regions show fluxes of opaline silica not significantly higher than elsewhere. The variability of flux over annual cycles was calculated and expressed as a Flux Stability Index (FSI) and the relationship between this and vertical flux of material examined. Somewhat surprisingly there is no significant relationship between FSI and fluxes of dry mass, organic carbon, inorganic carbon or opaline silica. At each site, net annual primary production was determined using published satellite derived estimates. There is a negative but weak relationship between FSI and the proportion of primary production exported to 2000 m (e sub(2000) ratio). The most variable of the nonpolar environments export to 2000 m about twice as much of the primary production as the most stable ones. Polar environments have very low e sub(2000) ratios with no apparent relationship to FSI. At primary production levels below 200 g C/m super(2)/y there is a positive correlation between production and organic carbon flux at 2000 m but above this level, flux remains constant at about 3.5g C/m super(2)/y. A curve derived to describe this relationship was applied to estimates of annual primary production in each of 34 of the open ocean biogeochemical provinces proposed by Longhurst et al. (1995). Globally, open ocean flux of organic carbon at 2000 m is 0.34 Gt/yr which is 1% of the total net primary production in these regions. This flux is nearly equally divided between the Atlantic, Pacific and Southern Oceans. The Indian and Arctic oceans between them only contribute 5% to the total. The eight planktonic climatological categories proposed by Longhurst (1995) provide a most useful means of examining the data on flux and its variability. A characteristic level of FSI was found in each category with highest levels in the tropics and lowest levels in the Antarctic. There is also a characteristic level of export ratio in each category with the highest in monsoonal environments (1.7%) and the lowest in Antarctica (0.1%).
AN: 4241086

                                                                     111 of 313  
TI: Oceanic dissolved organic carbon is the main sink of atmospheric CO sub(2)
AU: Gorshkov,-V.G.
AF: Petersburg Nuclear Phys. Inst., Gatchina, 188350 Leningrad Dist., Russia
SO: WORLD-RESOUR.-REV. 1997 vol. 9, no. 2, pp. 153-169
LA: English
ER: M (Marine)
AB: Production of the dissolved organic carbon (DOC) in the equilibrium preindustrial state constituted about 0.2% of the oceanic net primary production. Ocean biota negatively feedbacks to the CO sub(2) concentration change in the environment. Modern share of DOC production in the oceanic net primary production has increased nearly twenty-fold during the industrial era. Rate of DOC destruction has remained unchanged. Rate of DOC mass increase is about 2 Gt C/year now and coincides with land use estimation of carbon release by terrestrial biota. This coincidence resolves the problem of "missing carbon sink". All the results were obtained from data on distribution of prebomb and postbomb  super(14)C in the ocean. Surface DOC in equilibrium state had a negligibly small fraction with decadal turnover time. The observed increase of radiocarbon in surface DOC is a result of broken equilibrium state and DOC mass increase during the whole industrial era. The obtained results agree with modern data on atmospheric O sub(2)/N sub(2) ratio change.
AN: 4239784

                                                                     112 of 313  
TI: [Chromium in marine environment]
OT: Le chrome en milieu marin
AU: Chiffoleau,-J.F.
SO: Reperes-Ocean Plouzane-France IFREMER 1994 no. 8, 43 pp
LA: French
ER: M (Marine)
AB: This document constitutes a synthesis of current knowledge on the chromium biogeochemical cycle. The natural and anthropogenic sources are evaluated, the fluxes between the various geochemical compartments are assessed, with special attention to the riverine and atmospheric inputs to the marine environment. Chromium levels in these compartments are described and show in several areas a very high contamination of marine organisms. Due to the important toxicity of this element, further investigations are absolutely required to better understand its behaviour in the marine environment.
AN: 4236621

                                                                     113 of 313  
TI: Surface activation of manganese oxide electrode for oxygen evolution from seawater
AU: Izumiya,-K.; Akiyama,-E.; Habazaki,-H.; Kawashima,-A.; Asami,-K.; Hashimoto,-K.; Kumagai,-N.
AF: Inst. for Materials Res., Tohoku Univ., Sendai 980-77, Japan
SO: J.-APPL.-ELECTROCHEM. 1997 vol. 27, no. 12, pp. 1362-1368
LA: English
ER: M (Marine)
AB: Utilizing the fact that the equilibrium potential of oxygen evolution is lower than that of chlorine evolution, oxygen evolution in seawater electrolysis was enhanced by decreasing the polarization potential under galvanostatic conditions through increasing the effective surface area of manganese oxide electrodes. Electrodes were prepared by a thermal decomposition method. IrO sub(2)-coated titanium (IrO sub(2)/Ti electrode) was used as the substrate on which manganese oxide was coated (MnO sub(X)/IrO sub(2)/Ti electrode). Subsequently, oxide mixtures of manganese and zinc were coated (MnO sub(X)-ZnO/MnO sub(X)/IrO sub(2)/Ti electrode). The effective surface area of the MnO sub(X)-ZnO/MnO sub(X)/IrO sub(2)/Ti electrodes was increased by selective dissolution of zinc (leaching) into hot 6 M KOH. The oxygen evolution efficiency of the MnO sub(X)/IrO sub(2)/Ti electrode was 68-70%. Leaching of zinc from the MnO sub(X)-ZnO/MnO sub(X)/IrO sub(2)/Ti electrodes with 25 mol% or less zinc led to a significant increase in the oxygen evolution efficiency. The maximum efficiency attained was 86% after leaching of zinc from the MnO sub(X)-25 mol%ZnO/MnO sub(X) /IrO sub(2)/Ti electrode. However, large amounts of zinc addition, such as 40 mol% or more are detrimental because of a decrease in the oxygen evolution efficiency. This is due to the formation of a double oxide, ZnMnO sub(3), which is hardly dissolved in hot 6 M KOH.
AN: 4229740

                                                                     114 of 313  
TI: Short-term effects of salinity reduction and drainage on salt-marsh biogeochemical cycling and Spartina (cordgrass) production
AU: Portnoy,-J.W.; Valiela,-I.
AF: United States Geol. Surv., Cape Cod Natl. Seashore, 99 Marconi Rd., Wellfleet, MA 02667, USA
SO: ESTUARIES 1997 vol. 20, no. 3, pp. 569-578
LA: English
ER: B (Brackish)
AB: To assess the biogeochemical effects of tidal restrictions on salt-marsh sulfur cycling and plant growth, cores of short-form Spartina alterniflora peat were desalinated and kept either waterlogged or drained in greenhouse microcosms. Changes in net Spartina production, and porewater and solid phase chemistry of treated cores were compared to natural conditions in the field collection site over a 21-mo period. Net production among treatments increased significantly in drained and waterlogged peat compared to field conditions during the first growing season. Constantly high sulfide in waterlogged cores accompanied reduced plant growth. Aeration invigorated growth in drained cores but led to oxidization of sulfide minerals and to lowered pH. During the second growing season, growth declined in the drained treatment, probably because of acidification and decreased dissolved inorganic nitrogen. Results are pertinent to the success of current wetland protection and restoration activities in the coastal zone.
AN: 4228948

                                                                     115 of 313  
TI: Biomass and productivity of tropical macroalgae on three nearshore fringing reefs in the central Great Barrier Reef, Australia
AU: Schaffelke,-B.; Klumpp,-D.W.
AF: Australian Inst. Mar. Sci., PMB #3, Townsville 4810, Australia
SO: BOT.-MAR. 1997 vol. 40, no. 5, pp. 373-383
LA: English
ER: M (Marine)
AB: Recently, concerns about human disturbance on coral reef communities have focused attention on macroalgae of nearshore fringing coral reefs of the Great Barrier Reef, Australia (GBR). However, the scarcity of baseline information makes it difficult to establish whether nearshore reef communities in the central GBR are perturbed or in a 'natural' state. This study provides data on biomass and productivity of nearshore reef macroalgae to serve as background information for the detection of future community changes. Over a period of 15 months, we estimated: i) biomass of conspicuous macroalgae in transects at three nearshore fringing reefs and ii) in situ net growth rates and net production of Sargassum baccularia. In summer, biomass was significantly dominated by large Fucales, especially S. baccularia (up to 200 g ash free dry weight m super(-2)). Ephemeral algae (species of Padina, Hydroclathrus, Colpomenia, Chnoospora, Laurencia) were most abundant in austral spring (up to 40 g AFDW m super(-2)). Maximum growth rates of S. baccularia of 3-4% day super(-1) (entire thalli) occurred during the summer, preceding the reproductive period. Subsequent shedding of lateral branches resulted in negative growth rates during autumn/winter. In situ growth of excised shoots showed seasonal patterns comparable to entire thalli, except that growth rates were always positive. Biomass specific net production of excised shoots was significantly higher from spring to autumn than during winter. Areal productivity of S. baccularia had a significant maximum of 3 g C m super(-2) day super(-1) in spring, a value comparable to the productivity of coral-reef epilithic algal communities or temperate kelp forests. The high standing biomass, high productivity and a presumably rapid turnover of biomass via detrital pathways suggest that fucoid macroalgae are important contributors to the stock of organic compounds on these nearshore reefs.
AN: 4228939

                                                                     116 of 313  
TI: The dissolved silica budget as a constraint on the meridional overturning circulation of the Indian Ocean
AU: Robbins,-P.E.; Toole,-J.M.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 5, pp. 879-906
LA: English
ER: M (Marine)
AB: The geostrophic circulation at 32 degree S in the Indian Ocean, based on hydrographic data collected in 1987 on the R.R.S. Charles Darwin, is re-examined with the inclusion of the advective flux of dissolved silica. Consideration of the physical mechanisms of silica transport at 32 degree S in conjunction with the silica budget of the Indian Ocean basin requires modification of the geostrophic reference levels. The resulting meridional overturning circulation composed of northward flowing deep waters returning south at shallower levels becomes 11.9  plus or minus  2.7 x 10 super(9) kg s super(-1), roughly half the magnitude of a previous estimate using the same data. The bulk of the northward flowing bottom and lower deep water is converted to intermediate and upper deep water, which exits the basin as southward flow across 32 degree S. Less than one-third of the northward flowing deep waters upwells into the thermocline. Though the magnitude of the overturning circulation is reduced compared with previous estimates with this data set, the maximum basin-mean upwelling velocity required for mass continuity, 4.5 x 10 super(-5) cm s super(-1), is consistent with other estimates for the Indian Ocean basin and remains large compared with estimates for the deep Pacific basin. Since the meridional circulation is a major conveyor of heat and salinity in the Indian Ocean basin, a constraint on the magnitude of the meridional circulation provides bounds on the net heat and freshwater budgets of the region. The divergence of heat across the Indian Ocean basin north of 32 degree S is estimated to be 0.42  plus or minus  0.19 Petawatts and the convergence of freshwater to be 0.31  plus or minus  0.09 x 10 super(9) kg s super(-1). Both of these values are consistent with independent estimates, but reduced compared with calculations that do not consider the dissolved silica budget.
AN: 4228909

                                                                     117 of 313  
TI: Phosphorus-limited bacterioplankton growth in the Sargasso Sea
AU: Cotner,-J.B.; Ammerman,-J.W.; Peele,-E.R.; Bentzen,-E.
AF: Dep. Wildl. and Fish. Sci., Texas A&M Univ., Coll. Stn., TX 77843-2258, USA
SO: AQUAT.-MICROB.-ECOL. 1997 vol. 13, no. 2, pp. 141-149
LA: English
ER: M (Marine)
AB: Oceanic central gyres cover large areas of the earth and contribute significantly to global productivity. Oceanic phytoplankton production is believed to be limited by nitrogen (N) in central gyres and iron (Fe) in high-nutrient low-chlorophyll regions. Bacterioplankton have been less studied but are believed to be limited by organic carbon. We report here that bacterioplankton in the Sargasso Sea were phosphorus (P) limited on cruises in 1992 and 1993. This assertion is supported by measurements of high dissolved and particulate N:P and C:P ratios, high alkaline phosphatase activity and phosphate uptake rates, and bacterioplankton growth rate responses in bioassays where inorganic P was added. Particulate C:P ratios were always higher than the Redfield ratio (106:1) and occasionally greater than 400:1. N:P ratios were 75:1 and 46:1 on 2 cruises and time-series data indicated that ratios were always greater than 24:1 over nearly a 2 yr span. Phosphate concentrations were extremely low in the euphotic zone (<10 nM) and biomass-normalized alkaline phosphatase activities indicated moderate to severe P limitation, with most severe limitation occurring in the spring. Bioassays indicated that heterotrophic bacteria may be P limited in the northwestern Sargasso Sea, especially in the spring. Limitation by P and not dissolved organic carbon may explain why dissolved organic carbon accumulates in the water column at that time.
AN: 4228310

                                                                     118 of 313  
TI: The seasonal cycle of nitrate in the Clyde Sea
AU: Rippeth,-T.P.; Jones,-K.J.
AF: Sch. Ocean Sci., Univ. Wales, Bangor, Menai Bridge, Gwynedd, UK
CO: 27. Int. Liege Colloquium on Ocean Hydrodynamics, Liege (Belgium), 8-12 May 1995
SO: Journal-of-Marine-Systems 1997 vol. 12, no. 1-4, pp. 299-310
NT: Special Volume: Processes in Regions of Freshwater Influence (PROFILE)
LA: English
ER: M (Marine); B (Brackish)
AB: The Clyde Sea is a deep, partially enclosed basin on the West Coast of Scotland which communicates with the adjacent North Channel of the Irish Sea via exchange flow over a relatively shallow entrance sill. The basin receives large inputs of nutrient rich freshwater which induces a reduction in surface salinities of up to 1.5 psu and maintains almost continuous stratification. Time series data collected in the area show a well defined seasonal cycle of stratification which has previously been explained with the aid of a one-dimensional filling box model. This model has been extended to examine the extent to which the observed seasonal cycles of nitrate and chlorophyll can be explained by the stepwise inclusion of additional non-conservative terms. The results show that, as a result of the interaction between the physical and biological seasonal cycles, nitrate accumulates in the Clyde Sea during the summer, which is then supplied to the North Channel of the Irish Sea during the winter and spring.
AN: 4227491

                                                                     119 of 313  
TI: Influence of dissolved silicate on vertical flux of particulate biogenic matter
AU: Wassmann,-P.; Egge,-J.K.; Reigstad,-M.; Aksnes,-D.L.
AF: Norwegian Coll. Fish. Sci., Univ. Tromso, N-9037 Tromso, Norway
SO: MAR.-POLLUT.-BULL. 1997 vol. 33, no. 1-6, pp. 10-21
NT: Special issue: Programme on Marine Pollution (PMF). A Norwegian Research Programme (1992-1996).
LA: English
ER: M (Marine)
AB: The influence of dissolved silicate (DSi) addition on primary production, phytoplankton development and subsequent vertical export of particulate matter was studied in enclosures. Blooms of different phytoplankton communities were initiated in the upper part of 10 m deep enclosures supplied with nitrate and phosphate (NP) and nitrate, phosphate and silicate (NPS). Primary production was 31% higher in the NPS enclosure as compared to the NP enclosure over the experimental period of 27 days. Increased phytoplankton growth was mainly caused by mass development of diatoms in the NPS enclosure. Enhanced growth was accompanied by an increased vertical flux of organic matter (86, 15.9 and 16.9% in terms of chlorophyll, particulate nitrogen and particulate carbon, respectively) and was dominated by diatoms. The present study indicates that for each gram of DSi added, vertical flux was enhanced by 3.6 g C, implying that the ratio of DSi added/carbon exported was close to the Redfield ratio. Thus DSi presence appears to decrease the nutrient turn-over time in the euphotic zone by increasing vertical export. This may improve water quality of the surface layer of eutrophicated environments, but can lead to oxygen depletion of bottom waters.
AN: 4227046

                                                                     120 of 313  
TI: Assessment of the role of copepods and ciliates in the release to solution of particulate DMSP
AU: Christaki,-U.; Belviso,-S.; Dolan,-J.R.; Corn,-M.
AF: Station Zoologique, URA 2077, BP 28, F-06230 Villefranche-sur-Mer, France
SO: Mar.-Ecol.-Prog.-Ser. 1996 vol. 141, no. 1-3, pp. 119-127
LA: English
ER: M (Marine)
AB: The exchanges between pools of particulate DMSP (pDMSP) and the total dissolved pool of DMSP and DMS [MS(P)], as well as dDMS(P) removal rates were investigated in 4 shipboard incubations of amended and size-fractionated natural planktonic assemblages of the Mediterranean Sea in spring 1995 and in a laboratory experiment with cultured populations. In the shipboard experiments, the effects of different concentrations of copepods and the presence /absence of micrograzers were assessed. Removal rates of dDMS(P), obtained from seawater samples spiked with dDMSP (dissolved DMSP), were linearly correlated with dDMS(P) levels in the range 10 to 50 nM and were unrelated to size-fractionation treatments. The biological turnover rate constant of dDMS(P) was 0.5/d. In most of the experiments, production of dDMS(P) was independent of copepod concentration and lowest in waters from which both copepods and micrograzers >10  mu m had been removed. Overall, the results of the shipboard experiments suggested that (1) dDMS(P) production occurred in the microplanktonic food web, probably because pDMSP occurred predominately in the size fraction <10  mu m and was unavailable for direct copepod consumption, and (2) dDMS(P) removal rates were likely due to organisms <10  mu m in size, probably bacteria. The laboratory experiment involved a common Mediterranean microplanktonic ciliate species (Strombidium sulcatum) grazing on a DMSP-containing Prymnesiophyceae (Isochrysis galbana). The rate of dDMS(P) release from algal DMSP was greatly increased when the phytoplankton was subjected to grazing by ciliates. The majority of prey pDMSP (>66%) was released to solution.
AN: 4213621

                                                                     121 of 313  
TI: Continental-scale biogeochemical cycles of the Amazon River system
AU: Richey,-J.E.; Victoria,-R.L.
AF: School of Oceanography, University of Washington, Seattle, WA, USA
CO: 26. Congress in Sao Paulo, Sao Paulo (Brazil), 23-29 Jul 1995
SO: heor.-Appl. Williams,-W.D.;Sladeckova,-A.-eds. Stuttgart-FRG Schweizerbart'-sche-Verlagsbuchhandlung 1996 vol. 26, no. 1 pp. 219-226
ST: Verh.-Int.-Ver.-Theor.-Angew.-Limnol.-Proc.-Int.-Assoc.-Theor.-Appl.-Limnol.-Trav.-Assoc.-Int.-Limnol.-Theor.-Appl. vol. 26, no. 1
LA: English
ER: F (Freshwater)
AN: 4212991

                                                                     122 of 313  
TI: Variability of nutrients and particulate matter in backbarrier tidal flats of the East Frisian Wadden Sea
AU: Liebezeit,-G.; Behrends,-B.; Kraul,-T.
AF: Forschungszentrum TERRAMARE, Schleusenstrasse 1, D-26382 Wilhelmshaven, FRG
SO: Senckenb.-Marit. 1996 vol. 26, no. 3-6, pp. 195-202
LA: English
ER: M (Marine)
AB: Dissolved inorganic nutrients and bulk particulate parameters (seston, organic carbon, total nitrogen, total phosphorus) were determined in May 1993, April 1994 and February 1995 in the backbarrier tidal systems of the East Frisian Islands, Norderney and Spiekeroog, using hourly sampling over 24 hours. Marked variability was encountered in all cases. This could not be related exclusively to tidal state alone. Possible causes including physical and biological mechanisms are discussed.
AN: 4212796

                                                                     123 of 313  
TI: Fluxes and masses of organic carbon in the ocean
AU: Romankevich,-E.A.; Vetrov,-A.A.
AF: Shirshov Inst. Oceanology, Russian Acad. Sci., ul. Krasikova 23, Moscow 117851, Russia
SO: GEOCHEM.-INT.;GEOKHIMIYA 1997 vol. 35, no. 9, pp. 829-836;no. 9, pp. 945-952
LA: English
ER: M (Marine); B (Brackish)
AB: The fluxes and masses of organic matter (OM) in the ocean were evaluated based on an analysis of data obtained by the Shirshov Institute of Oceanology, as well as on published data on the content of dissolved and particulate organic carbon in the surface layer of bottom sediments, in phytoplankton biomass, and in material introduced into the ocean from the land. The total influx of terrigenous OM from the land is estimated at 0.66 x 10 super(15) g C. The major contributors to the influx are river discharge of dissolved (210 x 10 super(12) g C sub(org)/yr) and particulate (250 x 10 super(12) g C sub(org)/yr) matter and eolian precipitation (174 x 10 super(12) g C sub(org)/yr). New data on primary productivity in the ocean (60 x 10 super(15) g C/yr) and the amount of C sub(org) buried in the marginal (150-240 x 10 super(12)) and deep-ocean (10 x 10 super(12) g C sub(org)/yr) sediments are discussed. The fossilization coefficients of OM in sediments at the ocean margin (0.8-1.3%), in the deep ocean (0.02%), and the world oceans as a whole (0.3-0.4%) are calculated.
AN: 4226670

                                                                     124 of 313  
TI: Geochemical consequences of microbiological processes on the northwestern Black Sea shelf
AU: Lein,-A.Yu.; Pimenov,-N.V.; Rusanov,-I.I.; Miller,-Yu.M.; Ivanov,-M.V.
AF: Vernadsky Inst. Geochemistry and Analytical Chem., Russian Acad. Sci., ul. Kosygina 19, Moscow 117975, Russia
SO: GEOCHEM.-INT.;GEOKHIMIYA 1997 vol. 35, no. 10, pp. 865-883;no. 10, pp. 985-1004
LA: English
ER: M (Marine); B (Brackish)
AB: The rates of H sub(2)S and CH sub(4) production and microbial CH sub(4) oxidation on the surface (0-30 cm) of the bottom sediments on the low-depth northwestern Black Sea shelf, which suffers the highest industrial impact, were estimated from  super(35)S and  super(14)C radioisotope measurements. It was shown that microbial processes of sulfate reduction and methane production are accompanied with changes in O sub(2) concentration in the near-bottom waters, salt composition of mud waters, and isotopic composition of sulfate sulfur and bicarbonate carbon. Solid phases of mud feature the formation of hydrogen sulfide derivatives and carbonate minerals. An expressed exponential dependence of the isotopic composition of reduced sulfur compounds on sulfate reduction rate was observed. In sediments that exhibit high rates of sulfate reduction, the  super(13)C concentration of autogenic carbonates and C sub(org) decline. Values of  delta  super(13)C (from -68 to -72ppt) prove its autochtonous microbial origin. Comparing these values of hydrogen sulfide flow with those of the past reveals a trend towards decline of hydrogen sulfide formation rate. In August 1995, no oxygen deficiency was observed in the surveyed area. The main peak of methane production was observed below the 0- to 30-cm layer. The methane concentrations in sediments in the Danube estuary and on the northern Bulgarian shelf reached 4-5 l/m super(2). A substantial amount of methane can transfer from sediments into water and air. The CH sub(4) flow from 0- to 30-cm layer, allowing for microbial CH sub(4) oxidation, proceeds at a rate of at least 1000 m super(3)/year.
AN: 4226669

                                                                     125 of 313  
TI: A timescale for dissolved organic carbon production in Equatorial Pacific surface waters
AU: Archer,-D.; Peltzer,-E.T.; Kirchman,-D.L.
AF: Dep. Geophysical Sci., Univ. Chicago, Chicago, IL, USA
SO: GLOBAL-BIOGEOCHEM.-CYCLES 1997 vol. 11, no. 3, pp. 435-452
LA: English
ER: M (Marine)
AN: 4223038

                                                                     126 of 313  
TI: One-dimensional modeling of nitrogen and sulfur cycles in the aphotic zones of the Black and Arabian Seas
AU: Yakushev,-E.V.; Neretin,-L.N.
AF: P.P. Shirshov Inst. Oceanology, Russian Acad. Sci., Anokhin St. 6-486, Moscow 117602, Russia
SO: GLOBAL-BIOGEOCHEM.-CYCLES 1997 vol. 11, no. 3, pp. 401-414
LA: English
ER: M (Marine)
AN: 4223037

                                                                     127 of 313  
TI: Active uptake of bicarbonate by diatoms
AU: Tortell,-P.D.; Reinfelder,-J.R.; Morel,-F.M.M.
AF: Dep. Ecol. and Evol. Biol., Princeton Univ., Princeton, NJ 08544, USA
SO: NATURE 1997 vol. 390, no. 6657, pp. 243-244
LA: English
ER: M (Marine)
AB: Marine diatoms play a predominant role in the biological carbon pump transferring carbon dioxide from surface to deep waters. Laboratory studies show that a number of species take up HCO sub(3) super(-) and concentrate inorganic carbon intracellularly allowing rapid growth despite low CO sub(2) availability. In contrast, many oceanographers, particularly when interpreting carbon isotope data, have made the assumption that diatoms do not utilize the abundant HCO sub(3) super(-) in seawater but rather take up CO sub(2) by diffusion. This has led to the hypothesis that large diatoms may be CO sub(2)-limited in the oceans. We now demonstrate active uptake of HCO sub(3) super(-) in the field and a carbon-concentrating mechanism in coastal Atlantic diatoms. By manipulating p sub(CO2) we show that growth of large diatoms in the California upwelling is not limited by CO sub(2) availability. We ran short-term H super(14)CO sub(3) super(-)-uptake experiments using samples dominated by large (> 30  mu m) diatoms (Asterionella, Nitzchia and Rhizosolenia) collected from Delaware Bay in 1997 during a spring phytoplankton bloom.
AN: 4222179

                                                                     128 of 313  
TI: Evolution of cadmium and lead contents in Antarctic coastal seawater during the austral summer
AU: Scarponi,-G.; Capodaglio,-G.; Turetta,-C.; Barbante,-C.; Cecchini,-M.; Toscano,-G.; Cescon,-P.
AF: Dep. Environ. Sci., Univ. Venice Ca' Foscari, I-30123 Venice, Italy
SO: INT.-J.-ENVIRON.-ANAL.-CHEM. 1997 vol. 66, no. 1, pp. 23-49
LA: English
ER: M (Marine)
AB: The seasonal evolution of the cadmium and lead distribution in the water column of the Gerlache Inlet (Ross Sea) was studied during the 1990-91 austral summer. Measurements were carried out by Anodic Stripping Voltammetry in Antarctica immediately after the collection and filtration of samples. The concentrations of both metals were homogeneous before the phytoplankton bloom with mean values of 0.71 (SD 0.10) and 0.116 (SD 0.014) nmol/l for cadmium and lead respectively. A subsequent depletion in metal concentration was observed in the shallow waters. The surface concentration of cadmium decreased to about 0.1 nmol/l at the end of the season. The vertical distribution of lead was less affected by the seasonal evolution and the mean surface concentration decreased to 0.044 nmol/l in the same period. The results are evaluated with respect to physical and biological processes in the area examined and compared with those obtained on previous expeditions in the same area.
AN: 4221707

                                                                     129 of 313  
TI: Riverine contribution of biogenic silica to the oceanic silica budget
AU: Conley,-D.J.
AF: Natl. Environ. Res. Inst., Dep. Mar. Ecol. and Microbiol., P.O. Box 358, DK-4000 Roskilde, Denmark
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 4, pp. 774-777
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Biological uptake of dissolved silicate (DSi) and formation of biogenic silica (BSi) during diatom growth modifies the form of Si carried from the continents to the world ocean. Significant concentrations of BSi, averaging 28.0  mu mol L super(-1), are found in all sizes of rivers. The global contribution of BSi carried by rivers was estimated as 1.05  plus or minus  0.20 Tmol Si year super(-1). Combined with the global mean riverine DSi concentration of 150  mu mol liter super(-1), 16% of the gross riverine Si load is delivered to the world ocean as BSi. Most of this BSi would be remobilized by dissolution in marine environments. These results demonstrate that the contribution of biogenic silica carried in suspension by rivers is an important component in the world ocean Si budget that has not been recognized previously.
AN: 4221072

                                                                     130 of 313  
TI: Biogeochemistry of trace metals (Mn, Sr, Rb, Ba, Cu, Zn, Pb and Cd) in a river-wetland-lake system (Balaton Region, Hungary)
AU: Elbaz-Poulichet,-F.; Nagy,-A.; Cserny,-T.; Pomogyi,-P.
AF: ISTEEM-UMR CNRS Geofluides-Bassins-Eau, Univ. Montpellier II, CC057.34095 Montpellier Cedex 5, France
SO: AQUAT.-GEOCHEM. 1997 vol. 2, no. 4, pp. 379-402
LA: English
ER: F (Freshwater)
AB: Mn, Sr, Ba, Rb, Cu, Zn, Pb and Cd concentrations have been measured seasonally in the water and deposited sediments of the system comprising: Zala river (main input) - Lakes Kis-Balaton 1 and 2 (small artificial lakes created in a former bay of Lake Balaton) - Keszthely bay (hypertrophic part of Lake Balaton). The concentrations of the trace elements together with pH, alkalinity, dissolved cations (Ca super(2+), Mg super(2+), Na super(+), and K super(+)), dissolved inorganic ligands (Cl super(-), SO sub(4) super(2-)), particulate Al, Ca, inorganic and organic carbon are used to assess the contamination of the study area and biogeochemical processes controlling trace element concentrations. Thermodynamic speciation calculations have also been utilized to enhance our understanding of the system. In the sediments Rb, Ba, Cu and Zn concentrations were mainly controlled by the abundance of the aluminosilicate fraction. Strontium was mainly associated with the calcium carbonate fraction. The aluminosilicate fraction constitutes a major sink for Mn and Cd but the concentration of these elements are also strongly related to calcite precipitation. The main processes that control the dissolved distribution of trace elements in the Balaton system were: solid phase formation (carbonate) for Mn; coprecipitation with calcite for Sr, Ba, Rb and possibly Mn and Cd; adsorption /desorption processes (pH dependent) for Zn and Pb; solubilization of Mn and precipitation of Cd and Cu in reed covered wetland areas where anoxic conditions were probably existing during the warm season. A preliminary budget of atmospheric and river input to Lake Balaton has also been outlined. Although Lake Balaton, is subjected to anthropogenic inputs mainly from agricultural and domestic activities, their impact on trace element concentrations in the Balaton system is very limited due to the efficiency of removal processes (i.e. adsorption and co-precipitation) and to high sedimentation rates and strong sediment re-suspension. Anthropogenic inputs are only detected for Pb.
AN: 4220912

                                                                     131 of 313  
TI: Aerobic conversion of dimethyl sulfide and hydrogen sulfide by Methylophaga sulfidovorans: Implications for modeling DMS conversion in a microbial mat
AU: De-Zwart,-J.M.M.; Kuenen,-J.G.
AF: Dep. Microbiol. and Enzymology, Delft Univ. Technol., Julianalaan 67, 2628 BC Delft, The Netherlands
SO: FEMS-MICROBIOL.-ECOL. 1997 vol. 22, no. 2, pp. 155-165
LA: English
ER: M (Marine)
AB: Methylophaga sulfidovorans is an obligately methylotrophic, DMS-oxidizing organism, isolated from microbial mat sediment. DMS and H sub(2)S, both present in marine microbial mats, can be used as energy sources by this organism. In batch cultures of M. sulfidovorans, sequential H sub(2)S and DMS utilization occurred. In energy-limited continuous cultures, with DMS, methanol and H sub(2)S as substrates, mixotrophic growth of M. sulfidovorans was observed, showing that at low concentrations these substrates can be used simultaneously. Oxygen and H sub(2)S uptake experiments showed that the critical concentration at which sulfide inhibition of DMS oxidation occurred was between 15 and 40  mu mol l super(-1). Also in crude enrichments of DMS oxidizers a decrease of 50% in DMS-oxidizing capacity for about 200  mu mol l super(-1) H sub(2)S was observed. The new physiological data obtained with the pure cultures of M. sulfidovorans were incorporated in a compartment model of a microbial mat and gave improved predictions of DMS profiles and DMS emissions from the mat, both when phototrophic activity is present (day) and when it is absent (night).
AN: 4220666

                                                                     132 of 313  
TI: The population structure and ecology of the Antarctic scallop Adamussium colbecki (Smith, 1902) at Terra Nova Bay (Ross Sea, Antarctica)
AU: Cattaneo-Vietti,-R.; Chiantore,-M.; Albertelli,-G.
AF: Istituto di Scienze Ambientali Mar., Univ. di Genova., C.P. 79, 16038 S. Margherita Ligure, Genova, Italy
CO: 12. Int. Malacological Congress: Symp. on Ecology of Molluscs, Vigo (Spain), 3-8 Sep 1995
SO: ECOLOGY-OF-MARINE-MOLLUSCS. Ros,-J.;Guerra,-A.-eds. 1997 vol. 61, no. suppl. 2 pp. 15-24
ST: Scientia-Marina-Barcelona vol. 61, no. suppl. 2
RN: NIPO 179-97-037-5 (179970375)
LA: English
ER: M (Marine)
AB: One of the main purposes of the core project "Ecology and Biogeochemistry of the Southern Ocean" (Italian Antarctic Programme-PNRA) is to understand the utilization and ultimate fate of the organic matter sedimenting through the water column and its influence in the structure of the macrobenthic assemblages. At Terra Nova Bay (Ross Sea), the scallop Adamussium colbecki (Smith, 1902) constitutes large beds up to 70-80 m depth. The importance of this population in the local community structure requires a closer examination of its structure and dynamics, in order to assess its role in the coastal organic matter flux, and for this reason it has been studied during several years (1987-92) in areas close to the Italian Station and particularly in the Summer 1993/94. Its high density (up to 60 ind m super(-2)) and biomass (up to 120 g m super(-2) dry weight of soft tissues) values are probably linked to slow growth rate and reduced reproductive capacities. X-ray studies on the shell confirmed the slow growth rate of this species, which averages about 0.8 cm yr super(-1). The analysis of the ratio between length and height of the shell (generally  similar to  1) shows a significative inversion at the age of maturity, when the byssally attached juveniles become free from the adult valves. A comparison of the gonadosomatic index in the population between December and January suggests that sexual maturity is reached late in this season and is strongly related to the water column food supply consequent to the phytoplankton bloom. Comparing the size-frequency distribution of this population in different years, it is possible to observe a cohort gap, shifting through the study period, and probably caused by unsuccessful recruitments from 6 to 9 years before 1994. Slow growth rate and intermittent recruitment suggest that an eventual commercial exploitation of this species, abundant but patchly distributed in a narrow bathymetric range, would quickly result in overfishing and commercial failure.
AN: 4220662

                                                                     133 of 313  
TI: Cycling of iron, manganese, and phosphate in a meromictic lake
AU: Hongve,-D.
AF: Natl. Inst. Public Health, P.O. Box 4404 Torshor, N-0403 Oslo, Norway
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 4, pp. 635-647
LA: English
ER: F (Freshwater)
AB: Lake Nordbytjernet (Southeast Norway) had up to 40 mg liter super(-1) dissolved iron and 67 mg liter super(-1) dissolved manganese in a stagnant layer. The ratio between iron and manganese loading was around 3:1, while the inventory of manganese was six times higher than for iron. High concentrations of dissolved iron occurred solely under strictly anoxic conditions, while dissolved manganese was unaffected by intrusion of oxygen during the autumnal partial circulation. Mixed potentials caused by oxidation of ferrous iron and reduction of manganic oxide or O sub(2) controlled the redox potential values, while dissolved manganese appeared to have no influence. The following main processes controlled the sedimentation rates: fluvial supply of suspended material, precipitation of ferric hydroxide and manganese oxide from the water column, and plankton production. Sorption to ferric hydroxide in the oxic zone and reductive desorption in the anoxic zone controlled the deep water stratification of phosphorus, dissolved organic carbon, and some major cations. No similar effects were seen for manganese sedimentation. The iron sedimentation rate was enhanced in the anoxic zone due to redox coupling of iron oxidation and manganese reduction. Phosphorus was depleted in the anoxic zone during periods of substantial ferric hydroxide sedimentation. Sedimentation of manganese under anoxic conditions seemed to be governed by precipitation of carbonate and phosphate. Residence times in the lake were 0.2 yr for iron and phosphorous vs. 3.3 yr for manganese and 1.4 yr for water.
AN: 4219577

                                                                     134 of 313  
TI: Short-term sediment trap fluxes from Chatham Rise, southwest Pacific Ocean
AU: Nodder,-S.D.
AF: New Zealand Oceanographic Institute, National Institute of Water & Atmospheric Research Ltd, P.O. Box 14-901, Wellington, New Zealand
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 4, pp. 777-783
LA: English
ER: M (Marine)
AB: Sediment trap, nephelometer, and particulate matter (PM) data were collected in the vicinity of the Subtropical Convergence, north of Chatham Rise (42-43 degree S), southwest Pacific Ocean, in austral autumn 1992. Free-floating cylindrical sediment traps were deployed below the euphotic zone at 200-, 300-, and 500-m water depths. Increases in total mass flux and concomitant proportional decreases in other particulate fluxes (total carbon, nitrogen, and phosphorus) with depth reflected the collection of relatively refractory material, enriched in particulate carbon, as evinced by increases in C:N and C:P ratios below 300 m. Nephelometer and PM concentration profiles indicate that resuspension of sea-floor sediments from the nearby submarine high (Chatham Rise) probably contributed to the observed increase in total mass flux with depth. Published pCO sub(2) estimates, biological productivity data, and moderate particulate fluxes, as indicated by the present study suggest that oceanic water types east of New Zealand may be a biologically mediated regional sink for atmospheric CO sub(2).
AN: 4218502

                                                                     135 of 313  
TI: Experimental determination of the organic carbon flux from open-ocean surface waters
AU: Emerson,-S.; Quay,-P.; Karl,-D.; Winn,-C.; Tupas,-L.; Landry,-M.
AF: Sch. Oceanogr., Univ. Washington, Seattle, WA 98195, USA
SO: NATURE 1997 vol. 389, no. 6654, pp. 951-954
LA: English
ER: M (Marine)
AB: The flux of biologically produced organic carbon from the euphotic zone of the ocean to the deep waters below--the "biological organic carbon pump"--is one of the main controls on the carbon dioxide partial pressure in the atmosphere. Accurate determination of this flux is therefore critically important for understanding the global carbon cycle and its response to climate change. Our goal is to assess how accurately the biological organic carbon pump can be determined at a single location and to constrain estimates of the global value. As there are no standards against which such environmental fluxes can be measured, we assess accuracy by comparing results from three independent experimental approaches for measuring the net annual export of organic carbon from the euphotic zone in the subtropical North Pacific Ocean near Hawaii. Mass balances of dissolved oxygen, inorganic carbon and organic carbon yield estimates of the organic carbon export flux of 2.7  plus or minus  1.7, 1.6  plus or minus  0.9 and 2.0  plus or minus  0.9 mol C/m super(2)/yr, respectively. These three estimates are not significantly different, and establish the present analytically attainable accuracy at this location to be about  plus or minus  50%. If 2.0 mol C/m super(2)/yr is typically of the organic carbon export flux in the subtropical ocean, then this vast region, often considered to be a biological desert, may be responsible for up to half of the global-ocean biological organic carbon pump.
AN: 4115446

                                                                     136 of 313  
TI: Selenate-regulation of sulfur metabolism in a cyanobacterium, Phormidium uncinatum
AU: Bagchi,-D.; Verma,-D.
AF: Dep. Biol. Sci., R.D. Univ., Jabalpur 482 001 M.P., India
SO: J.-PLANT-PHYSIOL. 1997 vol. 150, no. 6, pp. 762-764
LA: English
ER: F (Freshwater)
AB: Selenate-mediated regulation of sulfate assimilation was studied in Phormidium uncinatum and its selenate resistant mutant. Selenate-caused suppression of sulfate-supported wild type growth was due to inactivation of ATP-sulfurylase activity. Mutation led to loss of this enzyme and growth with sulfate; therefore, thiosulfate served as sulfur source. Both strains grew with several alternate sulfur sources, cysteine and methionine included. L-cysteine repressed sulfurylase and cysteine synthase but activated its desulfhydrase and thiosulfate reductase activities. Mutant enzymes were deregulated for activation.
AN: 4215866

                                                                     137 of 313  
TI: Mineralization and burial of organic carbon in sediments of the southern Weddell Sea (Antarctica)
AU: Hulth,-S.; Tengberg,-A.; Landen,-A.; Hall,-P.O.J.
AF: Dep. Analytical and Mar. Chem., Univ. Goeteborg, S-412 96 Goeteborg, Sweden
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 6, pp. 955-981
LA: English
ER: M (Marine)
AB: Benthic fluxes of oxygen, alkalinity (A sub(T)), total carbonate (C sub(T) or  capital sigma CO sub(2)) and dissolved organic carbon (DOC) were measured during sediment-water incubations at 16 stations in the southern Weddell Sea (Antarctica) with water depths between 280 and 2514 m. The total sediment oxygen consumption rates (TSOC) were in general low (1.74-3.61 mmol m super(-2) day super(-1)) and more comparable to measurements in slope and deep-sea sediments at a few thousand meters water depth. The decrease of TSOC with water depth was lower than that observed in many other seas. The mean carbon to nitrogen ratio (C/N) in the solid phase of surficial sediment was 8.3. Measured benthic fluxes of alkalinity, corrected for contributions from nitrification and denitrification, were quantitatively used to correct the fluxes of total carbonate for dissolution of solid phase carbonates. The  capital sigma CO sub(2) fluxes, originating from carbonate dissolution (0.166-1.77 mmol m super(-2) day super(-1)), were 2.6-71% of the  capital sigma CO sub(2) fluxes (0.984-3.73 mmol m super(-2) day super(-1)) resulting from organic carbon oxidation. Measured benthic fluxes of oxygen,  capital sigma CO sub(2) and nitrate were, together with estimated denitrification rates and sediment C/N ratios, used to model respiration quotients (RQ) for organic carbon oxidation and estimate composition of the organic matter undergoing degradation. Modelled RQ varied roughly between 2/3 and 1 (mean 0.87). Measured fluxes of  capital sigma CO sub(2) were 1.6-3.2 times higher than integrated organic C mineralization rates (measured during closed incubations of sieved, homogenized sediment), indicating macrofaunal (plus possibly meiofaunal) respiration to be important. However, low abundances of bioirrigating benthic macrofauna and small differences in benthic fluxes of oxygen,  capital sigma CO sub(2) and alkalinity found between replicate sediment cores, suggested that macrofaunal respiration was quantitatively unimportant in these sediments. The higher measured fluxes of  capital sigma CO sub(2), compared to the integrated mineralization rates, were therefore most likely caused by a large fraction of the respiration occurring directly on the sediment surface. This degradation of newly deposited organic matter was not reflected in the integrated organic C mineralization rates. Also, there was no obvious effect of this surficial degradation process on the pore water distributions of  capital sigma CO sub(2). Benthic mass balances of carbon revealed that benthic fluxes of DOC were 3-147% of the corrected fluxes of  capital sigma CO sub(2), and the recycling efficiencies (E) were up to 35% higher if the DOC fluxes were included in the calculations of E, rather than the inorganic  capital sigma CO sub(2) flux alone. The recycling efficiencies, including the benthic flux of DOC, ranged between 57 and 88% (mean 78%). Measured rates of inorganic C accumulation (for most stations <0.3 mmol C m super(-2) day super(-1)) were a factor of 6-7 lower than organic C accumulation rates (0.457-1.94 mmol C m super(-2) day super(-1)).
AN: 4215863

                                                                     138 of 313  
TI: Controls on the distributions of organic carbon and nitrogen in the eastern Pacific Ocean
AU: Hansell,-D.A.; Waterhouse,-T.Y.
AF: Bermuda Biol. Stn. for Res. Inc., 17 Biological Lane, St Georges, GE-01, Bermuda
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 5, pp. 843-857
LA: English
ER: M (Marine)
AB: Measurements of total organic carbon (TOC) and nitrogen (TON) were made on the WOCE P18 line (from 67 degree S to 23 degree N along 103/110 degree W). There was an accumulation of TOC on the equator and in the oligotrophic waters north and south of the equator. The concentrations of TOC were well correlated with temperature, indicating an important physical control on its distribution. The boundary separating shallow, TOC-rich water from deep, TOC-poor water overlaid the main thermocline. This observation suggests that water column stability or residence time imparted by the main thermocline is a primary determinant of TOC accumulation. Elevated TON concentrations were found in all surface waters, with the lowest values found in the region of 20-35 degree S. Net TON drawdown in the South Pacific subtropical gyre, likely due to biological utilization and vertical export of the nitrogen, was initiated with depletion of equatorially upwelled nitrate. The degree to which inorganic nitrogen was limiting in the surface layer south of the equator served to control the concentrations of TON. Such controls were not exerted on organic carbon, as reflected by increasing C:N ratios of organic matter as TON was removed. Unlike the findings in the South Pacific, TON concentrations in oligotrophic waters north of the equator were frequently higher than on the equator. Such accumulations are hypothesized to be maintained from nitrogen fixation, nitrogen input due to vertical migration of autotrophs or diffusive flux of inorganic nitrogen into the euphotic zone across the relatively shallow nitracline.
AN: 4215862

                                                                     139 of 313  
TI: The effect of resuspension on chemical exchanges at the sediment-water interface in the deep sea - A modelling and natural radiotracer approach
AU: Rutgers-van-der-Loeff,-M.M.; Boudreau,-B.P.
AF: Alfred-Wegener Inst. for Polar and Mar. Res., P.O. Box 120161, D-27515 Bremerhaven, Germany
SO: J.-MAR.-SYST. 1997 vol. 11, no. 3-4, pp. 305-342
NT: Includes special section: SCOR Working Group 95: Sediment Suspension and Sea Bed Properties.
LA: English
ER: M (Marine)
AB: We review the processes responsible for the formation of vertical gradients in the chemical composition of suspended particles across the benthic nepheloid layer. Such gradients have usually been explained by resuspension of surface sediments, but it is shown here that these gradients can only be understood as part of a dynamic exchange between the water column and the sediments. A coupled model, developed in a companion paper, is expanded to include chemical reactions above and below the sediment-water interface. Three cases are discussed: A tracer with first-order decay (Model 1), the dissolution of a major constituent (Model 2), and a particle-reactive tracer with first-order decay and production in the water column (Model 3). Using typical parameter values for a well-developed benthic nepheloid layer, the three models reproduce typical distributions of C sub(org) (organic carbon), opal, and  super(234)Th, respectively, on particles above and below the sediment-water interface. Sensitivity analyses illustrate how bioturbation can cause the large discrepancy observed between suspended and surface sediment C sub(org) values (Model 1). The model also reconciles this observed discrepancy with observations that the major part of the decomposition takes place within the sediment. For opal (Model 2), the influence of resuspension on the burial rate of opal is shown to be negligible, as long as dissolution follows first-order kinetics and is not enhanced by turbulence in the suspended phase. The modelling of  super(234)Th (Model 3) successfully links the depletion of  super(234)Th in bottom waters with the distribution of excess  super(234)Th in surface sediments and on resuspended particles.  super(234)Th is a powerful example of the tools supplied by the radioactive daughters of the natural U and Th decay series in studying fluxes and exchange rates of solutes and particles across the sediment-water interface. A short review is given of these tools, and it is shown how they can be used to obtain rate information required to apply and calibrate specific resuspension models.
AN: 4215227

                                                                     140 of 313  
TI: Biomass and litter dynamics in a Melaleuca forest on a seasonally inundated floodplain in tropical, northern Australia
AU: Finlayson,-C.M.; Cowie,-I.D.; Bailey,-B.J.
AF: Alligator Rivers Region Res. Inst., Office Supervising Scientist, Post Office, Jabiru, NT 0886, Australia
SO: WETLANDS-ECOL.-MANAGE. 1993 vol. 2, no. 4, pp. 177-188
LA: English
ER: F (Freshwater)
AB: Litterfall from a Melaleuca forest was investigated as part of chemical cycling studies on the Magela Creek floodplain in tropical, northern Australia. The forest contained two species of tree, Melaleuca cajaputi and Melaleuca viridiflora, with a combined average density of 294 trees ha super(-1). The M. viridiflora trees had diameter breast height measurements ranging from 11.8 to 62.0 cm, median class 25.1-30.0 cm and a mean value of 29.2  plus or minus  1.0 cm, compared to 13.0 to 66.3 cm, 30.1-35.0 cm and 33.5  plus or minus  1.0 cm for M. cajaputi trees. A regression model between tree height, diameter breast height and fresh weight was determined and used to calculate average tree weights of 775  plus or minus  1.6 kg for M. viridiflora and 1009  plus or minus  1.6 kg for M. cajaputi, and a total above-ground fresh weight of 263  plus or minus  0.3 t ha super(-1). The weight of litter recorded each month on the ground beneath the tree canopy ranged from 582  plus or minus  103 to 2176  plus or minus  376 g m super(-2) with a monthly mean value of 1105  plus or minus  51 g m super(-2). The coefficient of variation of 52% on this mean indicates the large spatial and temporal variability in litter distribution over the study site. This variability was greatly affected by the pattern of water flow and litter transport during the Wet season. Litterfall from the trees was evaluated using two techniques - nets and trays. The results from these techniques were not significantly different with annual litterfall collected in the nets being 705  plus or minus  25 g m super(-2) and in the trays 716  plus or minus  49 g m super(-2). The maximum monthly amount of litterfall, 108  plus or minus  55 g m super(-2), occurred during the Dry season months of June-July. Leaf material comprised 70% of the total annual weight of litter, 480  plus or minus  29 g m super(-2) in the nets and 495  plus or minus  21 g m super(-2) in the trays. The tree density and weight of litter suggest that the Melaleuca forests are highly productive and contribute a large amount of material to the detrital/debris turnover cycle on the floodplain. (DBO)
AN: 4214329

                                                                     141 of 313  
TI: Oxygen pore water profiles in continental shelf sediments of the North Sea: Turbulent versus molecular diffusion
AU: Lohse,-L.; Epping,-E.H.G.; Helder,-W.; Raaphorst,-W.-van
AF: Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB Den Burg, Texel, Netherlands
SO: Mar.-Ecol.-Prog.-Ser. 1996 vol. 145, no. 1-3, pp. 63-75
NT: Incl. bibliogr.: 52 refs.
LA: English
ER: M (Marine)
AB: Oxygen pore water profiles in North Sea sediments were measured with microelectrodes during 2 contrasting seasons. The measurements were conducted in a wide variety of sediments, including non-depositional areas on the southern shelf as well as depositional areas in the Skagerrak. All measurements were performed within minutes on board at in situ emperature. The curvature of oxygen profiles in sandy sediments on the southern shelf indicated the presence of a surface layer characterised by enhanced diffusion. The occurrence of enhanced diffusion was related to sedimentological and seasonal differences. Quantitative evaluation of the pore water profiles by a diffusion-reaction model indicated that the effective diffusion coefficients in a 0.2 to 16 mm subsurface layer were 1.5 to >100 times higher than the molecular diffusion coefficient. Highest effective diffusion coefficients were reported for non-depositional sediments characterised by low diffusive oxygen fluxes. Oxygen profiles in sediments of the depositional area of the Skagerrak indicated constant diffusivity throughout the sediment column. Diffusive fluxes calculated from profiles ranged from 5.2 to 8.9 mmol/m2/ in August 1991, and were between 0.8 and 6.2 mmol/m2/ in February 1992. Seasonal differences in sediments located in the Skagerrak area were minor. It is proposed that near-bottom tidal currents induce enhanced diffusion transport processes in the upper millimetres of the sandy sediments of the southern North Sea, while less energetic hydrodynamical conditions in the depositional area of the Skagerrak favour sediment-water exchange based on molecular diffusion only. Biogeochemical implications of the enhanced diffusivity close to the sediment-water interface are discussed.
AN: 4213835

                                                                     142 of 313  
TI: Rapid subduction of organic matter by maldanid polychaetes on the North Carolina slope
AU: Levin,-L.; Blair,-N.; DeMaster,-D.; Plaia,-G.; Fornes,-W.; Martin,-C.; Thomas,-C.
AF: Mar. Life Res. Group, Scripps Inst. Oceanogr., La Jolla, CA 92093-0218, USA
SO: J.-MAR.-RES. 1997 vol. 55, no. 3, pp. 595-611
LA: English
ER: M (Marine)
AB: In situ tracer experiments conducted on the North Carolina continental slope reveal that tube-building worms (Polychaeta: Maldanidae) can, without ingestion, rapidly subduct freshly deposited, algal carbon ( super(13)C-labeled diatoms) and inorganic materials (slope sediment and glass beads) to depths of 10 cm or more in the sediment column. Transport over 1.5 days appears to be nonselective but spatially patchy, creating localized, deep hotspots. As a result of this transport, relatively fresh organic matter becomes available soon after deposition to deep-dwelling microbes and other infauna, and both aerobic and anaerobic processes may be enhanced. Comparison of tracer subduction with estimates from a diffusive mixing model using  super(234)Th-based coefficients, suggests that maldanid subduction activities, within 1.5 d of particle deposition, could account for 25-100% of the mixing below 5 cm that occurs on 100-day time scales. Comparisons of community data from the North Carolina slope for different places and times indicate a correlation between the abundance of deep-dwelling maldanids and the abundance and the dwelling depth in the sediment column of other infauna. Pulsed inputs of organic matter occur frequently in margin environments and maldanid polychaetes are a common component of continental slope macrobenthos. Thus, the activities we observe are likely to be widespread and significant for chemical cycling (natural and anthropogenic materials) on the slope. We propose that species like maldanids, that rapidly redistribute labile organic matter within the seabed, probably function as keystone resource modifiers. They may exert a disproportionately strong influence (relative to their abundance) on the structure of infaunal communities and on the timing, location and nature of organic matter diagenesis and burial in continental margin sediments.
AN: 4209889

                                                                     143 of 313  
TI: Adsorption and pollutant transport by marine aerosol
AU: Cini,-R.; Loglio,-G.
AF: Dep. Organic Chem., Univ. Florence, Via G. Capponi 9, 50121 Florence, Italy
SO: MAR.-POLLUT.-BULL. 1997 vol. 34, no. 7, pp. 501-504
LA: English
ER: M (Marine)
AB: Many natural and man-made surfactants do not have a homogeneous distribution in the water column but spontaneously segregate (adsorb) at the marine water-air interface. The importance of this well-known process is often underestimated in marine aerosol studies. The humic substances represent one of the most important fractions of water soluble natural surfactants. The ability of these products to interact with inorganic ions and organic substances, many of which are objectionable, explains the pollutant presence and enrichment not only at the marine surface but also in marine aerosols. Analysis of the role played by the adsorption process in marine aerosol formation may give a new basis for a more complete explanation of the composition of the fine aerosol fraction and of long-range pollutant transport to remote areas. Additionally, a fuller interpretation of vegetation damage occurring in coastal areas may be achieved. We argue that the role of the biogenic surfactant matter, which is present in traces in marine surface water, is currently underestimated in transport processes.
AN: 4208223

                                                                     144 of 313  
TI: Leaf litter in a Sonoran Desert stream ecosystem
AU: Schade,-J.D.; Fisher,-S.G.
AF: Zool. Dep., Arizona State Univ., Tempe, AZ 85287-1501, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 3, pp. 612-626
LA: English
ER: F (Freshwater)
AB: Leaf litter is an important functional component of mesic stream ecosystems; however, the importance of leaf litter has not been established for streams of the southwestern North American deserts. These streams exhibit many functional and structural characteristics that are the result of the pattern and amount of precipitation and which differ from their mesic counterparts. Our objective was to determine the influence of leaf litter on ecosystem processes of Sycamore Creek, Arizona, a typical Sonoran Desert stream, and to compare these results with knowledge gained from other regions. Patterns of nitrogen dynamics and respiration during leaf decomposition were similar for leaf packs in Sycamore Creek and previous studies of mesic streams. Macroinvertebrates in Sycamore Creek colonized natural and artificial leaf packs equally, and taxonomic composition did not differ significantly between leaf types, or between leaf pack communities and benthic communities. Shredder macroinvertebrates feeding on leaf material were absent. Leaf litter input to Sycamore Creek was low and litter residence time was reduced by flash floods. As a result, leaves played an insignificant role in terms of nutrient dynamics, energy flow, and macroinvertebrate assemblages in this ecosystem. Differences in the role of leaf litter between regions are attributed to channel and riparian form and to the frequency of severe disturbance, which are functions of meteorologic, hydrologic, and geomorphic features of the landscape.
AN: 4208020

                                                                     145 of 313  
TI: Belgian scientific research programme on the Antarctic
SO: 1997 30 pp
RN: ANTAR/97/1 (ANTAR971)
LA: English
AB: This volume presents an overview of the results of the research projects funded under the Third Phase of the Belgian Scientific Research Programme on the Antarctic (1992-1996). Such research effort aimed at contributing to the development of the knowledge required for a science-based conservation and management of the Antarctic environment and to the assessment of the mechanisms through which the Antarctic and the global climate interact. Emphasis was given on a multi-disciplinary approach of the dynamics of the global functioning of Antarctic main natural systems and of their evolution and interactions. The programme comprises seven research lines under three priority areas. They are: ECODYNAMICS OF THE SOUTHERN OCEAN AND INTERACTIONS WITH THE CLIMATE: Biogeochemical fluxes and cycles in the main trophic compartments; Modelling the global dynamics of ecosystems; Assessment of the role of "new production" in the burial of atmospheric CO sub(2) by the Southern Ocean. EVOLUTION AND PROTECTION OF MARINE ECOSYSTEMS: Application of predictive ecological models to simulate ecosystem responses to man-made climatic disturbances; Study of hydrocarbons spills dispersion. ROLE OF THE ANTARCTIC IN GLOBAL CHANGES: Ocean-Cryosphere-Atmosphere interactions. Sedimentary palaeoenvironment.
AN: 4206769

                                                                     146 of 313  
TI: Benthic-pelagic links: Responses of benthos to water-column nutrient enrichment
AU: Blumenshine,-S.C.; Vadeboncoeur,-Y.; Lodge,-D.M.; Cottingham,-K.L.; Knight,-S.E.
AF: Dep. Biol. Sci., Univ. Notre Dame, Notre Dame, IN 46556, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 3, pp. 466-479
LA: English
ER: F (Freshwater)
AB: Although the responses of pelagic algae and invertebrates to gradients of nutrient enrichment are well known, less is known about the responses of benthos to such gradients or how benthic and pelagic responses may interact. We performed a 9-wk experiment in 2000-L mesocosms in the field to test for the effect of water-column nutrient enrichment on phytoplankton, algae on sediments (epipelon) and hard surfaces (plastic strips), as well as pelagic and benthic primary consumers. The experimental design consisted of 4 nutrient enrichment rates (0, 0.5, 1.0 and 2.0  mu g P L super(-1) d super(-1), together with N to yield an N:P ratio of 20:1 by weight). Nutrient enrichment induced significant increases in chlorophyll a in phytoplankton and attached algae, but not epipelon. Zooplankton biomass was significantly higher in enriched mesocosms than in controls over the initial 4 wk of enrichment, but the effect was not sustained over the course of the experiment. Densities of sediment-dwelling, and hard-substrata-associated invertebrates were higher in enriched treatments relative to controls. Emergence of benthic insects also increased with enrichment. Size and species composition of benthic macroinvertebrates differed between enriched treatments and controls. Our results suggest that nutrients added to the water column were quickly converted into benthic biomass, likely reducing pelagic responses to enrichment.
AN: 4206748

                                                                     147 of 313  
TI: Geochemical-focusing of manganese in lake sediments - an indicator of deep-water oxygen conditions
AU: Schaller,-T.; Wehrli,-B.
AF: Limnological Res. Cent., Swiss Federal Inst. for Environ. Sci. and Technol. (EAWAG) and Swiss Federal Inst. Technol. (ETH), CH-6047 Kastanienbaum, Switzerland
SO: AQUAT.-GEOCHEM. 1997 vol. 2, no. 4, pp. 359-378
LA: English
ER: F (Freshwater)
AB: The lateral distributions of Mn concentrations in the sediments of two Swiss lakes under varying oxygen conditions have been determined. The comparison of Mn distribution patterns with oxygen in the deep-water provides strong evidence for a geochemical-focusing effect, which is driven by the redox cycle of manganese. Conditions essential for this process to occur are anoxic sediments in contact with oxic deep-water. Average sedimentary manganese concentrations determined for different water-depth ranges are directly proportional to the area of shallower sediments. This result indicates that geochemical-focusing of manganese in lake sediments is a promising proxy indicator for the reconstruction of oxygen conditions during deposition.
AN: 4206661

                                                                     148 of 313  
TI: Group report: How do upwelling systems vary through time?
AU: Peterson,-L.C.; Abbott,-M.R.; Anderson,-D.M.; Caulet,-J.-P.; Conte,-M.H.; Emeis,-K.-C.; Kemp,-A.E.S.; Summerhayes,-C.P.
CO: Dahlem Workshop on Upwelling in the Ocean: Modern Processes and Ancient Records, Berlin (Germany), 25-30 Sep 1994
SO: UPWELLING-IN-THE-OCEAN:-MODERN-PROCESSES-AND-ANCIENT-RECORDS. Summerhayes,-C.P.;Emeis,-K.-C.;Angel,-M.V.;Smith,-R.L.;Zeitzschel,-B.-eds. JOHN-WILEY-and-SONS no. 18 pp. 285-312
ST: ENVIRON.-SCI.-RES.-REP. 1995 no. 18
LA: English
ER: M (Marine)
AB: Upwelling is a largely wind-driven process by which transfer of momentum from the prevailing wind fields to the surface ocean results in divergence, forcing cool, nutrient-rich subsurface waters up into the photic zone. Upwelling regions are among the most productive environments in the world and serve as both sources and sinks for many biologically active elements. They thus play a major role in the biogeochemical cycling of the oceans. By their very nature, upwelling systems are extremely sensitive to climatic and oceanographic change. In turn, through feedbacks in the carbon cycle, upwelling systems have the potential to influence climate as well. Sediments which underlie the major upwelling centers preserve important information on past variations in the strength and areal extent of upwelling, information of great relevance to studies of global carbon budgets and of the role of this process in climate change. (DBO)
AN: 4205468

                                                                     149 of 313  
TI: What are upwelling systems contributing to the ocean's carbon and nutrient budgets?
AU: Toggweiler,-J.R.; Carson,-S.
AF: GFDL/NOAA, Princeton Univ., P.O. Box 308, Princeton, NJ 08542, USA
CO: Dahlem Workshop on Upwelling in the Ocean: Modern Processes and Ancient Records, Berlin (Germany), 25-30 Sep 1994
SO: UPWELLING-IN-THE-OCEAN:-MODERN-PROCESSES-AND-ANCIENT-RECORDS. Summerhayes,-C.P.;Emeis,-K.-C.;Angel,-M.V.;Smith,-R.L.;Zeitzschel,-B.-eds. JOHN-WILEY-and-SONS no. 18 pp. 337-360
ST: ENVIRON.-SCI.-RES.-REP. 1995 no. 18
LA: English
ER: M (Marine)
AB: Understanding the effect of upwelling systems on the carbon cycle requires detailed knowledge of how nutrients and carbon enter and leave these systems. In this article we use recent findings of the JGOFS equatorial Pacific process study and a detailed three-dimensional model to look specifically at the nitrate budget in the equatorial Pacific. Nitrate enters the equatorial upwelling system in the far-western Pacific via the Equatorial Undercurrent. Because the equatorial biota tend to recycle nitrogen much more effectively than they export nitrogen in sinking particles, nitrate stocks build up in the eastern Pacific. A significant fraction of the nitrate entering the upwelling system seems to be lost to denitrification in the anoxic zones off Peru and Central America. Through denitrification, the equatorial upwelling system may function as a regulator of global nitrate stocks and air-sea partitioning of CO sub(2). (DBO)
AN: 4205465

                                                                     150 of 313  
TI: Group report: How do open ocean upwelling systems operate as integrated physical, chemical, and biological systems and influence the geological record?
AU: Angel,-M.V.; Baars,-M.A.; Barber,-R.T.; Chavez,-F.P.; Kastner,-M.; Leinen,-M.; Lutjeharms,-J.R.E.; Reverdin,-G.; Shimmield,-G.B.
CO: Dahlem Workshop on Upwelling in the Ocean: Modern Processes and Ancient Records, Berlin (Germany), 25-30 Sep 1994
SO: UPWELLING-IN-THE-OCEAN:-MODERN-PROCESSES-AND-ANCIENT-RECORDS. Summerhayes,-C.P.;Emeis,-K.-C.;Angel,-M.V.;Smith,-R.L.;Zeitzschel,-B.-eds. JOHN-WILEY-and-SONS no. 18 pp. 193-220
ST: ENVIRON.-SCI.-RES.-REP. 1995 no. 18
LA: English
ER: M (Marine)
AB: For the purposes of our group, we defined upwelling as being organized upward vertical motion, and thus those areas where seasonal mixing dominates the production cycle were excluded from discussion. Our deliberations were centered around five key questions, each of which is discussed in turn below. We conclude our report with a "wish list" for future research. (DBO)
AN: 4205464

                                                                     151 of 313  
TI: The chemical and biological consequences of coastal upwelling
AU: Hutchings,-L.; Pitcher,-G.C.; Probyn,-T.A.; Bailey,-G.W.
AF: Sea Fish. Res. Inst., Private Bag X2, Rogge Bay 8012, Cape Town, South Africa
CO: Dahlem Workshop on Upwelling in the Ocean: Modern Processes and Ancient Records, Berlin (Germany), 25-30 Sep 1994
SO: UPWELLING-IN-THE-OCEAN:-MODERN-PROCESSES-AND-ANCIENT-RECORDS. Summerhayes,-C.P.;Emeis,-K.-C.;Angel,-M.V.;Smith,-R.L.;Zeitzschel,-B.-eds. JOHN-WILEY-and-SONS no. 18 pp. 65-82
ST: ENVIRON.-SCI.-RES.-REP. 1995 no. 18
LA: English
ER: M (Marine)
AB: The chemical and biological dynamics in coastal upwelling areas are examined from the point of view that pulsed wind events operating at particularly active upwelling sites are responsible for the major injection of new nutrients into the euphotic zone. The rate of supply of new nutrients determines the scope for export to the sediments or fisheries. Inorganic nutrients are removed from the water in a matter of days; however, the sequence and efficiency is dependent on the seed populations and degree of mixing and stratification with more mature water. There is likely to be an optimal frequency of wind events to promote the dominance of large-celled phytoplankton. Mesozooplankton is ill-matched with phytoplankton development with poor grazing control of phytoplankton blooms, and there is considerable microbial activity and sedimentation. The extent of regenerative processes determines whether carbon is exported to the sediments or the atmosphere in upwelling systems. Fish populations in upwelling areas are constrained mostly by suitable areas for reproductive success; the enrichment, retention, and concentration factors are partially exclusive in coastal upwelling regions, resulting in compromise solutions and a high variability in recruitment success. (DBO)
AN: 4205457

                                                                     152 of 313  
TI: Summer bloom of Gloeotrichia echinulata and Aphanizomenon flos-aquae and phosphorus levels in Antermony Loch, central Scotland
AU: Pitois,-S.G.; Jackson,-M.H.; Wood,-B.J.B.
AF: Environ. Health Div., John Anderson Bldg., Univ. Strathclyde, Glasgow G4 0NG, Scotland, UK
SO: INT.-J.-ENVIRON.-HEALTH-RES. 1997 vol. 7, no. 2, pp. 131-140
LA: English
ER: F (Freshwater)
AB: Nutrient levels (phosphorus and nitrogen) were measured in a small reservoir in Scotland between March 1994 and October 1995. Algae species were identified. Dense blooms of Gloeotrichia echinulata have regularly occurred in late summer in the reservoir for many years, but it did not reach bloom proportions during the 1995 summer and seemed to have been replaced by Aphanizomenon. The bloom of the cyanobacterium Gloeotrichia echinulata that occurred in August 1994 was studied in relation to phosphorus levels present at the time in the water. Results show that the bloom developed after a slight increase in dissolved inorganic phosphorus; while the bloom was developing, particulate inorganic forms of phosphorus increased and were then replaced by particulate organic forms when the bloom reached its maximum density. All phosphorus fractions started to decrease shortly before the bloom collapsed. Our study showed that there did not seem to be any change in the distribution of phosphorus between its different fractions, at least during the first 24 h after collection when the sample was kept in a refrigerator in the dark. We therefore conclude that Gloeotrichia echinulata was probably responsible for transferring phosphorus from the sediments up to the water column in Antermony.
AN: 4204457

                                                                     153 of 313  
TI: Assessing selenium cycling and accumulation in aquatic ecosystems
AU: Bowie,-G.L.; Sanders,-J.G.; Riedel,-G.F.; Gilmour,-C.C.; Breitburg,-D.L.; Cutter,-G.A.; Porcella,-D.B.
AF: Tetra Tech, Inc., 3746 Mt. Diablo Blvd., Suite 300, Lafayette, CA 94549, USA
CO: Int. Clean Water Conf.: Clean Water: Factors That Influence Its Availability, Quality and Its Use, La Jolla, CA (USA), 28-30 Nov 1995
SO: Water,-Air-and-Soil-Pollution 1996 vol. 90, no. 1-2, pp. 93-104
LA: English
ER: F (Freshwater)
AB: We conducted a joint experimental research and modeling study to develop a methodology for assessing selenium (Se) toxicity in aquatic ecosystems. The first phase of the research focused on Se cycling and accumulation. In the laboratory, we measured the rates and mechanisms of accumulation, transformation, and food web transfer of the various chemical forms of Se that occur in freshwater ecosystems. Analytical developments helped define important Se forms. We investigated lower trophic levels (phytoplankton and bacteria) first before proceeding to experiments for each successive trophic component (invertebrates and fish). The lower trophic levels play critical roles in both the biogeochemical cycling and transfer of Se to upper trophic levels. The experimental research provided the scientific basis and rate parameters for a computer simulation model developed in conjunction with the experiments. The model includes components to predict the biogeochemical cycling of Se in the water column and sediments, as well as the accumulation and transformations that occur as Se moves through the food web. The modeled processes include biological uptake, transformation, excretion, and volatilization; oxidation and reduction reactions; adsorption; detrital cycling and decomposition processes; and various physical transport processes within the water body and between the water column and sediments. When applied to a Se-contaminated system (Hyco Reservoir), the model predicted Se dynamics and speciation consistent with existing measurements, and examined both the long-term fate of Se loadings and the major processes and fluxes driving its biogeochemical cycle.
AN: 4204150

                                                                     154 of 313  
TI: Arsenic in central Long Island Sound sediments: Natural levels and cycling patterns
AU: Chaloupka,-K.A.; Aller,-R.C.
AF: Chesapeake Biological Lab, P.O. Box 38, Solomons, MD 20688, USA
CO: Long Island Sound Research Conf.: Is the Sound Getting Better or Worse?, Stony Brook, NY (USA), 30 Sep 1994
SO: PROCEEDINGS-OF-THE-LONG-ISLAND-SOUND-RESEARCH-CONFERENCE:-IS-THE-SOUND-GETTING-BETTER-OR-WORSE? McElroy,-A.;Zeidner,-J.-eds. STONY-BROOK,-NY-USA NEW-YORK-SEA-GRANT-INST. 1995 p.74
RN: NYSGI-W-94-001 (NYSGIW94001)
LA: English
ER: M (Marine)
AB: Arsenic is controlled in the marine environment by redox cycling, organic matter degradation, physical/biological transport, and anthropogenic activity. To evaluate the relative importance of controlling factors in central Long Island Sound, the early diagenetic cycling of arsenic (As) was examined in surficial sediments during the annual spring phytoplankton bloom. Pore water As profiles and reactive solid phase distributions of As associated with metal oxides (defined by an operational leach) demonstrate a dynamic remobilization of As near the sediment water interface. Dissolved As generally increases to a subsurface maximum within the upper few centimeters, while reactive solid As decreases exponentially with depth. Maximum pore water and reactive solid As concentrations range from 0.06 - 0.24  mu M and 70-80 nmol/g respectively. Arsenic appears to be controlled by associations with Fe, Mn, and organic matter (represented by P). Regular relations between As and these elements become weaker as remobilization intensifies with organic loading during the spring bloom. Arsenic remobilization fluxes calculated from diagenetic models of dissolved and solid distributions are 0.02-0.63  mu mol/m super(2)/d and 1.4 - 12  mu mol/m super(2)/d respectively. Results from central Long Island Sound demonstrate that As levels and recycling behavior are comparable to other estuarine systems and that the studied region is not unusually contaminated with respect to total As (DBO).
AN: 4202341

                                                                     155 of 313  
TI: Acetate cycling in the water column and surface sediment of Long Island Sound following a bloom
AU: Wu,-H.; Scranton,-M.I.
AF: Marine Sciences Research Center, State University of New York at Stony Brook, Stony Brook, NY 11794-5000, USA
CO: Long Island Sound Research Conf.: Is the Sound Getting Better or Worse?, Stony Brook, NY (USA), 30 Sep 1994
SO: PROCEEDINGS-OF-THE-LONG-ISLAND-SOUND-RESEARCH-CONFERENCE:-IS-THE-SOUND-GETTING-BETTER-OR-WORSE? McElroy,-A.;Zeidner,-J.-eds. STONY-BROOK,-NY-USA NEW-YORK-SEA-GRANT-INST. 1995 p.67
RN: NYSGI-W-94-001 (NYSGIW94001)
LA: English
ER: M (Marine)
AB: Organic matter decomposition plays a key role in oxygen depletion in the waters and surface sediments of Long Island Sound (LIS). Rates of acetate cycling are often equivalent to rates of anaerobic decomposition of organic matter. Therefore, the concentration and uptake rate constants of acetate were measured every two to three weeks from early spring to early summer in LIS surface and bottom water, and sediment. Pore water acetate concentrations were measured at intervals of a few millimeters in the near surface sediment revealing a strong depth variation, with a concentration maximum in the surface millimeters. Peaks of acetate concentration seem to be associated with the redox boundary. Acetate uptake rates (rate constant times concentration) in the water column varied from less than 1 nM/L/h in the early spring to tens of nM/L/h in the early summer. In the sediment, acetate uptake rates averaged over the top 6 cm varied from 0.387  mu M/h to  similar to 8.9  mu M/h in the early spring following the bloom. Our data suggest that both temperature and the amount of fresh organic matter present in a system may strongly affect the acetate distribution, and that, in turn, acetate cycling rates may be excellent indicators of the remineralization of the most labile fractions of carbon (DBO).
AN: 4202317

                                                                     156 of 313  
TI: Processes of enzymolysis of organic macromolecules at different salinities and their relationship with physiologically important and toxic metals in the littoral zone of the Barents Sea.
OT: Protsessy fermentativnogo gidroliza organicheskikh makromolekul v vode razlichnoj solenosti i ikh vzaimosvya's fiziologicheski vazhnymi i toksichnymi metallami na litorali Barentseva morya
AU: Korneeva,-G.A.; Tropin,-I.V.; Romankevich,-E.A.
AF: IORAN, Moscow, Russia
SO: OKEANOLOGIYA 1997 vol. 37, no. 2, pp. 226-231
LA: Russian
ER: M (Marine)
AB: The paper presents data on the enzymatic hydrolysis of proteins and polysaccharides in natural sea, fresh and mixed waters and analyzes effect of different contents of individual heavy metals and their pairs on the processes of enzymolysis at different salinities.
AN: 4201355

                                                                     157 of 313  
TI: Biogenic silica recycling in surficial sediments across the polar front of the Southern Ocean (Indian Sector)
AU: Rabouille,-C.; Gaillard,-J.-F.; Treguer,-P.; Vincendeau,-M.-A.
AF: Cent. des Faibles Radioactivites, Lab. Mixte CNRS-CEA, Av. de la Terrasse, 91190 Gif sur Yvette, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1151-1176
NT: Special issue: ANTARES 1: France JGOFS.
LA: English
ER: M (Marine)
AB: The processes controlling preservation and recycling of particulate biogenic silica in superficial sediments must be understood before one uses biogenic silica as a proxy in paleo-oceanographic studies, and in order to compute oceanic mass balances for silica. In this respect, the Antarctic Ocean is certainly a key region due to its high productivity and export of biogenic silica. In order to quantify sedimentary fluxes and identify crucial processes that allow the preservation of biogenic silica, pore water and solid phase silica profiles were performed on sediment cores from the Southern Ocean (Indian Sector) during the ANTARES 1 cruise. In combination with solubility data reported by Van Cappellen and Qiu (1997a), a process model representing the early diagenesis of silica was developed. In this model, a dependence with depth of the kinetic constant was introduced to allow the preservation of biogenic silica in sediment porewater undersaturated with respect to that phase. Using this steady-state model, it is proposed that a proportionality of the reactivity of the biogenic silica with its settling flux is necessary to explain the observed profiles. It is then shown using this model that the preservation of biogenic silica is not a linear function of the deposited flux. Using a modified version of this model containing an explicit term of reprecipitation, we hypothesize that reprecipitation alone cannot counterbalance dissolution and that its effect is certainly related to a decrease in either surface solubility or kinetics of dissolution.
AN: 4201296

                                                                     158 of 313  
TI: Biogenic silica dissolution in sediments of the Southern Ocean. 2. Kinetics
AU: Van-Cappellen,-P.; Qui,-L.
AF: Sch. Earth and Atmos. Sci., Georgia Inst. Technol., Atlanta, GA 30332-0340, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1129-1149
NT: Special issue: ANTARES 1: France JGOFS.
LA: English
ER: M (Marine)
AB: The dissolution kinetics of biogenic silica in surface sediments collected during the ANTARES I cruise were measured in stirred flow-through reactors. The rate data exhibit a distinctly non-linear dependence on the degree of undersaturation. Near equilibrium, the rates of silica dissolution and precipitation define a single linear trend, i.e. the kinetics are symmetric about the equilibrium point. When the dissolved silica concentration drops below a critical level, however, the dissolution rate rises exponentially with increasing undersaturation. Hence, the data disagree with the linear rate law generally used to describe the dissolution kinetics of biogenic silica. It is hypothesized that the kinetic transition from the linear to the exponential regime represents the onset of localized dissolution centered on surface defects, e.g. small pores and crevices, or compositional defects. The effects of temperature and pH confirm that the critical process controlling the overall dissolution kinetics is the hydrolysis of bridging Si-O-Si bonds at the solid-solution interface. The rate measurements indicate that the reactivity of biogenic silica decreases substantially with depth in the sediment. The decrease in reactivity is explained by a progressive reduction of the defect density of the silica surfaces, through dissolution and reprecipitation of silica. It does not appear to result from the preferential dissolution of a more reactive fraction of biogenic debris deposited from the water column. Surface areas obtained by the N sub(2)-BET method or concentrations of extractable biogenic silica do not provide satisfactory proxies for the reactive surface area of silica in the sediments. However, a positive correlation was observed between the surface reactivity and the exchangeable Co super(2+) adsorption capacity of biogenic silica. Specific kinetic effects on silica dissolution of the aluminum content of the silica surfaces or organic matter coatings were not observed. Both the non-linear dissolution kinetics and the aging of the silica surfaces help restrict the dissolution of deposited biogenic silica to a narrow zone close to the water-sediment interface. The results of the flow-through experiments highlight the importance of in situ early diagenetic processes in controlling the behavior and fate of deposited biogenic silica: no evidence was found supporting a significant effect of differences in solubility or reactivity inherited from the biomineralization process in the water column.
AN: 4201295

                                                                     159 of 313  
TI: Dynamics of DOC in the Norwegian Sea inferred from monthly profiles collected during 3 years at 66 degree N, 2 degree E
AU: Boersheim,-K.Y.; Myklestad,-S.M.
AF: Lab. Biotechnol., Norwegian Univ. Sci. and Technol., N-7034 Trondheim, Norway
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 14, pp. 593-601
LA: English
ER: M (Marine)
AB: Water samples were collected monthly for 3 years at 66 degree N, 2 degree E in the Norwegian Sea, 250 nautical miles off the Norwegian coast. Concentrations of dissolved organic matter were measured with high temperature catalytic oxidation. DOC varied from 53  mu mol C/l to 149  mu mol C/l among all the samples collected. Blank readings from MilliQ water were less than 9.3  mu mol C/l, these values were not subtracted. In the 0-50 m layer DOC concentration was on average 1.2 times greater than in deep water. In the upper 50 m, annual variation was pronounced, with an increase in DOC concentration in spring and summer of variable timing and magnitude, and a less variable decrease in DOC concentration starting in August-September. The rates of increase were in the range 0.16-0.26  mu mol C/l/d. During 1992 we measured a pulse of DOC at depths between 400 and 800 m. The concentration increased consistently at a rate of 0.14-0.16  mu mol/l/day during 1 year. This change presumably was caused by advection, because these waters are well below the photic zone. Within our resolution limit, changes in the deep water from 1000 to 2000 m were hardly detectable and not related to annual cycles.
AN: 4201185

                                                                     160 of 313  
TI: Oceans
AU: Ittekkot,-V.
SO: CLIMATE-CHANGE-1995-IMPACTS,-ADAPTATIONS-AND-MITIGATION-OF-CLIMATE-CHANGE:-SCIENTIFIC-TECHNICAL-ANALYSES. Watson,-R.T.;Zinyowera,-M.C.;Moss,-R.H.-eds. NEW-YORK,-NY-USA CAMBRIDGE-UNIVERSITY-PRESS 1966 pp. 267-288
LA: English
ER: M (Marine); B (Brackish)
AB: Global warming as projected by Working Group I of the IPCC will have an effect on sea-surface temperature (SST) and sea level. As a consequence, it is likely that ice cover and oceanic circulation will be affected, and the wave climate will change. The expected changes affect global biogeochemical cycles, as well as ecosystem structure and functions, on a wide variety of time and space scales; however, there is uncertainty as to whether extreme events will change in intensity and frequency. We have a high level of confidence that: Redistribution of SST could cause geographical shifts in biota as well as changes in biodiversity, and in polar regions the extinction of some species and proliferation of others. A rise in mean SST in high latitudes should increase the duration of the growing period and the productivity of these regions if light and nutrient conditions remain constant; Sea-level changes will occur from thermal expansion and melting of ice, with regional variations due to dynamic effects resulting from wind and atmospheric pressure patterns, regional ocean density differences, and oceanic circulation; and Changes in the magnitude and temporal pattern of pollutant loading in the coastal ocean will occur as a result of changes in precipitation and runoff.
AN: 4110984

                                                                     161 of 313  
TI: Nutrient regeneration by the zebra mussel (Dreissena polymorpha)
AU: James,-W.F.; Barko,-J.W.; Eakin,-H.L.
AF: US Army Engineer Waterways Experiment Station, Eau Galle Aquatic Ecology Laboratory, Spring Valley, Wisconsin 54767, USA
SO: J.-Freshwat.-Ecol. 1997 vol. 12, no. 2, pp. 209-216
LA: English
ER: F (Freshwater)
AB: Changes in suspended seston and soluble nutrients were examined as a function of zebra mussel (Dreissena polymorpha) density in flow-through sediment-water microcosms to determine impacts on nutrient recycling. Overall, zebra mussels removed > 70% of the suspended seston and > 80% of the total chlorophyll a input to the microcosms. Declines in organic nitrogen in microcosms were accompanied by density-dependent increases in nitrate-nitrite nitrogen. It is suggested that microflora associated with the sediments in the microcosms were transforming ammonium nitrogen, which is an excretory product of zebra mussels, into nitrate nitrogen. Declines in total phosphorus in the microcosms also coincided with density-dependent increases in the concentration of soluble reactive phosphorus and its rate of regeneration, suggesting enhanced nutrient cycling via excretion. Calculated rates of soluble phosphorus regeneration due to zebra mussel activity ranged from 0.3 to 2.5 mg m super(-2) d super(-1) at mussel densities ranging between 170 to 1300 individuals m super(-2).
AN: 4117580

                                                                     162 of 313  
TI: A comparison of benthic foraminiferal paleoproductivity proxies in a sediment core from the NW Africa upwelling area
OT: Foraminiferes benthiques et paleoproductivite: reflexions sur une carotte de l'upwelling (NW africain)
AU: Guichard,-S.; Jorissen,-F.; Bertrand,-P.; Gervais,-A.; Martinez,-P.; Peypouquet,-J.P.; Pujol,-C.; Vergnaud-Grazzini,-C.
AF: Departement de geologie et d'oceanographie, CNRS URA 197, Univ. Bordeaux 1, avenue des Facultes, 33405 Talence cedex, France
SO: C.-R.-Acad.-Sci.-Ser.-2a-Sci.-Terre-Planet.-Earth-Planet.-Sci. 1997 vol. 325, no. 1, pp. 66-70
LA: French
ER: M (Marine)
AB: Two different paleoproductivity proxies, both based on benthic foraminiferal frequency data, are tested in a sediment core from the NW African upwelling area. A first proxy, the BFAR, enables us to estimate the total amount of organic matter introduced into the benthic ecosystem. The second one, the sample scores on the first axis of a P.C.A., enables us to estimate export-paleoproductivity when the oxygen concentration does not exceed 4.4 mL/L. The comparison of these micropaleontological proxies also allows us to evaluate the quality of the organic matter, and thus, to estimate what part of the organic matter introduced in the benthic ecosystem has been remineralized and what part has ultimately been stored in the sediment.
AN: 4117180

                                                                     163 of 313  
TI: Organic geochemistry of marine sediments of the subantarctic Indian Ocean sector: lipid classes - sources and fate
AU: Laureillard,-J.; Pinturier,-L.; Fillaux,-J.; Saliot,-A.
AF: Lab. de Physique et Chimie Marines, Unite de Recherche Associee au CNRS No. 2076, Univ. Pierre et Marie Curie, Case 134, Tour 25-24, 4 Place Jussieu, F-75252 Paris Cedex 05, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1085-1108
NT: Special issue: Antares 1: France JGOFS.
LA: English
ER: M (Marine)
AB: Nine sections of core KTB16 (47 degree 59'98 S, 55 degree 59'74 E, 4240 m) taken from the Indian Ocean sector of the Antarctic Polar Front Zone were analyzed for their lipid class and total chlorin contents using thin-layer chromatography-flame ionisation detection (TLC/FID). The following series were included: hydrocarbons, chlorins and chlorin esters, alcohols, sterols, triacylglycerols, free fatty acids and phospholipids. For these major classes, the distribution of their individual components was determined to evaluate the source and fate of each lipid class. Relationships between the lipid composition of overlying particles and of buried material were investigated. The sediment-water interface was found to be of primary importance in the biogeochemical transformations occurring in organic matter, such as loss of the major part of the lipids, and formation of a notable unresolved complex mixture (UCM), of biological origin. Some classes such as chlorin esters appeared to convey their lipid contents from the upper layers without major alteration. In contrast, several other classes, such as storage lipids, appeared to be degraded during sedimentation, indicating extensive recycling of labile lipids in the water column. The burial efficiency and bacterial inputs downcore were highly variable depending on the class considered. Several novel compounds are reported. They consist of alkyl chlorin esters and include a wide variety of saturated and unsaturated long-chain alcohols. Owing to the lack of lipid data in the study area, these results provide an insight into the various biological and chemical processes occurring in open-sea Antarctic sedimentary environments.
AN: 4114533

                                                                     164 of 313  
TI: Biogenic silica dissolution in sediments of the Southern Ocean. 1. Solubility
AU: Van-Cappellen,-P.; Qiu,-L.
AF: Sch. Earth and Atmos. Sci., Georgia Inst. Technol., Atlanta, GA 30332-0340, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1109-1128
NT: Special issue: Antares 1: France JGOFS.
LA: English
ER: M (Marine)
AB: A stirred flow-through reactor technique was used to determine silica solubilities in sediments collected with a multicorer in the Indian sector of the Southern Ocean (ANTARES I cruise). The results show that the apparent silica solubility in the cores may decrease, increase or remain constant with depth. The silica solubility profiles are best explained by the early diagenetic interactions between biogenic silica and soluble aluminum derived from detrital material. By combining the solubility data with measured dissolved silica profiles, it is shown that the variable asymptotic pore water silica levels in the cores cannot be explained solely by differences in silica solubility. In sediments that experience a significant detrital input, the simultaneous reprecipitation of dissolved aluminum and dissolved silica prevents pore water silicic acid from reaching saturation with the dissolving biogenic silica. The principal oceanographic control on pore water silica build-up in the cores studied is the ratio of the deposition fluxes of biogenic silica and detrital material. Solubility differences inherited from the biomineralization process in the surface waters do not appear to have a significant effect on the observed pore water silica levels.
AN: 4114532

                                                                     165 of 313  
TI: Distribution, cycling and mean residence time of  super(226)Ra,  super(210)Pb and  super(210)Po in the Tagus Estuary
AU: Carvalho,-F.P.
AF: Int. At. Energy Agency, Mar. Environ. Lab., P.O. Box 800, MC 98012, Monaco Cedex, Principaute de Monaco
SO: SCI.-TOTAL-ENVIRON. 1997 vol. 196, no. 2, pp. 151-161
LA: English
ER: B (Brackish)
AB: Results for dissolved and particulate  super(226)Ra,  super(210)Pb and  super(210)Po in the Tagus River, estuary and coastal sea system show different distribution and chemical behaviour patterns for these radionuclides in the three aquatic environments.  super(226)Ra from riverborne particles dissolves in the estuary and contributes to increased concentrations of dissolved  super(226)Ra in estuarine water. In the estuary, dissolved  super(210)Pb and  super(210)Po from river discharge and atmospheric deposition are scavenged by suspended matter, which in turn becomes enriched in these nuclides in comparison with riverborne particles. As a result of these processes, the estuarine water flowing into the coastal sea contains enhanced concentrations of dissolved  super(210)Pb and  super(210)Po. Under average river flow conditions, mass balance calculations for dissolved  super(210)Po and  super(210)Pb in the estuary allowed their mean residence times to be estimated as 18 and 30 days, respectively. Due to the rapid sorption of these radionuclides on to settling particles, bottom sediments in the estuary represent a sink for  super(210)Pb and  super(210)Po from both natural sources and industrial waste releases. Results also suggest that partial re-dissolution of these radionuclides from bottom sediments and intertidal mudflats is likely to occur in the mid- and low-estuary zones. Nevertheless, box-model computations indicate that the discharge of  super(210)Pb and  super(210)Po into the coastal sea takes place mainly with the transport of sediment, whereas the discharge in the dissolved fraction can only account for one third of the activities entering the estuary in the soluble phase. Implications of these results to the cycling of radionuclides in phosphate waste releases into estuarine environments are discussed.
AN: 4109561

                                                                     166 of 313  
TI: Fluxes and budgets of contaminants in the German Bight
AU: Suendermann,-J.; Radach,-G.
AF: Zent. Meeres-und Klimaforsch., Univ. Hamburg, Inst. Meereskunde, 22529 Hamburg, Germany
SO: MAR.-POLLUT.-BULL. 1997 vol. 34, no. 6, pp. 395-397
LA: English
ER: M (Marine)
AB: Contaminants in coastal waters such as heavy metals and organochlorines, but also oversupplied nutrients, endanger the marine ecosystem. At the same time, they influence the global cycles of matter in this key region and contribute to global change. In awareness of this essential role, many international and national projects are addressing fluxes and budgets of contaminants in coastal waters. This is especially true for the North Sea where the Quality Status Report of the North Sea is regularly produced as a joint effort of European countries. Nevertheless, our knowledge about regional fluxes, turnover rates and budgets of contaminants as well as their reliability is still in an early stage. These papers contain attempts at budgets for suspended particulate matter (SPM), nitrogen, cadmium, lead and the organochlorines HCH and PCB, as well as the herbicide atrazine, for the German Bight. With respect to SPM, its transport is a priori a natural process without danger for the marine environment. Many contaminants, however, are significantly or mainly transported not in the dissolved but in the particulate phase. This fact determines the importance of SPM fluxes and was the reason for including a chapter on it in these papers. The same is true for the water as a transport vehicle, but its transport rates for different temporal and spatial scales are much better known, so there is no specific chapter for water mass fluxes.
AN: 4109529

                                                                     167 of 313  
TI: Biological roles of trace metals in natural waters
AU: Hunter,-K.A.; Kim,-J.P.; Croot,-P.L.
AF: Dep. Chem., Univ. Otago, P.O. Box 56, Dunedin, New Zealand
CO: 5. Symposium on our Environment [np] [nd]
SO: PROCEEDINGS-OF-THE-5TH-SYMPOSIUM-ON-OUR-ENVIRONMENT. Lee,-H.K.;Wong,-M.K.-eds. 1997 vol. 44, no. 1-3 pp. 103-147
ST: Environmental-Monitoring-and-Assessment vol. 44, no. 1-3
LA: English
ER: M (Marine)
AB: For decades there has been an intense interest in the toxic effects of trace metals on biological organisms in the environment. This period of time has seen increasing improvements in analytical techniques for the measurement and study of trace metals and their subsequent application to a broad spectrum of water systems around the globe. This work has included studies of the geographical distributions of trace metals in different water types in the ocean, the modes of transport and uptake of trace metals and the study of historical changes in trace metal accumulation. Early research highlighted strong similarities in the behaviours of many trace metals and those of well-understood chemical nutrients such as phosphate, nitrate and silicate, known to be essential for phytoplankton growth in the ocean. This suggests that phytoplankton regulate the trace metal composition of seawater for their own benefit. A major achievement in this regard has been the ability to measure, at the sub-nmol/L level, trace metal species that are complexed by naturally-occurring organic ligands of biological origin in ocean waters. It is now clear that the free ion activities of many essential and/or toxic trace metals are regulated by highly specific, strongly complexing ligands exuded by marine phytoplankton. This research encourages a new paradigm in which the growth rates and species composition of primary marine organisms are affected by trace metals at concentration levels orders of magnitude lower than is conventionally believed. As a consequence, the capacity of natural waters to assimilate trace metal-contaminants may be correspondingly much lower than is currently thought reasonable.
AN: 4101665

                                                                     168 of 313  
TI: A balance analysis of phosphorus elimination by artificial calcite precipitation in a stratified hardwater lake
AU: Dittrich,-M.; Dittrich,-T.; Sieber,-I.; Koschel,-R.
AF: Inst. Freshwater Ecol. and Inland Fish., Dep. Stratified Lakes, Alte Fischerhuette 2, D-16775 Neuglobsow, Germany
SO: WATER-RES. 1997 vol. 31, no. 2, pp. 237-248
LA: English
ER: F (Freshwater)
AB: Elimination of phosphorus was achieved by artificial calcite precipitation in the Dagowsee, a stratified eutrophic hardwater lake. The artificial calcite precipitation was induced by hypolimnetic injection of CaO in enclosures during the summer stagnation. The hypolimnetic injection of CaO was combined with aeration for 1 day. The coprecipitation of phosphorus with calcite was shown by energy dispersive X-ray analysis. The content of phosphorus in the calcite was about 0.1 wt%. Phosphorus was homogeneously distributed throughout the precipitated calcite and throughout the calcinated particles of water and sediment. The phosphorus coprecipitation efficiency was calculated from the ratio of the decrease of phosphorus to decrease of calcium in the water according to the House's coprecipitation model.
AN: 4101122

                                                                     169 of 313  
TI: Comparison of Cu and Zn cycling in eutrophic lakes with oxic and anoxic hypolimnion
AU: Xue,-HanBin; Gaechter,-R.; Sigg,-L.
AF: Swiss Fed. Inst. for Environ. Sci. and Technol. (EAWAG), Limnol. Res. Cent., CH-6047 Kastanienbaum, Switzerland
SO: AQUAT.-SCI. 1997 vol. 59, no. 2, pp. 176-189
LA: English
ER: F (Freshwater)
AB: Data on the cycling of Cu and Zn in two eutrophic lakes are presented: Lake Greifen that becomes seasonally anoxic in its hypolimnion and Lake Sempach that is aerated during winter and oxygenated during summer. They suggests that hypolimnetic oxygenation 1) enhances the release of copper from the sediment but 2) also accelerates the entrapment and deposition of Cu and Zn by freshly formed Mn- and Fe-oxides.
AN: 4098574

                                                                     170 of 313  
TI: Patterns of retention and utilization of aerially deposited nitrogen in boreal peatlands
AU: Li,-Yenhung; Vitt,-D.H.
AF: Dep. Biol. Sci., Univ. Alberta, Edmonton, Alberta T6G 2E9, Canada
SO: ECOSCIENCE 1997 vol. 4, no. 1, pp. 106-116
LA: English
ER: F (Freshwater)
AB: Nitrogen dynamics were quantified for two years using  super(15)N (as NH sub(4)Cl at 3 g N m super(-2) year super(-1)) in a bog and a rich fen in continental western Canada. After two years, 81-88% of the applied nitrogen was recovered; 98.4-98.7% of the recovered nitrogen occurred in the top 45 cm of the moss-peat layer and 1.3-1.6% occurred in the above ground shrub component. In the bog, 29% was recovered from the top 0-5 cm of Sphagnum fuscum, while in the fen 19% was recovered from this zone in Tomenthypnum nitens. Sphagnum sequestered the applied nitrogen more efficiently than did Tomenthypnum. However, over time Tomenthypnum retained it better in the upper moss layers. Overall, after two years Sphagnum retained 42% and Tomenthypnum 48% in the top 12 cm of the ground layer. The nitrogen of the current year's moss growth contained 26-28% applied nitrogen (% NDFF) after one season and 19-20% after two seasons. Moss production increased from 4-300% annually over the two year period, while production for Betula pumila in the fen and Ledum groenlandicum in the bog did not increase significantly. Decomposition of S. fuscum the bog was significantly less than T. nitens in the fen after two years, but no differences were evident after nitrogen additions in either peatlands. We conclude that 1) nearly all nitrogen is immediately sequestered by the moss layer; 2) much of this new nitrogen is found in the actively growing region and moss production increases; 3) shrubs are little affected by the additional nitrogen during the first two years and direct absorption of nitrogen through leaves is unimportant; and 4) newly deposited nitrogen is tightly controlled by the moss layer in both bogs and fens. However retention patterns are different. Subsequent use of nitrogen by vascular plants is determined by nutrient release through decompositional processes deeper in the moss layer.
AN: 4109060

                                                                     171 of 313  
TI: Manganese flux associated with dissolved and suspended manganese forms in Lake Fukami-ike
AU: Yagi,-A.
AF: Fac. Home Econ., Nagoya Women's Univ., 3-40, Shioji-cho, Mizuho-ku, Nagoya 467, Japan
SO: WATER-RES. 1996 vol. 30, no. 8, pp. 1823-1832
LA: English
ER: F (Freshwater)
AB: Redissolved, particulate and sedimentary manganese were studied in the anoxic hypolimnion of the small monomictic Lake Fukami-ike in central Japan. The amounts of particulate and dissolved manganese in the water column were observed. The release of dissolved manganese starts gradually beginning in March. DMn reaches especially high levels of 93 mgMn m super(-2) d super(-1) from the end of May to the end of June calculated from the gradient of a regression formula for the daily change in DMn. The rate of accumulated PMn is 0.64 mgMn m super(-2) d super(-1) from the end of July calculated from the gradient of a regression formula for the daily change in PMn. An accumulation of PMn and an associated decrease in dissolved organic carbon (DOC) were observed at the transition zone of oxic and anoxic layers. These facts seem to suggest that the DOC decrease involves the consumption of DOC as an electron donor by bacterial catalysis for the reduction of MnO sub(2). The upward and downward DOC fluxes, 0.320 mmolC m super(-2) d super(-1), were calculated by the mean gradient values of the upward and downward DOC concentrations. The mean DOC flux was calculated by the both the mean gradient DOC and the vertical diffusion coefficient (0.0304 m super(-2) d super(-1)). Manganese-reducing bacteria could contribute as much as 24% to the DOC decrease in the oxic and anoxic layers, considering bacterial assimilation efficiency (64%). Vertical diffusion Mn flux from the interstitial water to the hypolimnion is then assumed to be 2 mgMn m super(-2) d super(-1). Mn for the vertical eddy diffusion flux, the vertical diffusion from the interstitial water of the bottom sediment, the sinking flux and microbiological Mn flux were obtained, and the biogeochemical manganese cycle in Lake Fukami-ike was calculated. DMn flux in the oxic and anoxic layers by manganese-reducing bacteria is 0.004 gMn m super(-2) d super(-1), a value corresponding to 10% of DMn flux.
AN: 4105593

                                                                     172 of 313  
TI: Study of marine sulfate-reducing bacterial population using fluorescent in situ hybridization method during decomposing processes of detrital material and polypepton in microcosms
AU: Park,-Young-Tae; Nishimura,-Masahiko; Ohwada,-Kouichi
AF: Dep. Microbiol., Pukyong Natl. Univ., Pusan, Korea
SO: FISH.-SCI. 1997 vol. 63, no. 1, pp. 105-110
LA: English
ER: M (Marine)
AB: Microcosm experiments were performed to know the dynamics of sulfate-reducing bacterial population and volatile fatty acids (VFA) during decomposition of polypepton and detrital material in the surface sediments from Tokyo Bay and Sagami Bay. Population of sulfate-reducing bacteria were detected and counted through fluorescent in situ hybridization with SRB probe which has wide specificity to sulfate-reducing bacterial group, and with Desulfobacter probe which has narrow specificity only to genus Desulfobacter. In the microcosms of the Tokyo Bay sample, vibrioid (0.7-1.0x2-2.5 mu m) and rod (1.5-1.8x2.5-3.5 mu m)shaped SRB were detected on day 3, SRB population changed to cocci(0.7-1.0 mu m) and rod (1.5-1.8x2.5-3.5 mu m) shaped cells on day 8. These rod shaped SRB were hybridized also with Desulfobacter probe. The increase of Desulfobacter followed by the increase of utilized acetate. In the Sagami Bay sample, only rod shaped SRB (0.7-1.2x2.5-6 mu m) was detected on day 35. On day 100, cocci (2-3 mu m) and short rod (0.7-1.2x1.7-2.2 mu m) shaped SRB were detected. No cell was hybridized with Desulfobacter probe. It was considered that there was the succession of sulfate-reducing bacterial population during decomposition of detrital material in the surface sediments. The probe method would be helpful to understand population changes of sulfate-reducing bacteria in the natural bacterial communities.
AN: 4104834

                                                                     173 of 313  
TI: A study of plankton cycles with a parcel-mixed layer model
AU: Xu,-Yongfu; Wang,-Mingxing
AF: LAPC, Inst. Atmos. Phys., Acad. Sin., Beijing 100029, People's Rep. China
SO: MAR.-SCI.-BULL.-HAIYANG-TONGBAO 1996 vol. 15, no. 5, pp. 17-24
LA: Chinese
AB: A simple food web, including plankton (phytoplankton, zooplankton and bacteria) and nonliving nitrogen (detritus, dissolved organic nitrogen, nitrate and ammonium) is used to represent the biological processes taking place in the upper mixed layer of the ocean. This biological model is applied into a parcel of water moving from the Strait of Florida (24 degree N, 80 degree W) to the Norwegian Sea 68 degree N, 10 degree E) in the Extended Gulf Stream System (EGSS) to simulate evolution of plankton and nutrients with time. Results give the life cycle of plankton driven by the nutrients, and also produce the spring bloom. The results are more reasonable than those from the most simple biological model of phytoplankton-zooplankton-nutrient (PZN). On the basis of calculation of various production, the dynamics processes of plankton cycles and their influence factors are further discussed.
AN: 4104753

                                                                     174 of 313  
TI: Sediment trap and global change study
AU: Chen,-Jianfang; Zheng,-Lianfu
AF: 2nd Inst. Oceanogr., SOA, Hangzhou 310012, People's Rep. China
SO: MAR.-SCI.-BULL.-HAIYANG-TONGBAO 1996 vol. 15, no. 1, pp. 41-47
LA: Chinese
AB: Marine particles contain a lot of information on chemical, physical, biological processes in the interior of the ocean. In the last decade, based on time series sediment trap experiments, multidisciplinary researches have been carried out in order to investigate particle flux and composition, their temporal and spatial changes as well as the controlling factors. These studies not only are very useful to answer how marine biogeochemical processes control the atmospheric CO sub(2) variations, but also make a great contribution to understanding the role of ocean in global change.
AN: 4104704

                                                                     175 of 313  
TI: The behavior of dissolved cadmium, copper, lead and their relationship to nutrients in the Ming River Estuary
AU: Zou,-Dongliang; Gao,-Shuying
AF: Dep. Oceanogr., Inst. Subtrop. Oceanol., Xiamen Univ., Xiamen 361005, People's Rep. China
SO: TROP.-OCEANOL.-REDAI-HAIYANG 1996 vol. 15, no. 1, pp. 74-79
LA: Chinese
ER: B (Brackish)
AB: The behavior of dissolved Cd, Cu, Pb and their relationship to nutrients in the Ming River Estuary were studied in June and Oct. 1990. The results indicated additional appearance for Cd, and respectively conservative and removal behavior for Cu and Pb, in June and October. The addition of Cd mainly comes from the remineralization of plankton detritus by microbial activities, whereas Pb removal is dominated by abiotic processes.
AN: 4104613

                                                                     176 of 313  
TI: Size-fractionated phosphate uptake by phytoplankton in West Xiamen Harbour
AU: Huang,-Bangqin; Hong,-Huasheng; Wang,-Haili; Hong,-Liyu
AF: Res. Cent. Environ. Sci., Xiamen Univ., Xiamen 361005, People's Rep. China
SO: J.-OCEANOGR.-TAIWAN-STRAIT-TAIWAN-HAIXIA 1995 vol. 14, no. 3, pp. 269-273
LA: Chinese
ER: M (Marine)
AB: By using carrier-free  super(32)P radiotracer method, the study on size- fractionated phosphate uptake rate, rate constant and uptake percentage by phytoplankton was carried out in West Xiamen Harbour. The correlationship among phosphate uptake, standing crop (Chl-a) and photosynthetic rate is discussed. The results indicated that nanophytoplankton (3-20mum) played the most important role in phosphate uptake percentage (74.85%), rate constant (8.28x10 super(-5) /s) and uptake rate [by volume, 5.38x10 super(-5)mumol/(dm super(3).s)] in the three different size phytoplanktons, but in uptake rate (by biomass), picophytoplankton (0.2-3mum) [5.38x10 super(-5)mumol/(mug.s)] was more important than nanophytoplankton [1.79x10 super(-5)mumol /(mumg.s)] and microphytoplankton (20-200mum) [1.14x10 super(-5)mumol /(mug.s)]. The good positive correlationship was found between phosphate uptake percentage with standing crop (Chl-a) and photosynthetic rate, respectively. The study further showed that nanophytoplankton played a key role in phosphorus biogeochemical cycle in West Xiamen Harbour.
AN: 4104351

                                                                     177 of 313  
TI: Bacterial utilization of dissolved humic substances from a freshwater swamp
AU: Bano,-N.; Moran,-M.A.; Hodson,-R.E.
AF: Dep. Mar. Sci., Univ. Georgia, Athens, GA 30602-2206, USA
SO: AQUAT.-MICROB.-ECOL. 1997 vol. 12, no. 3, pp. 233-238
LA: English
ER: F (Freshwater)
AB: Dissolved humic substances from 5 different aquatic habitats in the Okefenokee Swamp, USA, ecosystem were tested for their ability to support growth of natural bacterial communities in batch bioassay experiments. The in situ dissolved organic carbon (DOC) concentration in samples from all sites was high, ranging from 46 to 58 mg Cl super(-1); 63 to 78% of the DOC was humic substances. Humic substances were isolated by adsorption onto Amberlite XAD-8 resin and provided to natural bacterial communities either from the same site or one of the other sites as the only carbon source. Humic substances from all sites supported bacterial growth; generally there were no significant differences among the bacterial communities in the rates or extent of utilization of humic substances. The average specific growth rates of bacteria, determined as changes in biovolume, were 0.026 to 0.044 h super(-1) for all experiments and were comparable to rates measured in situ. The cumulative bacterial carbon production ranged from 58 to 176  mu g Cl super(-1). Based on measures of bacterial carbon production and oxygen consumption, bacterial growth efficiency on humic substances was estimated at 22%, and the percentage of the humic substances pool utilized during the 1 wk bioassay was 0.8 to 1.8%.
AN: 4096635

                                                                     178 of 313  
TI: Transformation of organogenic substances and rates of production - destruction processes in the Okhotsk Sea ecosystem.
OT: Transformatsiya organogennykh veshchestv i skorosti produktsionno-destruktstonnykh protsessov v ehkosisteme Okhotskogo morya
AU: Leonov,-A.V.; Sapozhnikov,-V.V.
AF: Nauchn.-Koordinats, Tsentr 'Kaspij' RAN, Moscow, Russia
SO: OKEANOLOGIYA 1997 vol. 37, no. 1, pp. 67-80
LA: Russian
ER: M (Marine)
AB: The annual dynamics of chemical and biological components in 8 sea areas is reproduced in an ecological model using 1991-1973 observation data on variations in water temperature, surface illumination intensity and water regime characteristics. The model results are used to estimate internal (recycling) and external advection fluxes of organogenic substances (C, N, Si, P, O), and the rates of production - destruction processes in the ecosystem. Biogenic substances accumulated in the surface layer during winter determine primary production in spring. During the summer-autumn period, primary production develops due to recycling of nutrients. In the most productive areas (Kamchatka and Sakhalin coasts), upwelling provides a continuous supply of organogenic substances and creates favourable conditions for phytoplankton development and active biotransformation of the substances. The integral phytoplankton production during the vegetation period is determined by the activity of diatoms (37.6 - 44.6%), peridineans (28.1 - 32.4%) and green algae (27.2 - 30%). The integral phytoplankton production in the surface layer is 59.8 - 66.3% higher than the bacterial destruction of organic matter.
AN: 4095301

                                                                     179 of 313  
TI: On amounts of organic matter buried in marine sediments of marginal seas.
OT: O masshtabakh bassejnovykh 'zakhoronenij' organicheskogo veshchestva v morskikh osadkakh
AU: Kuznetsov,-A.P.; Geodekyan,-A.A.; Marina,-M.M.
AF: IORAN, Moscow, Russia
SO: IZV.-RAN-BIOL. 1997 no. 1, pp. 59-63
LA: Russian
ER: M (Marine)
AB: With particular reference to the Bering Sea, the authors analyze and estimate components of production-destruction biotic balance, contributions of marginal seas to the total amount of organic matter accumulated in ocean sediments, and their oil and gas potentialities.
AN: 4095260

                                                                     180 of 313  
TI: Biogeochemical nutrient cycling in the upper Great Ouse Estuary, Norfolk, U.K.
AU: Sanders,-R.; Klein,-C.; Jickells,-T.
AF: Sch. Environ. Sci., Univ. East Anglia, Norwich, Norfolk, UK
SO: ESTUAR.-COAST.-SHELF-SCI. 1997 vol. 44, no. 5, pp. 543-555
LA: English
ER: M (Marine); B (Brackish)
AB: The cycling of dissolved inorganic nutrients in the Great Ouse Estuary, Norfolk, U.K. was studied over a 50-day period in the early summer of 1994. The cycling of nutrients within the estuary and the export of nutrients to the surrounding coastal waters is quantified using mass balancing and conservative mixing considerations. Overall, the estuary was a minor sink for nitrate + nitrite (8%), a modest sink for silicate and phosphate (12 and 22%, respectively), a large source of ammonium (95%), and, overall, a small sink for dissolved inorganic nitrogen (2%). Water-column processes account well for the observed silicon and phosphorus removals; however, sedimentary processes are required to account for most of the ammonium source and some of the nitrate sink. The most significant water-column processes were primary production and nutrient regeneration from particulate material. The former process appears to be driven mainly by nitrogen imported directly at the head of the estuary, not recycled nitrogen. Regenerative processes returned approximately half of the silicate assimilated in primary production to the water column, and reduced the inferred respiratory releases of nitrogen and phosphorus by 40 and 60%, respectively. The two approaches to quantifying export, mass balancing and conservative mixing considerations, complement each other well, with the mixing analysis suggesting magnitudes and locations for nutrient-cycling processes not quantified by the mass-balance model.
AN: 4094599

                                                                     181 of 313  
TI: Spring development of phytoplankton biomass and composition in major water masses of the Atlantic sector of the Southern Ocean
AU: Bathmann,-U.V.; Scharek,-R.; Klaas,-C.; Dubischar,-C.D.; Smetacek,-V.
AF: Alfred-Wegener-Inst. for Polar and Mar. Res., 27515 Bremerhaven, Germany
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 51-67
LA: English
ER: M (Marine)
AB: The distribution and composition of phytoplankton stocks in relation to water masses were studied during the SO-JGOFS cruise of R.V. Polarstern in the Atlantic sector of the Southern Ocean in October/November 1992. The cruise comprised one west-to-east transect along the ice edge from 49 degree W to 6 degree W and several meridional transects along 6 degree W that extended from the closed pack ice of the Weddell Sea, across the southern Antarctic Circumpolar Current (ACC) and into the Polar Frontal Zone. Chlorophyll (chl a concentrations, temperature and salinity were recorded continuously in surface water during the transects. Vertical distribution and species composition of microplankton were assessed microscopically in discrete water samples collected at stations. Contrary to expectations, no significant enhancement of phytoplankton biomass was found in the vicinity of the retreating ice cover. Melt-water-influenced zones were indicated by low salinity but also by abundance of characteristic sea-ice species such as Nitzschia closterium and N. prolongatoides, but chlorophyll concentrations averaged only 0.3 mg chl a m super(-3) and barely increased during the spring. Values were even lower and remained constant in the southern ACC (ca 0.2 mg chl a m super(-3)). In contrast, large phytoplankton blooms developed during the 6 weeks of investigation in the region of the Polar Front (PFr), from 0.7 to >4 mg chl a m super(-3). Three distinct blooms extended below 70 m depth, each dominated by a different diatom species (Fragilariopsis kerguelensis, Corethron inerme and C. criophilum). We speculate that the large phytoplankton stocks below 40 m depth are a result of subduction of surface layers as sinking and in situ growth can be ruled out. The factors leading to the accumulation of high phytoplankton stocks in the PFr (up to 270 mg chl m super(-2)), but not in the meltwater zones or in the front between ACC and Weddell Gyre, are not clear, but higher iron concentrations in the former region seem to have played a role.
AN: 4092491

                                                                     182 of 313  
TI: Ecology and biogeochemistry of the Antarctic Circumpolar Current during austral spring: A summary of Southern Ocean JGOFS cruise ANT X/6 of R.V. Polarstern
AU: Smetacek,-V.; De-Baar,-H.J.W.; Bathmann,-U.V.; Lochte,-K.; Rutgers-Van-Der-Loeff,-M.M.
AF: Alfred Wegener Inst. for Polar and Mar. Res., D-27515 Bremerhaven, Germany
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 1-21
LA: English
ER: M (Marine)
AB: The R.V. Polarstern cruise ANT X/6, part of the international Southern Ocean JGOFS programme, investigated plankton spring bloom development and its biogeochemical effects in different water masses of the Atlantic sector of the Southern Ocean: the Polar Frontal region (PFr), the southern Antarctic Circumpolar Current zone (sACC), its boundary with the Weddell Gyre (AWB) and the marginal ice zone (MIZ). The relative roles of physical stability, iron limitation and grazing pressure in enhancing or constraining phytoplankton biomass accumulation were examined. Three sections were carried out between the PFr and the ice edge along the 6 degree W meridian from early October to late November 1992. This paper summarises the major findings of the cruise and discusses their implications for our understanding of Southern Ocean ecology and biogeochemistry. A major finding was the negligible build-up of plankton biomass and concomitant absence of CO sub(2) drawdown associated with seasonal retreat of the ice cover. In striking contrast to this unexpected poverty of both the MIZ and the frontal region of the AWB, distinct phytoplankton blooms, dominated by different diatom species, accumulated in the PFr. Chlorophyll stocks in the sACC remained monotonously low throughout the study. Our findings confirm those of other studies that frontal regions are the major productive sites in the Southern Ocean and that input of meltwater and associated ice algae to the surface layer from a retreating ice edge is by itself an insufficient condition for induction of phytoplankton blooms. The blooms in the PFr developed under conditions of shallow mixing layers, high iron concentrations and relatively low grazing pressure. However, in all three blooms, high biomass extended to deeper than 70 m, which cannot be explained by either in situ growth or sinking out of a part of the population from the upper euphotic zone. Subduction of adjoining, shallower layers to explain depth distribution is invoked. Despite a clear CO sub(2) drawdown in the Polar Frontal region, the highly variable conditions encountered render reliable estimation of annual CO sub(2) fluxes in the Southern Ocean difficult.
AN: 4092490

                                                                     183 of 313  
TI: Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992
AU: Queguiner,-B.; Treguer,-P.; Peeken,-I.; Scharek,-R.
AF: UMR CNRS 6539, Inst. Univ. Europeen de la Mer, Univ. de Bretagne Occidentale, BP 809, F-29285 Brest Cedex, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 69-89
LA: English
ER: M (Marine)
AB: High biogenic silica (BSi) concentrations (maximum: 11.7  mu mol l super(-1)) were recorded during late November at the southern border of the Polar Frontal region (PFr). Position of the BSi maximum at depth suggested the occurrence of a sinking diatom population. By contrast, siliceous biomass was low (BSi <0.6  mu mol l super(-1)) in the Marginal Ice Zone (MIZ) despite a sea-ice retreat of 200 km during the study period. Diatoms released from the receding ice were not actively growing. The Permanently Open Ocean Zone also showed very low BSi biomass (<0.5  mu mol l super(-1)) and appeared as an area where phytoplankton are not dominated by siliceous organisms, especially in its middle part where BSi/POC (particulate organic carbon) molar ratios ranged between 0.04 and 0.06 at 53 degree S, from surface to 200 m depth. At the southern border of the PFZ, the bloom coincided with an area of high lithogenic silica concentrations probably of aeolian origin. In addition, Bsi/POC molar ratios measured in the PFZ were the highest ever recorded in the surface waters of the Southern Ocean (maximum: 1.75). This could be due to the presence of heavily silicified diatoms such as Fragilariopsis kerguelensis or also could reflect the more rapid recycling of POC as compared to BSi. Within the bloom area BSi concentrations were positively correlated to pyrophaeophytin pigments, possibly indicating the occurrence of a senescent diatom population. High concentrations of BSi (>1.5  mu mol Si l super(-1)) extended to 200 m between 49 degree S and 51 degree S. Numerous empty frustules also were observed, suggesting significant sedimentation of siliceous particles between 49 degree S and 51 degree S. Estimates of the BSi production of the Polar Frontal region are derived from  super(14)C primary production and appropriate BSi/POC ratios, and implications for the total annual production of BSi for the Southern Ocean are discussed.
AN: 4092482

                                                                     184 of 313  
TI: Particulate barium stocks and oxygen consumption in the Southern Ocean mesopelagic water column during spring and early summer: Relationship with export production
AU: Dehairs,-F.; Shopova,-D.; Ober,-S.; Veth,-C.; Goeyens,-L.
AF: Analytische Chemie, Vrije Univ. Brussel, Pleinlaan 2, B-1050, Brussels, Belgium
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 497-516
LA: English
ER: M (Marine)
AB: Particulate barium was analysed in the upper 600 m of the Southern Ocean water column during repeated transects along the 6 degree W meridian in October-November 1992. The transects extended between the northern edge of the Weddell Gyre (57 degree 30'S) in the south to 47 degree S within the Polar Front Zone (PFZ) in the north. From earlier studies, it is known that the largest fraction of Ba in oceanic suspended matter occurs as barite micro-crystals. In the PFZ, an increase in the particulate Ba content in surface waters and at mesopelagic depths can be significant over the investigation period (1 month) and follows the increase of primary production during bloom development. Using an inverse one-dimensional advection-diffusion-consumption model, O sub(2) consumption between the base of the mixed layer and 1000 m was estimated. The shapes of the vertical particulate Ba profiles are very similar to those of calculated O sub(2) consumption rates, emphasizing the close link between organic matter oxidation and Ba-barite release at a mesopelagic depth. For the southern Antarctic Circumpolar Current (ACC), depth-integrated rates of O sub(2) consumption correlate significantly with primary production and mesopelagic particulate Ba concentration. For the PFZ, these relationships are subject to more speculation since this is a region of intense mixing, and the appropriate value of the turbulent diffusion coefficient is uncertain. For the ACC, the observed relationship presents the possibility of defining a transfer function between export production to the mesopelagic depth zone and mesopelagic Ba accumulation. The observed regression between rate of O sub(2) consumption and primary production in the southern ACC suggests that about 10% of the synthesized organic carbon can be oxidized in the upper 1000 m of the water column.
AN: 4092479

                                                                     185 of 313  
TI: A comparison of primary production in stream ecosystems
AU: Lamberti,-G.A.; Steinman,-A.D.
AF: Dep. Biol. Sci., Univ. Notre Dame, Notre Dame, IN 46556, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 95-104
LA: English
ER: F (Freshwater)
AB: The objective of this paper is to identify physical, chemical, and biological variables that might help explain the wide range of primary production observed in streams from a variety of biomes and locations throughout the world. We used regression approaches to search for predictive, statistical relationships that might reveal how aquatic, riparian, and watershed variables are associated with differences in primary production among 30 streams from the original data set for which primary production was measured.
AN: 4091296

                                                                     186 of 313  
TI: Solute transfer across the sediment surface of a eutrophic lake: 1. Porewater profiles from dialysis samplers
AU: Urban,-N.R.; Dinkel,-C.; Wehrli,-B.
AF: Dep. Civ. & Mineral Eng., Michigan Technol. Univ., Houghton, MI 49931, USA
SO: AQUAT.-SCI. 1997 vol. 59, no. 1, pp. 1-25
LA: English
ER: F (Freshwater)
AB: Porewater profiles often are used to identify and quantify important biogeochemical processes occurring in lake sediments. In this study, multiple porewater profiles were obtained from two eutrophic Swiss lakes using porewater equilibrators (peepers) in order to examine spatial and seasonal trends in biogeochemical processes. Variability in profile shapes and concentrations was small on spatial scales of a few meters, but the uncertainty in calculated diffusive fluxes across the sediment surface was, on average, 35%. Focusing of Fe and Mn oxides toward the lake center resulted in systematic increases in porewater concentrations and diffusive fluxes of Fe super(2+) and Mn super(2+) with increasing water depth; these fluxes are postulated to be regulated by the pH-dependent dissolution of reduced-metal phases. Despite higher concentrations of inorganic carbon, NH sub(4) super(+), Si and P in pelagic compared to littoral sites, diffusive fluxes of these substances across the sediment surface increased only slightly or not at all with increasing water depth. Porewater profiles did reveal temporal changes in Fe super(2+), Mn super(2+), Ca super(2+) and Mg super(2+) that were an indirect result of the large, seasonal changes in seston deposition, but no clear seasonal variations were found in diffusive fluxes of nutrients across the sediment surface. The intense mineralization occurring at the sediment surface was not reflected in the porewater profiles nor in the calculated diffusive fluxes. Calculated diffusive fluxes across the sediment surface resulted from decomposition occurring primarily in the top 5-7 cm of sediment. Diffusive fluxes from this subsurface mineralization were equal to the solute release from mineralization occurring at the sediment-water interface. Buried organic matter acts as a memory of previous lake conditons; it will require at least a decade before reductions in nutrient inputs to lakes fully reduce the diffusive fluxes into the lake from the buried reservoir of organic matter.
AN: 4086920

                                                                     187 of 313  
TI: Microorganisms in bottom sediments of Lake Baikal and environmental conditions.
OT: Mikroorganizmy donnykh osadkov oz. Baikal i ehkologicheskie usloviya sredy
AU: Zemskaya,-T.I.; Namsaraev,-B.B.; Parfenova,-V.V.; Khanaeva,-T.A.; Golobokova,-L.P.; Granina,-L.Z.
AF: Limnol. Inst. SO RAN, Irkutsk, Russia
SO: EHKOLOGIYA 1997 no. 1, pp. 40-44
LA: Russian
ER: F (Freshwater)
AB: The paper presents data on the abundance and distribution of microorganisms, participating in the carbon and sulphur cycles, in sediments differing in their lithological, chemical and physical characteristics. The data for 1991-1994 are comparable to those for earlier years, suggesting the stable state of microflora in bottom sediments of Lake Baikal.
AN: 4086483

                                                                     188 of 313  
TI: Empirical relationships for use in global diagenetic models
AU: Middelburg,-J.J.; Soetaert,-K.; Herman,-P.M.J.
AF: Netherlands Inst. Ecol., Cent. for Estuarine and Coastal Ecol., Vierstraat 28, 4401 EA Yerseke, The Netherlands
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 2, pp. 327-344
LA: English
ER: M (Marine)
AB: A database containing published rates of sediment and pore-water transport and biogeochemical transformations has been established to derive empirical predictive equations to calibrate and parameterize global diagenetic models. Rates of sediment accumulation, organic carbon burial, organic matter decomposition via aerobic and anaerobic pathways and bioturbation (in terms of bioturbation coefficients) can be predicted quite well using exponential relationships with water depth as an independent variable. The relationships are corrected for skewness to reduce the bias inherent in the back transformation from a lognormal to an arithmetic estimate. Bioturbation is shown to be the dominant mode of sediment transport in the upper centimeters of oceanic sediments. The derived empirical relationships are combined with bathymetric maps to estimate globally integrated rates of benthic processes. Ocean margin sediments account for about 85% of the materials accumulating in the ocean and about 80-90% of the mineralization in marine sediments.
AN: 4083807

                                                                     189 of 313  
TI: Sediment-water exchange of nitrogen compounds and oxygen in the North Sea
AU: Lohse,-L.
SO: ANNU.-REP.-NETH.-INST.-SEA-RES. 1996 pp. 32-34
LA: English
AB: On a global scale, the importance of continental margins in biogeochemical cycles is large, despite the relatively small area they occupy. Although their area comprises only 8% of the ocean, between 18% and 33% of the global primary production takes place on the shelves. The shallow depth of continental shelf seas ensures that a substantial part of the primary production reaches the sea floor. There, intensive chemical and biological processes modify the composition of the organic material settled. The degradation of particulate organic matter produces a variety of dissolved organic and inorganic compounds, which may be further mineralised, sorbed to the sediment matrix, or diffuse out of the sediment. The current debate focusses on the question whether benthic processes along the continental margin can affect the amount of elements participating in global biogeochemical cycles. Recent literature compilations on global nitrogen fluxes revealed a pronounced imbalance of the present-day ocean. It was demonstrated that the nitrogen-loss (175 to 418) Tg N yr super(-1) strongly exceeded the nitrogen supply (90 to 293 Tg N yr super(-1)). This imbalance was primarily caused by an up-ward revision of denitrification rates in shelf-and deep-ocean sediments, which accounted for 101 and 185 Tg N yr super(-1) of the global sedimentary denitrification rate, respectively. Given the small surface area occupied by shelf sediments the validation of benthic denitrification rates as well as the associated fluxes of other inorganic nitrogen compounds is indispensable. These fluxes are subject to considerable seasonal and spatial variation, since production and deposition of biogenic material on the continental shelf affect benthic nitrogen biogeochemistry. The coupling of denitrification and nitrification received particular attention in this project, since a tight coupling between both processes may lead to a removal of fixed nitrogen from the shelf, thereby counterbalancing eutrophication effects.
AN: 4083296

                                                                     190 of 313  
TI: Biogeochemical control on the flux of trace elements from estuarine sediments: Water column oxygen concentrations and benthic infauna
AU: Riedel,-G.F.; Sanders,-J.G.; Osman,-R.W.
AF: Acad. Nat. Sci., Benedict Estuarine Res. Cent., St. Leonard, MD 20685, USA
SO: ESTUAR.-COAST.-SHELF-SCI. 1997 vol. 44, no. 1, pp. 23-38
LA: English
ER: M (Marine); B (Brackish)
AB: Trace element (arsenic, copper and manganese) fluxes between sediment and water were examined for approximately 2 months in replicated sediment/water microcosms. Treatments consisted of three oxygen levels in the water column (saturated, 10% saturation and anaerobic) and three different organism treatments (control, Macoma balthica and Nereis succinea). Both arsenic and manganese were released from the sediment in the anoxic treatment, while copper was lost from the water. With the water column either saturated or at 10% oxygen saturation, both arsenic and manganese fluxes were negligible. In contrast, copper fluxes out of the sediment increased with increasing oxygen concentrations. The effect of organisms on the trace element fluxes were greatest immediately after their introduction to the microcosms, and declined substantially thereafter. Nereis caused a substantial initial increase in manganese fluxes, but caused a negative flux (out of the water column) for arsenic. Macoma had a much smaller effect on flux than Nereis. Neither organism had a substantial effect on copper fluxes. Porewater profiles gave good predictions of arsenic and manganese fluxes in the anoxic treatment, but not in the 10% or saturated-oxygen treatments. Porewater profiles underestimated copper fluxes in the oxygenated treatments somewhat, and predicted copper flux in the opposite direction in the anoxic treatment. These results suggest that the annual cycle of anoxia in systems like Chesapeake Bay, and the resulting annual cycle of organism death and recruitment, can significantly alter the cycling of trace elements between the sediment and water column.
AN: 4082901

                                                                     191 of 313  
TI: The use of mass balance investigations in the study of the biogeochemical cycle of sulfur
AU: Evans,-H.E.; Dillon,-P.J.; Molot,-L.A.
AF: RODA Environ. Res., PO Box 447, Lakefield, Ontario K0L 2H0, Canada
SO: HYDROL.-PROCESS. 1997 vol. 11, no. 7, pp. 765-782
NT: Special issue: Geochemical mass balance.
LA: English
ER: F (Freshwater)
AB: The use of mass balances in the investigation of the biogeochemical cycle of sulfur is reviewed for three systems: 1) upland catchments, 2) wetlands, and 3) lakes. In upland catchments, the major inputs of sulfur are via wet and dry atmospheric deposition, whereas outputs or losses occur primarily through volatilization and/or runoff. In addition, sulfur may be stored in vegetation and in the forest floor. In wetlands (particularly peatlands), a large proportion of the sulfur inputs are derived from surface and groundwater originating in the upland system. Because of the fluctuating water table in wetlands, they can act as a source or sink for sulfate, depending on the redox conditions. Wetlands, therefore, can significantly affect input-output budgets for lakes. In most lakes, only a small portion of the sulfate input is retained, (i.e. not lost from the lake via outflow), indicating that there is an excess of sulfate relative to biological needs. Seepage lakes are exceptions to this generalization. Although the reactivity of the sulfate input to many lakes is low, sulfate levels, especially in regions receiving substantial atmospheric sulfur deposition, are high enough that the portion reduced results in substantial in-lake alkalinity production; in fact, in many cases, alkalinity production from sulfate reduction is greater than that resulting from not only other in-lake processes but from external sources (the catchment) as well. The importance of mass balance investigations in elucidating the biogeochemical cycling of sulfur is stressed and the need for additional studies on a whole-system basis stressed.
AN: 4080121

                                                                     192 of 313  
TI: Spatial and temporal response of stream bacteria to sources of dissolved organic carbon in a blackwater stream system
AU: Koetsier,-P.,III; McArthur,-J.V.; Leff,-L.G.
AF: Savannah River Ecology Laboratory, Division of Wetland Ecology, PO Drawer E, Aiken, SC 29802, USA
SO: FRESHWAT.-BIOL. 1997 vol. 37, no. 1, pp. 79-89
LA: English
ER: F (Freshwater)
AB: Spatial differences were examined in assemblage growth by culturing bacteria sampled along the stream continuum on gradient plates using leachates from four common riparian species (Taxodium distichum, Carya spp., Acer rubrum and Decumaria barbara). Bacteria from the lowest site were able to use all sources provided and at all concentrations, whereas bacteria from upper reaches could not. Colony density was correlated to relative leachate concentration at all sites along the continuum. Leachates from fresh and senescent A.rubrum leaves were used to determine temporal differences. Winter assemblages of bacteria could not grow on fresh leaf leachate at any concentration but grew well on autumn leaf leachate at higher concentrations. Differential response of bacterial assemblages indicated local adaptation to potential sources of dissolved organic matter. Growth response of stream bacterial colonies appeared to be dependent on the timing and source of leachate as well as on sources of dissolved organic carbon from further upstream. Growth of bacterial assemblages exhibited 'generalist' characteristics in headwater reaches and 'specialist' characteristics at the mouth of our study stream drainage.
AN: 4079152

                                                                     193 of 313  
TI: The lipid composition of the coccolithophore Emiliania huxleyi and its possible ecophysiological significance
AU: Pond,-D.W.; Harris,-R.P.
AF: Plymouth Marine Laboratory, Prospect Place, Plymouth, UK
SO: J.-MAR.-BIOL.-ASSOC.-U.K. 1996 vol. 76, no. 3, pp. 579-594
LA: English
ER: M (Marine)
AB: The lipid class and fatty acid composition of eight geographically disperse isolates of Emiliania huxleyi, grown under 12 h L:D cycles and harvested during logarithmic and stationary growth phases, were examined. Cell size and chlorophyll content tended to decrease from logarithmic to stationary growth phase. Methyl and ethyl ketones were the dominant lipid classes, although proportions exhibited no clear pattern either between strains or growth phases. Neutral lipid hardly accumulated over the course of the growth experiments, and triacylglycerol was either absent or only present at low levels. In all trains with the exception of a South African isolate, levels of total fatty acid per cell decreased markedly between logarithmic and stationary phases, primarily attributable to reductions in the levels of saturated and monounsaturated fatty acids. Major fatty acids in all strains during both growth phases were 14:0, 16:0, 18:1 (n-9), 18:4 (n-3), 18:5 (n-3) and 22:6 (n-3). Although all strains were rich in polyunsaturated fatty acids (47-72% of total fatty acids) stationary phase cultures consistently contained the highest proportions. The polyunsaturated fatty acid docosahexanoic acid (22:6, n-3) was the most abundant fatty acid in all strains, comprising a maximum of 38.4% of total fatty acids in strain M181 during stationary phase. Multivariate analysis (PCA) allowed logarithmic and stationary phase cultures to be distinguished although no obvious intra-isolate variability was apparent. The results are discussed in terms of the importance of lipids for the ecophysiology of E. huxleyi and the role of this dominant coccolithophore in the marine food chain.
AN: 4079120

                                                                     194 of 313  
TI: Freshwater outflow and Subtropical Convergence influence on phytoplankton biomass on the southern Brazilian continental shelf
AU: Ciotti,-A.M.; Odebrecht,-C.; Fillmann,-G.; Moeller,-O.O.,Jr
AF: Department of Oceanography, Dalhousie University, Halifax, N.S., Cananda
SO: CONT.-SHELF-RES. 1995 vol. 15, no. 14, pp. 1737-1756
LA: English
ER: M (Marine)
AB: The present study discusses the role of different continental shelf water masses on inorganic nutrient levels and on phytoplankton biomass along the southern Brazilian coast during October 1987 and September 1988. In this productive area, variability of phytoplankton biomass has been related to the seasonal latitudinal displacement of the Subtropical Convergence and to the freshwater outflow of La Plata River and Patos Lagoon. Very distinct precipitation rates, as a consequence of the ENSO (El Nino-Southern Oscillation) cycle, preceding the two sampled periods of this study, allowed a first evaluation of the impact of this event on freshwater outflow and shelf phytoplankton biomass. The amount of chlorophyll in shelf waters was directly related to nutrients supplied by the Coastal Water (i.e. freshwater outflow), Subtropical and Subantarctic Waters. Comparing the results of this study with previous cruises performed in the area, it was found that high chl a concentrations are common features during periods of elevated precipitation rates. Apart from nutrient input by freshwater and the consequent changes in the vertical profiles of density, the extreme precipitation rates are also associated with different wind patterns, which, in turn, control the presence of particular water masses in the euphotic zone. Our results suggest that ENSO events have an important impact on the variability of phytoplankton production, and thus should affect biogeochemical cycles in the southern Brazilian coastal areas.
AN: 4079096

                                                                     195 of 313  
TI: Intraspecific stoichiometric variability and the ratio of nitrogen to phosphorus resupplied by zooplankton
AU: Carrillo,-P.; Reche,-I.; Cruz-Pizarro,-L.
AF: Departamento de Biologia Animal y Ecologia, Facultad de Ciencias, 18071 Granada, Spain
SO: FRESHWAT.-BIOL. 1996 vol. 36, no. 2, pp. 363-374
LA: English
ER: F (Freshwater)
AB: An in situ experiment was carried out in a high-mountain oligotrophic lake to quantify the specific release rates of ammonium and phosphorus in different phases of the seasonal succession of plankton. The zooplankton community was dominated by the calanoid copepod Mixodiaptomus laciniatus. The rates of release of N and P and the N:P released ratio fell within the range typical of oligotrophic lakes dominated by copepodite assemblages. The values of the zooplankton N:P ratio (5:1 to 10:1 by weight) were lower than those established for other species of calanoids, and followed a well-established pattern of seasonal variation from year to year with higher values after ice thaw and lower values as individual size increased. The elemental composition of the zooplankton depended on individual size while the released N:P ratio was inversely related to the N:P ration of the food. A feedback regulation was established between the stoichiometric composition of the zooplankton, their food and the released N:P ratio that can help explain changes in pelagic community structure during the ice-free period.
AN: 4078980

                                                                     196 of 313  
TI: Spatial and temporal variation of microbial respiration rates in a blackwater stream
AU: Fuss,-C.L.; Smock,-L.A.
AF: Department of Biology, Virginia Commonwealth University, Richmond, VA 23284-2012, USA
SO: FRESHWAT.-BIOL. 1996 vol. 36, no. 2, pp. 339-349
LA: English
ER: F (Freshwater)
AB: The extent of spatial and temporal variation of microbial respiration was determined in a first-order, sand-bottomed, blackwater stream on the coastal plain of south-eastern Virginia, U.S.A. Annual mean respiration rates (as g O sub(2) m super(-3) h super(-1)) differed significantly among substrata: Leaf litter, 12.9; woody debris, 2.4; surface sediment, 0.8; hyporheic sediment, 0.4; water column, 0.003. Rates associated with wood were higher than those with leaves when expressed per unit surface area. Highest respiration rates on leaves, wood and in the water column occurred during the summer, whereas rates in the sediments, were greatest during the late autumn and winter. Water temperature, as well as particulate organic matter and nitrogen content of the substrata, was correlated positively with respiration rates. Seventy per cent of respiration in the stream occurred in the hyporheic zone, 8-13% occurred in the surface sediment, leaf litter or woody debris, and less than 1% in the water column. Approximately 16% of total detritus, or 40% of non-woody detritus, stored in the stream during the year was lost to microbial respiration.
AN: 4078978

                                                                     197 of 313  
TI: Absence or masking of metabolic fractionations of  super(13)C in a freshwater benthic food web
AU: France,-R.L.
AF: Department of Biology, McGill University, 1205 Ave. Dr Penfield, Montreal, Quebec H3A 1B1, Canada
SO: FRESHWAT.-BIOL. 1996 vol. 36, no. 1, pp. 1-6
LA: English
ER: F (Freshwater)
AB: Although marine research has indicated that metabolic fractionations of  super(13)C due to differences in organismal trophic position and proximal composition can complicate the isotopic interpretation of energy flow pathways, such potentially confounding problems have never been examined in freshwater benthic food webs. The  delta  super(13)C values of animals comprising a littoral benthic food web composited from four Canadian Shield lakes showed no relation with either individual trophic position ( delta  super(15)N) or lipid content (C/N ratios). Differences in the relative incorporation of autochthonous and allochthonous energy sources by freshwater benthic organisms will alter their  delta  super(13)C and  delta  super(15)N values, thereby masking any possibility of observing  super(13)C enrichment.
AN: 4078953

                                                                     198 of 313  
TI: Spatial and temporal variability of benthic silica fluxes in the southeastern North Sea
AU: Gehlen,-M.; Malschaert,-H.; Van-Raaphorst,-W.R.
AF: Centre des Faibles Radioactivites, CNRS-CEA, Av. de la Terrasse, F-91190 Gif sur Yvette, France
SO: CONT.-SHELF-RES. 1995 vol. 15, no. 13, pp. 1675-1696
LA: English
ER: M (Marine)
AB: Sediment-water exchange fluxes and pore water profiles of Si(OH) sub(4) were determined in August 1991 and February 1992 for a total of 16 stations located along the northeastward transport path of organic matter in the North Sea. The shape of Si(OH) sub(4) profiles indicated that at several stations mass transport is controlled by turbulent diffusion induced by wave and current mixing in the upper, perturbated centimetres of the sedimentary column. The spatial distribution of silica effluxes clearly reflected the depositional environment, with highest exchange rates linked to areas of recent deposition. Outside the main deposition areas, transient deposition of fresh planktonic material is a key process in explaining observed silica effluxes. The temporal variability of silica effluxes followed the annual cycle of pelagic primary production. During August 1991, measured fluxes ranged from 0.18 to 8.90 mmoles Si m super(-2) day super(-1). Fluxes obtained during February 1992 were decreased by a factor between 2 and 8. Fluxes measured before and after inactivation of fauna with N sub(2)-flushing permitted an estimation of the bioirrigation to be made. The latter accounted for an enhancement of solute exchange ranging from 1.1 to 3.4.
AN: 4078931

                                                                     199 of 313  
TI: Decomposition and recycling of organic matter in muds of the Gulf of Papua, northern Coral Sea
AU: Alongi,-D.M.
AF: Australian Institute of Marine Science, PMB No.3, Townsville M.C., Queensland 4810, Australia
SO: CONT.-SHELF-RES. 1995 vol. 15, no. 11-12, pp. 1319-1337
LA: English
ER: M (Marine)
AB: Most sediment and organic material transported from rivers of southern Papua New Guinea enters into the Gulf of Papua, depositing on the inner shelf as either laminated or bioturbated, silt-dominated mud. These facies are the major trawling grounds for a growing penaeid prawn fishery. In contrast to most other terrigenous shelf deposits, decomposition processes in the upper 20 cm of these Papuan silts are apparently dominated by oxic and suboxic diagenesis. Rates of surface oxygen consumption were high (mean = 26.9; range = 17.8-46.8 mmol O sub(2) m super(-2) d super(-1)) as were bacterial numbers (range: 1-4 x 10 super(10) cells g super(-1) DW) and rates of bacterial carbon production (tritiated thymidine uptake; range; 3-10 gCm super(-2) d super(-1)). Rates of sulfate reduction were low (range: 3.6-6.8 mmol S m super(-2) d super(-1)) with little (18-25%) of the total reduced  super(35)SO sub(4) recovered as acid-volatile sulfide. Free sulfides were not detected in porewaters. Total solid-phase S concentrations were low (0.15-0.20% DW) indicating low net S precipitation in the upper 20 cm. Concentrations of dissolved Fe and Mn were elevated in porewaters in the laminated silts. Solid-phase Fe concentrations were moderately high (range: 4.6-5.3% DW) and measured dissolved metal and nutrient fluxes suggest active Fe and Mn reduction (at some stations) and generally high turnover of the porewater N pools. The domination of oxidants other than sulphate and probable C limitation in these moderately Fe-rich silts, results in a S/C signature comparable to freshwater sediments. These diagenetic patterns are reminiscent of those measured in muds on the Amazon shelf and may similarly be attributed to dilution of reactive organic matter combined with intense physical reworking and/or bioturbation, promoting oxidant recharge and favoring decomposition processes other than sulfate reduction. Rapid rates of detrital decomposition lead to fast rates of benthic nutrient release that contribute, on average, 71% and 35% of the daily N and P requirements of shelf phytoplankton production. This close benthic-pelagic coupling may serve to maintain the penaeid prawn fishery in the Gulf of Papua.
AN: 4078889

                                                                     200 of 313  
TI: A preliminary study of carbon system in the East China Sea
AU: Tsunogai,-Shizuo; Watanabe,-Shuichi; Nakamura,-Junya; Ono,-Tsuneo; Sato,-Tetsuro
AF: Lab. Mar. and Atmospheric Geochem., Grad. Sch. Environ. Earth Sci., Hokkaido Univ, Sapporo, Hokkaido 060, Japan
SO: J.-OCEANOGR. 1997 vol. 53, no. 1, pp. 9-17
LA: English
ER: M (Marine)
AB: In the central part of the East China Sea, the activity of CO sub(2) in the surface water and total carbonate, pH and alkalinity in the water column were determined in winter and autumn of 1993. The activity of CO sub(2) in the continental shelf water was about 50 ppm lower than that of surface air. This decrease corresponds to the absorption of about 40 gC/m super(2)/yr of atmospheric CO sub(2) in the coastal zone or 1 GtC/yr in the global continental shelf, if this rate is applicable to entire coastal seas. The normalized total carbonate contents were higher in the water near the coast and near the bottom. This increase toward the bottom may be due to the organic matter deposited on the bottom. This conclusion is supported by the distribution of pH. The normalized alkalinity distribution also showed higher values in the near-coast water, but in the surface water, indicating the supply of bicarbonate from river water. The residence time of the East China Sea water, including the Yellow Sea water, has been calculated to be about 0.8 yr from the excess alkalinity and the alkalinity input. Using this residence time and the excess carbonate, we can estimate that the amount of dissolved carbonate transported from the coastal zone to the oceanic basin is about 70 gC/m super(2)/yr or 2 GtC/yr/area-of-global-continental-shelf. This also means that the rivers transport carbon to the oceans at a rate of 30 gC/m super(2)/yr of the coastal sea or 0.8 GtC/yr/area-of-global shelf, the carbon consisting of dissolved inorganic carbonate and terrestrial organic carbon decomposed on the continental shelf.
AN: 4078732

                                                                     201 of 313  
TI: Dynamics of millenary organic deposits resulting from the growth of the Mediterranean seagrass Posidonia oceanica
AU: Mateo,-M.A.; Romero,-J.; Perez,-M.; Littler,-M.M.; Littler,-D.S.
AF: Netherlands Inst. Ecol., Vierstraat 28, 4401 EA Yerseke, The Netherlands
SO: ESTUAR.-COAST.-SHELF-SCI. 1997 vol. 44, no. 1, pp. 103-110
LA: English
ER: M (Marine); B (Brackish)
AB: The Mediterranean seagrass Posidonia oceanica accumulates large quantities of organic debris as roots, rhizomes and leaf sheaths are progressively buried forming a bioconstruction called 'matte'. The organic material remains with little morphological alteration for millennia. Several strata from these accumulations in various P. oceanica meadows were sampled. Radiocarbon dating of samples yielded a range of 0-3370 years before present. From these data, accretion rates averaging 0.175 cm year super(-1) (range: 0.061-0.414) were inferred. Significant differences between sites were found. Accretion rates showed significant differences between matte strata (i.e. with time), but no defined patterns were appreciated. Such differences were not coherent across sites. It is concluded that accretion rates are mainly controlled by local factors. Analysis of carbon, nitrogen and phosphorous in the organic debris showed that there was not a net release during the process of matte construction; in some sites, nitrogen and phosphorus concentration remained constant throughout the matte profile, while in the other sites, their concentration increased significantly with age. This confirms the role of P. oceanica meadows as sinks for biogenic elements.
AN: 4075947

                                                                     202 of 313  
TI: Stoichiometry of some marine planktonic crustaceans
AU: Gismervik,-I.
AF: Univ. Oslo, Dep. Biol., Sect. Mar. Chem. and Mar. Zool., PO Box 1064, Blindern, N-0316 Oslo, Norway
SO: J.-PLANKTON-RES. 1997 vol. 19, no. 2, pp. 279-285
LA: English
ER: M (Marine)
AB: Atomic C:N ratios in calanoid copepods were generally below the Redfield ratio (6.6), except for the fifth copepodid stage of Calanus sp. The C:P ratios in copepods were generally close to, or higher than the Redfield ratio of 106, but low C:P ratios were found in Acartia clausi (63  plus or minus  7) and in the cladocerans (Podon sp.: 34  plus or minus  5 and Evadne sp.: 59  plus or minus  22).
AN: 4075939

                                                                     203 of 313  
TI: A regional analysis of the physical characteristics of streams
AU: Webster,-J.R.; D'-Angelo,-D.J.
AF: Dep. Biol., Virginia Polytechnic Inst. and State Univ., Blacksburg, VA 24061, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 87-95
LA: English
ER: F (Freshwater)
AB: Physical characteristics of streams are determined by complex interactions between climate and geology, often indirectly mediated by vegetation. These characteristics vary considerably among regions of the world. For example, Wolman and Gerson suggested that stream geomorphology is driven by the frequency of extreme events and the timing and capacity for recovery. In temperate regions, extreme storms and floods that scour and widen the stream channel typically occur at 50- to 200-y intervals. Time between events may therefore be long enough for stream flow, vegetation, and hillslope slumps to return the channel to pre-storm widths. In contrast, arid regions experience severe flooding more frequently. With little time between floods, slow vegetation growth, and often no flow at all between floods, these arid land channels tend to widen to a greater extent than streams in temperate regions. Interactions of climate and geology with their effects on vegetation and physical stream characteristics are the prime determinants of organic processes occurring in streams. In this chapter we describe and compare 8 physical characteristics of the 35 streams described in the preceding chapters. Because of the limited geographic extent of the streams, this analysis is not a comprehensive treatment of the physical characteristics of streams. The primary purpose of this paper is to provide a background for the analyses of organic matter processes presented in subsequent chapters.
AN: 4071916

                                                                     204 of 313  
TI: Organic matter dynamics in Buzzards Branch, a blackwater stream in Virginia, USA
AU: Smock,-L.A.
AF: Dep. Biol., Virginia Commonwealth Univ., Richmond, VA 23284, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 54-58
LA: English
ER: F (Freshwater)
AB: Buzzards Branch is a 1st-order blackwater stream in Surry County, Virginia, USA (37 degree 05'N, 77 degree 03'W). The stream is a tributary of Otterdam Swamp Creek, which is part of the Blackwater River system in the Coastal Plain physiographic province of southeastern Virginia. The stream has characteristics typical of many streams throughout the southeastern Coastal Plain, including low gradient, loose sand sediment, and a well-developed flood plain in its lower reach.
AN: 4071613

                                                                     205 of 313  
TI: Organic matter dynamics in Keppel Creek, southeastern Australia
AU: Treadwell,-S.A.; Campbell,-I.C.; Edwards,-R.T.
AF: Dep. Ecol. and Evolution. Biol., Monash Univ., Clayton, Vic. 3168 Australia
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 58-61
LA: English
ER: F (Freshwater)
AB: Keppel Creek is a 4th-order stream draining 1428 ha of mixed eucalypt forest in the Victorian central highlands in southeastern Australia. Elevation ranges from 400 m to 1200 m. Geology is a mix of ignimbritic rhyodocite and granodiorite and soils are deep, friable mountain loams. Annual precipitation averages 125 cm, some falling as snow, during winter, above 1000 m. Vegetation within the catchment is dominated by mountain ash (Eucalyptus regnans), one of the tallest hardwood trees in the world. Riparian vegetation comprises manna gum (E. viminalis) and messmate stringy bark (E. oblique) with an understorey of blackwood (Acacia melanoxylon), hazel pomaderris (Pomaderris aspera), blanket leaf (Bedfordia arborescens), fishbone water fern (Blechnum nudum), and soft tree fern (Dicksonia antarctica).
AN: 4071612

                                                                     206 of 313  
TI: Organic matter dynamics in the Breitenbach, Germany
AU: Marxsen,-J.; Schmidt,-H.-H.; Fiebig,-D.M.
AF: Limnologische Flussstation des Max-Planck-Instituts fuer Limnologie, D-36110 Schlitz, Germany
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 28-32
LA: English
ER: F (Freshwater)
AB: The Breitenbach is a small, unpolluted 1st-order stream in eastern Hesse (Germany) between the Vogelsberg and Rhoen mountains, 100 km northeast of Frankfurt am Main. Most of the 820-ha catchment was designated a nature reserve in 1990. Early limnological studies were conducted on the stream in the 1960s, but the main thrust of research has been carried out since 1969, when the Breitenbach became the focus of investigations at the Limnological River Station of the Max Planck Institute of Limnology (Limnologische Flussstation des Max-Planck-Instituts fuer Limnologie) in Schlitz. The stream fauna has been studied intensively since this time, and only more recently have aspects such as chemistry, hydrology, bacteria, algae, and POM and DOM dynamics been considered.
AN: 4071611

                                                                     207 of 313  
TI: Organic matter dynamics in 5 subarctic streams, Quebec, Canada
AU: Naiman,-R.J.; Link,-G.L.
AF: Sch. Fish., Box 357980, Univ. Washington, Seattle, WA 98195, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 33-39
LA: English
ER: F (Freshwater)
AB: The 5 principal sites used for these investigations are 25-40 km east of Sept-Iles, Quebec, Canada on the north shore of the Gulf of the St. Lawrence. A full account of these sites, the longitudinal trends as smaller streams coalesce into large rivers, and a summary of changes in organic carbon dynamics and community structure are described by Naiman et al. (1987). This subarctic, Precambrian Shield region is forested with typical boreal species: black and white spruce (Picea mariana and P. glauca; 47% of area), balsam fir (Abies balsamea; 44%), paper birch (Betula papyrifera), trembling aspen (Populus tremuloides), speckled alder (Alnus rugosa), and willow (Salix spp.). There is  approximately 112 cm of precipitation annually, evenly distributed throughout the year, with mean monthly values ranging from 8.0 cm in April to 10.6 cm in September and December. Precipitation occurs mostly as snow from October to April. The mean annual temperature is 1 degree C, with a growing season of 105 d (i.e., mean daily air temperature >5.6 degree C). All stream sites are ice-covered from early November to mid April. Most streams are low gradient (<1.5% slope), have high concentrations of DOC (10-15 mg/L), low concentrations of nitrogen (NO sub(3):20-43  mu g/L) and phosphorus (PO sub(4):11-29  mu g/L), and have  approximately 2100 degree-days annually ( degree C/y). There is a strong freshet in April and May when 50% of the annual discharge occurs. Minimum flows in January and February are only 3-5% of the annual maximum.
AN: 4071610

                                                                     208 of 313  
TI: Organic matter dynamics in the Kuparuk River, a tundra river in Alaska, USA
AU: Harvey,-C.J.; Peterson,-B.J.; Bowden,-W.B.; Deegan,-L.A.; Finlay,-J.C.; Hershey,-A.E.; Miller,-M.C.
AF: Ecosystems Cent., Mar. Biol. Lab., Woods Hole, MA 02543, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 18-23
LA: English
ER: F (Freshwater)
AB: The Kuparuk River originates in the foothills of the Brooks Range in northern Alaska, USA, and flows north-northeast into the Arctic Ocean, draining a total area of 8107 km super(2). Since the late 1970s, research has been conducted on the upper 24.6 km of the river (143 km super(2) drainage), from its headwaters to its intersection with the trans-Alaska pipeline and the Dalton Highway. The estimated streambed area of the upper Kuparuk watershed is 4.9 x 10 super(5) m super(2) (mainstem length x 20 m, the mean width at the lowest portion of the study reach). At the highway crossing, the Kuparuk is a 4th-order stream. At its headwaters (elevation 1250 m), the Kuparuk River drains primarily alpine communities that give way to moist tundra communities, dominated by the sedge Eriophorum vaginatum, at lower elevations. Terrestrial plant cover is minimal, with streamside patches of dwarf birches (Betula nana) and willows (Salix spp.) generally less than 1 m high. The 15-km segment of the river immediately upstream of the highway crossing is meandering, with a sinuosity (the ratio of channel length to down-valley distance). The upper Kuparuk is relatively undisturbed by human activity. The entire watershed is underlain with permafrost, which greatly reduces deep seepage.
AN: 4071609

                                                                     209 of 313  
TI: Benthic organic matter storage in streams: Influence of detrital import and export, retention mechanisms, and climate
AU: Jones,-J.B.,Jr.
AF: Dep. Biol. Sci., Univ. Nevada, Las Vegas, 4505 Maryland Pkwy., Las Vegas, NV 89154-4004, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 109-119
LA: English
ER: F (Freshwater)
AB: In lotic ecosystems, BOM is a major energy source for secondary production, influences nutrient cycles, and affects export of DOM and POM. Benthic detritus also influences channel stability and retention characteristics and provides habitat for stream microorganisms, macroinvertebrates and fish. However, in spite of the great importance of BOM to stream ecosystem function, benthic detrital storage is one of the most poorly understood components of stream organic matter budgets. In this synthesis I address questions of how BOM and the factors potentially governing storage vary over a range or spatial scales. BOM data were from streams with varying geomorphologies distributed in a range of biomes with vastly different vegetation characteristics. Data were analyzed by subdividing independent variables into 3 categories, 1) organic matter import and export rates, 2) channel characteristics, and 3) latitude and climate, to determine the best predictors of stream BOM. The results were used to assess how BOM storage is coupled to terrestrial litter production, in-stream primary production, and organic matter retention mechanisms.
AN: 4071608

                                                                     210 of 313  
TI: Large-scale trends for stream benthic respiration
AU: Sinsabaugh,-R.L.
AF: Biol. Dep., Univ. Toledo, Toledo, OH 43606, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 119-131
LA: English
ER: F (Freshwater)
AB: Carbon dioxide is the ultimate product of organic matter processing; the release of one mole of CO sub(2) through respiration represents the dissipation of about 470 kJ of energy. Within streams, benthic respiration rates are proximally controlled by the availability of electron acceptors (e.g., oxygen, nitrate), electron donors (organic matter), and inorganic nutrients. The availability of these substrates is often linked to trophic processes which, in turn, reflect local riparian and geomorphic influences and regional hydrologic and climatic patterns. The consequences of this regulatory hierarchy are that 1) spatial and temporal patterns in respiratory activity can be related to many environmental variables and 2) observed patterns are scale-dependent. Estimating system respiration at a single location requires extensive effort. When comparisons are made among sites, large-scale signals may easily be obscured by finer-scale variation. Even if large-scale patterns are detected, experimental verification of causal mechanisms is a daunting prospect. What makes the effort worth pursuing is the possibility of establishing regression models that can predict long-term continental or global responses in ecosystem process rates from disturbance scenarios. Toward that goal, I analyzed stream benthic respiration rates in relation to stored benthic organic matter, water temperature, primary production and other system variables using data collected from 35 long-term study sites.
AN: 4071607

                                                                     211 of 313  
TI: Dissolved organic matter concentration and flux in streams
AU: Mulholland,-P.J.
AF: Environ. Sci. Div., Oak Ridge Natl. Lab., P.O. Box 2008, Oak Ridge, TN 37831-6036, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 131-141
LA: English
ER: F (Freshwater)
AB: Dissolved organic matter (DOM) in streams is important as an energy resource for food webs, a regulator of nutrient uptake and cycling by heterotrophic microbes, a complexing agent for metals, and a determinant of pH and alkalinity. DOM has been shown to be an important metabolic substrate in some streams, with DOM use contributing significantly to total stream metabolism. Sources of DOM are both the terrestrial watershed and instream processes, such as leaching and decomposition of allochthonous particulate organic matter and release by stream algae. For small streams, the primary site of DOM use is the stream bottom, including the interstitial waters of streambed sediments. In large rivers, the water column may also be an important site for DOM use. In this paper, I focus on the concentrations and flux of DOM in streams whose organic matter budgets are presented in the preceding chapters. My objective is to define the variation in annual average DOM concentrations and flux and to identify what factors might be most responsible for this variation.
AN: 4071606

                                                                     212 of 313  
TI: Organic matter budgets for streams: A synthesis
AU: Webster,-J.R.; Meyer,-J.L.
AF: Dep. Biol., Virginia Polytechnic Inst. and State Univ., Blacksburg, VA 24061, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 141-161
LA: English
ER: F (Freshwater)
AB: Estimating the efficiency of ecological processes has been a goal of ecologists since publication of Lindeman's paper on Cedar Bog Lake. Many different definitions and kinds of ecological efficiencies have been determined in the ensuing years. In an analysis of ecosystem budgets, the most significant efficiency is the overall efficiency with which ecosystems use available energy. Two questions are raised by this statement: 1) How do we quantify "energy available"? and 2) How do we define energy "use"? Calculations of ecosystem efficiencies for streams are further complicated by 2 additional questions: 1) How do we deal with both allochthonous and autochthonous inputs? and 2) How are our calculations affected by the transport of organic materials through and out of streams? Our objective was to use simple organic matter budgets to provide an integrated view of stream ecosystem function.
AN: 4071605

                                                                     213 of 313  
TI: Organic matter dynamics in 3 subarctic streams of interior Alaska, USA
AU: Irons,-J.G.,III; Oswood,-M.W.
AF: Inst. Northern Forest., US Forest Serv., 308 Tanana Dr., Fairbanks, AK 99775, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 23-28
LA: English
ER: F (Freshwater)
AB: The predominant biome in interior Alaska is known as the taiga, or northern boreal forest. In these high latitude forests (about 60 degree N-67 degree N in Alaska), the angle of solar radiation with respect to the land surface is a major factor controlling ecological processes, including those relevant to organic matter dynamics in streams. Sun angle determines mean annual air temperature, which in interior Alaska is about -3.3 degree C. Temperature extremes in this continental climate can range from -50 to +35 degree C. One result of this harsh thermal regime is the presence of permafrost in the colder microclimates. Indeed, much of interior Alaska is in the zone of discontinuous permafrost, in which south-facing slopes are generally permafrost-free, and cold north-facing slopes and poorly drained valley bottoms are generally underlain by permafrost. Soil carbon densities reflect the balance between input (organic matter production) and decomposition. In the cold and often water-saturated soils common at high latitudes, decomposition is reduced and soil carbon may accumulate as peat over very long time periods. Thus there is often a positive relationship between the amount of soil organic matter and the amount of permafrost in a watershed. Permafrost affects the hydrological regimes of subarctic streams. Streams dominated by permafrost are more "flashy" than those that are relatively permafrost-free. Snowmelt runoff is later and greater in a permafrost-dominated basin than snowmelt runoff from a permafrost-free basin. Likewise, peak stormflow discharge from a permafrost-dominated basin is much higher than in a non-permafrost stream; but during rain-free periods and in winter, flow is much lower. This pattern is a result of the flow-paths of precipitation as it travels to the stream. On permafrost-dominated north-facing slopes, precipitation enters the thick organic layer and flows above the permafrost to the stream. On permafrost-free south-facing slopes, precipitation enters the groundwater and is released much more slowly to the stream. Differences in discharge result in different patterns of carbon and sediment flux from basins with differing amounts of permafrost.
AN: 4071604

                                                                     214 of 313  
TI: Comparison of litterfall input to streams
AU: Benfield,-E.F.
AF: Dep. Biol., Virginia Polytechnic Inst. and State Univ., Blacksburg, VA 24061, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 104-108
LA: English
ER: F (Freshwater)
AB: Allochthonous organic matter is an important source of energy for many streams and the major energy source for woodland streams or streams with well developed riparian corridors of vegetation. Litterfall may be defined as allochthonous material entering streams from riparian vegetation. It may include leaves and leaf fragments, floral parts, bark, wood (branches and twigs), cones and nuts, fruits, and other plant parts. Litter may reach streams by direct fall or lateral movement (blowing or sliding down the stream banks). The relative amounts of material reaching streams by these 2 routes vary considerably. The objectives of this chapter are to summarize data on direct fall and lateral movement of litter to streams that were included in the earlier site-description chapters, and to analyze whether patterns of direct litterfall to these streams might be explained.
AN: 4071603

                                                                     215 of 313  
TI: Organic matter dynamics in Bear Brook, Hubbard Brook Experimental Forest, New Hampshire, USA
AU: Findlay,-S.; Likens,-G.E.; Hedin,-L.; Fisher,-S.G.; McDowell,-W.H.
AF: Inst. Ecosystem Stud., Millbrook, NY 12545, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 43-46
LA: English
ER: F (Freshwater)
AB: Bear Brook is a 2nd-order stream at the Hubbard Brook Experimental Forest (HBEF) in the White Mountains of New Hampshire, USA. There has been extensive research on this and other tributaries to Hubbard Brook over the past 30 y and most data used in this synopsis have been published previously. The climate is relatively wet and cool with approximately 123 cm of precipitation fairly evenly distributed throughout the year. The experimental catchments at the HBEF are relatively small; the W6 catchment (upper reach of Bear Brook) is 13.2 ha. Mean annual discharge at the weir is 3.75 L/s with maximum monthly average flows ( similar to 11 L/s) in April of most years. Flow at the weir can approach zero in the period from July through September. For the purposes of this organic matter budget, the reach is from the head of the stream channel ( similar to 500 m above the weir) to the point where it discharges to the main Hubbard Brook. Catchment area at this point is 132 ha.
AN: 4071602

                                                                     216 of 313  
TI: Organic matter dynamics in White Clay Creek, Pennsylvania, USA
AU: Newbold,-J.D.; Bott,-T.L.; Kaplan,-L.A.; Sweeney,-B.W.; Vannote,-R.L.
AF: Stroud Water Res. Cent. Acad. Nat. Sci. Philadelphia, 970 Spencer Rd., Avondale, PA 19311, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 46-50
LA: English
ER: F (Freshwater)
AB: White Clay Creek drains agricultural and wooded land in the Piedmont Province of southeastern Pennsylvania and northern Delaware, joining the Christina River in Delaware near the Christina's discharge to the Delaware Bay. This chapter reports studies in a 725-ha watershed forming the headwaters of the East Branch. Elevations in the study watershed range from 100 m to 164 m. The stream draining the study watershed is 3rd order. The total length of stream channels (orders 1-3) is 12,900 m, and the total streambed area assessed at baseflow is 24,000 m super(2).
AN: 4071601

                                                                     217 of 313  
TI: Organic matter dynamics in Kings Creek, Konza Prairie, Kansas, USA
AU: Gray,-L.J.
AF: Dep. Biol., Ottawa Univ., Ottawa, KS 66067, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 50-54
LA: English
ER: F (Freshwater)
AB: The Kings Creek basin encompasses 1059 ha within the Konza Prairie Research Natural Area, a tallgrass prairie in the Flint Hills Uplands of eastern Kansas, USA. This region consists of ridges and valleys underlain by chert-bearing limestones alternating with softer shales of Permian age. Because of the relatively steep topography and rocky soils characteristic of the region, this grassland has never been plowed. Extensive fractures within the rocks result in numerous springs and seeps along the main channels. Elevation ranges from 338 m to 430 m. Konza Prairie was established as a research facility in 1972 after many years as a cattle ranch. The research area is subdivided into watersheds that are burned at varying frequencies. Overlaid on this design is a grazing experiment with blocks of watersheds designated as ungrazed, grazed by native ungulates (bison, Bos bison), and grazed by domestic cattle. Bison were reintroduced to Konza Prairie in 1987, and cattle grazing returned in 1992.
AN: 4071600

                                                                     218 of 313  
TI: Organic matter dynamics in Rattlesnake Springs, Washington, USA
AU: Cushing,-C.E.
AF: 1610 Woodbury St., Richland, WA 99352, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 39-43
LA: English
ER: F (Freshwater)
AB: The cold desert region in southeastern Washington, USA, where Rattlesnake Springs is located has been botanically characterized as a shrub-steppe. Because of the aridity, the productivity of both plants and animals is relatively low compared with other natural communities. In the early 1800s, the most abundant plant in the watershed was big sagebrush (Artemesia tridentata) with an understory of perennial bunchgrasses, especially Sandberg's bluegrass (Poa sandbergii segunda) and bluebunch wheatgrass (Agropyron spicatum). With European settlement that brought livestock grazing and crop raising, the natural vegetation mosaic was opened to a persistent invasion of alien annuals, especially cheatgrass (Bromus tectorum), which is dominant on fields that were cultivated 40 y ago. Mean annual precipitation is about 14 cm. This chapter presents data on the organic matter budget of Rattlesnake Springs, a small cold desert spring-stream. These data were collected as part of a broader study of primary productivity during 1969-1970.
AN: 4071599

                                                                     219 of 313  
TI: Organic matter dynamics in the Ogeechee River, a blackwater river in Georgia, USA
AU: Meyer,-J.L.; Benke,-A.C.; Edwards,-R.T.; Wallace,-J.B.
AF: Inst. Ecol., Univ. Georgia, Athens, GA 30602, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 82-87
LA: English
ER: F (Freshwater)
AB: The Ogeechee River is a 6th-order river in the coastal plain of Georgia, USA. Most of our studies of this blackwater river were done at a site in Effingham County (32 degree 08'N, 81 degree 25'W), 331 km from the river's source and 63 km from its mouth near Savannah. The river at the study site drains a watershed of 6860 km super(2): 5% in the Piedmont, 95% in the Coastal Plain. Human population in the watershed is primarily rural (12 persons/km super(2)) with permitted point source discharges that total 0.6% of mean annual river discharge. The watershed is primarily in agriculture with forested areas of hardwood and pine, which is extensively harvested. Watershed geology consists of sandy sediments of marine origin deposited on igneous and metamorphic rock. The Ogeechee is one of relatively few rivers of its length in North America with no major dams. There are a few mill ponds in the headwaters, but the main stem escaped damming because of its extremely low gradient (0.0002 m/m at the study site).
AN: 4071594

                                                                     220 of 313  
TI: Organic matter dynamics in Sycamore Creek, a desert stream in Arizona, USA
AU: Jones,-J.B.,Jr.; Schade,-J.D.; Fisher,-S.G.; Grimm,-N.B.
AF: Dep. Biol. Sci., Univ. Nevada-Las Vegas, 4505 Maryland Pkwy., Las Vegas, NV 89154-4004, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 78-82
LA: English
ER: F (Freshwater)
AB: Sycamore Creek is an intermittent Sonoran Desert stream in the Basin and Range Province 32 km northeast of Phoenix, Arizona, USA. The drainage basin (505 km super(2)) varies in elevation from 427 to 2164 m and is composed of igneous and metamorphic rock with shallow overlying soil and unconsolidated sediments. Precipitation in the Sycamore Creek watershed averages only 34 and 58 cm/y in lower and upper elevations, respectively, and nearly all falls as rain. Evapotranspiration is quite high (pan evaporation = 310 cm/y); consequently mean annual discharge from this 5th-order river is only 0.8 m super(3)/s, and on average only 8% of precipitation runs off. Rain at higher elevations in the watershed feeds permanent flow in lower-elevation reaches of Sycamore Creek. High-elevation precipitation recharges aquifers that drain into porous alluvium. Lower-elevation permanent reaches occur where geologic faulting brings impervious bedrock to the surface. Downstream from these "sources," surface flow may exist for a few m to several km before water seeps back into sediments.
AN: 4071593

                                                                     221 of 313  
TI: Organic matter dynamics in Hugh White Creek, Coweeta Hydrologic Laboratory, North Carolina, USA
AU: Webster,-J.R.; Meyer,-J.L.; Wallace,-J.B.; Benfield,-E.F.
AF: Dep. Biol., Virginia Polytechnic Inst. and State Univ., Blacksburg, VA 24061, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 74-78
LA: English
ER: F (Freshwater)
AB: Hugh White Creek is a 2nd-order stream at Coweeta Hydrologic Laboratory in western North Carolina, USA. The 61.1-ha watershed drained by this stream was logged in the early 1900s but has been undisturbed since it became part of the National Forest in 1923, except for the death of one of the dominant forest trees (Castanea dentata) by chestnut blight in the 1930s. The major forest trees are now oaks (Quercus spp.), hickories (Carya spp.), red maple (Acer rubrum), and yellow poplar (Liriodendron tulipifera). Streamside vegetation also has considerable birch (Betula spp.) and dense stands of rhododendron (Rhododendron maximum). The watershed has been used as a reference for hydrologic studies and except for one 3-y period has been continuously gaged since 1937. The stream has been the site of many ecological studies since being chosen as a reference for a clearcut logging experiment in 1975. In addition to measurements made on Hugh White Creek, many other streams at Coweeta have been studied by various researchers, and we have used some data from other streams in this summary. The climate at Coweeta is mild and humid. Mean monthly air temperatures range from 3 degree C (January) to 22 degree C (July). Annual precipitation is 188 cm for the watershed drained by Hugh White Creek. Rainfall occurs fairly evenly throughout the year though is somewhat less probable in autumn. On average 133 storms occur annually. Only 2-10% of annual precipitation occurs as snow.
AN: 4071592

                                                                     222 of 313  
TI: Stream organic matter inputs, storage, and export for Satellite Branch at Coweeta Hydrologic Laboratory, North Carolina, USA
AU: Wallace,-J.B.; Cuffney,-T.F.; Eggert,-S.L.; Whiles,-M.R.
AF: Dep. Entomol., Univ. Georgia, Athens, GA 30602, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 67-73
LA: English
ER: F (Freshwater)
AB: Catchment 55 (C 55) is a forested 7.5-ha area of the Coweeta Hydrologic Laboratory in western North Carolina. The stream draining C 55 has the unofficial name of Satellite Branch. The catchment was established in 1984 to serve as a reference stream for a manipulation of benthic invertebrates in a nearby stream. Most of the Coweeta Basin was logged in the early 1900s prior to purchase by the US Forest Service in 1923. Other than experimental manipulations of several catchments, the area within the Coweeta Experimental Forest has not been cut following acquisition by the Forest Service. Since the 1920s, 2 additional basin-wide disturbances have been the chestnut blight in the 1930s, which destroyed one of the major trees, Castanea dentata (Marsh.), and for 2 y (1961 and 1962) the entire Coweeta Basin was sprayed with DDT to control outbreaks of elm spanworm. Terrestrial vegetation of C 55 consists primarily of mixed hardwood forest. Rhododendron (Rhododendron maxima, L.) forms a dense riparian understory and provides year-round shading of the stream. Catchment size, gradient, discharge, and thermal regime are presented.
AN: 4071591

                                                                     223 of 313  
TI: Organic matter dynamics in the West Fork of Walker Branch, Tennessee, USA
AU: Mulholland,-P.J.
AF: Environ. Sci. Div., Oak Ridge Natl. Lab., P.O. Box 2008, Oak Ridge, TN 37831-6036, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 61-67
LA: English
ER: F (Freshwater)
AB: The West Fork of Walker Branch is a 1st-order stream on the US Department of Energy's Oak Ridge National Environmental Research Park in the Ridge and Valley Province of eastern Tennessee, USA. The 38.4-ha catchment drained by the West Fork and an adjacent 59.1-ha catchment drained by the East Fork of Walker Branch were established as research catchments in 1968 when 120 degree  V-notched weirs were installed to continuously monitor streamflow. These catchments have been undisturbed since the US government acquired the Oak Ridge Reservation in 1942. Before that time, the Walker Branch Watershed was inhabited by a few families practicing subsistence agriculture, resulting in some areas of cultivation and pasture. There is no evidence that the entire catchment was clear-cut, although all areas were cut at one time or another. In 1967 2 fires burned a total of 38% of the watershed area, with about 15% burned severely. The forest is currently dominated by oaks (Quercus spp.), hickories (Carya spp.), and red maple (Acer rubrum), with scattered pine (Pinus echinata Mill. and P. virginiana Mill.) on the ridgetops and mesophytic hardwoods (predominantly Liriodendron tulipfera L. and Fagus grandifolia Ehrh.) in protected coves and along the stream.
AN: 4071590

                                                                     224 of 313  
TI: Changes in pH in the eastern Equatorial Pacific across stage 5-6 boundary based on boron isotopes in foraminifera
AU: Sanyal,-A.; Hemming,-N.G.; Broecker,-W.S.
AF: Lamont Doherty Earth Observatory Columbia Univ., Palisades, NY, USA
SO: GLOBAL-BIOGEOCHEM.-CYCLES 1997 vol. 11, no. 1, pp. 125-133
LA: English
ER: M (Marine)
AB: Estimates of paleo-pH for the eastern equatorial Pacific Ocean across the oxygen isotopic stage 5-6 boundary have been made based on the boron isotopic composition of planktonic (Orbulina universa) and benthic (mixed species) foraminifera from core V19-28. The estimated deep ocean pH during the penultimate glacial period was about 0.3 plus or minus 0.1 pH units higher compared to the modern deep ocean. This is consistent with previously estimated deep ocean pH changes across the stage 1-2 boundary in the western equatorial Pacific and tropical Atlantic, thus arguing against the possibility that the benthic foraminifera analyzed to estimate deep ocean pH changes have been significantly affected by anomalous local environment and/or diagenesis. The estimated changes in the deep ocean carbonate chemistry require a decoupling (of several kilometers) between the saturation horizon and the lysocline during the glacial periods. Though such a decoupling could be achieved by enhanced respiration CO sub(2) driven calcite dissolution in sediments during glacial periods, it lacks support from the calcite sedimentary records. The boron isotopic compositions of planktonic foraminifera, on the other hand, indicate no significant pH change in the eastern equatorial Pacific surface ocean during the glacial-interglacial transition. This is inconsistent with an expected higher surface ocean pH during the glacial period due to lower atmospheric pCO sub(2) and is also in contrast with the previously estimated boron isotope based glacial-interglacial pH change of 0.2 plus or minus 0.1 pH units in the western equatorial Pacific and tropical Atlantic. The lack of change in eastern equatorial Pacific surface ocean pH between glacial-interglacial periods could be attributed to less nutrient utilization efficiency and/or enhanced calcite production during glacial periods. Such a decrease in nutrient utilization efficiency and/or increase in calcite production would lead to a greater disequilibrium between the pCO sub(2) of eastern equatorial Pacific surface ocean and that of the atmosphere, making this part of the ocean a greater source of CO sub(2) to the atmosphere during glacial periods compared to today.
AN: 4071171

                                                                     225 of 313  
TI: Changes in extent of phosphorus release in a shallow lake (Lake Grosser Muggelsee; Germany, Berlin) due to climatic factors and load
AU: Kleeberg,-A.; Dudel,-G.E.
AF: Technical University Cottbus, Faculty of Environmental Sciences, Seestr. 45, D-15526 Bad Saarow, Germany
SO: MAR.-GEOL. 1997 vol. 139, no. 1-4, pp. 61-75
LA: English
AB: Based upon biweekly investigations of interstitial and pelagial water parameters as well as sediment phosphorus (P) speciation, the mechanisms important for the summer P release in eutrophic Lake Grosser Muggelsee (Germany) are described. Microbial processes were the driving force of mainly anaerobic and also aerobic P release from iron, reductant-soluble and organic P-rich sediments. For 1992 and 1993, two years of very different runoff characteristics, the extent of P release was indirectly controlled by external factors, including the supply of dissolved oxygen and nitrate via inflow (high runoff), changes in land use (e.g., decreasing nitrogen fertilization), and climatic factors, and it was facilitated by wind-induced rapid changes of stratification and mixing events.
AN: 4070903

                                                                     226 of 313  
TI: Lipid distribution in surface sediments from the eastern Central Arctic Ocean
AU: Schubert,-C.J.; Stein,-R.
AF: Alfred Wegener Institute for Polar, Marine Research, Columbusstrasse, D-27568 Bremerhaven Germany
SO: MAR.-GEOL. 1997 vol. 138, no. 1-2, pp. 11-25
LA: English
AB: During the ARCTIC '91 expedition with RV "Polarstern", numerous short (multicorer) and long cores (kastenlot cores), including surface sediments, were recovered along a transect crossing the eastern part of the Arctic Ocean. In this paper we present data on the concentration and distribution of short- (C17+C19) and long-chain (C27, C29, C31) n-alkanes as well as fatty acids (16:0, 16:1, 18:0, 18:1) in the surface sediments from this transect. These compounds, among others, have been used to distinguish between autochthonous marine organic matter and allochthonous terrigenous organic matter supply. Changes in short-chain n-alkane as well as fatty acid contents of the sediments allow us to distinguish between regions characterized by higher or lower marine productivity. Organic carbon contents of the surface sediments are generally high and vary between 0.3% and 2%. In general, the high organic carbon content of the sediments is derived from a high input of terrigenous organic matter. Marine productivity in the Arctic Ocean is mainly controlled by reduced sea-ice cover which allows a higher production rate of phytoplankton. Regions with a higher marine organic matter content are the area NW of Svalbard, the Yermak Plateau, a part of the Lomonosov Ridge and Makarov Basin, and the Morris Yesup Rise. The pattern of distribution of long-chain n-alkanes in Arctic Ocean surface sediments is mainly controlled by sea-ice and/or direct transport from the adjacent shelf areas, although dilution by turbidites influences the deep basins.
AN: 4070885

                                                                     227 of 313  
TI: Terrestrial carbon storage during the past 200 years: A Monte Carlo analysis of CO sub(2) data from ice core and atmospheric measurements
AU: Bruno,-M.; Joos,-F.
AF: Physics Inst., Univ. Bern, Bern, Switzerland
SO: GLOBAL-BIOGEOCHEM.-CYCLES 1997 vol. 11, no. 1, pp. 111-124
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AN: 4070062

                                                                     228 of 313  
TI: Flux of particulate matter through copepods in the Northeast Water Polynya
AU: Daly,-K.L.
AF: Dep. Ecol. and Evolution. Biol. Univ. Tennessee, Knoxville, TN 37996, USA
CO: Northeast Water Polynya Symp., Helsingor (Denmark), 1-5 May 1995
SO: J.-MAR.-SYST. 1997 vol. 10, no. 1-4, pp. 319-342
LA: English
ER: M (Marine)
AB: Particulate organic carbon (POC) and nitrogen (PON) production by large calanoid copepods was investigated on the Northeast Greenland shelf during August 1992 and May to August 1993. Both Calanus hyperboreus and C. glacialis females, when suspended in seawater collected from the chlorophyll maximum, produced about 40 pellets per day, which contained a carbon and nitrogen content equivalent to 8% and 6% of body carbon, respectively, and 2% of body nitrogen. In experiments, the carbon:nitrogen (C:N) ratio by weight of suspended particulates, C. hyperboreus, and fecal pellets was 6.7, 7.7 and 28.5, respectively. The unusually high C:N ratio for pellets, in part, may be attributed to elevated ratios of > 20  mu m size fractions of particulate organic matter, the size fraction more common in the diet of these large copepods and the fraction dominated by diatoms according to microscopic and pigment data. The implied elevated C:N ratios of large phytoplankton cells were probably due to nitrogen deficiency, as shown by other studies in this region. In addition, female C. hyperboreus appeared to be more efficient in assimilating nitrogen than carbon, which also would have contributed to high C:N ratios in egested pellets. Unfractionated POC concentrations explained 54% of the variability in carbon egestion and 70% of the variability in nitrogen egestion in copepods, whereas copepod body content accounted for little of the variation on the short time scales of the experiments. Carbon egestion by C. hyperboreus was positively correlated with POC concentrations at the depth of the chlorophyll maximum, while nitrogen egestion was negatively correlated with PON concentrations in the euphotic zone. Estimates of potential community egestion rates for the upper water column indicate that copepods represent a major pathway of organic carbon transformation in this Arctic shelf system. On average, copepods may have ingested 45% of the primary production and egested fecal matter equivalent to 20% of the carbon and 12% of the nitrogen particulate flux sedimenting from the surface layer. However, several lines of evidence suggest that pellets were remineralized in the water column and, hence, may have contributed little organic carbon and nitrogen to the benthos.
AN: 4066126

                                                                     229 of 313  
TI: New production along 140 degree W in the Equatorial Pacific during and following the 1992 El Nino event
AU: McCarthy,-J.J.; Garside,-C.; Nevins,-J.L.; Barber,-R.T.
AF: Mus. Comparative Zool., 26 Oxford St., Harvard Univ., Cambridge, MA 02138, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1065-1093
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: This study was conducted as part of two JGOFS transects along 140 degree W between 12 degree N and 12 degree S during February-March 1992 and August-September 1992. Although its purpose was to investigate seasonal variability in nitrogenous nutrient availability and biological utilization in support of primary production, the occurrence of the 1992 El Nino during the first transect permitted us to compare El Nino and post-El Nino conditions. We had hypothesized that an El Nino-related reduction in upwelling of cold nutrient-rich water would lead to a reduction in surface nutrient concentrations and rates of new and primary production in the vicinity of the equator. However, during the height of the El Nino, NO sub(3) super(-) concentrations from 2 degree N to 7 degree S remained high enough (>2  mu mol kg super(-1)) to preclude nitrogen-limited primary production. Total nitrogen uptake rates measured 6 months after the El Nino were 2.4 times greater than those observed during the El Nino. The mean f-ratio for 2 degree N-2 degree S was slightly lower and less variable (0.06-0.13; x super(-)=0.11) during the El Nino than after (0.08-0.20; x=0.13). Over a broader meridional band (5-7 degree N to 5-8 degree S) f-ratios during the El Nino were similar to values determined in 1988, a non-El Nino year, during the same season. Significantly higher rates of new production with only a small increase in f-ratio in the period following the El Nino may constitute a more prominent feature in the ENSO cycle of equatorial biological production and export than the El Nino event per se.
AN: 4062000

                                                                     230 of 313  
TI: Particulate barium fluxes and their relationships to biological productivity
AU: Dymond,-J.; Collier,-R.
AF: Oregon State Univ., Coll. Oceanic and Atmos. Sci., Corvallis, OR 97331, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1283-1308
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: To understand better the processes that control the transport of particulate barium through the water column and its preservation in marine sediments, we measured particulate barium fluxes along an equatorial transect at 140 degree W using moored sediment traps. The fluxes of barium correlate strongly with the fluxes of organic carbon; however, this relationship is non-linear - higher carbon fluxes have proportionately less associated barium. As a result we observe spatial and temporal variations of roughly a factor of three in the barium-to-organic carbon ratio. Understanding this variability may help to define the processes that determine the geochemical behavior of Ba in the oceans. Several hypotheses that could influence the flux of Ba and its relationship to organic carbon flux have been proposed: barite formation in barium- and sulfate-enriched microenvironments formed during particle settling; lateral advection of carbon and barium from continental margins; the influence of seawater barium concentration; and Ba scavenging by aluminosilicates. Our study reveals temporal variability in the Ba/C sub(org) values that occurs over timescales of less than one month. Also, depth profiles of carbon and Ba fluxes show that the variability originates at depths less than 1200 m and is conveyed throughout the water column. Both the rapid changes and the upper water column origin of the signals point to upper-ocean biological processes as the predominant cause of the variability in the barium-to-organic carbon ratios. We also observe, however, a 25% increase in Ba flux below 1200 m. The deep sources of Ba could result from barite formation linked to continued organic carbon degradation or from lateral sources of particulate barium. Because the spatial and temporal changes in Ba/C sub(org) values correlated to changes in particulate opal and organic carbon fluxes, ocean ecology appears to have an important influence on barium fluxes. A better understanding of the processes that contribute to the particulate barium flux is needed before the accumulation of barium in marine sediments can be used as a quantitative proxy for ocean productivity.
AN: 4061994

                                                                     231 of 313  
TI: Spatial and temporal variability of total organic carbon along 140 degree W in the Equatorial Pacific Ocean in 1992
AU: Peltzer,-E.T.; Hayward,-N.A.
AF: Mar. Chem. and Geochemistry Dep., Woods Hole Oceanographic Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1155-1180
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Total organic carbon (TOC) was analyzed on four transects along 140 degree W in 1992 using a high temperature combustion/discrete injection (HTC/DI) analyzer. For two of the transects, the analyses were conducted on-board ship. Mixed-layer concentrations of organic carbon varied from about 80  mu M C at either end of the transect (12 degree N and 12 degree S) to about 60  mu M C at the equator. Total organic carbon concentrations decreased rapidly below the mixed-layer to about 38-40  mu M C at 1000 m across the transect. Little variation was observed below this depth; deep water concentrations below 2000 m were virtually monotonic at about 36  mu M C. Repeat measurements made on subsequent cruises consistently found the same concentrations at 1000 m or deeper, but substantial variations were observed in the mixed-layer and the upper water column above 400 m depth. Linear mixing models of total organic carbon versus  sigma  sub( theta ) exhibited zones of organic carbon formation and consumption. TOC was found to be inversely correlated with apparent oxygen utilization (AOU) in the region between the mixed-layer and the oxygen minimum. In the mixed-layer, TOC concentrations varied seasonally.
AN: 4061993

                                                                     232 of 313  
TI: Neutral carbohydrate geochemistry of particulate material in the Central Equatorial Pacific
AU: Hernes,-P.J.; Hedges,-J.I.; Peterson,-M.L.; Wakeham,-S.G.; Lee,-C.
AF: Sch. Oceanogr., Univ. Washington, Box 357940, Seattle, WA 98195-7940, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1181-1204
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Neutral carbohydrate compositions were determined for particulate samples from plankton net tows, shallow floating sediment traps, mid-depth and deep moored sediment traps, and sediment cores collected along a north-south transect in the central equatorial Pacific Ocean during the U.S. JGOFS EqPac program. Total neutral carbohydrate depth profiles and patterns along the transect follow essentially the same trends as bulk and organic carbon (OC) fluxes-attenuating with depth, high near the equator and decreasing poleward. OC-normalized total aldose (TCH sub(2)O) yields along the transect and with depth do not show any consistent patterns. It appears that compositional signatures of neutral carbohydrates in sediments are more dependent upon their planktonic source than on any particular diagenetic pathway. Based on weight per cent glucose, comparisons of samples between Survey I (El Nino) and Survey II (non-El Nino) indicate that during Survey I, organic material in the epipelagic zone in the northern hemisphere may have undergone more degradation than organic material in the southeastern hemisphere.
AN: 4061992

                                                                     233 of 313  
TI: Origin and maintenance of a high nitrate condition in the Equatorial Pacific
AU: Chai,-Fei; Lindley,-S.T.; Barber,-R.T.
AF: Dep. Oceanogr., Univ. Maine, Orono, ME 04469-5741, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1031-1064
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: The physical and biological causes for the equatorial nutrient anomaly were investigated using an ecosystem model embedded within an ocean general circulation model to determine the nitrate budget for the equatorial Pacific Ocean. In the 140 degree W region the effects of mixing on nitrate concentration were small compared to the effects of advection; upwelling and zonal transport to the east in the Equatorial Undercurrent were the major processes in the nitrate budget. At 140 degree W on the equator annual J sub(NO3), the total net physical supply of nitrate to the euphotic layer, was 3.76 mmol m super(-2) day super(-1); the vertical integrated (0-120 m) new production calculated from the ecosystem model was 3.36 mmol m super(-2) day super(-1) or, in carbon units, 22.26 mmol C m super(-2) day super(-1). The vertical supply of nitrate (-w partial differential NO sub(3)/ partial differential z) due to the upwelling is controlled by two factors, the vertical velocity and vertical gradient of nitrate concentration. The vertical velocity reaches the maximum during climatological fall, but the vertical gradient of nitrate is weaker in the fall. Therefore, the vertical supply of nitrate is smaller than in spring. To investigate the role of physiological limitation of phytoplankton photosynthesis and specific growth rate on the maintenance of the high nutrient-low chlorophyll (HNLC) condition, a model experiment was performed that included, unchanged from previous model runs, the physical conditions and density-dependent grazing function, but greatly reduced physiological limitations by increasing  alpha  (initial slope of P-I and curve) and P sub(max) (maximum specific growth rate) values. When this was done, vertical integrated primary production at 140 degree W on the equator doubled (from 83 to 166 mmol C m super(-2) day super(-1)), but the zooplankton grazing on the phytoplankton also doubled (from 75 to 150 mmol C m super(-2) day super(-1)). Zooplankton biomass doubled, but there was only a slight increase in phytoplankton biomass; no phytoplankton bloom formed in this model experiment. With potential physiological limitations of phytoplankton rates greatly reduced, the characteristic equatorial plume of unused surface layer nitrate still persisted; but the nitrate-rich plume was smaller in horizontal extent and the maximum concentration was reduced by half from observed concentrations. While the reduction in the extent of the nitrate-rich plume indicates that physiological limitation plays a significant role in the maintenance of the nutrient anomaly, its persistence demonstrates that physical processes and grazing also are involved.
AN: 4061973

                                                                     234 of 313  
TI: Phytodetritus at the abyssal seafloor across 10 degree  of latitude in the Central Equatorial Pacific
AU: Smith,-C.R.; Hoover,-D.J.; Doan,-S.E.; Pope,-R.H.; Demaster,-D.J.; Dobbs,-F.C.; Altabet,-M.A.
AF: Dep. Oceanogr., Univ. Hawaii, 1000 Pope Rd., Honolulu, HI 96822, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1309-1338
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Fresh phytoplankton detritus (or phytodetritus) has been reported from numerous deep seafloor sites in the temperate North Atlantic and Pacific Oceans following seasonal phytoplankton blooms. Here we report the first strong evidence for abyssal accumulations of phytodetritus in the tropics, in the central equatorial Pacific. In November-December 1992 we obtained photographs and/or sediment-core samples from 61 abyssal stations (water depths of 4280-5012 m) between 12 degree S and 9 degree N along  similar to 140 degree W. Greenish flocculent material was recovered from the top of multiple-core samples from 5 degree S to 5 degree N. Microscopic examination of greenish material recovered from core tops and a burrow lumen revealed relatively intact diatoms (including Rhizosolenia sp.) and other microalgae with chloroplasts containing chlorophyll. The greenish material was 1-12.5% organic carbon by weight, i.e. 5-39 times richer than associated seafloor sediments. We conclude that fresh, organic-rich phytodetritus was present on the seafloor from 5 degree S to 5 degree N along 140 degree W in November-December 1992, with highest concentrations within 2-3 degree  of the equator. Because the degradation rate of this material appears to be very high, its presence at the seafloor for several months per year could yield significant phytodetrital contributions to the annual seafloor organic-carbon budget.
AN: 4061972

                                                                     235 of 313  
TI: Wetland mercury research: A review with case studies
AU: Rood,-B.E.
AF: Environ. Sci. Prog., Mercer Univ., 1400 Coleman Ave., Macon, GA 31207, USA
SO: CURR.-TOPICS-WETLAND-BIOGEOCHEM. 1996 vol. 2, pp. 73-108
LA: English
ER: F (Freshwater)
AB: Interestingly, there is a paucity of information regarding the role that wetlands play in the regional and global cycles of mercury (Zillioux et al., 1993). Eugene Odum has said that "a healthy wetland is an indicator of a healthy watershed" (Oglethorpe Power Corporation, 1990). As such, there is a compelling need to: 1) evaluate the status of mercury contamination in a variety of wetland types, both impacted and unimpacted by regional anthropogenic activities, 2) examine chemical and biological transformations of mercury under the unique ambient conditions associated with wetlands, and 3) reconstruct trends of mercury accumulation in wetlands preserved in the sediment record. The goals of this literature review are to provide wetland scientists with an overview of current issues and observations regarding research of environmental mercury contamination, to identify the critical need for mercury researchers to incorporate detailed wetland studies into current research, and to overview current studies of mercury in wetlands including a case study of mercury paleoecological research in the Florida Everglades.
AN: 4060829

                                                                     236 of 313  
TI: Stream organic matter budgets
AU: Webster,-J.R.; Meyer,-J.L.-(eds.)
AF: Dep. Biol., Virginia Polytechnic Inst. and State Univ., Blacksburg, VA 24061, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 3-161
LA: English
ER: F (Freshwater)
AB: This analysis of organic matter dynamics in streams has 3 objectives: 1) to explore the relationships between physical characteristics of streams and their watersheds (climate, geomorphology) and stream organic matter dynamics using data from a broad geographic area; 2) to compare stream organic matter dynamics in a diverse array of streams in order to suggest determinants of observed patterns; and 3) to reveal deficiencies in currently available data on organic matter dynamics in streams. Streams were included in this analysis not to represent the global diversity of stream types but because organic matter data were available. In the introductory chapter we describe the kinds of data included for each stream and provide brief descriptions of previously published organic matter data for streams included in the comparative analysis but not described in individual chapters. The next 16 chapters present organic matter data for streams from North America, Europe, Australia, and Antarctica. Most of the streams represented are in the temperate zone of North America. Data presented include climate and geomorphic variables and organic matter inputs, exports, and standing crops. The chapters on individual streams are followed by 7 chapters analyzing physical features of these streams and specific components of the organic matter budgets.
AN: 4060498

                                                                     237 of 313  
TI: Canada Stream: A glacial meltwater stream in Taylor Valley, south Victoria Land, Antarctica
AU: McKnight,-D.M.; Tate,-C.M.
AF: US Geol. Surv., Water Resour. Div., 3215 Marine St., Boulder, CO 80303, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 14-17
NT: Special section: Stream organic matter budgets.
LA: English
ER: F (Freshwater)
AB: The McMurdo Dry Valleys of south Victoria Land, Antarctica, form the largest of the desert oases found along the coast of Antarctica. Although this region is an extreme cold desert, glacial meltwater streams, which flow for 6-10 wk during the austral summer, are a prominent feature of the landscape. Canada Stream is in Taylor Valley and is one of 3 major streams draining Canada Glacier. The surrounding landscape is characterized by an absence of plant life, an underlying permafrost at a depth of 0.5 m, and prominent "patterned ground" features, which are large (3-5 m across) polygonal patterns formed through freeze/thaw cycles. In contrast to the barren landscape, many of the streams contain perennial algal mats and mosses, illustrating that the presence of liquid water allows for a photosynthetically based ecosystem even under the harshest conditions. Canada Stream is one of 10 streams that flow into Lake Fryxell and is representative of 6 of those streams that have abundant algal mats for most of their length. Canada Stream has been the site of several studies of the species composition and productivity of the algal mats. Ecological and hydrologic studies of Canada Stream and 22 other streams in Taylor Valley are currently being conducted as part of the McMurdo Long-Term Ecological Research program. Most of these streams are continuously gauged, with records beginning in 1990-1993.
AN: 4059041

                                                                     238 of 313  
TI: Stream organic matter budgets -- introduction
AU: Webster,-J.R.; Meyer,-J.L.
AF: Dep. Biol., Virginia Polytechnic and State Univ., Blacksburg, VA 24061, USA
SO: J.-N.-AM.-BENTHOL.-SOC. 1997 vol. 16, no. 1, pp. 5-13
NT: Special section: Stream organic matter budgets.
LA: English
ER: F (Freshwater)
AB: Cummins et al. discussed the many problems associated with constructing a stream budget and concluded that stream ecology would not benefit from the development of budgets for numerous streams with short-term data. They noted that what was needed was determination of total stream budgets at a few selected sites with long-term data and sustained research programs. Although stream researchers continued to study organic matter dynamics over the next decade, no complete organic matter budgets were published. We observed that the information needed to construct organic matter budgets probably existed for numerous streams and that it would be useful to systematically assemble and analyze the available data to assess the current status of research on organic matter dynamics in streams and to suggest fruitful directions for future research. Consequently, we organized a workshop, which was held on 23 and 24 May 1993 prior to the NABS meeting in Calgary, Alberta. We invited individuals who we thought had data on, and interest in, organic matter dynamics in streams and encouraged them to suggest additional people who could contribute to the workshop; 57 scientists participated. At the workshop, we attempted to compile and analyze organic matter budgets for 27 streams. As a result of these discussions, we requested modified data sets for each site, and, over the next 2 y, we reanalyzed those data, sent them back to the research teams for verification and feedback, and synthesized the resulting information. This paper is the product of those efforts by many individuals. In addition to the sites represented at the workshop, we have added data from several other streams based on published information.
AN: 4059040

                                                                     239 of 313  
TI: Eukaryotic microbiota in the surface waters and sea ice of the Southern Ocean: Aspects of physiology, ecology and biodiversity in a "two-phase" ecosystem
AU: Priddle,-J.; Leakey,-R.J.G.; Archer,-S.D.; Murphy,-E.J.
AF: British Antarctic Survey, NERC, High Cross, Madingley Rd., Cambridge CB3 0ET, UK
SO: BIODIVERS.-CONSERV. 1996 vol. 5, no. 11, pp. 1473-1504
NT: Special Issue: Antarctic Microbial Diversity.
LA: English
ER: M (Marine)
AB: The Southern Ocean provides a habitat for microplankton which is strongly influenced by physical factors. Of these, one of the most important and striking is the formation of sea ice. Organisms in the ice form a unique community with specific properties and adaptations. Material and organisms are exchanged between the water column and the ice during the annual cycle, and ice is an important factor in modifying biogeochemical processes and exchange between ocean and atmosphere. The coupled system, in which a range of organisms alternate between a fluid and a solid medium, provides an interesting exercise in community ecology, and has implications for the assessment of biodiversity in understanding large-scale change.
AN: 4057772

                                                                     240 of 313  
TI: Bacterial chemotaxis and its potential role in marine dimethylsulfide production and biogeochemical sulfur cycling
AU: Zimmer-Faust,-R.K.; de-Souza,-M.P.; Yoch,-D.C.
AF: Department of Biology, University of California, Box 951606, Los Angeles, CA 90095-1606, USA
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 6, pp. 1330-1334
LA: English
ER: M (Marine)
AB: Dimethylsulfide (DMS) gas constitutes 90% of biogenic sulfur emissions from oceans and is an important agent in climate regulation. DMS in seawater arises primarily via lyase degradation of dimethylsulfoniopropionate (DMSP), an osmolyte produced in high concentrations by some marine phytoplankton. After being induced to synthesize DMSP lyase, cells of a marine bacterium (Alcaligenes strain M3A) significantly reduce their rate of change in direction and tumbling frequency, and they are attracted to DMSP at levels similar to those occurring near senescing phytoplankton cells (10 super(-7)-10 super(-6) M). In contrast, genetically identical bacteria without lyase induction are not attracted to DMSP. Combined with lyase activity, bacterial chemotaxis to DMSP could increase the rate of DMS production and therefore play a critical role in biogeochemical sulfur cycling between dissolved organic matter in seawater and the atmosphere.
AN: 4057139

                                                                     241 of 313  
TI: Bromoperoxidase and iodoperoxidase enzymes and production of halogenated methanes in marine diatom cultures
AU: Moore,-R.M.; Webb,-M.; Tokarczyk,-R.; Wever,-R.
AF: Dep. Oceanogr., Dalhousie Univ., Halifax, NS, Canada
SO: J.-GEOPHYS.-RES.-C-OCEANS 1996 vol. 101, no. C9, pp. 20,899-20,908
LA: English
ER: M (Marine)
AB: Halogenated methanes produced in the oceans are important as carriers of chlorine, bromine, and iodine into the atmosphere. There they play roles in the regulation of ozone in the stratosphere and perhaps in the Arctic troposphere at polar sunrise. While the mechanisms for the production of some polyhalogenated compounds by marine macrophytes have previously been substantially elucidated, the same has not been true in the case of marine phytoplankton. We describe laboratory experiments on the production of various brominated and iodinated compounds in cultures of marine diatoms, obtained from the Provasoli-Guillard Center for Culture of Marine Phytoplankton collections (Bigelow Laboratory for Ocean Sciences, Maine, USA; CCMP). Species examined included Nitzschia sp. (CCMP 580), Nitzschia arctica, Porosira glacialis, and two Navicula sp. (CCMP 545 and 546).
AN: 4056424

                                                                     242 of 313  
TI: The fate of marine autotrophic production
AU: Duarte,-C.M.; Cebrian,-J.
AF: Centro de Estudios Avanzados de Blanes, CSIC, Cami de Santa Barbara s/n, 17300 Blanes, Girona, Spain
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 8, pp. 1758-1766
LA: English
ER: M (Marine)
AB: The fate of photosynthetic carbon in marine ecosystems dominated by different types of primary producers was examined by compiling published reports on herbivory, autotrophic respiration, decomposition, carbon storage, and export rates as fractions of net primary production (NPP) in ecosystems dominated by different types of autotrophs (i.e. oceanic and coastal phytoplankton, microphytobenthos, coral reef algae, macroalgae, seagrasses, marsh plants, and mangroves). A large fraction (>40%) of the NPP of marine ecosystems is decomposed within the system, except for microphytobenthos (decomposition,  similar to 25% of NPP). Herbivory tends to be highest for microalgae (planktonic and benthic, >40% of NPP) and macroalgae (33.6  plus or minus  4.9% of NPP) and is somewhat less for higher plants. Microphytobenthos export on average a much higher proportion of their NPP than do other microalgal communities, whereas marine macrophytes, except marsh plants, export a substantial proportion (24.3-43.5% on average) of their NPP. The fraction of NPP stored in sediments is 4-fold greater for higher plants ( similar to 10-17% of NPP) than for algae (0.4-6% of NPP). On average,  similar to 90% of the phytoplankton NPP is used to support local heterotrophic metabolism (i.e. grazed or decomposed). This fraction is even higher in oceanic communities. Mangrove forests, and to a lesser extent seagrass meadows and macroalgal beds, produce organic carbon well in excess of the ecosystem requirements, with excess photosynthetic carbon (i.e. export rate plus storage) in these ecosystems representing  similar to 40% of NPP. Extrapolation of these results to the global ocean identifies marine angiosperms, which only contribute 4% of total ocean NPP, as major contributors of the NPP stored (30% of total ocean carbon storage) and subsequently buried in marine sediments. Consideration of burial of NPP from marine angiosperms should lead to estimates of total burial of marine NPP that exceed current estimates by 15-50%.
AN: 4055952

                                                                     243 of 313  
TI: Dynamic response of deep-sea sediments to seasonal variations: A model
AU: Soetaert,-K.; Herman,-P.M.J.; Middelburg,-J.J.
AF: Netherlands Inst. Ecol., Vierstraat 28, 4401 EA Yerseke, The Netherlands
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 8, pp. 1651-1668
LA: English
ER: M (Marine)
AB: We present a dynamic, numerical model of early diagenetic processes that can be used to examine the response of different organic carbon mineralization pathways, concentration vs. depth profiles, and the resultant fluxes to seasonally varying carbon deposition. We show that there can be substantial temporal variability in sediment-water fluxes as well as in the relative contribution of different organic carbon mineralization pathways and oxygen consumption processes in deep-sea sediments. The timing and amplitude of the sediment response are most sensitive to the reactivity of the organic matter. We show that the fluxes of dissolved substances can be approximated by assuming that these constituents are at steady state with the carbon profiles. The model is used to reconcile a time series of community oxygen consumption rates, dissolved oxygen, nitrate, ammonia, and manganese profiles, and solid-phase organic carbon profiles at a deep-sea station in the Pacific. The organic carbon that is deposited is very reactive (7.2 yr super(-1)), which causes a fast response of the sediment community to seasonal pulses in carbon flux and significant temporal variation in oxygen and nutrient fluxes. The model predicts large seasonal variations in the relative importance of oxic (48-71%), denitrification (12-17%), and anoxic (16-37%) pathways. There is also substantial variation in the pore-water profiles of oxygen, nitrate, ammonia, and other reduced substances over the seasonal cycle, indicating that seasonal variability should be taken into account when extrapolating from a single observation to yearly averaged values.
AN: 4055948

                                                                     244 of 313  
TI: Nitrification in the euphotic zone as a source for nitrite, nitrate, and nitrous oxide at Station ALOHA
AU: Dore,-J.E.; Karl,-D.M.
AF: Dep. Oceanogr., Sch. Ocean and Earth Sci. and Technol., Univ. Hawaii, Honolulu, HI 96822, USA
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 8, pp. 1619-1628
LA: English
ER: M (Marine)
AB: We measured chemoautotrophic bacterial nitrification rates in the lower euphotic zone at the North Pacific Time-series Station ALOHA using low-level chemical assays and inhibitor-sensitive radiocarbon uptake experiments. These measurements were compared with independent nitrification rate estimates based on nitrous oxide distributions, nitrate assimilation rates based on nitrate changes during an in situ incubation, and historical estimates of nitrification and nitrate assimilation from this region. Ammonium oxidation rates ranged from 1.0 to 137.4  mu mol m super(-3) d super(-1), and nitrite oxidation rates varied from undetectable to 138.0  mu mol m super(-3) d super(-1). Conservative estimates of depth-integrated euphotic zone nitrification rates from the complete three-cruise data set were 0.69 mmol m super(-2) d super(-1) for nitrite oxidation and 1.64 mmol m super(-2) d super(-1) for ammonium oxidation. The highest nitrification rates were found below the primary nitrite maximum, suggesting a significant contribution of euphotic zone ammonium oxidation to the nitrite pool below but not within this feature. A mass balance of nitrous oxide indicates that this gas is produced within the euphotic zone at a rate of 1.68-7.94  mu mol m super(-2) d super(-1). The nitrous oxide production rate provides an independent estimate of the total euphotic zone nitrification rate in the range of 0.34-1.59 mmol m super(-2) d super(-1). We estimate that the total euphotic zone nitrification rate is 47-142% of the concurrent nitrate assimilation rate, indicating that nitrification in the euphotic zone is an important source of regenerated nitrate.
AN: 4055934

                                                                     245 of 313  
TI: Wastewater discharge, seagrass decline and algal proliferation on the Cote d'Azur
AU: Chisholm,-J.R.M.; Fernex,-F.E.; Mathieu,-D.; Jaubert,-J.M.
AF: Australian Inst. Mar. Sci., PMB No. 3, Townsville MC, Queensland, Australia
SO: MAR.-POLLUT.-BULL. 1997 vol. 34, no. 2, pp. 78-84
LA: English
ER: M (Marine)
AB: The green alga, Caulerpa taxifolia, has recently proliferated in areas of the N-W Mediterranean that were previously dominated by the seagrass Posidonia oceanica. Sediments in areas of proliferation had high exoenzyme activities, NH sub(4) super(+) concentrations and production rates, but very low capacities to transform organic-N into NH sub(4) super(+) relative to the quantity of organic material available. All sediments supporting C. taxifolia contained large quantities of precipitated phosphorus and exhibited extremely low capacities to transform NH sub(4) super(+) into NO sub(2) super(-) and NO sub(3) super(-). Low transformative capacities and high phosphate concentrations are characteristic of sediments that have been polluted by urban wastewater. Where C. taxifolia did not exist, or where growth had stabilized, sediments had exoenzyme activities, NH sub(4) super(+) concentrations and NH sub(4) super(+) production rates that were proportional to organic-N transformative potential. All sediments contained significant concentrations of non-crystalline sulphide. Caulerpa taxifolia proliferation may be linked to enrichment of substrata by urban wastewater and dead or dying seagrass vegetation.
AN: 4055364

                                                                     246 of 313  
TI: Trace metals in mesozooplankton of the North Sea: Concentrations in different taxa and preliminary results on bioaccumulation in copepod collectives (Calanus finmarchicus/C. helgolandicus)
AU: Zauke,-G.-P.; Krause,-M.; Weber,-A.
AF: FB Biologie (ICBM), Carl von Ossietzky Universitaet, Postfach 2503, D-26111 Oldenburg, FRG
SO: INT.-REV.-GESAMT.-HYDROBIOL. 1996 vol. 81, no. 1, pp. 141-160
NT: Incl. bibliogr.: 56 refs.
LA: English
ER: M (Marine)
AB: Trace metals (Cd, Cu, Zn, Ph, Ni) were determined in different zooplankton taxa to assess their role in the biogeochemical cycle in the North Sea. Results of semi-static bioaccumulation experiments on board ship using collectives of Calanus finmarchicus/C. helgolandicus were in agreement with a net accumulation strategy, thus meeting an inevitable precondition for their utilization as biomonitors. Cd, Cu and Zn concentrations in field samples of zooplankton displayed a pronounced variability between taxa, with Cd ranging from 0.13 mg/kg (d.w.) in fish larvae to 51 mg/kg in hyperiid amphipods. Almost no information is available ahout metal requirements of copepods. However, most of our and worldwide reported Cu concentrations in calanoid copepods (6-22 mg/kg of enzymatic requirements of decapod crustaceans. Cd levels in Calanus collectives increased significantly from 0.68 mg/kg in the German Bight to 11 mg/kg at some station around Scotland ahove 59 degree  N, in line with literature data reported for benthic decapod crustaceans.
AN: 4053713

                                                                     247 of 313  
TI: North Pacific Ocean CO sub(2) disequilibrium for spring through summer, 1985-1989
AU: Landrum,-L.L.; Gammon,-R.H.
AF: Sch. Oceanography, Univ. Washington, Seattle, WA, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS 1996 vol. 101, no. C12, pp. 28539-28555
LA: English
ER: M (Marine)
AB: Extensive measurements of CO sub(2) fugacity in the North Pacific surface ocean and overlying atmosphere during the years 1985-1989 are synthesized and interpreted to yield a basin-wide estimate of  Delta fCO sub(2). The observations, taken from February through early September, suggest that the subtropical and subarctic North Pacific is a small sink for atmospheric CO sub(2) (0.07 to 0.2 Gton C (half year) for the region north of 15 degree N). Objective analysis techniques are used to estimate uncertainty fields resulting from constructing basin-wide contours of oceanic fCO sub(2) on the basis of individual cruise transects. The uncertainties are significant and imply that future sampling programs need to recognize that estimating oceanic uptake of anthropogenic CO sub(2) from ship-transect observations of oceanic fCO sub(2) alone will require very extensive sampling.
AN: 4052810

                                                                     248 of 313  
TI: Biogeochemical tracers of the marine cyanobacterium Trichodesmium
AU: Carpenter,-E.J.; Harvey,-H.R.; Fry,-B.; Capone,-D.G.
AF: Mar. Sci. Res. Cent., State Univ. New York, Stony Brook, New York, NY 11794-5000, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 1, pp. 27-38
LA: English
ER: M (Marine)
AB: We examined the utility of several biogeochemical tracers for following the fate of the planktonic diazotrophic cyanobacterium Trichodesmium in the sea. The presence of a (C sub(10)) fatty acid previously reported was observed in a culture of Trichodesmium but was not found in natural samples. This cyanobacterium had high concentrations of C sub(14) and C sub(16) acids, with lesser amounts of several saturated and unsaturated C sub(18) fatty acids. This composition was similar to that of other marine cyanobacteria. The major hydrocarbon identified was the C sub(17) n-alkane, which was present in all samples from the five stations examined. Sterols common to algae and copepods were observed in many samples along with hopanoids representative of bacteria, suggesting a varied community structure in colonies collected from different stations. We found no unique taxonomic marker of Trichodesmium among the sterols. Measurements of the  delta  super(15)N and  delta  super(13)C in Trichodesmium samples from the SW Sargasso and NW Caribbean Seas averaged -0.4ppt (range from -0.7 to -0.25ppt) and -12.9ppt (range from -15.2 to -11.9ppt), respectively, thus confirming previous observations that this cyanobacterial diazotroph has both the lowest  delta  super(15)N and highest  delta  super(13)C of any marine phytoplankter observed to date. A culture of Trichodesmium grown under diazotrophic conditions had a  delta  super(15)N between -1.3 and -3.6ppt. Our results support the supposition that the relatively low  delta  super(15)N and high  delta  super(13)C values observed in suspended and sediment-trapped material from some tropical and subtropical seas result from substantial input of C and N by Trichodesmium.
AN: 4051874

                                                                     249 of 313  
TI: Relationship between Minjiang River Estuary trace metals and nutrients
AU: Zou,-Dong-liang; Gao,-Shu-ying
AF: Dep. Oceanogr., Inst. Subtropical Oceanology, Xiamen Univ., Xiamen 361005, People's Rep. China
SO: CHIN.-J.-OCEANOL.-LIMNOL. 1996 vol. 14, no. 3, pp. 261-265
LA: English
ER: B (Brackish)
AB: This study on the relationships between dissolved Cd, Cu, Pb and nutrients in the Minjiang River Estuary during high and low discharges (in June and Oct., 1990) showed that during both high and low discharges Cd, Cu and Pb exhibited additive, conservative and removal behaviour, respectively. Cd increase appeared to be primarily related to Cd regeneration from microplankton and its organic remains, while Pb removal was dominated by abiotic processes.
AN: 4051197

                                                                     250 of 313  
TI: A vertical distribution model of nutrients and dissolved oxygen in the southern Taiwan Strait
AU: Shang,-Shao-ling; Hong,-Hua-sheng
AF: Environ. Sci. Res. Cent., Xiamen Univ., Xiamen 361005, People's Rep. China
SO: CHIN.-J.-OCEANOL.-LIMNOL. 1995 vol. 13, no. 1, pp. 51-61
LA: English
ER: M (Marine)
AB: Since vertical transport of nutrients and dissolved oxygen are quite important in the water column and have drawn serious attention these recent years, a one-dimension numerical model is tried to simulate the vertical distribution of nutrients and dissolved oxygen in June at two research sites in the southern Taiwan Strait. Physical transport parameters are calibrated by temperature simulation, and then are used to simulate the profiles of NO sub(3), PO sub(4) and dissolved oxygen. The simulation was generally successful for both stations. The importance of various factors, such as upwelling, tidal current and biogeochemical activities, which influence the vertical distribution of nutrients and dissolved oxygen, is revealed by analysis of the modeling results. Some important rates, fluxes and ratios are also estimated and discussed on the basis of simulation.
AN: 4051193

                                                                     251 of 313  
TI: Trichodesmium, a globally significant marine cyanobacterium
AU: Capone,-D.G.; Zehr,-J.P.; Paerl,-H.W.; Bergman,-B.; Carpenter,-E.J.
AF: Chesapeake Biol. Lab., Cent. Environ. and Estuarine Stud., Univ. Maryland, Solomons, MD 20688, USA
SO: SCIENCE-WASH. 1997 vol. 276, no. 5316, pp. 1221-1229
LA: English
ER: M (Marine)
AB: Planktonic marine cyanobacteria of the genus Trichodesmium occur throughout the oligotropic tropical and subtropical oceans. Their unusual adaptations, from the molecular to the macroscopic level, contribute to their ecological success and biogeochemical importance. Trichodesmium fixes nitrogen gas (N sub(2)) under fully aerobic conditions while photosynthetically evolving oxygen. Its temporal pattern of N sub(2) fixation results from an endogenous daily cycle that confines N sub(2) fixation to daylight hours. Trichodesmium colonies provide a unique pelagic habitat that supports a complex assemblage of consortial organisms. These colonies often represent a large fraction of the plant biomass in tropical, oligotropic waters and contribute substantially to primary production. N sub(2) fixation by Trichodesmium is likely a major input to the marine and global nitrogen cycle.
AN: 4049443

                                                                     252 of 313  
TI: super(15)N evidence for the origin and cycling of inorganic nitrogen in a small Amazonian catchment
AU: Brandes,-J.A.; McClain,-M.E.; Pimentel,-T.P.
AF: Univ. Washington, Sch. Oceanogr., Box 357940, Seattle, WA 98195-7940, USA
SO: BIOGEOCHEMISTRY 1996 vol. 34, no. 1, pp. 45-56
LA: English
ER: F (Freshwater)
AB: The  delta  super(15)N composition of the dominant form of dissolved inorganic nitrogen (DIN) was determined in upland groundwater, riparian groundwater, and stream water of the Barro Branco catchment, Amazonas, Brazil. The  delta  super(15)N composition of organic nitrogen in riparian and upland leaf litter was also determined. The data for these waters could be divided into three groups: upland groundwater DIN predominately composed of NO sub(3) super(-) with  delta  super(15)N values averaging 6.25  plus or minus  0.9ppt; riparian groundwater DIN primarily composed of NH sub(4) super(+) with  delta  super(15)N values averaging 9.17  plus or minus  1.0ppt, and stream water DIN predominately composed of NO sub(3) super(-) with  delta  super(15)N values averaging 4.52  plus or minus  0.8ppt. Nitrate samples taken from the stream source and from the stream adjacent to the groundwater transects showed a downstream increase in  delta  super(15)N from 1.0ppt to 4.5ppt. Leaf litter samples averaged 3.5  plus or minus  1.2ppt. The observed patterns in isotopic composition, together with previously observed inorganic nitrogen species and concentration shifts between upland, riparian and stream waters, suggest that groundwater DIN is not the primary source of DIN to the stream. Instead, the isotopic data suggest that remineralization of organic nitrogen within the stream itself may be a major source of stream DIN, and that the majority of DIN entering the stream via groundwater flowpaths is removed at the riparian-stream interface.
AN: 4048129

                                                                     253 of 313  
TI: Nitrate reduction in sediments of lowland tropical streams draining swamp forest in Costa Rica: An ecosystem perspective
AU: Duff,-J.H.; Pringle,-C.M.; Triska,-F.J.
AF: U.S. Geol. Surv., Water Resour. Div., Mail Stop 496, 345 Middlefield Rd., Menlo Park, CA 94025-3591, USA
SO: BIOGEOCHEMISTRY 1996 vol. 33, no. 3, pp. 179-196
LA: English
ER: F (Freshwater)
AB: Nitrate reduction and denitrification were measured in swamp forest streams draining lowland rain forest on Costa Rica's Atlantic slope foothills using the C sub(2)H sub(2)-block assay and sediment-water nutrient fluxes. Denitrification assays using the C sub(2)H sub(2)-block technique indicated that the full suite of denitrifying enzymes were present in the sediment but that only a small fraction of the functional activity could be expressed without adding NO sub(3) super(-). Under optimal conditions, denitrification enzyme activity averaged 15 nmoles cm super(-3) sediment h super(-1). Areal NO sub(3) super(-) reduction rates measured from NO sub(3) super(-) loss in the overlying water of sediment-water flux chambers ranged from 65 to 470 umoles m super(-2) h super(-1). Oxygen loss rates accompanying NO sub(3) super(-) depletion averaged 750 umoles m super(-2) h super(-1). Corrected for denitrification of NO sub(3) super(-) oxidized from NH sub(4) super(+) in the sediment, gross NO sub(3) super(-) reduction rates increase by 130 umoles m super(-2) h super(-1), indicating nitrification may be the predominant source of NO sub(3) super(-) for NO sub(3) super(-) reduction in swamp forest stream sediments. Under field conditions approximately 80% of the increase in inorganic N mass along a 1250-m reach of the Salto River was in the form of NO sub(3) super(-) with the balance NH sub(4) super(+). Scrutiny of potential inorganic N sources suggested that mineralized N released from the streambed was a major source of the inorganic N increase. Despite significant NO sub(3) super(-) reduction potential, swamp forest stream sediments appear to be a source of inorganic N to downstream communities.
AN: 4048128

                                                                     254 of 313  
TI: Chemical fluxes on the sediment-water interface: Direct measurements
AU: Rozanov,-A.G.
AF: P.P. Shirshov Inst. Oceanol., Russian Acad. Sci., Russia
CO: 30. Int. Geological Congress, Beijing (China), 4-14 Aug 1996
SO: ABSTRACTS-OF-PAPERS-PRESENTED-AT-THE-30TH-INTERNATIONAL-GEOLOGICAL-CONGRESS. 1996 vol. 1, p. 28
NT: Volume 1 of 3.
LA: English
ER: M (Marine)
AB: Concentrations of many dissolved chemical components are drastically changed in vicinity of the surface and in the top layers of marine sediments as a result of postsedimentation processes mediated chemically and biochemically. Chemical diffusion as well as physical (waves, tides, currents, fluxes) and biological treatment (bioturbation, bioirrigation) are responsible for chemical fluxes being generated between the bottom water and the sediment. Studies of the pore water composition do not give full estimates of the chemical exchange on the water-sediment interface but are very fruitful when combined with direct flux measurements i.g. with benthic chamber method. In this case both diagenetic processes within the upper sediment and processes on the sediment surface are taken into account. In benthic chamber experiments carried out on the shelf area of the Black, Azov and Baltic Seas the methods of measurements and result processing gave not only the values of fluxes of dissolved components but also such parameters as thickness of the diffusion sublayer, depth of penetration into the sediment (for oxygen), orders of the reactions etc. Experimental method was offered to correct the data obtained in closed system (benthic chambers) for the open water-sediment system. The values of oxygen consumption by the sediment vary from 1 to 200 mM m super(-2) day super(-1), the fluxes of nutrients from the sediment amounts to 1 for HPO sub(4) super(2-), 20 for SiO sub(4) super(4-), 40 for NH sub(4) super(+), 400 mM m super(-2) day super(-1) for HCO sub(3) super(-). In some cases directions of the fluxes can be opposite (HPO sub(4) super(2-), NH sub(4) super(+)). Chemical exchange on the water-sediment interface in a global scale is still not very certain, but this is evidently important for regional biogeochemical cycles i.g. in marginal parts of the ocean. (DBO)
AN: 4048083

                                                                     255 of 313  
TI: Evolution of the nitrogen cycle and its influence on the biological sequestration of CO sub(2) in the ocean
AU: Falkowski,-P.G.
AF: Oceanogr. and Atmos. Sci. Div., Brookhaven Natl. Lab., Upton, NY 11973, USA
SO: NATURE 1997 vol. 387, no. 6630, pp. 272-275
LA: English
ER: M (Marine)
AB: Over geological time, photosynthetic carbon fixation in the oceans has exceeded respiratory oxidation of organic carbon. The imbalance between the two processes has resulted in the simultaneous accumulation of oxygen in, and drawdown of carbon dioxide from, the Earth's atmosphere, and the burial of organic carbon in marine sediments. It is generally assumed that these processes are limited by the availability of phosphorus, which is supplied by continental weathering and fluvial discharge. Over the past two million years, decreases in atmospheric carbon dioxide concentrations during glacial periods correlate with increases in the export of organic carbon from surface waters to the marine sediments, but variations in phosphorus fluxes appear to have been too small to account for these changes. Consequently, it has been assumed that total oceanic primary productivity remained relatively constant during glacial-to-interglacial transitions, although the fraction of this productivity exported to the sediments somehow increased during glacial periods. Here I present an analysis of the evolution of biogeochemical cycles which suggests that fixed nitrogen, not phosphorus, limits primary productivity on geological timescales. Small variations in the ratio of nitrogen fixation to denitrification can significantly change atmospheric carbon dioxide concentrations on glacial-to-interglacial timescales. The ratio of these two processes appears to be determined by the oxidation state of the ocean and the supply of trace elements, especially iron.
AN: 4043833

                                                                     256 of 313  
TI: The short-term fate of fresh algal carbon in continental slope sediments
AU: Blair,-N.E.; Levin,-L.A.; DeMaster,-D.J.; Plaia,-G.
AF: Dep. Mar., Earth and Atmos. Sci., North Carolina State Univ., Raleigh, NC 27695-8208, USA
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 6, pp. 1208-1219
LA: English
ER: M (Marine)
AB: Emplacement of a tracer mixture containing  super(13)C-labeled green algae on the sea floor of the continental slope offshore of Cape Hatteras, North Carolina, elicited a rapid response over 1.5 d from the dense benthic community. Certain deposit-feeding annelids (e.g. Scalibregma inflatum and Aricidea quadrilobata) became heavily labeled with  super(13)C as a result of ingestion of the algae.  super(13)C-labeled organic matter was transported to a depth of at least 4-5 cm into the seabed during the 1.5-d period, presumably as a consequence of a feeding-associated activity. Nonlocal transport produced subsurface peaks in organic  super(13)C at 2-3 cm. Dissolved inorganic  super(13)C, produced by the oxidation of the labeled algae, penetrated to 10-cm depth. The transport of highly reactive organic matter from the sediment surface at initial velocities  greater than or equal to 3 cm d super(-1) is expected to be an important control of subsurface benthic processes in slope environments characterized by abundant macro-faunal populations. Anaerobic processes, which are enhanced on the Cape Hatteras slope relative to adjacent areas, may be promoted by the rapid injection of reactive material into subsurface sediments. The transport, in turn, is a consequence of the dense infaunal populations that are supported by the rapid deposition of organic carbon in this region.
AN: 4041152

                                                                     257 of 313  
TI: Nitrogen speciation and nitrification potential in the Skagerrak area during the SKAGEX IV experiment
AU: Enoksson,-V.; Fogelqvist,-E.; Fonselius,-S.
AF: Dep. Gen. and Mar. Microbiol., Goeteborg Univ., Medicinaregatan 9C, S-413 90 Goeteborg, Sweden
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1996 vol. 43, no. 7, pp. 1029-1044
LA: English
ER: M (Marine)
AB: Nitrification is the oxidation of ammonium to nitrite by Nitrosomonas-like bacteria and the further oxidation of the nitrite to nitrate by Nitrobacter-like bacteria. Nitrification was studied in relation to the inorganic nitrogen species in the Skagerrak in May 1991 during the SKAGEX IV expedition. The distribution of density, ammonium, nitrite and nitrate are shown for the four north-south sections and, for two of these, the distribution of nitrification potential (NP, i.e. nitrification with excess ammonium during incubation) and oxygen saturation values are also presented. Highly saline and ammonium rich Atlantic/North Sea water was sinking into the Skagerrak along the Danish slope, where it gradually mixed with the "old" and relatively stagnant Skagerrak water with high nitrate concentrations but very low ammonium concentrations. The zone of mixing was characterised by high concentrations of nitrite, an intermediate product during the bacterial oxidation of ammonium to nitrate. The NP rates were in the range 0-60 nmol/l/day. Water masses with undetectable or low NP included the upper water layers and water flowing in at depth. Maximum NP rates were found in or near the zone with high nitrite concentrations just below the upper layers and at the border between inflowing water and "old" Skagerrak water at depth. It is postulated that nitrification was stimulated in the mixture of inflowing, ammonium rich water and "old" Skagerrak water.
AN: 4041018

                                                                     258 of 313  
TI: Mercury content in ecosystem components of the Alekseev Inlet (Peter the Great Bay, Sea of Japan).
OT: Soderzhanie rtuti v komponentakh ehkosistemy bukhty Alekseeva (zaliv Petra Velikogo Yaponskogo morya)
AU: Luchsheva,-L.N.
AF: TINRO, Vladivostok, Russia
SO: BIOL.-MORYA-MAR.-BIOL. 1995 vol. 21, no. 6, pp. 412-415
LA: Russian
ER: M (Marine)
AB: Elevated mercury concentrations were recorded in the water, bottom sediments and the soft tissues of 3 bivalve species from the Alekseev Inlet. Maximum Hg concentrations in water (0.237  mu g/l) and sediments (0.529  mu g/l) exceeded those in the control area (Peter the Great Bay) by over 10 and 5 times, respectively. The anomalous zone at the northeastern coast of the inlet is formed by Hg entering the near-bottom water layer from an endogenous submarine spring and being distributed over the inlet by currents. In molluscs from the anomalous zone, Hg content exceeding maximum permissible concentration (MPC 0.2  mu g/g wet weight) was recorded in the mantle (0.540  mu g/g), digestive gland (0.450  mu g/g) and gonad (0.390  mu g/g) of the horse mussel Modiolus kurilensis, and in the digestive gland (0.560  mu g/g) of the giant mussel Crenomytilus grayanus. Hg concentrations close to MPC were recorded in the digestive gland and adductor muscle of the scallop Mizuhopecten yessoensis.
AN: 4040737

                                                                     259 of 313  
TI: Temporal and spatial stability of bacterioplankton biomass and productivity in an atoll lagoon
AU: Torreton,-J.-P.; Dufour,-P.
AF: Cent. ORSTOM de Tahiti, BP 529, Papeete, French Polynesia
SO: AQUAT.-MICROB.-ECOL. 1996 vol. 11, no. 3, pp. 251-261
LA: English
ER: M (Marine)
AB: Spatial and temporal variations of bacterioplankton biomass, production and growth rates were investigated 6 times from 1991 to 1994 in Tikehau lagoon (Tuamotu, French Polynesia). The water column was homogeneous from the surface to the bottom (20 m) at the reference station but some horizontal variations were detected, with biomass and production increasing from the reef-flat spillways (oceanic water inflow) to the main part of the lagoon and decreasing from the relatively eutrophic shore (near the village) to the main part of the lagoon. However, both of these perturbations were limited to the immediate vicinity of these areas. Diel fluctuations of bacterial biomass and growth rate were slight (coefficient of variation, CV < 20 %) and showed no significant pattern. Day-to-day variations recorded over periods of up to 20 consecutive days appeared also to be limited (CV < 25 %). A significant correlation between wind and total abundance of bacteria in the water column suggested that these day-to-day variations may be in part explained by wind, probably inducing resuspension of sediments. No significant pattern appeared from comparison of the 6 cruises spread over different seasons. Cruise averages differed slightly from each other, with CV for all cruises averaging 34, 10 and 41 % for bacterioplankton biomass, production and growth rate, respectively. Tikehau lagoon appears to be a very stable ecosystem for bacterioplankton processes and therefore differs strongly from other reef water column systems. This untypical stability might be explained by the long residence time of water (170 d), the strong stability of the oceanic surrounding water (South Pacific Gyre), the weak seasonality of primary producers and the limited inputs from corals, bordering islands and sediments.
AN: 4039083

                                                                     260 of 313  
TI: Inhibition of bacterial activities by solar radiation in nearshore waters and the Gulf of Mexico
AU: Aas,-P.; Maille-Lyons,-M.; Pledger,-R.; Mitchell,-D.L.; Jeffrey,-W.H.
AF: Univ. West Florida, Cent. for Environ. Diagnostics and Bioremediation, 11000 Univ. Pkwy., Pensacola, FL 32514, USA
SO: AQUAT.-MICROB.-ECOL. 1996 vol. 11, no. 3, pp. 229-238
LA: English
ER: M (Marine)
AB: The effects of ultraviolet (UV) radiation on thymidine and leucine incorporation were examined in surface waters from the Gulf of Mexico and Santa Rosa Sound, a mesotrophic estuary in northwest Florida, USA. Whole and 0.8  mu m filtered surface waters were incubated with  super(3)H-thymidine and  super(14)C-leucine in UV transparent containers under natural solar radiation. Solar radiation was either not filtered (samples exposed to UV-B, UV-A, and photosynthetically active radiation, PAR), filtered through Mylar 500D (samples exposed to UV-A and PAR), or filtered through Acrylite OP3 (samples exposed only to PAR). In Santa Rosa Sound, thymidine incorporation was inhibited an average of 44% relative to dark controls when exposed to unfiltered solar radiation. PAR contributed 23% to the total thymidine inhibition, while UV-A and UV-B contributed 37% and 39%, respectively, to total inhibition. Leucine incorporation in Santa Rosa Sound was inhibited 29% by full solar radiation. The majority of the total leucine inhibition was due to UV-B (83%), while PAR only treatments showed leucine incorporation rates 10% higher than dark controls. For the Gulf of Mexico experiments, full solar radiation inhibited thymidine incorporation approximately twice as much as leucine incorporation. However, there were no consistent patterns in differences due to different wavelengths. Both thymidine and leucine incorporation were inhibited to a greater extent in <0.8  mu m filtered water samples than in whole water samples, suggesting that the presence of primary producers may mediate the detrimental effects of solar radiation on bacterioplankton. Surface water was also incubated in situ with thymidine at fixed depths in UV transparent and darkened containers at 3 locations in the Gulf of Mexico. Total inhibition was 60 to 70% at the surface and was evident to 15 m. Comparison with radiometric data and DNA dosimeters indicated that UV-B exerted the greatest effect in the upper 5 m while below that the inhibition was most likely due to longer wavelengths. Our results suggest that both UV and visible solar radiation can negatively affect bacterial metabolism and failure to take into account the effects of light may result in the overestimation of bacterioplankton production in surface waters.
AN: 4038237

                                                                     261 of 313  
TI: Mineralization in a northeastern Greenland sediment: Mathematical modelling, measured sediment pore water profiles and actual activities
AU: Rysgaard,-S.; Berg,-P.
AF: Natl. Environ. Res. Inst., Vejlsovej 25, DK-8600 Silkeborg, Denmark
SO: AQUAT.-MICROB.-ECOL. 1996 vol. 11, no. 3, pp. 297-305
LA: English
ER: M (Marine)
AB: A mathematical computer model describing mineralization processes and transport of solutes within sediments was developed based on the degradation of organic matter, stoichiometrically coupled to the consumption of O sub(2) in the oxic layers, and to NO sub(3) super(-) and SO sub(4) super(2-) in the anoxic layers. The reaction rates obey Michaelis-Menten type kinetics and all transport of solutes is assumed to take place by diffusion. The model was tested on a northeastern Greenland sediment and gave accurate simulations of the measured concentration profiles. In addition, measured processes of nitrification, coupled nitrification-denitrification, denitrification of water column NO sub(3) super(-), NH sub(4) super(+) mineralization and the fluxes of NH sub(4) super(+) and NO sub(3) super(-) across the sediment-water interface were predicted with great accuracy. Since the model is based on Michaelis-Menten type kinetics and diffusional transport mechanisms, it is of general use and provides an important tool to evaluate the regulation of biogeochemical cycling in sediments. This is shown in a series of simulations predicting the effect of various concentrations in the water column of O sub(2) and NO sub(3) super(-) on the rates of nitrification and denitrification. The results are in good agreement with previously published measurements.
AN: 4038234

                                                                     262 of 313  
TI: Abundant populations of iron and manganese sequestering bacteria in coastal water
AU: Heldal,-M.; Fagerbakke,-K.M.; Tuomi,-P.; Bratbak,-G.
AF: Dep. Microbiol., Univ. Bergen, Jahnebk. 5, N-5020 Bergen, Norway
SO: AQUAT.-MICROB.-ECOL. 1996 vol. 11, no. 2, pp. 127-133
LA: English
ER: M (Marine)
AB: It has recently been suggested that iron is a limiting factor for phytoplankton production in nutrient-rich seas. Here we report on a group of bacteria in coastal marine surface waters forming extensive appendages with apparently high affinity for iron and manganese (Fe-Mn bacteria). Bacteria and particles were harvested by centrifugation onto grids for Transmission Electron Microscope (TEM) X-ray microanalysis. Four different morphotypes of Fe-Mn bacteria were identified. The total numbers of these bacteria were at the highest in the range of 5.5 x 10 super(3) to 1.5 x 10 super(4)/ml. The amount of iron bound was 10 to 110 fg/cell including appendages, and the Mn:Fe ratio (w/w) of the metal-encrusted appendages varied between 0.37 and 5.7. In some environments the Fe content of these bacteria was equivalent to a bulk concentration of about 10 nM. The Fe and Mn content per unit biomass of these bacteria is 1000 to 10000 times that of most other microorganisms. These organisms may thus be important for both cycling and sedimentation of Fe and Mn in marine ecosystems and for marine productivity.
AN: 4038207

                                                                     263 of 313  
TI: Effects of Tubifex tubifex (Oligochaeta: Tubificidae) on N-mineralization in freshwater sediments, measured with  super(15)N isotopes
AU: Pelegri,-S.P.; Blackburn,-T.H.
AF: Dep. Biol., Univ. Southwestern Louisiana, PO Box 42451, Lafayette, LA 70504-2451, USA
SO: AQUAT.-MICROB.-ECOL. 1995 vol. 9, no. 3, pp. 289-294
LA: English
ER: F (Freshwater)
AB: Sediment cores containing different densities of Tubifex tubifex, ranging from 0 to 70000 ind/m super(2), were incubated in the laboratory. Rates of O sub(2) and NO sub(3) super(-) uptake, NH sub(4) super(+) production, nitrification and denitrification were determined from sediment-water fluxes. Pore water NH sub(4) super(+) was measured at the end of the experiment. At natural densities,  similar to 50000 ind. m super(-2), there were increased rates of O sub(2) consumption (x2), denitrification of water phase NO sub(3) super(-) (x3) and NH sub(4) super(+) efflux (x26). Nitrification was stimulated at low worm densities, but inhibited at higher worm densities. The transport of reduced compounds and organic matter, with the fecal pellets, to the sediment surface stimulated anoxic conditions in the inhabited microcosms. These anoxic conditions led to increased rates of denitrification and were responsible for the decrease in nitrification at higher worm densities. Approximately 25% of the NO sub(3) super(-) produced by nitrification within the sediment was subsequently denitrified. Denitrification was responsible for 25% of the NO sub(3) super(-) disappearance from the system. The higher rates of denitrification were counterbalanced by higher rates of NH sub(4) super(+) flux from the sediment. It is likely, however, that the presence of T. tubifex resulted in a net loss of nitrogen that could otherwise have been used by the primary producers.
AN: 4038080

                                                                     264 of 313  
TI: Impact of the soft-shell clam Mya arenaria on sulfate reduction in an intertidal sediment
AU: Hansen,-K.; King,-G.M.; Kristensen,-E.
AF: Inst. Biol., Odense Univ., Campusvej 55, DK-5230 Odense M, Denmark
SO: AQUAT.-MICROB.-ECOL. 1996 vol. 10, no. 2, pp. 181-194
LA: English
ER: M (Marine)
AB: Sulfate reduction and various parameters related to the sulfur cycle were examined at mm to cm scales around burrows of the soft-shell clam Mya arenaria in an intertidal sediment (Lowes Cove, Maine, USA). Sulfate reduction rates were 1.5 to 2 times higher in the inner 1 to 5 mm region surrounding the burrow than in ambient sediment. In contrast, pools of reduced sulfur increased with the distance from the burrow wall to values  approximately 1.5 times higher in ambient sediment. The highest numbers of sulfate-reducing bacteria (estimated using a most-probable-number technique) and microbial biomass (estimated from phospholipid phosphorous content) relative to ambient sediment were found in the innermost zone around burrows. Results from an artificial burrow experiment showed that artificial burrow irrigation suppressed sulfate reduction in the innermost zone around burrows, while radial profiles of reduced sulfur resembled those from M. arenaria burrows, indicating loss of reduced sulfur from the burrow wall. M. arenaria burrows are thus sites of enhanced microbial activity and a dynamic sulfur cycle, with turnover times of reduced sulfur compounds increasing with distance from the burrow wall. Enhanced sulfate reduction rates near burrows are likely caused by substrate enrichment, perhaps due to organic excretions from M. arenaria. The pattern of reduced sulfur turnover likely results from periodic oxygen inputs during burrow irrigation.
AN: 4038071

                                                                     265 of 313  
TI: Metabolism and organic carbon fluxes in the tidal freshwater Hudson River
AU: Howarth,-R.W.; Schneider,-R.; Swaney,-D.
AF: Sect. Ecol. and System., Corson Hall, Cornell Univ., Ithaca, NY 14853, USA
SO: ESTUARIES 1996 vol. 19, no. 4, pp. 848-865
NT: Dedicated issue: The Hudson River Estuary. Most papers were presented at 12th ERF conference, Hilton Head I, SC (USA), in 1993.
LA: English
ER: F (Freshwater)
AB: We summarize rates of metabolism and major sources and sinks of organic carbon in the 148-km long, tidally influenced, freshwater Hudson River. The river is strongly heterotrophic, with respiration exceeding gross primary production (GPP). The P:R ratio averages 0.57 (defined as the ratio of GPP to total ecosystem respiration) if only the aquatic portion of the ecosystem is considered and 0.70 if the emergent marshes are also included. Gross primary production (GPP) by phytoplankton averages approximately 300 g C m super(-2) yr super(-1) and is an order of magnitude greater than that by submersed macrophytes. However, the river is deep, well mixed, and turbid, and phytoplankton spend a majority of their time in the dark. As a result, respiration by living phytoplankton is extremely high and net primary production (NPP) by phytoplankton is estimated to be only some 6% of GPP. NPP by phytoplankton and submersed macrophytes are roughly equal (approximately 20 g C m super(-2) yr super(-1) each) when averaged over the river. Emergent marshes are quite productive, but probably less than 16 g C m super(-2) yr super(-1) enters the aquatic portion of the ecosystem from these marshes. Heterotrophic respiration and secondary production in the river are driven primarily by allochthonous inputs of organic matter from terrestrial sources. Rates of metabolism vary along the river, with depth being a critical controlling factor. The P:R ratio for the aquatic portion of the ecosystem varies from 1 in the mid-river to 0.2 in the deeper waters. NPP is actually negative in the downstream waters where average depths are greater since phytoplankton respiration exceeds GPP there; the positive rates of NPP occurring upriver support a downstream advection of phytoplankton to the deeper waters where this C is largely respired away by the algae themselves. This autotrophic respiration contributes significantly to oxygen depletion in the deeper waters of the Hudson. The tidally influenced freshwater Hudson largely fits the patterns predicted by the river continuum model for larger rivers. However, we suggest that the continuum model needs to more clearly distinguish between GPP and NPP and should include the importance of autotrophic respiration by phytoplankton that are advected along a river. The organic carbon budget for the tidally influenced freshwater Hudson is balanced to within a few percent. Respiration (54%) and downstream advection into the saline estuary (41%) are the major losses of organic carbon from the ecosystem. Allochthonous inputs from nonpoint sources on land (61%) and GPP by phytoplankton (28%) are the major sources to the system. Agricultural erosion is the major source of allochthonous inputs. Since agricultural land use increased dramatically in the last century, and has fallen in this century, the carbon cycle of the tidally influenced freshwater Hudson River has probably changed markedly over time. Before human disturbance, the Hudson was probably a less heterotrophic system and may even have been autotrophic, with gross primary production exceeding ecosystem respiration.
AN: 4038025

                                                                     266 of 313  
TI: Monitoring, mass balance calculation of nutrients and the future of the Gulf of Bothnia
AU: Wulff,-F.; Perttilae,-M.; Rahm,-L.
AF: Department of Systems Ecology, Univ. of Stockholm, S-106 91 Stockholm, Sweden
SO: AMBIO 1996 vol. Special Report, no. 8, pp. 27-33
LA: English
ER: B (Brackish)
AB: Based on the intensive hydrochemical measurements of the Gulf of Bothnia Year 1991, descriptions are presented of the regional variations of freshwater and nutrient inputs and hydrographic and nutrient conditions for this particular year. These data are then used to construct nutrient budgets for the Bothnian Sea and Bay, for silicate, inorganic and organic nitrogen and phosphorous. The seasonal variations of internal sources and sinks and advective transports between the basins and with the Baltic proper, show the relative importance and magnitude of biochemical and physical processes for the development of nutrient concentrations in those basins. Annual budget estimates show that the Bothnian Sea appears to function as a very efficient sink for nitrogen and phosphorus. There is a very small exchange of nitrogen with the Baltic proper, in contrast to the large amounts of phosphorus imported and silica exported. Overall N:P ratios show the high rates typical of the Bothnian Bay, which are drastically reduced in the Bothnian Sea, particularly for inorganic nutrients. In spite of the highly variable N/P rations of the different pools, the calculated net transfers of inorganic nutrients into organic matter follow classical Redfield ratios in both basins.
AN: 4034630

                                                                     267 of 313  
TI: Biogeochemical transformations of nitrogen and phosphorus in the marine environment -- coupling hydrodynamic and biogeochemical processes in models for the Baltic Proper
AU: Savchuk,-O.; Wulff,-F.
CA: Stockholm Univ. [Sweden]. Inst. of Syst. Ecology
SO: SYST.-ECOL.-CONTRIB. STOCKHOLM-SWEDEN 1996 vol. 2, 79 pp
LA: English
ER: M (Marine); B (Brackish)
AB: The Baltic Sea was one of the first areas in the world where large-scale effects of increased inputs of nutrients and toxic substances were recognized. Numerical models simulating complex interactions between physical and biochemical processes are important tools in studying such phenomena at the ecosystem level. With the overall objective to develop a numerical model that describes the biogeochemical cycles of nutrients in the entire Baltic Sea a coupled hydrodynamic-biogeochemical model is presented. The model has evolved in a cooperation between the Swedish research program on the large-scale effects of pollution in the Baltic and the Russian "Project Baltica" and is a development of that presented by Stigebrandt & Wulff (1987). A first submodel describing nitrogen and phosphorous pelagic cycles was given in Savchuk & Wulff 1993. The present model is a development including nitrogen fixation and sediment-water interactions which has been coupled with the hydrodynamic sub-model and implemented for the Baltic. The model was verified by comparing the model results in an analysis with observations from the Baltic showing that the model was capable to reproduce a number of key features of biochemical cycles such as quantitative description of the seasonal, inter-annual and long-term dynamics of nutrients and oxygen; the plausible simulation of seasonal dynamics of plankton variables; the imitation of depth distribution of benthic variables; realistic values of pelagic and benthic biochemical fluxes.
AN: 4034615

                                                                     268 of 313  
TI: Zooplankton. Pivotal role in the control of ocean production
AU: Banse,-K.
AF: University of Washington, School of Oceanography, Box 357940, Seattle, WA 98195-7940, USA
CA: International Counc. for the Exploration of the Sea, Copenhagen [Denmark]
CO: ICES Symp. on Zooplankton Production, Plymouth (UK), 15-19 Aug 1994
SO: ZOOPLANKTON-PRODUCTION.-PROCEEDINGS-OF-A-SYMPOSIUM-HELD-IN-PLYMOUTH,-ENGLAND,-15-19-AUGUST-1994. Harris,-R.-eds. LONDON-UK ACADEMIC-PRESS 1995 vol. 52, no. 3-4 pp. 265-277
ST: ICES-J.-MAR.-SCI. vol. 52, no. 3-4
NT: Issued also as: ICES Mar. Sci. Symp., v. 200.
LA: English
ER: M (Marine)
AB: The article focuses on the nutrient-depleted (oligotrophic) areas of the oceans, including stratified temperate seas during summer, all showing little temporal change of phytoplankton concentrations. Zooplankton-mediated processes that lead from physically caused, nitrate-fueled new production to total primary production are emphasized. Under oligotrophic conditions, the rate of phytoplankton cell division in the light-saturated part of the euphotic zone depends directly on the rate of nutrient regeneration by the zooplankton; indirectly, it depends on the liberation of dissolved organic matter that provides the bacterial substrate, mainly from "sloppy" feeding of the zooplanton, excretion, and release from feces, and a small contribution from exudation by phytoplankton. The bacterial division rate is low and is inferred as being controlled by supply rate of dissolved organic carbon. The possibility is discussed that, via nutrient regeneration, temperature-controlled zooplankton physiology largely controls the rate of phytoplankton production, given a physically set rate of new production. Phytoplankton-zooplankton interactions are treated briefly for the high nutrient-low chlorophyll regions that also have little temporal change of phytoplankton concentrations, and the open-sea regions with seasonal blooms. All available marine measurements >9 degree C of bulk phytoplankton division rates are plotted on temperature to improve upon Eppley's standard curve for modeling phytoplankton production.
AN: 4034315

                                                                     269 of 313  
TI: Undersaturation of CH sub(3)Br in the Southern Ocean
AU: Lobert,-J.M.; Yvon-Lewis,-S.A.; Butler,-J.H.; Montzka,-S.A.; Myers,-R.C.
AF: Cooperative Inst. for Res. in Environ. Sci., Boulder, CO, USA
SO: GEOPHYS.-RES.-LETT. 1997 vol. 24, no. 2, pp. 171-172
LA: English
ER: M (Marine)
AB: Dry mole fractions of methyl bromide (CH sub(3)Br) in marine boundary layer air and in air equilibrated with surface water were measured in the Southern Ocean. Saturation anomalies were consistently negative at -36 plus or minus 7%. The observed undersaturations do not support recently published predictions of highly supersaturated Antarctic waters, but instead suggest a net uptake of atmospheric CH sub(3)Br by cold, productive oceans. The observations do not appear to be supported by known chemical degradation rates and present strong evidence for an unidentified, oceanic sink mechanism such as biological breakdown. Our estimate for the global, net, oceanic sink for atmospheric methyl bromide remains negative at -21 (-11 to -32) Gg y super(-1).
AN: 4033778

                                                                     270 of 313  
TI: A laboratory study of the biogeochemical cycling of Fe, Mn, Zn and Cu across the sediment-water interface of a productive lake
AU: Hamilton-Taylor,-J.; Davison,-W.; Morfett,-K.
AF: Inst. Environ. and Biol. Sci., Lancaster Univ., Lancaster LA1 4YQ, UK
SO: AQUAT.-SCI. 1996 vol. 58, no. 3, pp. 191-209
LA: English
ER: F (Freshwater)
AB: Laboratory incubation experiments were carried out on sediment cores collected from Esthwaite Water, U.K., during April 1987, when the sediments displayed a characteristic surface (1.5 to 2 cm) oxide floc. The experiments were undertaken at 10 degree C, in the dark, under variable redox and pH conditions for periods of  similar to 720 h (30 d). In some cases, realistic amounts of decomposing lake algae were added to simulate the deposition of an algal bloom. Pore waters and overlying waters were obtained from the incubated sediment cores at various time intervals and the samples analysed for pH and dissolved Fe, Mn, Zn and Cu by AAS. The results demonstrated that trace metal concentrations at the sediment-water interface can show rapid, pulsed responses to episodic events associated with controlling factors such as algal deposition and mixing conditions. The variations in dissolved Fe and Mn concentrations could generally be explained by their well known redox behaviour. Appreciable loss of Mn from solution under conditions of well-developed anoxia was consistent with adsorption of Mn super(2+) by FeS. Cu and Zn were both rapidly (24 h) released into solution during incubation of sediment cores prior to the development of anoxia in the overlying waters. Their most likely sources were the reductive remobilization of Mn oxides and the decomposition of organic matter. The addition of decomposing algae to a series of cores resulted in even higher interfacial dissolved concentrations of Cu and Zn, probably through acting as a supplementary source of the metals and through increased oxide dissolution. Switching from anoxic to oxic conditions also rapidly increased dissolved Cu and Zn concentrations, possibly due to their release during the oxidation of metal sulphides. The enhanced releases of dissolved Cu and Zn were generally short-lived with removal being attributed to the formation of sulphides during anoxia and to adsorption by Fe and Mn oxides under oxic conditions.
AN: 4032172

                                                                     271 of 313  
TI: Measured and modeled primary production in the Northeast Atlantic (EUMELI JGOFS program): The impact of natural variations in photosynthetic parameters on model predictive skill
AU: Morel,-A.; Antoine,-D.; Babin,-M.; Dandonneau,-Y.
AF: Lab. de Physique et Chimie Marines, Univ. Pierre et Marie Curie and CNRS, BP 8, F-06230 Villefranche-sur-Mer, France
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1996 vol. 43, no. 8, pp. 1273-1304
LA: English
ER: M (Marine)
AB: Use of ocean color satellite data in global biogeochemical studies requires models to predict primary production from the satellite-derived chlorophyll fields. In this paper, measured bio-optical and photo-physiological data are used in place of standard (constant) parameters to adjust a previously published primary production model. In the JGOFS-France program, systematic studies were carried out at three locations in the tropical northeast Atlantic, selected to represent typical EUtrophic, MEsotrophic and oLIgotrophic regimes (EUMELI cruises). During cruise no. 4, these studies included the spectral measurements of the photosynthetically available radiation at sea level and within the water column, the determination of the algal absorption spectra and the determination of the physiological parameters derivable from P versus E experiments (photosynthesis-irradiance responses). The model predictions are compared with in situ determinations made by the  super(14)C technique (JGOFS core parameter). At the three sites, the physical structure (mixed layer and euphotic depths), the algal abundance and community structure, as well as their bio-optical and physiological properties, are very different, so that the predictive performance of the model was tested in trophic conditions that span most of those expected in the global open ocean. The model, when adjusted by entering the actual physiological parameters (chlorophyll-specific absorption of algae, maximum quantum yield, and light saturated carbon fixation rate), provides satisfying results compared to those observed in situ. The relative roles of the physiological parameters are analyzed and sensitivity studies are performed. For global applications, and in the absence of specific information when all seasons and provinces of the world ocean are considered, it will remain necessary for a while to rely on generic models and a selected standard set of physiological properties. The sensitivity studies here presented help in this choice, and a modified set of parameters is proposed and tested. With this set, reconstructed production profiles are close to those determined in the field, and the integrated values are retrieved with no bias and a reduced scatter (18% at one SD) for 17 stations (cruises 3 and 4) and daily production ranging from 0.3 to 2.3 gC m super(-2).
AN: 4029371

                                                                     272 of 313  
TI: Cycling of high-molecular-weight dissolved organic matter in the Middle Atlantic Bight as revealed by carbon isotopic ( super(13)C and  super(14)C) signatures
AU: Guo,-L.; Santschi,-P.H.; Cifuentes,-L.A.; Trumbore,-S.E.; Southon,-J.
AF: Dep. Oceanogr., Texas A&M Univ., 5007 Ave. U, Galveston, TX 77551, USA
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 6, pp. 1242-1252
LA: English
ER: M (Marine); B (Brackish)
AB: Carbon isotopes ( super(13)C and  super(14)C) and elemental composition (C and N) in two fractions of colloidal organic matter (COM) were measured to study the origin and cycling of dissolved organic matter (DOM) in the Middle Atlantic Bight (MAB). COM sub(1) (1 kDa-0.2  mu m) was 59% of the bulk DOM in surface Chesapeake Bay waters and decreased to 30-35% in waters of the MAB. COM sub(10) (10 kDa-0.2  mu m), which was the high-molecular-weight (HMW) component of COM sub(1), comprised 3-12% of the bulk DOM, with highest concentrations in Chesapeake Bay waters and the lowest in deep waters in the MAB.  Delta  super(14)C values of COM sub(1) decreased from nearshore (-21 to +12ppt) to offshore and from surface (-166 to -85ppt) to bottom waters (-400 to -304ppt). Although  Delta  super(14)C values of surface-water HMW COM sub(10) were generally high (-2 to -7ppt), values for bottom-water COM sub(10) were much lower (-129 to -709ppt). The high  Delta  super(14)C values in the surface water suggest a particulate origin of pelagic COM, consistent with the contemporary  Delta  super(14)C values of particulate organic matter (POM). The very low  Delta  super(14)C values of bottom-water COM sub(10) imply that in addition to the pelagic origin, sedimentary organic C may serve as an important source for the benthic colloids in the bottom nepheloid layer. The general flow direction of organic carbon is from POM to HMW and to LMW DOM. Three colloidal end-members were identified in the MAB as well as in the Gulf of Mexico: estuarine colloids with high  Delta  super(14)C values, high C:N ratios, and lower  delta  super(13)C values; offshore surface water colloids with intermediate  Delta  super(14)C values, lower C:N ratios, and higher  delta  super(13)C values; and offshore deep-water colloids with low  Delta  super(14)C values, intermediate C:N ratios, and variable  delta  super(13)C values.
AN: 4028380

                                                                     273 of 313  
TI: Biominerals as trace element sinks
AU: Davies,-N.A.; Simkiss,-K.
AF: Sch. Animal and Microbial Sci., Univ. Reading, Reading RG6 2AJ, England, UK
CO: Biomineralization '93: 7. International Symposium on Biomineralization, (Monaco), 17-20 Nov 1993
SO: BIOMINERALIZATION-'-93:-7TH-INTERNATIONAL-SYMPOSIUM-ON-BIOMINERALIZATION.-MONACO-17-20-NOVEMBER-1993. Allemand,-D.;Cuif,-J.-P.-eds. 1996 vol. 14, no. 4 pp. 209-214
ST: BULL.-INST.-OCEANOGR.-MONACO ISBN-2-7260-0179-3 vol. 14, no. 4
LA: English
ER: M (Marine)
AB: Fecal pellets egested by a number of marine organisms contain biominerals in the form of inorganic granules. These granules accumulate a wide range of metal ions both from within the animal and on their passage through the water column. Subsequent ingestion by filter feeding organisms could result in the absorption of these metals and present a pathway for the bioaccumulation of heavy metals and their cycling through the biota. In an experiment involving zinc uptake in mussels (Mytilus edulis) the granules were incubated in sea water containing radioactively labelled zinc and then fed to mussels. Radiolabelled zinc in solution was used as a control to the particulate experiment. The results indicate that zinc in solution is absorbed across the gills and mantle. When in particulate form, the zinc is ingested, passed through the gut, and is absorbed into the digestive gland.
AN: 4026690

                                                                     274 of 313  
TI: Biological aspects of the long term carbon cycle
AU: Berner,-R.A.
AF: Dep. Geol. and Geophys., Yale Univ., New Haven, CT 06511, USA
CO: Biomineralization '93: 7. International Symposium on Biomineralization, (Monaco), 17-20 Nov 1993
SO: BIOMINERALIZATION-'-93:-7TH-INTERNATIONAL-SYMPOSIUM-ON-BIOMINERALIZATION.-MONACO-17-20-NOVEMBER-1993. Allemand,-D.;Cuif,-J.-P.-eds. 1996 vol. 14, no. 4 pp. 11-22
ST: BULL.-INST.-OCEANOGR.-MONACO ISBN-2-7260-0179-3 vol. 14, no. 4
LA: English
ER: M (Marine)
AB: A computer model (GEOCARB II) of the long term, or multimillion year, global carbon cycle has been constructed that represents the exchange of carbon between sedimentary rocks and the surficial system consisting of the atmosphere + hydrosphere + biosphere. Processes treated quantitatively by the model include weathering of silicate and carbonate rocks and ancient organic matter (kerogen) on the continents, the deposition of carbonate minerals and organic matter in the ocean, and the metamorphic/volcanic/ diagenetic thermal breakdown of carbonates and organic matter, with consequent degassing of CO sub(2), upon deep burial of the sediments. The carbon cycle model enables calculation of paleolevels of atmospheric CO sub(2) over Phanerozoic time (past 600 million years) and results agree well with independent estimates based on measurements of paleosols and sedimentary rocks. Sensitivity analysis indicates that biological effects on CO sub(2) were especially important during certain periods of the Phanerozoic. During the mid Paleozoic vascular plants arose and populated the continents which brought about a large drop in CO sub(2) to balance the acceleration of silicate rock weathering by the plants. Additional Paleozoic drop in CO sub(2) was caused by the enhanced burial during the Carboniferous and Permian of organic matter emanating from land plants. The refractory fraction (eg. lignin) of land plants joined the remains of marine organisms as a principal source for global carbon burial. During the mid-Mesozoic the rise of coccoliths and foraminifera brought about enhanced deposition of CaCO sub(3) in the deep sea. Combined with dissolutive weathering of shallow water limestones on land, this deep water deposition brought about the slow subsequent transfer of CaCO sub(3) from the continents to the deep ocean basins. This in turn resulted in accelerated degassing of CO sub(2) because deep sea sediments have a higher probability of thermal decomposition due to their subduction along plate margins. The question remains whether similar carbonate transfers between shallow platforms and the deep sea occurred during periods older than the oldest remaining seafloor.
AN: 4026689

                                                                     275 of 313  
TI: The distribution of  super(10)Be and  super(9)Be in the South Atlantic
AU: Measures,-C.I.; Ku,-T.L.; Luo,-S.; Southon,-J.R.; Xu,-X.; Kusakabe,-M.
AF: Univ. Hawaii at Manoa, Sch. Ocean Earth Sci. and Technol., Dep. Oceanogr., 1000 Pope Rd., Honolulu, HI 96822, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1996 vol. 43, no. 7, pp. 987-1009
LA: English
ER: M (Marine)
AB: Vertical and surface-water distributions of  super(10)Be and  super(9)Be in the South Atlantic Ocean were studied. The major input of  super(9)Be to the surface waters of the region is from the partial dissolution of eolian dusts, with the extent of the dissolution being about seven times that of aluminum from the dust particles. The gradients in surface-water  super(10)Be concentrations appear to reflect the magnitude of the local precipitation. The imprinting of the surface water signals onto the deep water masses appears rapid, particularly in regions of enhanced productivity. Bottom waters of Antarctic origin have characteristic isotope signatures that can be traced along their advective route into the Guinea Basin of the eastern Atlantic. Elevated  super(9)Be concentrations in the Angola Basin are indicative of diagenetic input in this region of restricted circulation. The corresponding anomalous  super(10)Be in the bottom waters indicates historically lower surface-water  super(10)Be/ super(9)Be ratios in the region, perhaps as a result of the further southward penetration of the Inter-Tropical Convergence Zone at those times. The budgets of  super(10)Be and  super(9)Be in the South Atlantic were estimated. The results show that cross-equator transport of  super(10)Be and  super(9)Be from the North Atlantic is 0.3  plus or minus  10 super(23) atoms/year and 5.7  plus or minus  10 super(6) mol/year, respectively, accounting for less than 5% of  super(10)Be and about 10% of  super(9)Be entering the North Atlantic. There is a net export across 50 degree S to the Antarctic/Indian/Pacific Oceans of 0.9  plus or minus  10 super(23) atoms/year for  super(10)Be and 7.5  plus or minus  10 super(6) mol/year for  super(9)Be. Using  super(10)Be as a tracer, we evaluate accumulation rates of lithogenic minerals to be 1.7  plus or minus  10 super(14) g/year in the North Atlantic and 4.8  plus or minus  10 super(13) g/year in the South Atlantic. While the North Atlantic rate agrees with the observed eolian dust input, the estimated lithogenic flux in the South Atlantic is about twice the eolian input, suggesting that the riverine input of  super(9)Be to the open ocean may become non-negligible in areas of low eolian dust flux.
AN: 4026033

                                                                     276 of 313  
TI: Wet and dry deposition of nitrogen compounds in the southeast Pacific coast: Montemar, central Chile
AU: Prado-Fiedler,-R.; Fuenzalida,-H.A.
AF: Inst. Oceanologia Montemar, Univ. de Valparaiso, Vina del Mar, Chile
SO: J.-GEOPHYS.-RES.-D-ATMOS. 1996 vol. 101, no. D17, pp. 22845-22853
LA: English
ER: M (Marine)
AB: Atmospheric concentration in the marine boundary layer and direct deposition measurements of total nitrate and ammonium for an eastern South Pacific coastal site on Valparaiso Bay, Chile, were carried out during the period January 1992 through March 1993. Concentrations in air for both nitrogen forms exhibit a seasonal pattern with low values in summer and a pronounced increase in winter, having a mean annual concentration of 32.6 nmol m super(-3) for total nitrate and of 44.8 nmol m super(-3) for total ammonium. Wet deposition is characterized by annual precipitation weighted concentrations of 6.0 and 8.1  mu mol dm super(-3) for nitrate and ammonium, respectively. The main factor regulating wet deposition for both nitrate and ammonium is rainfall amount, so that changes in precipitation amount alone originated by climatological factors can produce changes in their relative deposition levels. Existing climatological pattern determines an overall dominance of dry over wet deposition, with totals of 12.9 and 7.34 mmol m super(-2) per year, the reduced forms of nitrogen being generally more abundant.
AN: 4025125

                                                                     277 of 313  
TI: In situ analyses of methane oxidation associated with the roots and rhizomes of a bur reed, Sparganium eurycarpum, in a Maine wetland
AU: King,-G.M.
AF: Darling Mar. Cent., Univ. Maine, Walpole, ME 04573, USA
SO: APPL.-ENVIRON.-MICROBIOL. 1996 vol. 62, no. 12, pp. 4548-4555
LA: English
ER: F (Freshwater)
AB: Methane oxidation associated with the belowground tissues of a common aquatic macrophyte, the burweed Sparganium eurycarpum, was assayed in situ by a chamber technique with acetylene or methyl fluoride as a methanotrophic inhibitor at a headspace concentration of 3 to 4%. Acetylene and methyl fluoride inhibited both methane oxidation and peat methanogenesis. However, inhibition of methanogenesis resulted in no obvious short-term effect on methane fluxes. Since neither inhibitor adversely affected plant metabolism and both inhibited methanotrophy equally well, acetylene was employed for routine assays because of its low cost and ease of use. Root-associated methanotrophy consumed a variable but significant fraction of the total potential methane flux; values varied between 1 and 58% (mean  plus or minus  standard deviation, 27.0%  plus or minus  6.0%) with no consistent temporal or spatial pattern during late summer. The absolute amount of methane oxidized was not correlated with the total potential methane flux; this suggested that parameters other than methane availability (e.g., oxygen availability) controlled the rates of methane oxidation. Estimates of diffusive methane flux and oxidation at the peat surface indicated that methane emission occurred primarily through aboveground plant tissues; the absolute magnitude of methane oxidation was also greater in association with roots than at the peat surface. However, the relative extent of oxidation was greater at the latter locus.
AN: 4022730

                                                                     278 of 313  
TI: Nitrogen cycling networks of coastal ecosystems: Influence of trophic status and primary producer form
AU: Christian,-R.R.; Fores,-E.; Comin,-F.; Viaroli,-P.; Naldi,-M.; Ferrari,-I.
AF: Biol. Dep., East Carolina Univ., Greenville, NC 27858, USA
SO: ECOL.-MODEL. 1996 vol. 87, no. 1-3, pp. 111-129
LA: English
ER: B (Brackish); F (Freshwater)
AB: We have used ecological network analysis to compare nitrogen cycles from five well-researched coastal ecosystems. These included a representative ricefield and two lagoons (Tancada and Encanysada lagoons) in the Ebro River delta, Spain; a region of the Sacca di Goro, a lagoon at the mouth of the Po River, Italy; and a drowned river estuary in North Carolina, USA, the Neuse River estuary. We constructed networks for the various systems and ranked them by trophic status (i.e., degree of eutrophication) using four indices. We then considered the importance of (1) trophic status, (2) growth form of dominant primary producer and (3) water residence time to the intensity and pattern of recycling and to the manner in which the systems can "filter" N. Three indices of flux (rate of import, primary producivity and total systems throughput) gave similar rankings of trophic status among ecosystems with the Italian and U.S. systems being most eutrophic, ricefields next, and then the two Spanish lagoons. Patterns of N export and of cycling within the systems were most closely related to the growth form of dominant primary producers. Phytoplankton, with their rapid turnover rate, foster rapid recycling within the water column and continuous transfer to sediments and export. Submersed and emergent aquatic vegetation and macroalgae create lags and pulses within systems by sequestering N during growth and releasing it during senescence, death and decomposition. Trends in cycling among systems relative to trophic status or water residence appear largely secondary to primary producer growth form.
AN: 4021540

                                                                     279 of 313  
TI: Molecular microbial ecology manual
AU: Akkermans,-A.D.L.; Van-Elsas,-J.D.; De-Bruijn,-F.J.-(eds.)
SO: DORDRECHT-THE-NETHERLANDS KLUWER-ACADEMIC-PUBLISHERS 1995 507 pp
NT: Price: Dfl. 250, US$ 177.50,  pound sterling  112.50.
LA: English
AB: For a long time microbial ecology has been developed as a distinct field within Ecology. In spite of the important role of microorganisms in the environment, this group of 'invisible' organisms remained unaccessable to other ecologists. Detection and identification of microorganisms remain largely dependent on isolation techniques and characterisation of pure cultures. We now realise that only a minor fraction of the microbial community can be cultivated. As a result of the introduction of molecular methods, microbes can now be detected and identified at the DNA/RNA level in their natural environment. This has opened a new field in ecology: Molecular Microbial Ecology. In the present manual we aim to introduce the microbial ecologist to a selected number of current molecular techniques that are relevant in microbial ecology. The first edition of the manual contains 33 chapters and an equal number of additional chapters will be added this year. Since the field of molecular ecology is in a continuous progress, we aim to update and extend the Manual regularly and will invite anyone to deposit their new protocols in full detail in the next edition of this Manual. We hope this book finds its place where it was born: at the lab bench!
AN: 4021236

                                                                     280 of 313  
TI: Carbon budget and network analysis of a high-energy beach/surf-zone ecosystem
AU: Heymans,-J.J.; McLachlan,-A.
AF: Zool. Dep., Univ. Port Elizabeth, Box 1600, Port Elizabeth 6000, South Africa
SO: ESTUAR.-COAST.-SHELF-SCI. 1996 vol. 43, no. 4, pp. 485-505
LA: English
ER: M (Marine)
AB: A carbon budget, compiled for a high-energy beach/surf-zone ecosystem in South Africa, consists of 14 living and two non-living compartments, namely dissolved organic carbon and suspended particulate organic carbon. The living compartments constitute three trophic assemblages; the microbial loop, the interstitial system and the macrofauna. The food web budget was subjected to network analysis to assess the status of the system. Input-output analysis indicated that the microbial loop is the most important trophic assemblage in this system, with the interstitial assemblage second in importance. Lindeman trophic analysis estimated that detritivory amounts to 868 mgC m super(-2) day super(-1) and the detritivory:herbivory ratio is 13:1. Biogeochemical cycle analysis concluded that this system is not under any anthropogenic stress, having a nexus with 48 cycles, three 24-cycle nexuses, a single cycle including 11 compartments, and only seven single-cycle nexuses. Based on global systems' properties, this ecosystem has a high normalized internal ascendency (A sub(i):C sub(i)) which suggests that it is well organized and stable. The system possesses significant internal stability and resistance, a feature that is expected from a physically controlled environment. The relative ascendency (A:C) of this system falls well within the range of relative ascendencies for other systems, being higher than most estuaries but lower than upwelling systems, bays and seas. Overall, this ecosystem is perceived to be unstressed and mature, with the physical control exerted on it providing significant internal stability.
AN: 4017590

                                                                     281 of 313  
TI: Biominerals as trace elements sinks
AU: Davies,-N.A.-W.; Simkiss,-K.
AF: School of Animal and Microbial Sciences, University of Reading, Reading, RG6 2AJ, UK
CO: 7. International Symp. on Biomineralization 93, Monaco (Monaco), 17-20 Nov 1993
SO: BIOMINERALIZATION-93.-7TH-INTERNATIONAL-SYMPOSIUM-ON-BIOMINERALIZATION.-5-BIOMINERALIZATION-AND-GLOBAL-OCEANOLOGY.-6-BIOMINERALIZATION-IN-ENVIRONMENTAL-STUDIES-AND-AQUACULTURE.-7-BIOMINERALIZATION-AND-FOSSIL-DATA. Allemand,-D.-eds.;Cuif,-J.P.-eds. MONACO-MONACO MUSEE-OCEANOGRAPHIQUE 1996 vol. NS 14, no. 4 pp. 209-214
ST: BULL.-INST.-OCEANOGR.-MONACO vol. NS 14, no. 4
LA: English
ER: M (Marine)
AB: Fecal pellets egested by a number of marine organisms contain biominerals in the form of inorganic granules. These granules accumulate a wide range of metal ions both from within the animal and on their passage through the water column. Subsequent ingestion by filter feeding organisms could result in the absorption of these metals and present a pathway for the bioaccumulation of heavy metals and their cycling through the biota. In an experiment involving zinc uptake in mussels (M. edulis) the granules were incubated in sea water containing radioactively labelled zinc and then fed to mussels. Radiolabelled zinc in solution was used as a control to the particulate experiment. The results indicate that zinc in solution is absorbed across the gills and mantle. When in particulate form, the zinc is ingested, passed through the gut, and is absorbed into the digestive gland.
AN: 4015979

                                                                     282 of 313  
TI: Biomineralization 93. 7th International Symposium on Biomineralization. 5 -- Biomineralization and Global Oceanology. 6 -- Biomineralization in environmental studies and aquaculture. 7 -- Biomineralization and fossil data
AU: Allemand,-D.; Cuif,-J.P.-(eds.)
CO: 7. International Symp. on Biomineralization 93, Monaco (Monaco), 17-20 Nov 1993
SO: BULL.-INST.-OCEANOGR.-MONACO. MONACO-MONACO MUSEE-OCEANOGRAPHIQUE 1996 vol. NS 14, no. 4, 432 pp
LA: English
ER: M (Marine)
AB: The papers contained in the 5 th session address the complex interactions of the oceanic carbon dioxide system from a variety of complementary perspectives. A major conclusion to be drawn from this session is that there are great needs and opportunities in determining the fluxes and feedbacks of biomineralizing processes in global geochemical cycles, and the factors that control the sensitivities of these processes to environmental conditions or changes. Biomineralization operates as both cause and effect at all scales, and its significance can be fully appreciated only through the sort of interdisciplinary integration exemplified and encouraged by this Symposium. The topics of the 6 th session elucidate various aspects of biomineralization:1) Variations in structure, growth rates and elemental concentrations in shells of gastropods and bivalves, related to environmental parameters 2) Biomineralization and diseases in molluscan aquacultures 3) Calcification control in pearl cultivation 4) Modifications of bivalve shell structures caused by polydora infections 5) Heavy metal accumulation, and their cycling through the biota, in molluscs, crabs and algae 6) Influence of heavy metal concentrations on coccolith ultrastructure. The 7th session reports the new domains of palaeontology open by the recent improvements in analytical techniques. Understanding the sedimentological behaviour of biominerals, and what happens to these organo-mineral architectures when they enter the geological world is the challenge we now face. This approach will certainly improve our interpretation of fossil data in the chemical sense. It can also help us to obtain more precise information on the characteristics of ancient environments. But although this change in scale of palaeontological investigations is only at its beginning. Presently, the palaeontological study of biominerals offers what is still a highly puzzling panorama. However we can already see that the importance of this molecular-scale palaeontology cannot be over-estimated. From both theoretical and applied stand points, current ideas concerning relationships between life and geological processes, will certainly be transformed as strongly as they have been changed in the past.
AN: 4015955

                                                                     283 of 313  
TI: Rates of microbial degradation of dissolved organic carbon from phytoplankton cultures
AU: Chen,-Wenhao; Wangersky,-P.J.
AF: Sch. Earth and Ocean Sci., PO Box 1700, Univ. Victoria, Victoria, BC V8W 2Y2, Canada
SO: J.-PLANKTON-RES. 1996 vol. 18, no. 9, pp. 1521-1533
LA: English
ER: M (Marine)
AB: Dissolved organic carbon (DOC) decay was measured for samples from cultures of the diatoms Chaetoceros gracilis and Phaeodactylum tricornutum, the flagellate Isochrysis galbana, the dinoflagellate Alexandrium tamarense, and a natural algal assemblage from the Northwest Arm, Nova Scotia, Canada, by a high-temperature catalytic oxidation (HTCO) method. Decay rate constants were determined using first-order reaction kinetics in the multi-G model of Berner (In Early Diagenesis, a Theoretical Approach, Princeton University Press, 1980). Decay rates as high as 0.37 day super(-1) were obtained, which demonstrated that DOC released by phytoplankton might be highly labile to bacterial utilization and could be degraded significantly within hours. Decay rates for most species tested followed much the same pattern, with K sub(01) values around 0.3-0.4, K sub(02) values around 0.03, and K sub(03) and K sub(04) values around 10 super(-3) day super(-1) DOC released by the senescent cells of A. tamarense was found to be essentially bacteria resistant, in contrast to that of the other species tested. The decay of DOC was directly temperature dependent over the 10-20 degree C range. Six methods for DOC preservation were tested. Acidification with HCl and refrigerated storage was demonstrated to be the most convenient and practical method. This method can be used for both short- and long-term preservation of DOC samples containing highly labile organic compounds.
AN: 4015075

                                                                     284 of 313  
TI: Marine biotic responses to environmental change and feedbacks to climate
AU: Denman,-K.; Hofmann,-E.; Marchant,-H.
AF: Inst. Ocean Sci., Canada
SO: CLIMATE-CHANGE-1995-THE-SCIENCE-OF-CLIMATE-CHANGE. Houghton,-J.T.;Meira-Filho,-L.G.;Callander,-B.A.;Harris,-N.;Kattenberg,-A.;Maskell,-K.-eds. NEW-YORK,-NY-USA CAMBRIDGE-UNIVERSITY-PRESS 1996 pp. 483-516
LA: English
ER: M (Marine)
AB: Marine biogeochemical processes both respond to and influence climate. Atmospheric carbon dioxide (CO sub(2)) is the most important greenhouse gas increasing rapidly due to human activities. The oceans contain about 40,000 GtC in dissolved, particulate, and living forms. By contrast, land biota, soils and detritus total about 2200 GtC. Living and dead biogenic matter in the ocean contains at least 700 GtC, almost equal to the amount of CO sub(2) in the atmosphere (about 750 GtC). The increase in atmospheric carbon since pre-industrial times (150 GtC) is equivalent to that cycled through the marine planktonic ecosystem in less than 5 years. Simulation models calibrated with oceanic observations indicate that instead of the pre-industrial atmospheric CO sub(2) concentration of 280 ppmv, the atmospheric concentration of CO sub(2) would have been 450 ppmv in the absence of marine biota. Clearly, it is imperative that we understand the contribution of biogeochemical processes in maintaining the steady state functioning of the ocean carbon cycle. In addition to their importance in the global cycling of CO sub(2), marine organisms are significant sources of climatically active trace gases, especially dimethyl sulphide (DMS). Because of the complexity of biological systems, we cannot yet say whether some likely feedbacks from the marine biota in response to climate related changes will be positive or negative. However improved quantitative understanding is likely within the next decade.
AN: 4012897

                                                                     285 of 313  
TI: A simple modelling approach towards hydrochemical seasonality of major cations in a central Amazonian floodplain lake
AU: Weber,-G.E.; Furch,-K.; Junk,-W.J.
AF: Dep. Ecol. Modelling, UFZ-Cent. for Environ. Res. Leipzig-Halle, Permoserstr. 15, 04318 Leipzig, Germany
SO: ECOL.-MODEL. 1996 vol. 91, no. 1-3, pp. 39-56
LA: English
ER: F (Freshwater)
AB: To identify causes of hydrochemical seasonality, dynamic mass balance models are developed. They describe a hypothetical floodplain lake designed according to literature data supplemented by unpublished data on Lago Camaleao, an island channel lake in the lower Solimoes River. The conservative model accounts for advective and atmospheric cation fluxes, the non-conservative model additionally for biogenic cation fluxes due to growth and decomposition of the macrophyte vegetation. During much of the hydroperiod, seasonal evolutions observed for Na, Ca, and Mg, were in accordance with conservative expectation. Increasing concentrations during falling water were not explained by the conservative model. Differences between predictions of the conservative, and the non-conservative model were negligible. Thus, for the evolution of Na, Ca, and Mg, biogenic fluxes are insignificant. We suggest that cation loading during falling water is caused by an abiotic process. Evolution of K was non-conservative during much of the hydroperiod. Deviations from conservative expectation due to K loading during rising, as well as during falling water, were in accordance with predictions of the non-conservative model. Hence, during rising water, macrophyte-derived influxes of K are the key factor for deviations from conservative expectation. During falling water, however, macrophyte decomposition is still poorly understood, and unknown processes causing Na, Ca, and Mg loadings might also procure additional K loading, and thus biogenic K fluxes might not be the sole cause for increasing concentrations.
AN: 4012081

                                                                     286 of 313  
TI: Sedimentation and carbon flux in a Scottish sea loch, Loch Linnhe
AU: Overnell,-J.; Young,-S.
AF: Dunstaffnage Mar. Lab., P.O. Box 3, Oban, Argyll PA34 4AD, UK
SO: ESTUAR.-COAST.-SHELF-SCI. 1995 vol. 41, no. 3, pp. 361-376
LA: English
ER: M (Marine)
AB: Sediment traps were deployed in the upper basin of Loch Linnhe in 120 m of water at depths of 20, 60, 90 and 110 m below the surface. They were serviced over 13 months during 1991-92 at intervals ranging from a week to a month and the following parameters measured: dry weight and concentrations of carbon, nitrogen and chlorophyll. The average sedimentation rates of total dry weight over a year at 20, 60, 90 and 110 m were 12.4, 20.4, 31.0 and 48.5 g/m super(2)/day respectively. The historical net sedimentation rate, calculated from the depth profile of  super(210)Pb, was 12.7 g/m super(2)/day, suggesting that the sedimentation rate at 20 m is probably a good estimate of the present net sedimentation rate. On this basis the (estimated) sedimentation at the sediment surface (120 m) was composed of approximately 80% resuspended material. The estimate of input of organic carbon of phytoplankton origin was based on chlorophyll sedimentation rates and yielded a figure of 0.082 g C/m super(2)/day. A summary diagram indicating our estimate of the pathways of particulate organic carbon is presented.
AN: 4009507

                                                                     287 of 313  
TI: The effect of precipitation chemistry upon anion and cation fluxes from the surface layer of ombrotrophic mires in the UK
AU: Sanger,-L.J.; Billett,-M.F.; Cresser,-M.S.
AF: Dep. Biol. Sci., Hatherly Labs., Univ. Exeter, Exeter EX4 4PS, UK
SO: J.-APPL.-ECOL. 1996 vol. 33, no. 4, pp. 754-772
LA: English
ER: F (Freshwater)
AB: Replicate cores and monoliths (bearing intact vegetation) were sampled from the acrotelm and surface litter layer of ombrotrophic mires across a gradient in precipitation chemistry. Leaves from Calluna vulgaris shrubs growing on the surface of these mires were also sampled. The chemical characteristics of the cores as initially sampled and incident Calluna vulgaris leaves were determined. During a 1-year study the monoliths were subjected to 1200 mm of simulated rainfall of the same chemical composition as they received in the field. Drainage water was analysed periodically for component anions and cations. The results show that changes in the chemical quality of precipitation in the UK has induced changes in the N cycling and base status within the acrotelm, and surface litter layer of ombrotrophic mires. The processes affecting NO sub(3) super(-) and NH sub(4) super(+) concentrations in this layer were not the same. Ammonium concentrations were largely dependent upon ion exchange reactions whereas NO sub(3) super(-) concentrations were more dependent upon biologically mediated processes. The results of the study of total element chemistry in Calluna vulgaris stands showed that leaves contained higher N and lower P and Mg concentrations in areas receiving high concentrations of chemical components, delivered in precipitation associated with industrial and domestic atmospheric emissions. Fluxes of all of the ions from monoliths were highly seasonal, and generally reflected fluctuations in nutrient uptake by the vegetation and the activity of soil microbes and fauna. Unlike NH sub(4) super(+), NO sub(3) super(-) and P were rapidly immobilized in the acrotelm and surface litter layer of mires in areas receiving high H, N and S atmospheric inputs. Total P concentrations in this layer were highest in areas receiving high concentrations of H, N and S in precipitation. This probably reflected the rate of litter decomposition and hence the mineralization of organic-P; and may be linked to the chemical composition of Calluna vulgaris leaves.
AN: 4007180

                                                                     288 of 313  
TI: Effects of plankton dynamics on seasonal carbon fluxes in an ocean general circulation model
AU: Six,-K.D.; Maier-Reimer,-E.
AF: Max-Planck-Inst. fuer Meteorologie, Hamburg, Germany
SO: GLOBAL-BIOGEOCHEM.-CYCLES 1994 vol. 10, no. 4, pp. 559-583
LA: English
ER: M (Marine)
AN: 4006223

                                                                     289 of 313  
TI: Oxidation of cobalt and manganese in seawater via a common microbially catalyzed pathway
AU: Moffett,-J.W.; Ho,-J.
AF: Dep. Mar. Chem. and Geochemistry, Woods Hole Oceanographic Inst., Woods Hole, MA 02543, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA 1996 vol. 60, no. 18, pp. 3415-3424
LA: English
ER: M (Marine)
AB: Cobalt and manganese uptake onto suspended particles was studied in waters collected from Waquoit Bay, Massachusetts and the upper water column of the Sargasso Sea using radiotracers, coupled with protocols used previously for Mn and Ce to distinguish biological and redox processes. Cobalt uptake onto suspended particles in Waquoit Bay was dominated by microbial oxidation. Moreover, there was a close relationship between Mn(II) and Co(II) oxidation, with Mn(II) specific rates approximately 7-10x faster. Oxidation of each element obeys Michaelis Menten kinetics, with identical values of K sub(m) in a given sample and values of V sub(max) which are 7x higher for Mn. Lineweaver-Burk plots, generated from saturation plots for Co and Mn oxidation at different Mn and Co concentrations, demonstrated competitive inhibition between Co and Mn. The results indicate that both elements are co-oxidized via the same microbial catalytic pathway, and that this is probably an important mechanism for the incorporation of Co into marine Mn oxides. In the Sargasso Sea, by contrast, Mn and Co uptake onto suspended particles were completely decoupled. Cobalt uptake was nonoxidative, biologically mediated, and enhanced by low to moderate levels of light. It is probably due primarily to uptake by phytoplankton. Manganese uptake was almost exclusively oxidative and was inhibited by light even at low intensities. The differences probably reflect a higher biological demand for Co in the Sargasso Sea (Co is a biologically essential element), where Co concentrations are low, and lower activity of Mn oxidizing bacteria. Results suggest that higher specific uptake rates of Co than Mn by phytoplankton in oceanic regimes could result in Co having a geochemistry intermediate between Mn and a more nutrient-type element, such as Zn. Nevertheless, Co and Mn cycling are expected to be closely coupled in regions of high microbial Mn oxidizing activity.
AN: 4006181

                                                                     290 of 313  
TI: Dynamic vs. apparent Redfield ratio in the oceans: A case for 3D-models
AU: Maier-Reimer,-E.
AF: Max Planck-Inst. fuer Meteorologie, Hamburg, Germany
SO: J.-MAR.-SYST. 1996 vol. 9, no. 1-2, pp. 113-120
NT: Special issue: EHUX (Emiliania huxleyi).
LA: English
ER: M (Marine)
AB: A three-dimensional model of global biogeochemical cycles (HAMOCC3) is used to discuss potential explanations for apparent observed deviations from a basin-wide Redfield ratio. Two examples are given in which model information can be taken to close the gaps of incomplete measurements or data analyses. A third example illustrates how the apparent covariation between phosphate and alkalinity is created by the circulation.
AN: 4005970

                                                                     291 of 313  
TI: Nitrogen fixation in the marine environment: Relating genetic potential to nitrogenase activity
AU: Zehr,-J.P.; Braun,-S.; Chen,-Y.; Mellon,-M.
AF: Dep. Biol., Rensselaer Polytechnic Inst., Troy, NY 12180-3590, USA
CO: Symposium on Marine Biology: Molecular and Genetic Advances, Plymouth (UK), Apr 1995
SO: J.-EXP.-MAR.-BIOL.-ECOL. 1996 vol. 203, no. 1, pp. 61-73
LA: English
ER: M (Marine)
AB: Nitrogen fixation can be an important source of nitrogen for biological productivity in the marine environment. Biological nitrogen fixation is catalyzed by the enzyme nitrogenase, which is possessed by diverse microorganisms representing virtually all phylogenetic groups. Interest in nitrogen fixation in the sea has usually been focused on rates of nitrogen fixation, but information on the types of species present with the capability for nitrogen fixation can be important for predicting nitrogen fixation rates in situ. Molecular tools for detection and characterization of the nitrogenase (nif) genes and immunoassays for nitrogenase protein can provide new information on the factors regulating the distribution and activity of diverse nitrogen fixing organisms in the marine environment. Amplification and characterization of nifH sequences has made it possible to identify the type(s) of organism responsible for nitrogen fixation, such as in aggregates of the cyanobacterium Trichodesmium. Differences in nitrogen fixation patterns have been linked to genetic differences between Trichodesmium strains. Further development of these approaches will provide new and powerful ways to link the genetic potential for nitrogen fixation to nitrogen fixation rates in the ocean.
AN: 4003712

                                                                     292 of 313  
TI: Carbon, nitrogen and sulfur cycling in sediments of the Ao Nam Bor mangrove forest, Phuket, Thailand: A review
AU: Kristensen,-E.; Holmer,-M.; Banta,-G.T.; Jensen,-M.H.; Hansen,-K.
AF: Institute of Biology, Odense University, DK-5230 Odense M, Denmark
SO: RES.-BULL.-PHUKET-MAR.-BIOL.-CENT. 1995 no. 60, pp. 37-64
NT: Includes bibliogr.: 124 refs.
LA: English
ER: M (Marine); B (Brackish)
AB: An attempt is made to review available data on sediment biogeochemistry of the Ao Nam Bor mangrove forest on the east coast of Phuket Island, Thailand. Aspects of sedimentary carbon, sulfur and nitrogen cycling are evaluated and compared in 3 intertidal zones: 1) The low-intertidal, non-vegetated mudflat outside the forest; 2) The mid-intertidal forest zone with dense growth of Rhizophora apiculata; and 3) The high-intertidal sparsely vegetated zone with high abundance of crab burrows. By compiling data on organic carbon and nitrogen input to (e.g. litterfall, benthic primary production) and output from (e.g. crab ingestion, microbial mineralization, plant assimilation) the sediment, preliminary budgets for the 3 intertidal zones at Ao Nam Bor may be established. However, the presented budgets have serious limitations caused by a general lack of data. In cases where no data are available from Phuket, results are either extrapolated from other mangrove forests, estimated based on assumptions or simply ignored. Furthermore, as most data on benthic carbon and nitrogen cycling used in the budgets are obtained only during the dry season, the carbon budgets most certainly do not represent annual averages, but should rather be considered dry season averages.
AN: 4001132

                                                                     293 of 313  
TI: Methylated arsenic in the southern North Sea
AU: Millward,-G.E.; Kitts,-H.J.; Comber,-S.D.W.; Ebdon,-L.; Howard,-A.G.
AF: Dep. Environ. Sci., Univ. Plymouth, Plymouth PL4 8AA, Devon, UK
SO: ESTUAR.-COAST.-SHELF-SCI. 1996 vol. 43, no. 1, pp. 1-18
LA: English
ER: M (Marine)
AB: Water samples collected in the southern North Sea in August 1988 (mid-summer), April 1989 (spring), September/October 1989 (late summer) and May 1990 were analysed for dissolved inorganic arsenic, monomethylarsenic (MMA) and dimethylarsenic (DMA). In mid-summer 1988, both MMA and DMA were observed throughout the southern North Sea, with lowest concentrations of dissolved inorganic arsenic (mean 6.48 nmol/l) and the highest proportions of methylated arsenic (29%) being found in highly productive continental coastal waters. In April 1989, waters of the North Sea had a mean inorganic arsenic concentration of 12 nmol/l and methylated species were not detected, even though phytoplankton blooms were present. Shipboard phytoplankton incubation studies (in May 1990) revealed that uptake of dissolved inorganic arsenic occurred at a rate of 0.57 nmol/l/day, but the appearance of dissolved methylated species was not observed. During September/October 1989, while MMA and DMA were present in all sectors of the North Sea, the relative proportion of methylated compounds (11%) in continental coastal waters was less than mid-summer 1988. It was shown that estuarine, porewater and atmospheric inputs of arsenic species were relatively small during the observational periods, and that almost all of the methylated compounds originated from decaying algal tissue. Demethylation of DMA and MMA throughout winter contributed to the dissolved inorganic arsenic pool. The results are discussed in the context of the development of a predictive model for the cycling of arsenic in the North Sea.
AN: 3999637

                                                                     294 of 313  
TI: Organism size, life history, and N:P stoichiometry
AU: Elser,-J.J.; Dobberfuhl,-D.R.; MacKay,-N.A.; Schampel,-J.H.
AF: Dep. Zool., Arizona State Univ., Tempe, AZ 85287, USA
SO: BIOSCIENCE 1996 vol. 46, no. 9, pp. 674-684
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Our approach in this article is as follows. First, we describe recent discoveries that establish the importance of consumer body nitrogen:phosphorus (N:P) ratio in modulating secondary production and consumer-driven nutrient cycling in ecosystems. Second, we review aspects of cellular biochemistry and ultrastructure through the eyes of an ecosystem scientist, focusing on the relative nitrogen and phosphorus contents of important biomolecules and cellular structures. Third, we present examples of how organismal characters such as growth rate and ontogeny are linked with biochemical and cellular investment and thus with body N:P ratio. Finally, we propose a general scenario for allometric variation in body N:P ratio among consumers ranging from bacteria to large vertebrates and use the scenario to predict patterns of consumer-driven nutrient cycling and food quality constraints. In the spirit of Reiners (1986), we employ stoichiometric theory as a complementary approach to the study of biological processes, one that we hope will both reinforce conclusions derived from energetic perspectives as well as provide new insights into biological phenomena that may be puzzling when considered from more traditional single-currency approaches.
AN: 3997804

                                                                     295 of 313  
TI: Major biochemical composition of dissolved high molecular weight organic matter in seawater
AU: McCarthy,-M.; Hedges,-J.; Benner,-R.
AF: University of Washington, School of Oceanography, Box 357940, Seattle, WA 98195-7940, USA
SO: MAR.-CHEM. 1996 vol. 55, no. 3-4, pp. 281-297
LA: English
AB: Ultrafiltered dissolved organic matter (UDOM) was isolated from surface, oxygen minimum, and deep waters of three ocean basins and its elemental as well as molecular-level aldose and amino acid compositions were determined. Surface concentrations account for 23-33% of total dissolved organic carbon, and are a factor of 2-3 greater than those in deeper waters. Oceanic UDOM has an extremely characteristic organic composition, clearly distinct from other marine materials such as fresh plankton, sinking particles or humic substances. Polysaccharides appear to be the major reactive component of UDOM. They have a distinctive aldose distribution rich in galactose and deoxy sugar that is almost ubiquitous regardless of depth or location, suggesting that UDOM carbohydrate is dominated by a very similar suite of polysaccharide throughout the ocean. In contrast, amino acids account for a relatively minor component of both total UDOM and of its organic nitrogen component. Amino acid distributions are similar to those from unfractionated seawater, and are not preferentially remineralized.In O2 minimum and deep ocean water, ultrafiltered material accounts for 18-25% of total dissolved organic carbon. Compositions are nearly invariant in these subsurface isolates, suggesting that ultrafiltered material is stable and unreactive throughout the subsurface ocean. Taken together with large compositional differences between UDOM and sinking particles, this observation suggests that dynamic aggregation is probably not an important formation or removal process for UDOM in the deep ocean. Amino acid and especially carbohydrate concentrations are lower in deep UDOM, but the overall molecular-level compositions remain similar to those from surface waters. This molecular-level homogeneity suggests that the UDOM biopolymers reflected in amino acid and carbohydrate data persist relatively unaltered in the deep ocean.
AN: 3997007

                                                                     296 of 313  
TI: Modelling the monthly sea surface
AU: Louanchi,-F.; Metzl,-N.; Poisson,-A.
AF: Laboratoire de Physique et Chimie Marines, URA 2076/CNRS -- Universite Pierre et Marie Curie, case 134, 4 place Jussieu, F-75252 Paris Cedex 05, France
SO: MAR.-CHEM. 1996 vol. 55, no. 3-4, pp. 265-279
LA: English
AB: In order to construct monthly fields of sea surface fugacity of carbon dioxide (fCO2) on a large scale in the Indian Ocean, we use a one-dimensional model which takes into account the main physical and biogeochemical processes controlling fCO2 variations in the ocean. Physical and biogeochemical processes are constrained by the monthly variations of sea surface temperature, salinity, chlorophyll concentration, wind speed and mixed-layer depth. The model is applied to four locations in the Indian Ocean and it well predicts observed temporal variations in fCO2 at these locations. Regarding to monthly fCO2 observations, the model also well simulates the fCO2 distribution and its temporal variations along a track located between 20 degree  and 50 degree S with a maximal error of  plus or minus 10  mu atm. The model is also used to predict fCO2 for 2 degree  x 2 degree  grids over the entire Indian Ocean and simulates seasonal cycles that are consistent with observations. The monthly fCO2 fields derived from the model are used to estimate a global air-sea CO2 flux over the Indian Ocean basin. We estimate a net sink of 0.5 Gt/yr C for the Indian Ocean (20 degree N-50 degree S), with the main sink located between 20 degree  and 50 degree S.
AN: 3997006

                                                                     297 of 313  
TI: The oceans: A source or a sink of methyl bromide?
AU: Pilinis,-C.; King,-D.B.; Saltzman,-E.S.
AF: Rosenstiel Sch. Mar. and Atmos. Sci., Univ. Miami, Miami, FL, USA
SO: GEOPHYS.-RES.-LETT. 1996 vol. 23, no. 8, pp. 817-820
LA: English
ER: M (Marine)
AN: 3992312

                                                                     298 of 313  
TI: Benthic Ba fluxes in the central Equatorial Pacific, implications for the oceanic Ba cycle
AU: Paytan,-A.; Kastner,-M.
AF: Scripps Inst. Oceanogr., Univ. California, San Diego, La Jolla, CA 92093-0212, USA
SO: EARTH-PLANET.-SCI.-LETT. 1996 vol. 142, no. 3-4, pp. 439-450
LA: English
ER: M (Marine)
AB: High resolution pore-water dissolved Ba concentration-depth profiles were determined at seven sites across an Equatorial Pacific productivity gradient from 12 degree 8 to 9 degree N, at 140 degree W. These data are important for understanding the physical, chemical, and biological controls on Ba recycling in the ocean, and for evaluating the paleo-oceanographic significance of Ba content in central Equatorial Pacific sediments. Pore-water Ba concentrations at all sites are higher than in the overlying bottom water, leading to a diffusive flux of Ba into the ocean. A pronounced subsurface concentration maximum exceeding barite solubility characterizes the dissolved Ba pore-water profiles, suggesting that the Ba regenerated in the upper few millimeters of sediment is not controlled by barite solubility. A few centimeters down-core Ba concentrations reach a relatively constant value of approximately barite saturation. The benthic Ba flux shows a clear zonal trend, with a maximum between 2 degree S and 2 degree N, most probably due to higher productivity at the equatorial divergence zone, and with lowest values at the southern and northern extremes of the transect. The dissolved Ba flux between 2 degree S and 2 degree N is  similar to 30 nmol cm super(-2) yr super(-1) and drops to 6 nmol cm super(-2) yr super(-1) at 12 degree S. Even the lowest fluxes are significantly higher than those previously reported for the open ocean. In the Equatorial Pacific the calculated Ba recycling efficiency is about 70%. Thus,  similar to  30% of the particulate Ba flux to the deep ocean is preserved in the sediments, compared with less than 1% for organic carbon and  similar to  5% for biogenic silica. Mass balance calculation of the oceanic Ba cycle, using a two-box model, implies benthic Ba fluxes similar to those reported here for a steady-state ocean.
AN: 3985021

                                                                     299 of 313  
TI: Secondary suspend particulate matters and the bioelement loop in sea water columns
AU: Wu,-Yuduan; Chen,-Cimei; Luo,-Xiaohong
AF: Dep. Oceanogr., Xiamen Univ., Xiamen 361005, People's Rep. China
SO: PROCEEDINGS-OF-SYMPOSIUM-OF-MARINE-SCIENCES-IN-TAIWAN-STRAIT-AND-ITS-ADJACENT-WATERS.-TAIWANHAIXIA-JI-LINJINHAIYU-HAIYANGKEXUE-TAOLUNHUI-LUNWENJI Yu,-Xiaoqun-eds. BEIJING-CHINA CHINA-OCEAN-PRESS 1995 pp. 326-332
LA: English
ER: M (Marine)
AB: The increasing discharge of aquaculture and domestic sewages has caused the formation of secondary suspended particulate matters in the nearshore waters. The paper discusses the problem in the following three aspects. (1) the formation mechanism of the secondary suspended particulate matters; (2) The effects of the secondary suspended particulate matters on the kinetics of transformation among various speciations of the bioelements and the level of nutrients in water; (3) The roles of buffering and controlling played by the secondary suspended particulate matters in the geochemical behaviour, processes, fate and cycling of the bioelements in water columns. It is concluded that the process causes potential eutrophication in coastal waters.
AN: 3983240

                                                                     300 of 313  
TI: The chemical structure of the ecological environment in Lake Honghu
AU: Yang,-Handong; Cai,-Shuming
AF: Inst. Geod. Geophys., Acad. Sin., Wuhan 430077, People's Rep. China
SO: ACTA-ECOL.-SIN.-SHENGTAI-XUEBAO 1995 vol. 15, no. 4, pp. 392-398
LA: Chinese
ER: F (Freshwater)
AB: Lake Honghu is a typical shallow lake and rich in aquatic plants in the middle reach of the Yangtze River. It is an example of and important of type wetland in China. This paper reports on the chemical structure of the ecological environment in the lake. In the lake water, Ca super(2+) and HCO sub(3) super(-) are major cation and anion, alkal capacity is rather low, acid capacity is 1.2x10 super(-3)-2.0x10 super(-3)mol/l H super(+). The equilibrium course of carbonates is the basic factor to control the geochemical process of water quality. Aquatic plants in the lake play the role of concentrating C,N,K,Ca and Cd. The sediment profile of the surface is rich in C,N,S,Ca and Cd. The Al content is relatively low in the sediment although there were large amount of aquatic plants. Most of the C exists in the aquatic plants and N, P, K, Ca and Mg exist in the sediment. The sediment compartment serves as a nutrient reserve.
AN: 3983146

                                                                     301 of 313  
TI: Spatial patterns in phytoplankton biomass and pigment distributions in the Ross Sea
AU: DiTullio,-G.R.; Smith,-W.O.,Jr.
AF: Grice Mar. Biol. Lab., Univ. Charleston, Charleston, SC 29401, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS 1996 vol. 101, no. C8, pp. 18467-18477
NT: Special section: Biogeochemical cycling in the Ross Sea.
LA: English
ER: M (Marine)
AB: The distribution of phytoplankton biomass and pigments was determined in the Ross Sea during late austral summer 1992. Large gradients in biomass were noted both in the east-west and north-south direction, with maximum particulate matter concentrations occurring in the southwest portion of the Ross Sea. Two xanthophyll pigments dominated the profiles, fucoxanthin (indicative of diatoms) and 19' hexanoyloxyfucoxanthin (hex) (indicative of the prymnesiophyte Phaeocystis antarctica). Fucoxanthin concentrations were greatest near the coast of Victoria Land and within the northern transect, whereas hex concentrations were highest offshore in the SE Ross Sea. Particulate carbon:chlorophyll a (POC:chl) ratios in diatom-dominated waters of the western Ross Sea were relatively high (210). The POC:chl ratio for Phaeocystis antarctica populations from the SE Ross Sea was substantially less (92) than the ratios observed in diatom-dominated waters. Pigment  super(14)C labeling indicated that phytoplankton carbon in the diatom-dominated northern Ross Sea accounted for approximately 30% of the POC, with a phytoplankton C:chl ratio of 130. Short-term (24 hour) vertical fluxes of pigments ranged from 3 to 40  mu g chl a m super(-2) d super(-1). Diatom-dominated regions had greater fluxes of phaeophorbides, suggesting that metazoans were the most important grazers at these locations. In contrast, the phaeophytin/total phaeopigment ratio was highest in waters dominated by Phaeocystis antarctica. The distribution of phytoplankton biomass and pigments revealed a spatially variable distribution of taxa, one which clearly has important consequences to food-web dynamics, biogeochemical cycles, and vertical flux patterns in the Ross Sea.
AN: 3982064

                                                                     302 of 313  
TI: Influence of temperature on pathways to methane production in the permanently cold profundal sediment of Lake Constance
AU: Schulz,-S.; Conrad,-R.
AF: Max-Planck-Inst. fuer Terrestrische Mikrobiologie, Karl-von-Frisch-Str., D-35043 Marburg, Germany
SO: FEMS-MICROBIOL.-ECOL. 1996 vol. 20, no. 1, pp. 1-14
LA: English
ER: F (Freshwater)
AB: The in situ temperature of the profundal sediment of Lake Constance is constant at 4 degree C. Methanogenic bacteria could not be detected at 6 degree C by the most probable number (MPN) technique using acetate and H sub(2)/CO sub(2) as methanogenic substrates. Instead, homoacetogenic bacteria were detected on H sub(2)/CO sub(2). At a higher temperature of 20 degree C, however, methanogenic bacteria were found in numbers of about 10 super(5) cells ml super(-1) with H sub(2)/CO sub(2) and about 5 x 10 super(4) cells ml super(-1) with acetate. However, CH sub(4) production was observed at both 4 degree C and 20 degree C. Production of CH sub(4) was inhibited by chloroform and fluoroacetate and the accumulation of intermediary metabolites was measured. At the in situ temperature of 4 degree C, only acetate accumulated in presence of chloroform. Hydrogen partial pressures were at the same low value of about 0.5 Pa as in the uninhibited control. The amount of accumulated acetate was similar to that of CH sub(4) in the uninhibited controls. Similar results were obtained with fluoroacetate which inhibits methanogenesis from acetate. Addition of H super(14)CO sub(3) super(-) did not result in the formation of  super(14)CH sub(4) after 28 days of incubation. However, [2- super(14)C]acetate was immediately converted to  super(14)CH sub(4). The results indicate that methanogenesis at 4 degree C was exclusively due to acetate cleavage. At 20 degree C, by contrast, accumulation of H sub(2) was observed in addition to that of acetate, propionate, valerate, caproate, methanol and isopropanol, when CH sub(4) production was inhibited by chloroform. Thermodynamic calculations indicated that the accumulation of the fatty acids was a consequence of feedback inhibition by the accumulated H sub(2). Balance calculations indicated that at 20 degree  about 22% of the CH sub(4) originated from reduction of CO sub(2). Experiments with H super(14)CO sub(3) super(-) indicated that about 33% of the CH sub(4) originated from H sub(2)/CO sub(2) at 20 degree C. Thermodynamic calculations showed that homoacetogenesis from H sub(2)/CO sub(2) was endergonic, whereas methanogenesis from acetate or H sub(2)/CO sub(2) was exergonic at both 4 degree C and 20 degree C. Low sediment temperatures obviously limited methanogenesis from H sub(2)/CO sub(2) for reasons other than thermodynamics. Simultaneously, degradation processes seemed to be dominated by homoacetogenic degradation of organic matter followed by acetoclastic methanogenesis. However, increase of temperature resulted in a dramatic shift of the degradation pathway enhancing the role of H sub(2) as an intermediate.
AN: 3981616

                                                                     303 of 313  
TI: Depth profile of sulfate-reducing bacterial ribosomal RNA and mercury methylation in an estuarine sediment
AU: Devereux,-R.; Winfrey,-M.R.; Winfrey,-J.; Stahl,-D.A.
AF: Microbial Ecol., Gulf Ecol. Div., Natl. Health and Environ. Effects Res. Lab., U.S. Environ. Prot. Agency, 1 Sabine Island Dr., Gulf Breeze, FL 32561, USA
SO: FEMS-MICROBIOL.-ECOL. 1996 vol. 20, no. 1, pp. 23-31
LA: English
ER: B (Brackish)
AB: The community structure of complex anaerobic microbial communities has been difficult to elucidate because of an inability to cultivate most of the contributing populations. In this study, the distribution of sulfate-reducing bacteria (SRB) in anaerobic sediments was determined using oligonucleotide probes complementary to the 16S ribosomal RNAs of major phylogenetic groups. Sediment cores were collected from Santa Rosa Sound in northwest Florida, and sectioned by depth into 1 to 2 cm fractions. Nucleic acids were extracted from each fraction and hybridized with the SRB-specific ribosomal RNA probes. SRB ribosomal RNAs accounted for almost 5% of the microbial community ribosomal RNA pool in the 3-4 cm depth fraction and were dominated by Desulfovibrionaceae ribosomal RNA. The SRB ribosomal RNA peak coincided with mercury methylation, an activity attributed to SRB. Profiles of the ribosomal RNAs indicate that SRB populations in sediments are stratified by depth.
AN: 3981615

                                                                     304 of 313  
TI: The role of the vertical fluxes of particulate organic matter and calcite in the oceanic carbon cycle: Studies using an ocean biogeochemical general circulation model
AU: Yamanaka,-Y.; Tajika,-E.
AF: Cent. for Climate System Res., Univ. Tokyo, Tokyo, Japan
SO: GLOBAL-BIOGEOCHEM.-CYCLES 1996 vol. 10, no. 2, pp. 361-382
LA: English
ER: M (Marine)
AN: 3980638

                                                                     305 of 313  
TI: The  super(13)C Suess effect in the world surface oceans and its implications for oceanic uptake of CO sub(2): Analysis of observations at Bermuda
AU: Bacastow,-R.B.; Keeling,-C.D.; Lueker,-T.J.; Wahlen,-M.
AF: Scripps Inst. Oceanogr., Univ. California at San Diego, La Jolla, CA 92093, USA
SO: GLOBAL-BIOGEOCHEM.-CYCLES 1996 vol. 10, no. 2, pp. 335-346
LA: English
ER: M (Marine)
AN: 3980635

                                                                     306 of 313  
TI: Biogeochemical cycling in the Ross Sea: An introduction
AU: Marra,-J.
AF: Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS 1996 vol. 101, no. C8, pp. 18453-18454
NT: Special section: Biogeochemical cycling in the Ross Sea.
LA: English
AB: The primary aim of biogeochemical cycling in the Ross Sea is to understand the relationship between surface production and sediment preservation. Background for the Biogeochemical Cycling in the Ross Sea program is presented by DeMaster et al. [1992]. The Ross Sea, like much of the Southern Ocean, exhibits a high percentage of opal in the sediments and is a major repository of biogenic silica in the world ocean. Does this represent high fertility of the surface layer? What relative fraction of organic carbon and biogenic silica produced at the surface is preserved in the sediments?
AN: 3979597

                                                                     307 of 313  
TI: Aerosol emissions by tropical forest and savanna biomass burning: Characteristic trace elements and fluxes
AU: Echalar,-F.; Gaudichet,-A.; Cachier,-H.; Artaxo,-P.
AF: LISA - URA CNRS 1404, Univ. Paris 7 et Paris 12, Creteil, France
SO: GEOPHYS.-RES.-LETT. 1995 vol. 22, no. 22, pp. 3039-3042
LA: English
AN: 3976977

                                                                     308 of 313  
TI: The role of organic matter in controlling copper speciation in precipitation
AU: Spokes,-L.J.; Campos,-M.L.A.M.; Jickells,-T.D.
AF: Sch. Environ. Sci., Univ. East Anglia, Norwich NR4 7TJ, UK
SO: ATMOS.-ENVIRON. 1996 vol. 30, no. 23, pp. 3959-3966
LA: English
ER: F (Freshwater)
AB: Organic complexation has been suggested to be an important mechanism by which the biogeochemistry of transition metals is altered in natural waters. We have conducted complexing ligand titrations on rainwater, collected during the winter and spring from a semi-urban U.K. location, using cathodic stripping voltammetry with tropolone as the added ligand. The results show that organic ligands capable of binding copper are present in all the precipitation samples measured. As a consequence of the method used, only those copper-natural ligand complexes with conditional stability constants (1:1 stoichiometry-log K' sub(CuL)) between 11 and 14 have been identified. Within this stability region, ligand concentrations vary from 10.2 to 34.5 nM, very similar to the total copper levels which range between 10.2 and 33.2 nM. While total copper has a concentration of the order of 10 super(-8) M, free Cu super(2+) ions exist at levels of just 10 super(-11)-10 super(-12) M, showing that copper is largely complexed in the rainwater samples measured. The existence of such low free ion concentrations must be considered when assessing the catalytic role of rain and aerosol trace metals in atmospheric reactions and determining the impact of atmospheric inputs on surface water biogeochemistry. Conditional stability constants increase with the detection window used (from log K' sub(CuL) = 11.4 at a detection window centred at log  alpha  sub(CuAL) = 2.68 to log K' sub(CuL) = 12.57 at log  alpha  sub(CuAL) = 4.47). As the method is specific to a limited range of conditional stabilities, dependent on the strength and amount of competitive ligand used, this concentration dependence suggests the presence of a wider range of natural ligands than those identified here. The source of the organic complexant in precipitation is unclear. We postulate, based on stable isotope measurements made on rains collected at the same location, that the organic ligands are likely to be terrestrial in origin.
AN: 3976279

                                                                     309 of 313  
TI: Preservation efficiencies and accumulation rates for biogenic silica and organic C, N, and P in high-latitude sediments: The Ross Sea
AU: DeMaster,-D.J.; Ragueneau,-O.; Nittrouer,-C.A.
AF: Dep. Mar., Earth, and Atmos. Sci., North Carolina State Univ., Raleigh, NC 27607, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS 1996 vol. 101, no. C8, pp. 18501-18518
NT: Special section: Biogeochemical cycling in the Ross Sea.
LA: English
ER: M (Marine)
AB: Rates of biogenic sediment accumulation (biogenic silica and organic C, N, and P) and pore water flux have been established for a variety of depositional environments in the Ross Sea. On the basis of  super(14)C measurements in kasten cores, sediment accumulation rates ranged from 250 cm kyr super(-1) in the coastal basin of Granite Harbor to 1-2 cm kyr super(-1) in the shelf and slope environments of the northern and eastern Ross Sea. Burial of biogenic material was most rapid in the southwestern Ross Sea, where biogenic silica accumulation rates ranged from 2 to 31 g cm super(-2) kyr super(-1) and organic carbon accumulation rates ranged from 0.05 to 1.4 g cm super(-2) kyr super(-1). In the northern and eastern Ross Sea, biogenic silica and organic carbon accumulation rates typically equaled 0.02-0.03 g SiO sub(2) cm super(-2) kyr super(-1) and 0.002-0.004 g C cm super(-2) kyr super(-1). Flux core measurements were used to estimate seabed regeneration rates for biogenic silica, organic carbon, and phosphorus. Pore water fluxes, in general, showed much less variability across the Ross Sea than did the biogenic accumulation rates. Pore water silicate fluxes in the study area ranged from 0.6 to 5.3 g SiO sub(2) cm super(-2) kyr super(-1), whereas carbon fluxes ranged from 0.1 to 1.2 g C cm super(-2) kyr super(-1) and phosphate fluxes varied from -0.006 to 0.012 g P cm super(-2) kyr super(-1). Seabed preservation efficiencies were calculated for biogenic silica, organic carbon, and phosphorus by combining the solid-phase and pore water data. The seabed preservation efficiencies for biogenic silica (1-86%) were greater than for organic carbon (1-71%) at all nine stations examined. The preferential preservation of biogenic silica relative to organic carbon also was apparent in Ross Sea sediments because the biogenic silica/organic carbon ratio in the material buried in the seabed generally was 2 times greater than the ratio in sediment particles arriving at the sediment-water interface. Sediment accumulation rate correlated strongly with both the biogenic silica and the organic carbon preservation efficiency data. P preservation efficiencies remained relatively high (24-65%) even when the accumulation rates were low (1-2 cm kyr super(-1)) because of the near-zero phosphate fluxes out of the seabed. Of the total P in the seabed (0.04-0.09 wt. %), approximately 25% existed in the form of organic P. The total amount of biogenic silica accumulating on the Ross Sea shelf is  similar to 2.3 x10 super(12) g SiO sub(2) yr super(-1), which is approximately an order of magnitude less than the Ledford-Hoffman et al. [1986] estimate that was based on  super(210)Pb chronologies. Biogenic silica accumulation rates in the southern, central, and western Ross Sea increased during the mid and late Holocene, reaching their maximum values during the past 500 to 1000 years.
AN: 3975737

                                                                     310 of 313  
TI: Cycling of organic carbon and biogenic silica in the Southern Ocean: Estimates of water-column and sedimentary fluxes on the Ross Sea continental shelf
AU: Nelson,-D.M.; DeMaster,-D.J.; Dunbar,-R.B.; Smith,-W.O.,Jr.
AF: Coll. Oceanic and Atmos. Sci., Oregon State Univ., Corvallis, OR 97331, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS 1996 vol. 101, no. C8, pp. 18061-18077
NT: Special section: Biogeochemical cycling in the Ross Sea.
LA: English
ER: M (Marine)
AB: We examined the cycling of organic carbon and biogenic silica in the water column and upper sediments of the Ross Sea, seeking to understand the processes leading to the formation of opal-rich, organic-poor sediments over much of the Southern Ocean. Between January, 1990 and December, 1994 we conducted three cruises, performing tracer incubation studies ( super(14)C,  super(15)N,  super(30)Si,  super(32)Si) to measure rates of primary production, nitrate-based "new" production, biogenic silica production and biogenic silica dissolution in the upper 50 m over most of the Ross Sea shelf in spring, mid summer and late summer. We deployed sediment traps from January, 1990 to early March, 1992 to measure the mid-water (250 m) and near-bottom gravitational fluxes of particulate organic carbon, nitrogen and biogenic silica year-round at three sites, and obtained sediment cores at 15 sites to assess the accumulation rates of organic carbon and biogenic silica in all known sediment regimes on the shelf. At 9 of those sites we also measured nutrient efflux from the sediments, enabling us to calculate benthic recycling fluxes of organic matter and opal. These data permit estimates of the annual production, near-surface recycling, vertical sinking flux, delivery to the seabed, benthic regeneration and long-term burial of both organic and siliceous material, integrated over a 3.3 x 10 super(5) km super(2) area that covers 75-80% of the Ross Sea shelf. The resulting annual budgets for carbon and silica indicate highly selective preservation of biogenic silica over organic carbon between 50 and 250 m in the water column, as well as in the upper seabed. Selective preservation of silica within the upper 50 m is not indicated, and both organic matter and silica are transported from 250 m to the sea floor with virtually 100% efficiency. The SiO sub(2)/C mass ratios for surface-layer production, 250-m sinking flux, delivery to the seabed and long-term burial are approximately 0.85, 6.1, 6.2 and 27, respectively. This progressive enrichment in silica results in long-term burial of 5.8% of the biogenic silica and 0.17% of the organic carbon produced by phytoplankton in the surface layer, a factor of 30 greater preservation efficiency for silica than for carbon. Nevertheless, the ratio of opal burial to opal production in the Ross Sea is only about twice the apparent global average of 3% and <1/3 of the estimated burial/production ratio for the Southern Ocean as a whole. It thus appears that both silica preservation and the decoupling between the cycles of silica and carbon must be even more effective in the waters overlying abyssal Southern Ocean sediments than they are over the Ross Sea shelf.
AN: 3975736

                                                                     311 of 313  
TI: Re-evaluation of colorimetric Cl super(-) data from natural waters with DOC
AU: Norton,-S.A.; Handley,-M.J.; Kahl,-J.S.; Peters,-N.E.
AF: Dep. Geol. Sci., Univ. Maine, Orono, ME 04469-5711, USA
SO: WATER,-AIR,-SOIL-POLLUT. 1996 vol. 91, no. 3-4, pp. 283-298
LA: English
ER: F (Freshwater)
AB: Colorimetric Cl super(-) data from natural solutions that contain dissolved organic carbon (DOC) may be biased high. We evaluated aquatic Cl super(-) concentrations in ecosystem compartments at the Bear Brook Watershed, Maine, and from lakes in Maine, using ion chromatography and colorimetry. DOC imparts a positive interference on colorimetric Cl super(-) results proportional to DOC concentrations at approximately 0.8  mu eq Cl super(-)/L per mg DOC/L. The interference is not a function of Cl super(-) concentration. The resulting bias in concentrations of Cl super(-) may be 50% or more of typical environmental values for Cl super(-) in areas remote from atmospheric deposition of marine aerosols. Such biased data in the literature appear to have led to spurious conclusions about recycling of Cl super(-) by forests, the usefulness of Cl super(-) as a conservative tracer in watershed studies, and calculations of elemental budgets, ion balance, charge density of DOC, and dry deposition factors.
AN: 3975030

                                                                     312 of 313  
TI: Biogeochemical cycles of carbon, nitrogen, and silicon, phytoplanktonic dynamics
OT: Cycles biogeochimiques du carbone, de l'azote et du silicium
AU: Delamo,-Y.; Le-Pape,-O.; Queguiner,-B.; Treguer,-P.; Menesguen,-A.; Cann,-P.
AF: URA CNRS 1513, Laboratoire Flux de Matiere et Reponses du Vivant, Institut Europeen de la Mer, UBO, BP 452, 29275 Brest cedex, France
CA: Communaute Urbaine de Brest [France]
CO: Le Programme Rade. 3. Rencontres Scientifiques Internationales, Brest (France), 14-16 Mar 1995
SO: ROADSTED-PROGRAM.-THIRD-INTERNATIONAL-SCIENTIFIC-MEETINGS:-PROCEEDINGS,-BREST-14-15-ET-16-MARCH-1995.-VOL.-1:-JOURNEE-DU-14-MARS-1995.-PROGRAMME-RADE;-3E-RENCONTRES-SCIENTIFIQUES-INTERNATIONALES:-ACTES-DE-COLLOQUE,-BREST-LES-14-15-ET-16-MARS-1995.-VOL.-1:-JOURNEE-DU-14-MARS-1995. BREST-FRANCE COMMUNAUTE-URBAINE 1995 pp. 42-58
LA: French
ER: M (Marine)
AB: The annual cycle of primary production in the Bay of Brest, and the spring species succession of the phytoplankton are presented and discussed, in relation to physical, chemical, and biological features of the environment. The winter stock of nutrients, characterized by, an excess of dissolved inorganic nitrogen as compared to the other nutrient, progressively decreased due to phytoplankton uptake during spring. The dissolved silicate stock exhibited depletion over the whole water column, at the end of the first, diatom dominated, spring bloom (Rhizosoleniaceae), leading to a dinoflagellate increase, including the toxic species (Dinophysis) sp. Later, the course of the productive period is characterized by a sequence of potentialy Si-, N-, and P- limited periods. The subsequent blooms occuring during this period should be supported by regenerated nutrients. During the entire productive period, primary production is dominated by the microplankton fraction. Nevertheless, its account to total production decreased over the season as this fraction got more and more heterotrophic; conversely, pico- and nannoplankton exhibited an increase in their contribution to total primary production. Picoplankton, mainly heterotrophic, exhibited a relatively, stable evolution during the all season, with the exception of an intportatit increase of heterotrophic contpotielits (probably bacteria), during the collapse of the first spring diatom bloom. The nannoplankton appeared as a potentially important contributor to primary production but it decreased rapidly at the beginning of the spring bloom, possibly due to microzooplankton grazing. The cryptophycean population were thus rapidly replaced by small dinoflagellates. In spite of the dissolved inorganic nitrogen overload during winter, the Bay of Brest exhibited no mark of eutrophication, as well by refering to the annual production rate (148 g Cm-2 y-1 in 1993) as compared to earlier studies, as with regards to dissolved oxygen saturation rates ( > 97 % during the all year).
AN: 3973563

                                                                     313 of 313  
TI: Effect of pesticides on hydrogen metabolism of Rhodobacter sphaeroides and Rhodopseudomonas palustris
AU: Chalam,-A.V.; Sasikala,-C.; Ramana,-C.V.; Rao,-P.R.
AF: Microbial Biotechnology Laboratory, Department of Botany, Osmania University, Hyderabad 500 007, India
SO: FEMS-MICROBIOL.-ECOL. 1996 vol. 19, no. 1, pp. 1-4
LA: English
ER: F (Freshwater)
AB: The present study reports the effect of 2,4-D, quinalphos, monocrotophos, captan and carbendazim on the hydrogen metabolism (nitrogenase, photoproduction of hydrogen and hydrogenase activities) of two purple non-sulfur bacteria isolated from paddy soils. In general, the pesticides were found to be inhibitory to both nitrogenase and hydrogen photoproduction activities of both the organisms, and their effect on hydrogenase-mediated reactions varied with the pesticides used and the organisms.
AN: 3972362


No.    Records  Request

1:        504   BIOGEOCHEMICAL
2:      >8530   CYCL*
3:        369   BIOGEOCHEMICAL CYCL*


                                                                       1 of 369  
TI: Estimates of degradable organic carbon in deep-sea surface sediments from  super(14)C concentrations.
AU: Emerson,-S.; Stump,-C.; Grootes,-P.M.; Stuiver,-M.; Farwell,-G.W.; Schmidt,-F.H.
AF: Sch. Oceanogr., Quaternary Res. Cent., Univ. Washington, Seattle, WA 98195, USA
SO: NATURE. 1987. vol. 329, no. 6134, pp. 51-53
LA: English
ER: M (Marine)
AB: Organic carbon sources, degradation and burial in surface marine sediments control the exchange of this carbon pool with that in the ocean and provide the key to understanding the response of the sedimentary reservoir to changing environmental conditions. The authors explore these subjects by organic-carbon concentration profiles and newly determined radiocarbon activities from three deep-water locations. Results suggest that the bulk of the organic matter in the surface mixed layer of marine sediments has a planktonic origin, and up to 50% of this reservoir is degradable on a timescale of  less than or equal to  1,000 yr; short enough to have responded to glacial interglacial changes. The degradable fraction is estimated to be presently 50  plus or minus  15 x 10 super(15) g C and may have been several times larger during the past glacial period.
AN: 1604658

                                                                       2 of 369  
TI: The use of mass balances to test and improve the estimates of carbon fluxes in an ecosystem.
AU: Klepper,-O.; Van-de-Kamer,-J.P.G.
AF: Delta Inst. Hydrobiol. Res., Vierstr. 28, 4401 EA Yerseke, Netherlands
SO: MATH.-BIOSCI. 1987. vol. 85, no. 1, pp. 37-49
LA: English
ER: B (Brackish)
AB: A method is presented to analyse the estimates of carbon fluxes in an ecosystem by demanding that (1) the carbon budget of each ecological group should be balanced and that (2) every carbon flux in these balanced budgets should fall within the range of experimentally obtained values. It is shown that the problem of finding an optimal balanced solution is equivalent to the solution of an overdetermined linear system in the Chebyshev norm. The method is illustrated with a small prototype model. Some results are shown of the analysis of a large data set from the Oosterschelde estuary, S.W. Netherlands. The results indicate that the method is powerful in reducing the uncertainties of fluxes. The method proves to be a useful tool both for decreasing the uncertainty of estimated fluxes without additional field work and (by indicating inconsistent or inconclusive data) for directing further research. In particular, consistency is a prerequisite for any simulation modeling effort.
AN: 1604644

                                                                       3 of 369  
TI: Biogeochemical cycling of metals in Barataria Basin.
AU: Feijtel,-T.C.J.
CA: Louisiana State Univ. and A&M Coll., Baton Rouge (USA)
SO: DISS.-ABST.-INT.-PT.-B-SCI.-and-ENG. 1987. vol. 47, no. 8, 303 pp
NT: Diss. Ph.D.: Order No. FAD DA8625334.
LA: English
ER: M (Marine); B (Brackish)
AB: Metal distribution, accumulation, and differential mobility were determined in the terrestrial and aquatic portions of Barataria Basin. Seasonal variations in surface water and interstital pore water constituents of marsh and bay bottom sediments, along a salinity transect were determined through a monthly sampling from March 1984 to August 1985.
AN: 1604176

                                                                       4 of 369  
TI: Organic carbon cycle in oceans.
OT: Tsikl organicheskogo ugleroda v okeanakh 
AU: Wangersky,-P.J.
AF: Dalhousie Univ., Halifax, N.S., Canada
SO: EHKOL.-MORYA. 1986. no. 24, pp. 3-24
NT: Incl. bibliogr.: 189 ref.
LA: Russian
ER: M (Marine)
AB: The present-day oceanographic literature (mainly English-language) devoted to different aspects of carbon exchange in the marine environment is reviewed. Main sources and flows of different organic carbon forms - mineral, organic, living, dead - as well as main changes in conceptual picture of the carbon exchange in marine environment are considered. An increasing scientific significance is emphasized for the data on rates of different processes, especially of primary production, sedimentation of suspensions, bacterial processes.
AN: 1604035

                                                                       5 of 369  
TI: Technetium distribution and accumulation in marine sediments and biota.
AU: Schulte,-E.H.
AF: CEC, c/o ENEA, La Spezia, Italy
SO: BEHAVIOUR-OF-LONG-LIVED-RADIONUCLIDES-ASSOCIATED-WITH-DEEP-SEA-DISPOSAL-OF-RADIOACTIVE-WASTES.-REPORT-OF-A-CO-ORDINATED-RESEARCH-PROGRAMME-ORGANIZED-BY-THE-INTERNATIONAL-ATOMIC-ENERGY-AGENCY,-1982-1984. International-Atomic-Energy-Agency,-Vienna-Austria 1986. pp. 133-135
RN: IAEA-TECDOC-368 (IAEATECDOC368)
LA: English
ER: M (Marine)
AB: Technetium normally exists in marine environments as pertechnetate Tc super(VII). However when sediments are reduced and organic rich, it becomes fixed rapidly to them. Bacterial activity does not seem to be responsible. Concentration factors for Tc in biota are generally 10-20 but two exceptions are macrophytic algae (1100) and polychaetes (300-800). Biological half lives are weeks or months. Retention was generally about 20% of that in the food source, and 25% of that was retained in the digestive gland or liver.
AN: 1603762

                                                                       6 of 369  
TI: Biological mixing and radionuclide redistribution in marine sediments.
AU: Schulte,-E.H.
AF: CEC, c/o ENEA, La Spezia, Italy
SO: BEHAVIOUR-OF-LONG-LIVED-RADIONUCLIDES-ASSOCIATED-WITH-DEEP-SEA-DISPOSAL-OF-RADIOACTIVE-WASTES.-REPORT-OF-A-CO-ORDINATED-RESEARCH-PROGRAMME-ORGANIZED-BY-THE-INTERNATIONAL-ATOMIC-ENERGY-AGENCY,-1982-1984. International-Atomic-Energy-Agency,-Vienna-Austria 1986. pp. 115-118
RN: IAEA-TECDOC-368 (IAEATECDOC368)
LA: English
ER: M (Marine)
AB: Literature survey indicates that bioturbation strongly affects the recycyling of radionuclides through the benthic boundary layer, and nuclides such as  super(239,240)Pu and  super(241)Am may be resolubilized by anionic complexers released by fauna. Transfer of nuclides to fauna which ingest particles is very low, whereas transfer from water is much more efficient. This suggests that interstitial water is probably the predominant source of transuranics for benthic organisms in sediments.
AN: 1603715

                                                                       7 of 369  
TI: Anaerobic dissolution of iron-phosphorus complexes in sediment due to the activity of nitrate-reducing bacteria.
AU: Jansson,-M.
AF: Inst. Geogr., Univ. Umeaa, S-901 87 Umeaa, Sweden
SO: MICROB.-ECOL. 1987. vol. 14, no. 1, pp. 81-89
LA: English
ER: F (Freshwater)
AB: Nitrate-reducing bacteria (Pseudomonas fluorescens  and Alcaligenes  sp.) as well as extracellular compounds from these bacteria increased the dissolution rate of iron and phosphorus sorbed to iron precipitates during anaerobic, nitrate-free conditions in experimental sediment-water systems. It is suggested that the influence of the bacteria is due to enzymatic catalyzation of chemical iron reduction.
AN: 1603696

                                                                       8 of 369  
TI: Potential rates of nitrification and denitrification in an oligotrophic freshwater sediment system.
AU: Dodds,-W.K.; Jones,-R.D.
AF: Dep. Biol., Univ. Oregon, Eugene, OR 97403, USA
SO: MICROB.-ECOL. 1987. vol. 14, no. 1, pp. 91-100
LA: English
ER: F (Freshwater)
AB: Potential rates of nitrification and denitrification were measured in an oligotrophic sediment system. Nitrification potential was estimated using the CO oxidation technique, and potential denitrification was measured by the acetylene blockage technique. The sediments demonstrated both nitrifying and denitrifying activity. E sub(h), O sub(2), and organic C profiles showed two distinct types of sediment. One type was low in organic C, had high O sub(2) and E sub(h), and had rates of denitrification 1,000 times lower than the other which had high organic C, low O sub(2), and low E sub(h). Potential nitrification and denitrification rates were negatively correlated with E sub(h). This suggests that environmental heterogeneity in denitrifier and nitrifier populations in oligotrophic sediment systems may be assessed using E sub(h) before sampling protocols for nitrification or denitrification rates are established. There was no correlation between denitrification and nitrification rates or between either of these processes and NH sub(4) super(+) or NO sub(3) super(-) concentrations.
AN: 1603449

                                                                       9 of 369  
TI: Conceptual evolution of a model of marine biocoenosis and its metabolism.
OT: Kontseptual'naya ehvolutsiya modeli morskogo biotsenoza i obmena veshchestv v nem 
AU: Khajlov,-K.M.
AF: Inst. Biol. Yuzhn. Morej AN Ukr.S.S.R., Sevastopol', USSR
SO: EHKOL.-MORYA. 1986. no. 24, pp. 25-33
LA: Russian
ER: M (Marine)
AB: The present-day biooceanographic literature devoted to different aspects of ecological biochemistry and ecology is reviewed. The general trend in the conceptual evolution of the model of marine biocoenosis implies the development of an initial simplified scheme of a pasture food chain into a complicated scheme in which cycles and momentum flux are no less important than energy metabolism. The main stages of the evolution are; 1) extension of knowledge on the role and dynamics of detritus; 2) studies of C escape into the medium in the form of mineral and dissolved organic metabolites; analysis of C regeneration and cycles; 4)special attention to groups of small organisms such as phemto-, pico- and nannoplankton and complicated exzometabolic relationships within and between the groups.
AN: 1601358

                                                                      10 of 369  
TI: The biogeochemical cycle of mercury: An overview.
AU: Zafiropoulos,-D.
AF: E.R.S., Anapiron Polemou 20, 11621 Athens, Greece
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 168-187
ST: FAO-FISH.-REP. no. 325,supp
NT: Incl. bibliogr.: pp. 183-187. ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: The biogeochemical cycle of mercury in the Mediterranean is reviewed, examining the sources and inputs of mercury, levels in seawater, sediments and marine organisms and transportation and fluxes between interfaces. Areas where further research is needed are detailed.
AN: 1581762

                                                                      11 of 369  
TI: Mercury and methylmercury distribution in sediments and in Mytilus galloprovincialis  from Kastela Bay (central Adriatic).
AU: Vukadin,-I.; Tusek-Znidaric,-M.; Byrne,-A.R.; Stegnar,-P.
AF: Inst. Oceanogr. Fish., Split, Yugoslavia
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 163-167
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: An account is given of research conducted on the distribution of mercury and methylmercury in sediments and Mytilus galloprovincialis  in Kastela Bay, an area which receives considerable amounts of waste from a chlor-alkali plant, chemical and cement industry was well as from a shipyard and also organic pollution produced by municipalities.
AN: 1581743

                                                                      12 of 369  
TI: The role of biochemical processes in the accumulation of mercury by marine organisms.
AU: Thibaud,-Y.
AF: IFREMER, Cent. Nantes, B.P. 1049, 44037 Nantes Cedex, France
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 150-162
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: The accumulation of mercury in marine populations is discussed with respect to time and correlation with organism weight. Biochemical mechanisms involved are examined; it is believed a neutralization of the toxic methylmercury form occurs. Thus the importance of specifying the different forms of mercury when monitoring quality of marine products is stressed.
AN: 1581730

                                                                      13 of 369  
TI: Chemical and biological distribution of mercury in the North Levantine.
AU: Salihoglu,-I.; Yemenicioglu,-S.
AF: Inst. Mar. Sci., Middle East Tech. Univ., P.O. Box 28, Erdemli, Icel, Turkey
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 140-149
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: The results are presented of sampling analyses of sediments, seawater, tarballs, and organisms in the northern Levantine Basin for mercury. The findings are discussed with respect to the biogeochemical cycle of mercury in the region.
AN: 1581720

                                                                      14 of 369  
TI: Measures to abate and control mercury pollution in the Mediterranean Sea.
AU: Saliba,-L.J.
AF: Mediterranean Action Plan, WHO, Reg. Off. For Europe, Copenhagen, Denmark
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 134-139
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: Mercury pollution in the Mediterranean and public health effects are discussed, considering the identification and monitoring of populations at risk, with respect to methylmercury. Possible measures for the prevention of mercury pollution are examined.
AN: 1581704

                                                                      15 of 369  
TI: Regulation and uptake of labelled iron ( super(55)Fe) and labelled mercury ( super(203)Hg) in the organs and flesh of Tilapia zillii  Gerv., living in fresh and saline water conditions.
AU: Saleh,-H.H.
AF: Alexandria Inst. Oceanogr. Fish., Alexandria, Egypt
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 128-133
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Experiments were conducted investigating the regulation of labelled iron and mercury in Tilapia zillii . Findings show that the species, living in fresh or saline water, is able to regulate the uptake of iron. The non-regulation of mercury causes a progressive increase of mercury content in its gills when in saline water and in flesh when in freshwater.
AN: 1581692

                                                                      16 of 369  
TI: Mercury in sediments of the northern Adriatic Sea.
AU: Orio,-A.A.
AF: Dep. Environ. Sci., Univ. Venice, Venice, Italy
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 125-127
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: An account is given of the distribution and source of mercury in the northern Adriatic sediments. The presence of mercury in organisms and seawater is also examined briefly.
AN: 1581681

                                                                      17 of 369  
TI: Preliminary investigation on methylmercury content in bivalves of different size.
AU: Najdek,-M.; Bazulic,-D.
AF: Cent. Mar. Res. Rovinj, "Rudjer Boskovic" Inst., 52210 Rovinj, Yugoslavia
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 122-124
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: An examination was made of methylmercury contents in mussels and oysters classified into size classes. Weight-specific contents were significantly correlated with dry weight. Higher accumulation values were observed in oysters.
AN: 1581664

                                                                      18 of 369  
TI: Sea-birds as indicators of mercury pollution in the Mediterranean.
AU: Leonzio,-C.; Focardi,-S.; Fossi,-C.; Renzoni,-A.
AF: Dep. Environ. Biol., Univ. Siena, Siena, Italy
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 116-121
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: An analysis was made of mercury in migratory water birds of the Mediterranean comparing results of analyses made a few days after survival in winter quarters with those made a few days before the flock's departure for breeding areas. Eggs of species breeding the Mediterranean Basin were also analysed. The liver was found to be the most contaminated organ in the birds, which clearly reflect the amount of mercury available in their feeding grounds.
AN: 1581643

                                                                      19 of 369  
TI: Ecological and human health effects of mercury.
AU: Jerneloev,-A.
AF: IOC/UNESCO, 7 Place de Fontenoy, 75700 Paris, France
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 111-115
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: The toxic effects of methylmercury in humans is discussed, considering sources of exposure and metabolism of the compound in the human body. Effects are primarily manifested in damage of the central nervous system, especially sensory centres. An evaluation is made of potential health effects.
AN: 1581625

                                                                      20 of 369  
TI: Assessment of mercury pollution in coastal marine sediments and in benthic organisms.
AU: Hornung,-H.
AF: Israel Oceanogr. and Limnol. Res. Ltd., Tel Shikmona, P.O.B. 8030, Haifa 31080, Israel
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 104-110
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: An examination was made of mercury levels in sediments and benthos in Haifa and coastal water to assess current state of mercury pollution in the Eastern Mediterranean. Findings show that the mercury released by the chlor-alkali plant in the Bay is retained in the nearby sediments. Benthic organisms show high mercury levels associated with feeding habits and intake during feeding in contaminated sediments Thus the organisms are representative of the environment to which they are exposed and therefore may serve as biological indicators.
AN: 1581605

                                                                      21 of 369  
TI: Chemical forms of mercury in flesh, gills and liver from fish species of different habits from two localities west of Alexandria.
AU: Halim,-Y.; Aboul-Dahab,-P.; El-Rayis,-O.
AF: Oceanogr. Dep., Alexandria Univ., Alexandria, Egypt
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 99-103
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: An investigation was made of total and organic mercury levels in the flesh, gills and liver of various fish from different habitats and trophic levels in El Mex Bay. The highest mercury content was found in Euthynnus alletteratus . Despite interspecific variability observed, the pattern of distribution in the fish tissues is constant, most mercury being concentrated in the liver of all species.
AN: 1581591

                                                                      22 of 369  
TI: A comparative study of mercury contamination in the Tagus Estuary (Portugal) and major French estuaries (Gironde, Loire, Rhone).
AU: Figueres,-G.; Martin,-J.M.; Meybeck,-M.; Seyler,-P.
AF: Ec. Norm. Super., Lab. Geol., 46, rue d'Ulm, 75230 Paris Cedex 5, France
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 78-98
ST: FAO-FISH.-REP. no. 325,supp
NT: 34 ref. ISBN 92-4-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: B (Brackish)
AB: Mercury levels in water, suspended matter and surficial bottom sediments of Tagus Estuary, Portugal are examined and compared to those in 3 French estuaries (Loire, Rhone and Gironde). Findings show the Tagus to be one of the most contaminated estuaries studied; the French estuaries are only slightly polluted, as are many other European and North American estuaries.
AN: 1581571

                                                                      23 of 369  
TI: Bioaccumulation of mercury in some coastal marine fish from Alexandria waters.
AU: El-Nady,-F.E.-S.
AF: Fac. Sci., Alexandria Univ., Alexandria, Egypt
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 74-77
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: Comparison was made of mercury concentrations in Mugil capito, Sparus aurata, Raja miraletus  and Solea vulgaris  in 2 different environments in Alexandria waters: Eastern Harbour and Abu-Kir Bay. Results showed that the concentration of mercury in all fish species from Abu-Kir Bay was higher than in fish from Eastern Harbour, reflecting the influence of additional sources of runoff from industrial wastes.
AN: 1581526

                                                                      24 of 369  
TI: Total mercury in the coastal marine ecosystem west of Alexandria.
AU: El-Rayis,-O.A.; Halim,-Y.; Aboul-Dahab,-O.
AF: Fac. Sci., Alexandria Univ., Alexandria, Egypt
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 58-73
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: A study was undertaken in El-Mex Bay to determine the mercury levels in water, suspended matter, plankton, sediments and fish. The pattern of distribution of mercury indicates that suspended particulate matter is the main vehicle for mercury from land-based sources to the bay, the particulate form representing 88% of the total input. All fish species greater than 220 mm in length reach or exceed the maximum permissible limit.
AN: 1581511

                                                                      25 of 369  
TI: Occurrence of mercury in the atmosphere and waters of the Mediterranean.
AU: Copin-Montegut,-G.; Courau,-P.; Laumond,-F.
AF: Lab. Phys. Chim. Mar., Univ. Pierre et Marie Curie, 06230 Villefranche-sur-Mer, France
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 51-57
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: A discussion is presented on the occurrence of mercury in the atmosphere and in the sea; levels in Mediterranean waters are considered in particular with respect to measurements made in the Ligurian Sea, Villefranche Bay and various stations during the PHYCEMED cruise in 1983. Findings indicate mercury concentrations to be low in the Mediterranean.
AN: 1581496

                                                                      26 of 369  
TI: A model of mercury accumulation in tuna.
AU: Bernhard,-M.
AF: Cent. Studi Ambiente Mar., ENEA, POB 316, 1-19100 La Spezia, Italy
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 44-50
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: A mathematical model is discussed which gives an indication of how the Mediterranean tunas can reach higher mercury levels than Atlantic tunas. Basic assumptions and equations are outlined and numerical simulation detailed.
AN: 1581488

                                                                      27 of 369  
TI: The biogeochemical cycle of mercury in the Tyrrhenian Sea.
AU: Baldi,-F.
AF: Dip. Biol. Ambient., Univ. Siena, 53100 Siena, Italy
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 29-43
ST: FAO-FISH.-REP. no. 325,supp
NT: 25 ref. ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: Findings are presented of investigations conducted on the mercury distribution in the Mediterranean, particularly the Tyrrhenian Sea, and are discussed with respect to the biogeochemical cycle of mercury, examining sediments, water, particulate matter and benthos levels.
AN: 1581473

                                                                      28 of 369  
TI: Recovery trends in a mercury-polluted marine area.
AU: Bacci,-E.; Baldi,-F.; Bargagli,-R.; Gacci,-C.
AF: Dep. Environ. Biol., Univ. Siena, Via delle Cerchia 3, 53100 Siena, Italy
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 20-28
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: Experiments were undertaken to investigate the origin of mercury in the northern Tyrrhenian Sea facing Rosignano Solvay, Italy, and to assess the mercury pollution in the area using indicator organisms. Data were also used to examine recovery trends.
AN: 1581462

                                                                      29 of 369  
TI: Mercury biogeochemistry in the Mediterranean marine environment: An assessment of contamination.
AU: Aston,-S.R.; Fowler,-S.W.; Whitehead,-N.
AF: Int. Lab. Mar. Radioactivity, c/o Mus. Oceanogr., Monaco, Monaco
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 8-19
ST: FAO-FISH.-REP. no. 325,supp
NT: 35 ref. ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: A review is made of data available on mercury in the Mediterranean marine environment. Water, sediment and pelagic organism concentrations show that there is no clear evidence that there are high ambient mercury levels outside the immediate coastal zone. Reasons for the observed high mercury concentrations in tuna some other pelagic fish remain an enigma.
AN: 1581450

                                                                      30 of 369  
TI: Mercury species in coastal marine organisms from different trophic levels west of Alexandria.
AU: Aboul-Dahab,-O.; Halim,-Y.; El-Rayis,-O.
AF: Fac. Sci., Alexandria Univ., Alexandria, Egypt
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: PAPERS-PRESENTED-AT-THE-FAO-UNEP-WHO-IOC-IAEA-MEETING-ON-THE-BIOGEOCHEMICAL-CYCLE-OF-MERCURY-IN-THE-MEDITERRANEAN,-SIENA,-ITALY,-27-31-AUGUST-1984. FAO,-Rome-Italy 1986. no. 325,supp pp. 1-7
ST: FAO-FISH.-REP. no. 325,supp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: Investigations assessed biological amplification of total mercury and its organic form in marine organisms from different levels in the food chain in the Alexandria coastal ecosystem. Comparable differences in the mercury level were observed in the organisms both for total and organic mercury. In all fish species, most of the mercury in flesh was in the organic forms.
AN: 1581444

                                                                      31 of 369  
TI: Papers presented at the FAO/UNEP/WHO/IOC/IAEA Meeting on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena, Italy, 27-31 August 1984.
CA: FAO, Rome (Italy)
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27 Aug 1984
SO: FAO-FISH.-REP. 1986. 187 pp
NT: ISBN 92-5-102386-7.
RN: FAO FIRI/R325(suppl) (FIRIR325suppl)
LA: English
ER: M (Marine)
AB: Abstracts of the 21 papers presented at the meeting are cited individually.
AN: 1581428

                                                                      32 of 369  
TI: The input of decomposable organic matter and biomass concentration in the plankton of reservoirs.
AU: Straskrabova,-V.
AF: Hydrobiol. Lab., Inst. Landscape Ecol., Na Sadkach 7, 370 05 Ceske Budejovice, Czechoslovakia
CO: Czechoslovak Conference on Hydrobiology and Water Quality of Reservoirs, Ceske Budejovice (Czechoslovakia), 6 Feb 1984
SO: LIMNOLOGY-OF-CZECHOSLOVAK-RESERVOIRS.-PAPERS-BASED-ON-RESULTS-OF-THE-CZECHOSLOVAK-CONFERENCE-ON-HYDROBIOLOGY-AND-WATER-QUALITY-OF-RESERVOIRS. Straskraba,-M.;Porcalova,-P.-eds. 1986. vol. 17, no. 2 pp. 283-290
ST: LIMNOLOGICA. vol. 17, no. 2
LA: English
ER: F (Freshwater)
AB: The concentration of biomass in the plankton of 3 reservoirs was evaluated. The reservoirs differed substantially in size, mean depth and theoretical flushing rate. Two were regularly sampled for 10 years. The average concentrations of bacteria, phytoplankton and zooplankton during the cold and warm half-year periods were transformed into energetic units. Inputs of decomposable organic substances both from inflow and primary production were expressed in comparable units. Total biomasses were directly correlated to total inputs for both cold and warm seasons, but indirectly correlated to flushing rates. The product of flushing rate and biomass concentration (biomass output) was significantly correlated to the inflow inputs during warm seasons. During cold seasons, the correlation only was significant for the heterotrophic component. Equations for predicting average autotrophic and heterotrophic biomass concentration from the flushing rate and BOD in the inflow were derived.
AN: 1580669

                                                                      33 of 369  
TI: Nitrogen dynamics in lower Narragansett Bay. 2. Phytoplankton uptake, depletion rates of nitrogenous nutrient pools, and estimates of ecosystem remineralization.
AU: Furnas,-M.J.; Smayda,-T.J.; Deason,-E.A.
AF: Australian Inst. Mar. Sci., Townsville, Qld. 4810, Australia
SO: J.-PLANKTON-RES. 1986. vol. 8, no. 4, pp. 755-769
LA: English
ER: M (Marine)
AB: Phytoplankton nitrogen demand in lower Narragansett Bay, Rhode Island, measured during the winter-spring of 1977-78 and summers of 1978 and 1979, is compared with estimates of zooplankton and the benthic nitrogen remineralization drawn from the results of experimental field studies. Measured uptake rates would generally lead to the depletion of available nitrogenous nutrient stocks within hours, and usually exceeded estimates of benthic plus zooplankton remineralization. Additional estimates of nitrogen inputs from sewage and riverine sources appear insufficient to make up the difference.
AN: 1579635

                                                                      34 of 369  
TI: Dissolved organic phosphorus production in surface seawaters.
AU: Orrett,-K.-(deceased); Karl,-D.M.
AF: Dep. Oceanogr., Univ. Hawaii, Honololu, HI 96822, USA
SO: LIMNOL.-OCEANOGR. 1987. vol. 32, no. 2, pp. 383-398
LA: English
ER: M (Marine)
AB: Measurements were made of the accumulation ( super(32)P)DOP during seawater sample incubations with  super(32)PO sub(4) super(3) super(-). Accumulation rates (i.e. nCi ( super(32)P)DOP liter super(-1) h super(-1)) were extrapolated to total DOP mass fluxes (i.e. ng P liter super(-1) h super(-1)) with two independent P-assimilation models. The first model assumed that the ( super(32)P)DOP produced had the same specific radioactivity (i.e. nCi  super(32)P per ng P) as the total dissolved phosphorus pool measured at the beginning of the incubation period. The second model assumed that the ( super(32)P)DOP produced had the same specific radioactivity as the P contained in recently synthesized RNA. Two North Pacific Ocean stations were investigated in detail. DOP production rates measured in mesotrophic waters off Manzanillo, Mexico, varied substantially with depth and time of day, whereas the production rates measured in the oligotrophic North Pacific Gyre were more constant.
AN: 1572289

                                                                      35 of 369  
TI: The role of suspended matter in the biogeochemical cycles in the Adige River Estuary (northern Adriatic Sea).
AU: Juracic,-M.; Vitturi,-L.M.; Rabitti,-S.; Rampazzo,-G.
AF: Cent. Mar. Res., Rudjer Boskovic Inst., Bijenicka 54, 41000 Zagreb, Yugoslavia
SO: ESTUAR.-COAST.-SHELF-SCI. 1987. vol. 24, no. 3, pp. 349-362
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Suspended matter and sediments from the Adige River mouth were analysed in an attempt to elucidate the transfer of heavy metals from the river to the sea. The vertical profile of grain-size spectra of suspended matter in front of the river mouth has shown that the riverine particles are limited to the upper brackish layer. The observed similarity of physico-chemical, mineralogical and geochemical characteristics of riverine suspended matter and recent marine sediments, indicates that most of the riverborne particulate matter is deposited in the proximity of the Adige River mouth.
AN: 1554811

                                                                      36 of 369  
TI: Technical recommendations for studying the biogeochemical cycle of trace metals.
AU: Amiard-Triquet,-C.; Metayer,-C.; Amiard,-J.C.
AF: Cent. Dosage Elements Traces, UER Sci. Pharm., Univ. Nantes, 1 rue Gaston Veil, 44035 Nantes Cedex, France
SO: REV.-INT.-OCEANOGR.-MED. 1984. no. 73-74, pp. 27-34
LA: English
ER: M (Marine)
AB: The measure of trace element concentrations in entire organisms including digestive content instead of purged organisms is often responsible of an overestimation. The importance of the error depends upon the level of metals in the digestive content which is determined by the nature of its constituents and then vary with the feeding-habits of animals. The highest overestimations are observed for Pb and Cd in benthic-feeding worms and fishes, for Cu in benthic-feeding and plankton-feeding fishes.
AN: 1549306

                                                                      37 of 369  
TI: Benthic metabolism in a natural coastal petroleum seep.
AU: Montagna,-P.A.; Bauer,-J.E.; Prieto,-M.C.; Hardin,-D.; Spies,-R.B.
AF: Univ. Texas at Austin, Mar. Sci. Inst., Port Aransas, TX 78373, USA
SO: MAR.-ECOL.-PROG.-SER.. 1986. vol. 34, no. 1-2, pp. 31-40
NT: Incl. 32 ref.
LA: English
ER: M (Marine)
AB: The rates of 3 processes known to be mediated by microbial metabolic activity were measured in the sediments of a shallow-water (18 m depth) natural petroleum seep and a nearby non-seep area near Santa Barbara, California. Measurements of oxygen flux, hydrocarbon degradation, and sulfate reduction were made in the sediments of 3 stations with varying amounts of petroleum seepage. Total oxygen flux was not statistically different among the 3 stations studied. Rates of sulfate reduction and hydrocarbon degradation were greater at seep than non-seep sites. Within the seep area, greater rates of sulfate reduction and hydrocarbon degradation were found at the station of moderate seepage than at the margin of active oil and gas seepage. The greater rates of metabolism at the seep correlate with previous findings of higher amounts of ATP and macroinfauna at the seep. It is hypothesized that the higher abundances of infauna and concentrations of ATP at the seep are sustained by heterotrophic bacterial degradation of petroleum and the consumption of those bacteria by infauna.
AN: 1548931

                                                                      38 of 369  
TI: Reduction of selenate to selenide by sulfate-respiring bacteria: Experiments with cell suspensions and estuarine sediments.
AU: Zehr,-J.P.; Oremland,-R.S.
AF: U.S. Geol. Surv., Middlebrook Rd., Menlo Park, CA 94025, USA
SO: APPL.-ENVIRON.-MICROBIOL. 1987. vol. 53, no. 6, pp. 1365-1369
LA: English
ER: B (Brackish)
AB: Washed cell suspensions of Desulfovibrio desulfuricans  subsp. aestuarii  were capable of reducing nanomolar levels of selenate to selenide as well as sulfate to sulfide. Reduction of these species was inhibited by 1 mM selenate or tungstate. The addition of 1 mM sulfate decreased the reduction of selenate and enhanced the reduction of sulfate. Increasing concentrations of sulfate inhibited rates of selenate reduction but enhanced sulfate reduction rats. The results indicate that sulfate is an inhibitor of the reduction of trace quantities of selenate. Therefore, direct reduction of traces of selenate to selenide by sulfate-respiring bacteria in natural environments is constrained by the ambient concentration of sulfate ions. The significance of this observation with regard to the role sediments play in sequestering selenium is discussed.
AN: 1540712

                                                                      39 of 369  
TI: Element cycling in wetlands: Interactions with physical mass transport.
AU: Hemond,-H.F.; Army,-T.P.; Nuttle,-W.K.; Chen,-D.G.
AF: Dep. Civ. Eng., Massachusetts Inst. Technol., Cambridge, MA 02139, USA
CO: 109. Meeting of the American Chemical Society, Chicago, IL (USA), 8-13 Sep 1985
SO: SOURCES-AND-FATES-OF-AQUATIC-POLLUTANTS. Hites,-R.A.;Eisenreich,-S.J.-eds. 1987. no. 216 pp. 519-540
ST: ADV.-CHEM.-SER. no. 216
LA: English
ER: F (Freshwater)
AB: In peatlands and other waterlogged ecosystems, a severely restricted physical transport regime may be regarded as a ratecontrolling factor for many biogeochemical processes. Transport in the liquid phase by advection, diffusion, and dispersion, and vapor-phase transport by ebullition and desaturation are the abiotic transport processes in wetland sediment. Biotic transport may also occur. Quantitative formulations for several of these transport processes exist, and specific, quantitative, useful examples of transport-oriented biogeochemical cycles are presented for two wetland ecosystems, namely, Belle Isle marsh and Thoreau's Bog.
AN: 1540691

                                                                      40 of 369  
TI: Molybdenum content in sea water and seaweeds from Saurashtra coast.
AU: Kesava-Rao,-C.
AF: Baddavanipeta, Urlam-532 425, Srikakulam (Dt.), A.P., India
SO: MAHASAGAR. 1986. vol. 19, no. 4, pp. 265-270
LA: English
ER: M (Marine)
AB: Molybdenum content has been estimated in sea water and 27 marine algal species. The ranges of Mo in sea water and seaweeds was found to be 9.86-10.87  mu g multiplied by kg super(-1) and 0.08-1.01 mg multiplied by kg super(-1) dry wt. respectively. Molybdenum to salinity ratios (Mo:S ppt) in sea water are in the range of 0.280-0.305. The observed differences in Mo:S ppt is attributed to the biological utlisation of Mo. Its narrow range of distribution in sea water and in seaweeds presumably indicate the relatively less biogeochemical reactivity of this micronutrient in marine environment. The three green algae Caulerpa scalpelliformis. Ulva lactuca  and Codium dwarkense  investigated do not show any definite trend in the bioaccumulation of Mo with their age.
AN: 1529490

                                                                      41 of 369  
TI: Chemical composition and mineralization of organic nitrogen in marine sediment.
OT: Kaitei taisekibutsu ni okeru yuki chisso kagobutsu no keitai to sono bunkai katei 
AU: Koike,-I.
AF: Ocean Res. Inst., Univ. Tokyo, Minamidai 1, Nakano, Tokyo 164, Japan
CO: Symp. on Biological Activities and Biogeochemical Cycles in Marine Sediments, Tokyo (Japan), 8 Apr 1985
SO: UMI-MER. 1986. vol. 24, no. 2, pp. 104-110
LA: Japanese
ER: M (Marine)
AB: Amino acid nitrogen is a major component of the identified forms of nitrogen in coastal surface sediments, occupying up to two-thirds of total nitrogen in these sediments. Amounts of organic nitrogen in the interstitial waters of Tokyo Bay sediments were a minor fraction of the total nitrogen (ca. 1% in the surface), and this percentage decreased drastically with depth. Total amino acids in the surface sediments occupied ca. 50% of total interstitial organic nitrogen and 40% of the amino acids were free amino acids.
AN: 1524782

                                                                      42 of 369  
TI: Microbial interactions in marine sediments.
OT: Kaitei taisekibutsu-chu deno yukibutsu bunkai katei ni okeru biseibutsu-kan no sogosayo, tokuni ryusan-kangen-saikin o chushin to shite 
AU: Shiba,-T.
AF: Otsuchi Mar. Res. Cent., Ocean Res. Inst., Univ. Tokyo, Akahama, Otsuchi, Iwate 028-11, Japan
CO: Symp. on Biological Activities and Biogeochemical Cycles in Marine Sediments, Tokyo (Japan), 8 Apr 1985
SO: UMI-MER. 1986. vol. 24, no. 2, pp. 97-103
LA: Japanese
ER: M (Marine)
AB: Interaction between fermentative and sulfate-reducing bacteria is discussed. Sulfate-reducing bacteria are present in the oxidized surface layer of marine sediments. Anaerobic biological processes take place within reduced micro-environments in the sediment. Interspecies transfer of fermentation products stimulates the growth of fermentative and sulfate-reducing bacteria. Such micro-environments influence the syntrophic growth of fermentative and sulfate-reducing bacteria.
AN: 1524771

                                                                      43 of 369  
TI: Geochemical studies of the degradation processes of organic matter in the sediments from coastal area.
OT: Naiwan taisekibutsu-chu ni okeru yukibutsu no bunkai ni kansuru chikyu-kagakuteki kenkyu 
AU: Matsunaga,-K.
AF: Water Res. Inst., Nagoya Univ., Furocho, Chikusa, Nagoya 464, Japan
CO: Symp. on Biological Activities and Biogeochemical Cycles in Marine Sediments, Tokyo (Japan), 8 Apr 1985
SO: UMI-MER. 1986. vol. 24, no. 2, pp. 89-96
LA: Japanese
ER: M (Marine)
AB: Sedimentary core samples were collected from Hiuchi Nada, and Ise and Mikawa bays (Japan), where local eutrophication leads to increase of primary production in each bay. Sedimentation rates for Hiuchi Nada, and Ise and Mikawa bays were found to lie in the range of 0.13-0.21, 0.14-0.97 and 0.22 g/cm super(2)/yr, respectively, by the 210-Pb method. Vertical profiles of organic matter in these sediments were analyzed. Pseudo-degradation rate constants of organic C and N had ranges of 2.3-5.2 and 2.3-5.3 x 10 super(-2)/yr, respectively. The degradation rates of organic matter in the sediments were also calculated and are discussed in relation to primary production.
AN: 1524764

                                                                      44 of 369  
TI: Several phenomena in the benthic boundary layer of the Seto Inland Sea.
OT: Taisekibutsu kyokaimen o meguru shomondai. Seto-naikai 
AU: Kawana,-K.; Hoshika,-A.; Tanimoto,-T.
AF: Gov. Ind. Res. Inst., Chugoku, Hiromachi 15000, Kure 737-01, Japan
CO: Symp. on Biological Activities and Biogeochemical Cycles in Marine Sediments, Tokyo (Japan), 8 Apr 1985
SO: UMI-MER. 1986. vol. 24, no. 2, pp. 81-99
LA: Japanese
ER: M (Marine)
AB: Detailed investigations on vertical and horizontal distributions of water quality (dissolved oxygen, nutrients, suspended matter, etc.) and their seasonal variation were carried out in the Seto Inland Sea. In summer, total suspended matter (TSM) concentration near the bottom was significantly influenced by water movement and turbid bottom water was observed in all areas with silty bottom sediments. Also in summer, oxygen-deficient bottom water was observed in regions of limited water movement and it contained large amounts of nutrients derived from bottom sediments.
AN: 1524757

                                                                      45 of 369  
TI: Oxygen profile in deep-sea calcareous sediment calculated on the basis of measured respiration rates of deep-sea meiobenthos and its relevance to manganese diagenesis.
OT: Shinkai-san meiobentosu no kokyu-ryo no sokutei kekka ni motozuite keisansareta shinkai sekkaishitsu taisekibutsu-chu no sanso bunpu to sono mangan no zokusei tono kankei 
AU: Shirayama,-Y.; Swinbanks,-D.D.
AF: Ocean Res. Inst., Univ. Tokyo, Minamidai 1, Nakano, Tokyo 164, Japan
CO: Symp. on Biological Activities and Biogeochemical Cycles in Marine Sediments, Tokyo (Japan), 8 Apr 1985
SO: UMI-MER. 1986. vol. 24, no. 2, pp. 75-80
LA: English
ER: M (Marine)
AB: The respiration rate of deep-sea meiobenthos was measured using a gradient stoppered-diver technique, and the vertical profile of dissolved oxygen concentration in the sediment was calculated on the basis of the respiration rate using a steady-state model. At stations where the vertical profile of MnO sub(2) content showed a distinct peak in the subsurface 20 to 30 m layer of the sediment, oxygen penetrated to significant depths in the sediment. However, at stations where an MnO sub(2) peak was seen in the top few centimeters of the sediment, oxygen was completely consumed by benthic organisms within the 0-1 cm layer. This result supports the idea that manganese diagenesis within calcareous sediment is mainly regulated by biological processes through the respiratory activities of benthic organisms.
AN: 1524739

                                                                      46 of 369  
TI: A model of the effects of an infaunal xenophyophore on  super(210)Pb distribution in deep-sea sediment.
OT: Naizaisei zenofaiofoa ga shinkai taisekibutsu-chu no namari 210 no bunpu ni oyobosu eikyo ni kansuru moderu 
AU: Swinbanks,-D.D.; Shirayama,-Y.
AF: Ocean Res. Inst., Univ. Tokyo, Minamidai 1, Nakano, Tokyo 164, Japan
CO: Symp. on Biological Activities and Biogeochemical Cycles in Marine Sediments, Tokyo (Japan), 8 Apr 1985
SO: UMI-MER. 1986. vol. 24, no. 2, pp. 69-74
LA: English
ER: M (Marine)
AB: An earlier study showed that the infaunal xenophyophore Occultammina profunda , collected from a box-core of sediment from the Izu-Ogasawara Trench (sample depth 8260 m), contains high levels of the natural radionuclide  super(210)Pb (450-500 dpm/g dry) in both its protoplasmic body (granellare) and waste products (stercomes). It was suggested that, through the excretion of stercomes rich in  super(210)Pb, O. profunda  may significantly affect the vertical distribution of  super(210)Pb in the sediment. The theory and assumptions behind the model of stercome excretion are described.
AN: 1524725

                                                                      47 of 369  
TI: Effects of benthos on coastal sediments.
OT: Engan taisekibutsu ni taisuru teiseiseibutsukoka 
AU: Matsumoto,-E.
AF: Geol. Surv. Japan, Yatabe, Ibaragi 305, Japan
CO: Symp. on Biological Activities and Biogeochemical Cycles in Marine Sediments, Tokyo (Japan), 8 Apr 1985
SO: UMI-MER. 1986. vol. 24, no. 2, pp. 64-68
LA: Japanese
ER: M (Marine)
AB: Benthos disturb coastal sediments, and enhance the flux of nutrients across the sediment-water interface. Bioturbation is quantified using natural radio-nuclide profiles in the sediment. Calculated diffusive fluxes of nutrients at the interface are often less than those measured in situ by the chamber method.
AN: 1524720

                                                                      48 of 369  
TI: Accumulation of Th, Pb, U, and Ra in marine phytoplankton and its geochemical significance.
AU: Fisher,-N.S.; Teyssie,-J.-L.; Krishnaswami,-S.; Baskaran,-M.
AF: Oceanogr. Sci. Div., Brookhaven Natl. Lab., Upton, NY 11973, USA
SO: LIMNOL.-OCEANOGR. 1987. vol. 32, no. 1, pp. 131-142
LA: English
ER: M (Marine)
AB: The bioaccumulation of U, Th, Ra, and Pb in four diverse nanoplanktonic algal species and a picoplanktonic blue-green alga was determined with radiotracers. Among the nanoplankton, differences of 1-2 orders of magnitude in volume/volume concentration factors (VCFs) were observed for a given nuclide, but larger differences were observed among the four nuclides, with VCF values of Th > Pb > Ra  approximately equals  U. The picoplankton cells, with greater surface: volume ratios, had significantly higher VCF values. The mean VCF values in the nanoplankton of Th and Pb were 1.5 x 10 super(5) and 3.6 x 10 super(4) in the light and 2.8 x 10 super(5) and 7.3 x 10 super(4) in the dark.
AN: 1523104

                                                                      49 of 369  
TI: Organic carbon in the water column and its sedimentation, Fladen Ground (North Sea), May 1983.
AU: Cadee,-G.C.
AF: Netherlands Inst. Sea Res., P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands
SO: NETH.-J.-SEA-RES. 1986. vol. 20, no. 4, pp. 347-358
LA: English
ER: M (Marine)
AB: POC, DOC and sedimentation were studied during the spring phytoplankton bloom from April 27 to May 25. POC in the euphotic layer consisted largely of phytoplankton, maximum values of 0.5 mg/dm super(-3) were found at the height of a bloom of the colonial microflagellate Corymbellus aureus . DOC increased during the waxing of this C. aureus  bloom to a maximum of 2.4 mg/dm super(-3) after the bloom. Data indicate that most of the primary produced material ended up in the DOC pool. Sedimentation accounted only for small losses from the euphotic zone: ca 1% of the daily primary produced material sank out, except at the end of the C. aureus  bloom when values increased to almost 10%.
AN: 1523043

                                                                      50 of 369  
TI: Aerobic uptake of Fe(III)-precipitated phosphorus by microorganisms.
AU: Fleischer,-S.
AF: Inst. Limnol., Box 65, D-22100 Lund, Sweden
SO: ARCH.-HYDROBIOL. 1986. vol. 107, no. 2, pp. 269-277
LA: English
AB: Phosphorus co-precipitated with Fe(III) was microbially released in mixed and pure cultures as well as in intact sediment-water systems. The precipitated P was labelled and the original P in microorganisms was left unlabelled in order to trace the P transfer. The microorganisms released P from the precipitate under aerobic conditions while the FE(III) gel was solubilized and probably underwent peptidization. P removed from the precipitate was to a large extent kept in the microorganisms as these later released P under anaerobic conditions. The results show that biotic exchange processes are far more important in phosphorus dynamics than previously thought.
AN: 1503101

                                                                      51 of 369  
TI: Processes controlling movement, storage and export of phosphorus in a fen peatland.
AU: Richardson,-C.J.; Marshall,-P.E.
AF: Sch. For. and Environ. Stud., Duke Univ., Durham, NC 27706, USA
SO: ECOL.-MONOGR. 1986. vol. 56, no. 4, pp. 279-302
LA: English
ER: F (Freshwater)
AB: Collectively, the authors' field research and microcosm studies on the Houghton Lake fen suggest that soil adsorption and peat accumulation (i.e., phosphorus stored in organic matter) control long-term phosphate sequestration. But microorganisms and small sediments control initial uptake rates, especially during periods of low nutrient concentration and standing surface water. Carex  P uptake increases later in the growing season during field fertilization, but algal populations in the fen water respond quickly and absorb significant amounts of P in areas where sewage effluent has been added. Both biotic and abiotic control mechanisms are thus functional in the peatland, and proportional effect of each on P transfers is dependent on water levels, the amount of available P, fluctuating microorganism populations, seasonal changes in P absorption by macrophytes, and P soil adsorption capacity.
AN: 1497463

                                                                      52 of 369  
TI: Seasonal study of uptake and regeneration of nitrogen on the Scotian Shelf.
AU: Cochlan,-W.P.
AF: Dep. Oceanogr., Univ. British Columbia, Vancouver, B.C. V6T 1W5, Canada
SO: CONT.-SHELF-RES. 1986. vol. 5, no. 5, pp. 555-577
LA: English
ER: M (Marine)
AB: Nitrate and ammonium uptake and regeneration rates were measured in the euphotic zone of the Scotian Shelf during three cruises (spring, summer and late winter). Nitrate, as a portion of the total nitrogen assimilated (NO super(-)@)d3 uptake/total (NO super(-)@)d3 + NH super(+)@)d4) uptake), decreased with increasing ambient NH super(+)@)d4 concentration and depth. A large portion of phytoplankton growth was supported by "regenerated" production (NH super(+)@)d4) during spring and summer. In winter, growth was supported primarily by "new" production since NO super(-)@)d3 uptake represented 67% of the total nitrogen uptake during that period. In all seasons the phytoplankton showed a consistent preference for NH super(+)@)d4 utilization relative to NO super(-)@)d3, despite the abundance of NO super(-)@)d3 at times. In 21 of 23 measurements, NH super(+)@)d4 remineralization exceeded uptake, suggesting that phytoplankton nitrogen requirements were met or exceeded by in situ NH super(+)@)d4 regeneration. Remineralization rates covaried with both productivity ( super(14)C) and NH super(+)@)d4 uptake rates within the euphotic zone. These relationships were most apparent during the summer when nitrogen and carbon fluxes and algal biomass (Chl a) were greatest. The experimental approach used in this study demonstrates a seasonal pattern of NH super(+)@)d4 and NO super(-)@)d3 utilization previously unreported for Scotian Shelf waters.
AN: 1486593

                                                                      53 of 369  
TI: Studies on the mangrove ecosystem of the Jiulongjiang River estuary in China. 3. Accumulation and biological cycle of calcium and magnesium in Kandelia candel  community.
AU: Lin,-P.; Chen,-R.-H.
AF: Dep. Biol., Xiamen Univ., Xiamen, People's Rep. China
SO: ACTA-OCEANOL.-SIN.-HAIYANG-XUEBAO. 1986. vol. 5, no. 3, pp. 447-455
LA: English
ER: B (Brackish)
AB: The accumulation and biological cycle of calcium and magnesium elements of the artificial 20-year old Kandelia candel  community in the Jiulongjiang River estuary of Fujian Province, China were studied. Measured quantities of the two elements in the standing crop were (kg multiplied by ha super(-1)) 772.91 for Ca and 526.57 for Mg. In the biological cycle of the two-elements, the annual uptakes were 174.86 for Ca and 89.30 for Mg (kg multiplied by ha super(-1)); the amounts of Ca and Mg returned via litter-fall were estimated to be (kg multiplied by ha super(-1) multiplied by a super(-1)) 103.28 for Ca and 40.42 for Mg; annual retention was (kg multiplied by ha super(-1) multiplied by a super(-1)) 71.58 for Ca and 48.88 for Mg, respectively. The turnover periods of Ca and Mg are 8 and 13 years, respectively.
AN: 1468386

                                                                      54 of 369  
TI: Do continental shelves export organic matter?.
AU: Rowe,-G.T.; Smith,-S.; Falkowski,-P.; Whitledge,-T.; Theroux,-R.; Phoel,-W.; Ducklow,-H.
AF: Oceanogr. Sci. Div., Dep. Appl. Sci., Brookhaven Natl. Lab., Upton, NY 11973, USA
SO: NATURE. 1986. vol. 324, no. 6097, pp. 559-560
LA: English
ER: M (Marine)
AB: The authors summarize the shelf-edge exchange processes (SEEP) experiment, designed to test the export hypothesis. The absence of a positive imbalance in the organic carbon budget, reinforced by modest sediment deposition and biomass on the continental slope, led to rejection of the concept. Only a small fraction of continental shelf phytodetritus is exported; that not consumed in the spring is for the most part used on the continental shelf during the ensuing stratified season. The original hypothesis failed to recognize the contribution of pelagic microbial consumption and the lag in coupling between seasonal production and consumption processes.
AN: 1468272

                                                                      55 of 369  
TI: Seasonal deposition of phytodetritus to the deep-sea floor.
AU: Rice,-A.L.; Billett,-D.S.M.; Fry,-J.; John,-A.W.G.; Lampitt,-R.S.; Mantoura,-R.F.C.; Morris,-R.J.
AF: Inst. Oceanogr. Sci., Brook Rd., Wormley, Godalming, Surrey GU8 5UB, UK
CO: Symposium on the Oceanography of the Rockall Channel, Edinburgh (UK), 27-29 Mar 1985
SO: THE-OCEANOGRAPHY-OF-THE-ROCKALL-CHANNEL. Mauchline,-J.-ed. 1986. vol. 88 pp. 265-279
ST: PROC.-R.-SOC.-EDINB.,-SECT.-B. vol. 88
LA: English
AB: This paper summarises the results of the Porcupine Seabight studies over the past five years or so, using time-lapse sea-bed photography and microscopic, microbiological and chemical analyses of samples of phytodetritus and of the underlying sediment. The data are to some extent equivocal, but they suggest that the seasonal deposition is a regular and dramatic phenomenon and that the material undergoes relatively little degradation during its passage through the water column. The mechanisms leading to the aggregation of the phytodetritus have not been identified, and it is not yet known whether the phenomenon is geographically widespread nor whether it is significance to the deep-living mid-water and benthic communities.
AN: 1468121

                                                                      56 of 369  
TI: Lipid composition of the pelagic crab Pleuroncodes planipes,  its feces, and sinking particulate organic matter in the Equatorial North Pacific Ocean.
AU: Wakeham,-S.G.; Canuel,-E.A.
SO: ORG.-GEOCHEM. 1986. vol. 9, no. 6, pp. 331-343
LA: English
ER: M (Marine)
AN: 1462369

                                                                      57 of 369  
TI: Early chlorin diagenesis in a Recent aquatic sediment.
AU: Keely,-B.J.; Brereton,-R.G.
SO: ORG.-GEOCHEM. 1986. vol. 10, no. 4-6, pp. 975-980
LA: English
ER: M (Marine)
AN: 1462299

                                                                      58 of 369  
TI: Biogeochemical processes of incorporation, transformation and migration of organic matter at the marine water-sediment interface: Simulation by 14C labelled compounds.
AU: Buscail,-R.
SO: ORG.-GEOCHEM. 1986. vol. 10, no. 4-6, pp. 1091-1097
LA: English
ER: M (Marine)
AN: 1462272

                                                                      59 of 369  
TI: Microbially mediated processes in environmental chemistry (lake sediments as model systems).
AU: Hanselmann,-K.W.
AF: Inst. Pflanzenbiol. (Mikrobiol.), Univ. Zurich, Zollikerstr. 107, CH-8008 Zurich, Switzerland
SO: CHIMIA. 1986. vol. 40, no. 5, pp. 146-147
LA: English
ER: F (Freshwater)
AB: Microbes alter environmental conditions through their metabolic activities which leads to changes in chemical equilibria. Thus microbes affect indirectly chemical processes like precipitation and dissolution, adsorption and desorption, oxidation and reduction, protonation and dissociation. In this presentation the author will summarize his views on a few basic questions of environmental microbiology: Where do microbes live in sediments? How do they live where they are? What do they do to the environment? It should soon become clear to the reader that we feel the best approach to understanding biochemical processes in lake sediments must be through interdisciplinary studies involving microbiologists, chemists, and geologists.
AN: 1455076

                                                                      60 of 369  
TI: Prerequisites for the development of mass balance models of the biogeochemical cycle of mercury in the Mediterranean Sea.
AU: Osman,-M.M.
SO: CENTRO. 1985. vol. 1, no. 2, pp. 21-34
LA: English
ER: M (Marine)
AN: 1451300

                                                                      61 of 369  
TI: Importance of ice edge phytoplankton production in the Southern Ocean.
AU: Smith,-W.O.,Jr.; Nelson,-D.M.
AF: Bot. Dep., Univ. Tennessee, Knoxville, TN 37996, USA
SO: BIOSCIENCE. 1986. vol. 36, no. 4, pp. 251-257
LA: English
ER: M (Marine)
AB: In view of the potentially great biogenic production in marginal ice zones, the authors have recently begun to assess the role of ice edge phytoplankton blooms and their impact on the entire ecosystem of the Southern Ocean. The ice edge may play a major role in biogeochemical cycles of the Southern Ocean.
AN: 1447693

                                                                      62 of 369  
TI: Biogeochemical studies of long-lived radionuclides in marine environments.
AU: Noshkin,-V.E.; Wong,-K.M.; Eagle,-R.J.; Jokela,-T.A.
CA: Lawrence Livermore National Lab., Livermore, CA (USA)
SO: 1985. 11 pp
NT: NTIS Order No.: DE86010783/GAR.
LA: English
ER: M (Marine)
AB: Research results from several studies relevant to seabed disposal of radioactive wastes are briefly discussed. The studies include: (1) mobilization of plutonium from Enewetak and Bikini lagoon sediments to seawater; (2) concentrations of sup 90 Sr, sup 137 Cs,/sup 239 + 240/Pu, sup 241 Am, sup 207 Bi and sup 210 Pb- sup 210 Bi-sup 210 Po in fish from the Marshall Islands; and (3) plutonium in northeast Atlantic sediments.
AN: 1444373

                                                                      63 of 369  
TI: Water, an endangered ecosystem.
AU: Stumm,-W.
AF: Swiss Fed. Inst. Water Resour. and Pollut. Control, Duebendorf, Zuerich CH 8600, Switzerland
SO: AMBIO. 1986. vol. 15, no. 4, pp. 201-207
LA: English
AB: Water is the most important link in all biogeochemical cycles; it acts as a mobile solvent, catalyst and reagent. Human activities such as phosphorus mining, pollution and over-use have disrupted these cycles. Of special concern is the perturbation of water cycles through the pursuit of energy for human development. The author postulates that first and second generation water problems, i.e. localized pollution by sewage and industrial wastes and pollution by synthetic chemicals, while often severe, may be solved. The third generation problem, i.e. perturbation of biogeochemical cycles, may be more difficult to address.
AN: 1440361

                                                                      64 of 369  
TI: (Microbiological processes involved in production and destruction of organic matter in inland water bodies.).
OT: Mikrobilogicheskie protsessy produktsii i destruktsii organicheskogo veshchestva vo vnutrennikh vodoemakh 
AU: Romanenko,-V.I.
SO: LENINGRAD-USSR-NAUKA 1985. 295 pp
NT: Incl. bibliogr.: 509 ref.
LA: Russian
ER: F (Freshwater)
AB: The first part of the book deals with abundance of bacteria in water and bottom sediments as related to the type of the water body and with general regularities of photosynthesis and organic matter destruction as revealed from laboratory experiments and field data. Special attention is paid to CO sub(2) assimilation by heterotrophic microorganisms. The last chapter summarizes the results of long-term standard observations in the Rybinsk Reservoir which have shown that long-term variations in the production and destruction of organic matter are governed by hydrometeorological events. The second part gives data on microflora in oligotrophic and eutrophic reservoirs.
AN: 1440167

                                                                      65 of 369  
TI: Biological activity of bottom sediments in some Antarctic areas and off Peruvian coast.
OT: Biologicheskaya aktivnost' donnykh osadkov v nekotorykh rajonakh Antarktiki i u beregov Peru 
AU: Andreeva,-N.M.; Agatova,-A.I.
AF: VNIRO, Moscow, USSR
SO: OKEANOLOGIYA. 1985. vol. 25, no. 6, pp. 959-965
LA: Russian
ER: M (Marine)
AB: A study was made of the content of organic matter, proteins, carbohydrates and lipids in the upper bottom sediments and their interstitial water along the shelf and slope of the Lazarev Sea, in the eastern part of the Bransfield Strait, to the north of South Georgia I. and off the northern Peru. Protease activity (decomposition of proteins down to amino acids) and electron transport system activity (organic matter oxidation rate down to CO sub(2) and H sub(2)O) were measured to reveal biological activity of bottom sediments. In the Antarctic areas the time of protein and organic matter cycle is shown to be, on average, 2-3 orders lower than off Peru. Interstitial water is supposed to be responsible for organic matter cycle across water-precipitation-interstitial water interface.
AN: 1422346

                                                                      66 of 369  
TI: Dinitrogen production from nitrite by a Nitrosomonas  isolate.
AU: Poth,-M.
AF: Pac. Southwest For. and Range Exp. Stn., U.S. Dep. Agric. For. Serv., Riverside, CA 92507, USA
SO: APPL.-ENVIRON.-MICROBIOL. 1986. vol. 52, no. 4, pp. 957-959
LA: English
AB: A chemolithotrophic ammonium-oxidizing bacterium that was able to reduce  super(15)NO sub(2) super(-) to  super(15)N sub(2) (m/z 30) while oxidizing ammonium under conditions of oxygen stress was isolated from stream sediments. Energy was derived from ammonium oxidation, as evidence by growth, with CO sub(2) serving as the sole C source. The organism was a gram-negative, motile, short rod that failed to grow either aerobically or anaerobically in heterotroph media. The organism was identified as a Nitrosomonas) sp.
AN: 1414555

                                                                      67 of 369  
TI: The health of the oceans and the need for its monitoring.
AU: Kullenberg,-G.
AF: Inst. Phys. Oceanogr., Univ. Copenhagen, Haraldsgade 6, 2200 Copenhagen, Denmark
CO: 1. International Symposium on Integrated Global Ocean Monitoring, Tallin (USSR), 2-10 Oct 1983
SO: INTEGRATED-GLOBAL-OCEAN-MONITORING. Izrael,-Yu.A.-ed. 1986. vol. 7, no. 1 pp. 47-58
ST: ENVIRON.-MONIT.-ASSESS. vol. 7, no. 1
LA: English
ER: M (Marine)
AB: Information contained in the recent Review of the Health of the Oceans carried out by the UN Joint Group of Experts on Scientific Aspects of Marine Pollution (GESAMP) is used in formulating monitoring requirements together with different aims of monitoring defined within the framework of the International Council for the Exploration of the Sea (ICES). The development is largely based on the concept of an interfaceflux model, which defines zones of interaction between oceanic processes and human activities. This is supplemented by consideration of biogeochemical cycles which describe the cycling of substances and may help elucidate specially important processes and fluxes. A definition of specific monitoring needs is obtained. Consideration is given separately to a series of waste or contaminant categories: sewage, organochlorines, petroleum, metals and radionuclides.
AN: 1396328

                                                                      68 of 369  
TI: Thallium in marine plankton.
AU: Flegal,-A.R.; Settle,-D.M.; Patterson,-C.C.
AF: Univ. California, Inst. Mar. Sci., Santa Cruz, CA 95064, USA
SO: MAR.-BIOL. 1986. vol. 90, no. 4, pp. 501-503
LA: English
ER: M (Marine)
AB: Concentrations of thallium in phytoplankton (0.02 to 0.8  mu g g super(-1)), zooplankton (0.03 to 0.5  mu g g super(-1)) and ichthyoplankton (0.1  mu g g super(-1)) from the central Pacific were comparable (x@u- = 0.2  mu g g super(-1)), as were the atomic ratios of thallium to calcium ( similar to  3 x 10 super(-6)) and to potassium ( similar to  1 x 10 super(-6) in those organisms. These relatively constant ratios plus the biounlimited ocean profile of thallium, indicate that it is rapidly cycled through plankton in the same manner as potassium, its principal biogeochemical analogue. The higher atomic ratios of thallium to potassium in pelagic clays (6 x 10) super(-)6) and ferromanganese nodules (4 x 10 super(-3)) suggest that both biological transport processes and abiotic transport processes influence this trace element's oceanic cycle.
AN: 1379894

                                                                      69 of 369  
TI: Dissolved humic substances of the Amazon River system.
AU: Ertel,-J.R.; Hedges,-J.I.; Devol,-A.H.; Richey,-J.E.; de-Nazare-Goes-Ribeiro,-M.; Ribeiro,-G.
AF: Chem. Dep., Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: LIMNOL.-OCEANOGR. 1986. vol. 31, no. 4, pp. 739-754
LA: English
ER: F (Freshwater)
AB: Aquatic humic and fulvic acids from nine mainstem and seven major tributary sites in the Amazon River Basion are characterized by their elemental and lignin phenol compositions. Combined humic substances represent 60% of the riverine dissolved organic carbon (DOC), with fulvic to humic acid (FA:HA) ratios in the mainstem averaging 4.7  plus or minus  1.0. All dissolved humic and fulvic acids have clearly recognizable lignin components at levels (8 and 3% of the carbon) suggesting a predominantly allochthonous source. Lignin compositional characteristics are dominated by diagenetic transformations, which include preferential loss of methoxylated structural units and oxidative degradation of lignin side chains. Over most of the mainstem humic and fulvic acids behave conservatively. However, downstream of the Rio Negro confluence, humic acids appear to be selectively absorbed onto fine suspended particles. Approximately 25 and 40% of the total fluxes of lignin and of carbon are represented in the dissolved humic substances. The annual flux of dissolved, chemically recognizable lignin in the Amazon River at Obidos is calculated to be 1.2 x 10 super(11) g yr super(-1).
AN: 1359805

                                                                      70 of 369  
TI: Compositions and fluxes of particulate organic material in the Amazon River.
AU: Hedges,-J.I.; Clark,-W.A.; Quay,-P.D.; Richey,-J.E.; Devol,-A.H.; de-M.-Santos,-U.
AF: Sch. Oceanogr., WB-10, Univ. Washington, Seattle, WA 98195, USA
SO: LIMNOL.-OCEANOGR. 1986. vol. 31, no. 4, pp. 717-738
LA: English
ER: F (Freshwater)
AB: Lignin, elemental, and stable carbon isotope compositions are reported for local plants and for coarse (> 63 mu m) and fine (< 63 mu m) suspended particulate materials collected along a 1,950-km reach of the lower Amazon River during four contrasting stages of the 1982-1983 hydrograph. Fluxes of chemically recognizable lignin in the two size classes generally parallel each other along the mainstem with the fine fraction usually predominating. Particulate organic matter transported in the coarse size fraction of the mainstem and its major tributaries is composed of recently formed and well preserved tree leaf debris along with some wood. Particulate organic matter in both size fractions is introduced largely from upstream sources within the Rio Solimoes and Rio Madeira drainage basins. Most of this organic matter is unreactive and is transported conservatively with mineral particles along the Amazon mainstem. However, some downstream compositional trends are seen in both size fractions which reflect the addition or exchange of highly degraded,  super(13)C-depleted, and lignin-poor organic materials from lower basin sources.
AN: 1359403

                                                                      71 of 369  
TI: Hydrodynamic control of phytoplankton in low salinity waters of the James River estuary, Virginia, U.S.A.
AU: Filardo,-M.J.; Dunstan,-W.M.
AF: Old Dominion Univ., Dep. Oceanogr., Norfolk, VA 23508, USA
SO: ESTUAR.-COAST.-SHELF-SCI. 1985. vol. 21, no. 5, pp. 653-667
LA: English
ER: B (Brackish)
AB: Autotrophic biomass and productivity as well as nutrient distributions and phytoplankton cell populations in the James River Estuary, Virginia, were quantified both spatially and temporally over a 17-month period. Emphasis was placed on the very low salinity region of the estuary in order to gain informantion on the fate of freshwater phytoplankters. Differing amounts of freshwater plant biomass are advected into the estuary as living material, DOC or POC and the demonstrated variablility of this input must play an important role in marine biogeochemical cycling. An inverse relationship exists between the phytoplankton abundance in very low salinity waters and the abundance of biomass measured in the lower portion of the river (estuary). Thus, autotrophic production in the fresh and very low salinity areas may indirectly regulate the onset of the spring bloom in the estuary by controlling the amount of nutrients available.
AN: 1358720

                                                                      72 of 369  
TI: The estuarine interaction of nutrients, organics, and metals: A case study in the Delaware Estuary.
AU: Sharp,-J.H.; Pennock,-J.R.; Church,-T.M.; Tramontano,-J.M.; Cifuentes,-L.A.
AF: Coll. Mar. Stud., Univ. Delaware, Lewes, DE, USA
CO: 7. Bienn. Conf. of the Estuarine Research Federation, Virginia Beach, VA (USA), 23 Oct 1983
SO: THE-ESTUARY-AS-A-FILTER. Kennedy,-V.S.-ed. 1984. pp. 241-258
NT: Incl. 23 ref.
LA: English
ER: B (Brackish)
AB: In the estuarine environment, biogeochemical processes alter concentrations of soluble nutrients, organic matter, and trace metals. Some constituents show geochemical reactivity and are filtered out by "flocculation" type reactions; these may be considered as a geochemical "filter". Other constituents show biochemical reactivity and are filtered out by organismic processes; these may be considered as a biochemical "filter". Through use of data from the Delaware Estuary, the geochemical filter is illustrated as it affects humic acids, phosphate, and iron; the biochemical filter as it affects ammonium, phosphate, silicate, and urea. Contrasting examples are presented for the transition elements copper and nickel which show little filtration, despite the potential for bioreactivity. Cadmium and phosphate are used to illustrate a combined biogeochemical filter.
AN: 1334299

                                                                      73 of 369  
TI: The estuary as a filter: An introduction.
AU: Schubel,-J.R.; Kennedy,-V.S.
AF: Mar. Sci. Res. Cent., State Univ. New York, Stony Brook, NY 11790, USA
CO: 7. Bienn. Conf. of the Estuarine Research Federation, Virginia Beach, VA (USA), 23 Oct 1983
SO: THE-ESTUARY-AS-A-FILTER. Kennedy,-V.S.-ed. 1984. pp. 1-11
LA: English
ER: B (Brackish)
AB: An account is given of estuaries and their role as a filter, considering estuarine circulation, geological and geochemical procedures, biological and biochemical procedures and management.
AN: 1334047

                                                                      74 of 369  
TI: The Estuary as a Filter.
AU: Kennedy,-V.S.-(ed.)
AF: Biol. Dep., St. Francis Xavier Univ., Antigonish, N.S., Canada
CO: 7. Bienn. Conf. of the Estuarine Research Federation, Virginia Beach, VA (USA), 23 Oct. 1983
SO: ORLANDO,-FL-USA-ACADEMIC-PRESS 1984. 511 pp
LA: English
ER: B (Brackish)
AN: 1334013

                                                                      75 of 369  
TI: Biomass, community structure, and metabolic activity of the microbiota in benthic marine sediments and sponge spicule mats.
AU: White,-D.C.; Smith,-G.A.; Stanton,-G.R.
AF: Dep. Biol. Sci., Florida State Univ., Tallahassee, FL 32306, USA
SO: ANTARCT.-J.-U.S. 1985. vol. 19, no. 5, pp. 125-126
NT: Special issue: 1984 Review.
LA: English
ER: M (Marine)
AB: Application of quantitative chemical measures of biomass and community structure to the microbiota (prokaryotes and microeukaryotes) of near-shore marine sediments and sponge spicule mats in McMurdo Sound at Cape Armitage yielded 4 distinctive microbial communities with a biomass equivalent to a subtropical Florida estuary and low metabolic activity. Sediment cores and sponge spicule mats were recovered by divers from 3 areas: an anchor ice area (14 m under the ice), a nonspicule mat area (18 m under the ice), the sponge spicule mat area (22 m under the ice), and the subspicule mat sediment. The spicule mat was  approximately equals 10 cm thick in this area. The subspicule mat sediments were characterized by low proportions of diatom "signature" fatty acids. The nonspicule mat sediments showed decreased proportions of sulfate reducing bacterial "signatures" possibly reflecting the relatively high level of sedimentary bioturbation.
AN: 1331524

                                                                      76 of 369  
TI: DOC dynamics in a Mediterranean seagrass system.
AU: Velimirov,-B.
AF: Univ. Wien, Inst. Zool., Abt. Meeresbiol., Althanst. 14, 1090 Vienna, Austria
SO: MAR.-ECOL.-PROG.-SER.. 1986. vol. 28, no. 1-2, pp. 21-41
NT: Incl. 71 ref.
LA: English
ER: M (Marine)
AB: In a study on energy flow in a Posidonia oceanica  system, an attempt was made to explain the marked seasonal variations in DOC, POM and bacteria concentrations in the water above and within a seagrass meadow at the Island of Ischia (Lacco Ameno) off the Gulf of Naples (Italy). There was no correlation between seasonal variations of the 3 parameters within and between stations from shallow to deep. DOC concentrations showed distinct peaks for nearly every sampling period and ranged from 0.4 to 31.4 mgl super(-1). Although similar variations could be recorded for bacteria over the year, densities remained below 1.2 x 10 super(5) cells ml super(-1). Variations in the concentration of POM over the seasons were less obvious than for DOC and bacteria; concentrations ranged from 3.5 to 30 mg AFDW l super(-1). Weighted average concentrations of DOC, bacteria and POM in 1 m super(3) water representative for the water body above the P. oceanica) bed showed that bacterial contribution to the overall POM standing stock is insignificant.
AN: 1323050

                                                                      77 of 369  
TI: Transport of Carbon and Minerals in Major World Rivers. Part 2.
AU: Degens,-E.T.; Kempe,-S.; Soliman,-H.-(eds.)
CA: ICSU Sci. Comm. Problems Environ., Paris (France)
Hamburg (FRG)
CO: SCOPE-UNEP Workshop on "Transport of Carbon and Minerals in Major World Rivers", Assiut (Egypt), 26 Feb 1983
SO: MITT.-GEOL.-PALAEONTOL.-INST.-UNIV.-HAMB. HAMBURG-FRG-SELBSTVERL.-GEOLOGISCH-PALAEONTOLOGISCHES-INST.-UNIV. 1983. no. 55, 551 pp
NT: Published as: SCOPE/UNEP Sonderband.
LA: English
ER: F (Freshwater)
AB: The SCOPE-UNEP international program of studies on biogeochemical cycles presents the proceedings of a workshop on transport of carbon and minerals in major world rivers, held at Assiut, Egypt in 1983. The workshop proceedings (part II) comprises 41 papers dealing with various aspects of world river carbon and mineral chemistry, including freshwater ecology. A great number of side aspects, concerning mineral and carbon chemistry of rivers are included as well, such as e.g. carbon balance and forest ecosystems, eutrophication of coastal regions, monitoring by satellites, or nitrogenous organic matter transported by the major world rivers.
AN: 1318291

                                                                      78 of 369  
TI: Transport of Carbon and Minerals in Major World Rivers. Part 3.
AU: Degens,-E.T.; Kempe,-S.; Herrera,-R.-(eds.)
CA: ICSU Sci. Comm. Problems Environ., Paris (France)
UNEP, Hamburg (FRG)
CO: SCOPE-UNEP Workshop on "Transport of Carbon and Minerals in Major World Rivers", Caracas (Venezuela), 25 Mar 1984
SO: MITT.-GEOL.-PALAEONTOL.-INST.-UNIV.-HAMB. HAMBURG-FRG-SELBSTVERL.-GEOLOGISCH-PALAEONTOLOGISCHES-INST.-UNIV. 1985. no. 58, 661 pp
NT: Published as: SCOPE/UNEP Sonderband.
LA: English
ER: F (Freshwater)
AB: The SCOPE-UNEP international program of studies on biogeochemical cycles presents the proceedings of a workshop on transport of carbon and minerals in major world rivers, held at Caracas, Venezuela in 1984. The workshop proceedings (part III) comprises 51 papers dealing with all aspects of freshwater ecology and chemistry, related to carbon and mineral transport of major world rivers, including methodological papers on remote sensing, data acquisition and processing as well as water chemistry of the major world rivers.
AN: 1318274

                                                                      79 of 369  
TI: Report of the FAO/UNEP/WHO/IOC/IAEA Meeting on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena, Italy, 27-31 August 1984.
CA: FAO, Rome (Italy)
CO: FAO/UNEP/WHO/IOC/IAEA Meet. on the Biogeochemical Cycle of Mercury in the Mediterranean, Siena (Italy), 27-31 Aug 1984
SO: FAO-FISH.-REP. 1985. no. 325, 17 pp
NT: ISBN 92-5-102242-9; 29 ref.
RN: FAO FIRI/R325 (FIRIR325)
LA: English
ER: M (Marine)
AB: The report presents data concerning the distribution, behavior and fate of mercury in the Mediterranean. Emphasis is placed upon those factors which make mercury different from other trace metals in biogeochemical cycles. Sources and budget calculations, levels in the Mediterranean, and selected processes in the Mediterranean are examined.
AN: 1317092

                                                                      80 of 369  
TI: Metabolism in interfacing zones between the watersheds and lakes: Effects on eutrophication.
AU: Wetzel,-R.G.
AF: W.K. Kellogg Biol. Stn., Michigan State Univ., Hickory Corners, MI 49060, USA
CO: Shiga Conf. '84 on Conservation and Management of World Lake Environment. Proceedings, Otsu (Japan), 27 Aug 1984
SO: SHIGA-CONFERENCE-'-84-ON-CONSERVATION-AND-MANAGEMENT-OF-WORLD-LAKE-ENVIRONMENT. Shiga-Prefectural-Gov.,-Otsu-Japan;-National-Inst.-for-Res.-Adv.-Japan 1985. pp. 133-138
LA: English
ER: F (Freshwater)
AB: A discussion is presented on the control of eutrophication, examining the biogeochemical cycling of nutrients and phytoplankton production and natural inter facing buffering systems which may be used as control measures. Vegetative cover on terrestrial drainage basins, economics of reducing external loadings of nutrients and interfacing zones between land and water are considered.
AN: 1316233

                                                                      81 of 369  
TI: Vertical flux and biogeochemical turnover regulate nutrient limitation of net organic production in the North Pacific Gyre.
AU: Smith,-S.V.; Kimmerer,-W.J.; Walsh,-T.W.
SO: LIMNOL.-OCEANOGR. 1986. vol. 31, no. 1, pp. 161-167
LA: English
ER: M (Marine)
AB: Water samples collected at a station in the North Pacific Gyre near Hawaii precisely define the temporal average vertical profile of dissolved inorganic and organic N and P (DON and DOP). DON and DOP concentrations decrease with depth. As shown by other studies, the regression of NO sub(3) super(-) (with or without NH sub(4) super(+)) vs. PO sub(4) super(3) super(-) yields an approximately Redfield slope and a negative nitrogen intercept. If DON and DOP are included in the regression equation, the intercept approaches 0. Vertical flux ratios of dissolved materials are calculated with a one-dimensional diffusion model. Downward mixing of DON offsets about 6% of the upward NO sub(3) super(-) flux; downward DOP mixing offsets only about 4% of the upward PO sub(4) super(3) super(-) flux. Net production of particulate organic matter in the euphotic zone is N limited because of slow biochemical turnover of dissolved organic N relative to that of dissolved organic P and to downward mixing.
AN: 1247404

                                                                      82 of 369  
TI: The interaction of trace metal radionuclides with humic substances.
AU: Musani-Marazovic,-L.; Faguet,-D.; Konrad,-Z.
AF: Cent. Mar. Res. Zagreb, "Rudjer Boskovic" Inst., Zagreb, Yugoslavia
CO: 189. Meeting of the American Chemical Society, Miami Beach, FL (USA), 28 Apr-3 May, 1985
SO: ORGANIC-MARINE-GEOCHEMISTRY. Sohn,-M.L.-ed. American-Chemical-Soc.,-Washington,-DC-USA.-Div.-Geochemistry 1986. no. 305 pp. 389-414
ST: ACS-SYMP.-SER. no. 305
LA: English
ER: M (Marine)
AB: The fate of trace metal radionuclides in the aquatic environment and their participation in the biogeochemical cycle depend strongly on the chemical and physicochemical form in which radionuclides are introduced natural waters. The abundance of natural humic substances and their ability to form metal complexes and to adsorb on suspended matter and sediment makes these substances especially important in transport, availability and accumulation of trace metal radionuclides in natural water environments. In that sense complexation of di- and tri-valent metal radionuclides with humic and fulvic acids of different origin was studied.
AN: 1247129

                                                                      83 of 369  
TI: Uptake and release of nitrogen compounds in coral reef and seagrass, Thalassia hemprichii  (Ehrenb.) Aschers., bed sediments at Lizard Island, Queensland.
AU: Boon,-P.I.
AF: Dep. Bot., Monash Univ., Clayton, Vic. 3168, Australia
SO: AUST.-J.-MAR.-FRESHWAT.-RES. 1986. vol. 37, no. 1, pp. 11-19
LA: English
ER: M (Marine)
AB: The interstitial water in sediments from coral reef areas and seagrass (T. hemprichii ) beds at Lizard Island contained 6-48  mu mol l super(-1) ammonium, 4-7  mu mol l super(-1) nitrate plus nitrite, and 1 multiplied by 5-2 multiplied by 5  mu mol l super(-1) soluble reactive phosphorus. Concentrations of total dissolved primary amines were an order of magnitude higher in sediments from seagrass beds (about 140  mu mol l super(-1)) than from coral reef areas (about 10  mu mol l super(-1)). Ammonium-nitrogen was produced at rates of 0 multiplied by 7, 6, and 10 nmol g super(-1) h super(-1) in sediments from a bare beach, reef flat and seagrass bed, respectively. Added glycine and nitrate were also rapidly metabolized by microbes in the sediment (3 to > 5 nmol g super(-1) h super(-1)).
AN: 1247115

                                                                      84 of 369  
TI: Biogeochemical cycling of sulfur: Thiols in coastal marine sediments.
AU: Mopper,-K.; Taylor,-B.F.
AF: Div. Mar. and Atmos. Chem., Rosenstiel Sch. Mar. and Atmos. Sci., Univ. Miami, Miami, FL 33149-1098, USA
CO: 189. Meeting of the American Chemical Society, Miami Beach, FL (USA), 28 Apr-3 May, 1985
SO: ORGANIC-MARINE-GEOCHEMISTRY. Sohn,-M.L.-ed. American-Chemical-Soc.,-Washington,-DC-USA.-Div.-of-Geochemistry 1986. no. 305 pp. 324-339
ST: ACS-SYMP.-SER. no. 305
LA: English
ER: M (Marine)
AB: Thiols are major intermediates in the microbial cycling of sulfur and, because of their high reactivity, they may also play important roles in geochemical processes. Preliminary studies using a new, highly sensitive HPLC assay revealed that thiols are present at concentrations up to 100 mu M in intertidal marine sediments from Biscayne Bay (FL). Methanethiol (MeS) and 3-mercaptopropionate (MP) were the major thiols found. The presence of the latter compound suggests that, in addition to protein degradation, anaerobic decomposition of dimethylpropiothetin (DMPT), a major sulfur compound of marine algae and higher plants, may be an important source of thiols and a significant degradation pathway for DMPT in the environment.
AN: 1247000

                                                                      85 of 369  
TI: Biogenic fluxes of carbon and oxygen in the ocean.
AU: Platt,-T.; Harrison,-W.G.
AF: Mar. Ecol. Lab., Bedford Inst. Oceanogr., P.O. Box 1006, Dartmouth, N.S. B2Y 4A2, Canada
SO: NATURE. 1985. vol. 318, no. 6041, pp. 55-58
LA: English
ER: M (Marine)
AB: Rates of oxygen utilization (OUR) at depth in the ocean have been interpreted as showing that rates of carbon fixation by phytoplankton, as estimated by  super(14)CO sub(2) assimilation in vitro, must be in error. The oxygen is consumed in the decomposition of organic matter sinking from the photic zone: there is a stoichiometrically equivalent flux of nitrate from the deep water towards the surface. For comparison with the  super(14)C data, it is conventional to extrapolate OUR to total equivalent phytoplankton production through a constant factor f, the ratio of nitrate-based production (P sub(new)) to total production (P sub(t)) as define by Dugdale and Goering. The authors show here that f is variable in space and time for most provinces of the ocean. Furthermore, they show that in nitrogen-limited systems, such as the pelagic of the open ocean, P sub(t) and f should be positively correlated. Applying these results to data from the Sargasso Sea, they find that the carbon fluxes estimated by  super(14)C assimilation are consistent with the oxygen fluxes estimated by OUR.
AN: 1241084

                                                                      86 of 369  
TI: In situ particle generation in a southern Swedish stream.
AU: Parker,-C.
AF: Address not stated
SO: LIMNOL.-OCEANOGR. 1986. vol. 31, no. 2, pp. 432-437
LA: English
ER: F (Freshwater)
AB: An increase in the number of particles was measured below a waterfall in a sourthern Swedish stream. POC increased below the falls by 0.12 mg C liter super(-1), 5% of the total POC present. DOC decreased by 0.1 mg C liter super(-1) but was not significant and inorganic content remained unchanged. The number of Celloscope-measured particles in the size range of 2-20  mu m increased below the falls, with a 66% increase in particles of 4-6- mu m diameter. Although POC generation was small it was greater than published allochthonous input rates to streams. Abiotic particle generation, although extremely difficult to measure, may be far more important to carbon dynamics in stream ecosystems than previously thought.
AN: 1236427

                                                                      87 of 369  
TI: Loss and uptake of  super(15)N-ammonium in submerged soils of a cattail marsh.
AU: Dean,-J.V.; Biesboer,-D.D.
AF: Dep. Agron., Univ. Illinois, Urbana, IL 61801, USA
SO: AM.-J.-BOT. 1985. vol. 72, no. 8, pp. 1197-1203
LA: English
ER: F (Freshwater)
AB: The uptake, distribution, and recovery of nitrogen by field populations of T. latifolia  L. (cattails) were determined using ( super(15)NH sub(4)) sub(2)SO sub(4). The results show that 75.3% (53.6% in the plant and 21.7% in the soil) of the isotopically labeled nitrogen added to sampling cylinders containing a single cattail plant could be recovered at the end of one growing season, whereas only 34.6% could be recovered from control cylinders. The increased recovery of  super(15)NH sub(4) super(+)-nitrogen in cylinders containing actively growing T. latifolia) compared to cylinders not containing plants suggests that T. latifolia  rapidly assimilates labeled nitrogen before it is lost via denitrification or uptake by free-living soil microorganisms. Measurements of redox potentials in a 60-cm-deep field core planted or not planted with T. latifolia  showed that only the top 2 and 5 cm of the water column was oxidized (greater than 200 mv at pH 7), respectively. The remaining 58 and 55 cm of the column, including the soil water interface, was reduced (less than 200 mv at pH 7).
AN: 1236407

                                                                      88 of 369  
TI: Metabolic activities in flocculent surface sediments and underlying sandy littoral sediments.
AU: Sweerts,-J.P.; Rudd,-J.W.M.; Kelly,-C.A.
AF: Limnol. Inst., Rijkstraatweg 6, 3631 AC Nieuwersluis, Netherlands
SO: LIMNOL.-OCEANOGR. 1986. vol. 31, no. 2, pp. 330-338
LA: English
ER: F (Freshwater)
AB: Parts of the sandy littoral sediment of a Precambrian shield lake (Lake 302S) were intermittently covered with a layer of flocculent organic-rich material 1-20 mm thick. Sandy sediments with flocculent surface sediment had higher rates of respiration (31-105%) and photosynthesis (37-224%) than those without. Densities of invertebrate macrofauna were 10 time shigher in the flocculent surface sediment than in the underlying sandy sediment, accounting for 17 vs. 5% of the total respiration. Microprofiles of oxygen concentration showed that almost all of the dissolved oxygen in the overlying water was consumed as it diffused through 5-7 mm of the flocculent surface sediment. The presence of flocculent surface sediment also decreased the depth of penetration of sulfate into the sandy sediment.
AN: 1236394

                                                                      89 of 369  
TI: Characterization of native bacteria and their utilization of algal extracellular products by a mixed-substrate kinetic model.
AU: Jensen,-L.M.
AF: Int. Agency for  super(14)C Determination, 11 Agern Alle, DK-2970 Hoersholm, Denmark
SO: OIKOS. 1985. vol. 45, no. 3, pp. 311-320
LA: English
ER: F (Freshwater)
AB: Assimilation and mineralization of  super(14)C labelled extracellular products (EOC) by native bacterial populations were followed in a diel study and from early spring through autumn in two eutrophic Danish lakes. Kinetic analyses according to a mixed-substrate kinetic model always revealed linear kinetics. The method was found useful in unveiling in situ specific algal-bacterial associations mediated through the release of EOC from the primary producers. Further, bacterial adaptation toward the phycosphere of Microcystis aeruginosa  could be detected by following the shift in X-intercepts for the lines of net uptake and respiration during the development of a bloom of M. aeruginosa . By simultaneous measurements of particulate primary production, EOC release and transport of EOC to the bacteria by a differential filtration technique, it is shown that the method presented does not generally estimate changes in the kinetic parameters, but does reveal qualitative changes. It is concluded that the mixed-substrate method is a powerful approach for elucidating specific algal-bacterial associations in situ, even in highly complex eutrophic environments.
AN: 1231707

                                                                      90 of 369  
TI: Mass transfer to and from small particles in the sea.
AU: Csanady,-G.T.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: LIMNOL.-OCEANOGR. 1986. vol. 31, no. 2, pp. 237-248
LA: English
AB: Slowly sinking particles exchange mass with their liquid environment if dissolution processes within the particles maintain a surface concentration excess or deficiency  chi  sub(0) of a soluble substance above background. If the exchange is controlled by diffusion in the liquid phase, the total mass loss is proportional to  chi  sub(0), diffusivity D, and particle diameter d. If advection associated with the sinking of the particle dominates over diffusion, the exchange rate varies as  chi  sub(0)D super(2/3)d super(2) and is weakly affected by particle density and fluid viscosity. This is the case for spherical particles of a diameter  greater than or approximate to  70  mu m. The resulting dissolution rate per unit depth of sinking is constant for large particles, but increases sharply once the particles are small and slow enough for mass exchange to be controlled by diffusion.
AN: 1231401

                                                                      91 of 369  
TI: Extracellular organic carbon (EOC) released by phytoplankton and bacterial production.
AU: Soendergaard,-M.; Riemann,-B.; Joergensen,-N.O.G.
AF: Bot. Inst., Univ. Aarhus, Nordlandsvej 68, DK-8240 Risskov, Denmark
SO: OIKOS. 1985. vol. 45, no. 3, pp. 323-332
LA: English
ER: F (Freshwater)
AB: Parts of the pelagic carbon cycle were investigated during ten diel cycles in five Danish lakes and one coastal area. The gross release of EOC ranged from 5 to 46% of the diel primary production and the major part of the released products were assimilated by bacteria. It was shown that diel time-course incubations should be used as opposed to short-time incubations. An analysis based on primary production and amino acid assimilation in the freshwater samples showed that the FDC-method tended to overestimate the bacterial production, whereas the thymidine-method probably represents the true order of magnitude with a trend toward underestimation. In the lakes the assimilation of EOC contributed substantially (> 80%) to the bacterial production in three cases, moderately (38-50%) in three cases and of less (< 38%) importance in one case.
AN: 1231319

                                                                      92 of 369  
TI: Accumulation of minerals and trace elements in biogenic mucus at hydrothermal vents.
AU: Juniper,-S.K.; Thompson,-J.A.J.; Calvert,-S.E.
AF: IFREMER, Cent. Brest, B.P. 337, 29273 Brest Cedex, France
SO: DEEP-SEA-RES. 1986. vol. 33, no. 3A, pp. 339-347
LA: English
ER: M (Marine)
AB: Several mechanisms have been found by which a hydrothermal vent organism enhances metal and metalloid deposition at vent sites. Mucus accumulations associated with an alvinellid polychaete worm at northeast Pacific vents were found to be usually rich in elemental sulfur, sulfide minerals and trace elements. Mucus production by the worm may be a mechanism for both internal and external detoxification of accumulating metals. Analyses indicate that inorganic components accumulate in the mucus through secretion or precipitation of elemental sulfur, occlusion of mineral particles, and adsorption and complexation of soluble species by the organic matrix of the mucus. Mucus-aggregated minerals contribute to the mass of sulfide deposits forming at these vents, but their quantitative significance is not clear.
AN: 1231208

                                                                      93 of 369  
TI: Reconciling measured and predicted fluxes of oxygen across the deep sea sediment-water interface.
AU: Reimers,-C.E.; Smith,-K.L.,Jr.
AF: Scripps Inst. Oceanogr., Univ. California, San Diego, La Jolla, CA 92093, USA
SO: LIMNOL.-OCEANOGR. 1986. vol. 31, no. 2, pp. 305-318
LA: English
ER: M (Marine)
AB: Rates of sediment community oxygen consumption determined in situ are compared to fluxes predicted from oxygen microelectrode gradients measured in cores from  similar to 3,750-m water depth in the eastern North Pacific. Oxygen concentrations decrease exponentially over > 1.5 cm and suggest that organic matter in the sediments is degraded most rapidly immediately below the sediment-water interface. Molecular diffusion of oxygen across the interface is modeled as an "internal regime" and can account for nearly all the directly measured in situ flux, 0.20  plus or minus  0.02  mu mol cm super(-2) d super(-1). Millimeter depth-scale profiles of porosity, organic C, carbonate c, and bacteria abundance are reported to provide additional constraints on interface processes, including the relative effects of organic matter degradation and bioturbation.
AN: 1231118

                                                                      94 of 369  
TI: Microorganisms in deep-sea hydrothermal plumes.
AU: Winn,-C.D.; Karl,-D.M.; Massoth,-G.J.
AF: Hawaii Inst. Geophys., Dep. Oceanogr., Univ. Hawaii, Honolulu, HI 96822, USA
SO: NATURE. 1986. vol. 320, no. 6064, pp. 744-746
LA: English
ER: M (Marine)
AB: The study of hydrothermal vents at oceanic spreading centres has led to a re-evaluation of some basic tenets concerning energy flux through oceanic ecosystems and the sources and sinks for dissolved ions in sea water. Hydrothermal vents vary considerably, from relatively low-temperature (< 25 degree C) fluid discharges to the spectacular high-temperature ( similar to 350 degree C) black smokers. The authors report the presence of elevated bacterial biomass in a hydrothermal plume originating from the Juan de Fuca Ridge, and discuss the potential geochemical significance of these microorganisms.
AN: 1230989

                                                                      95 of 369  
TI: Biogeochemical factors influencing the residence time of microconstituents in a large tidal estuary, Delaware Bay.
AU: Church,-T.M.
AF: Coll. Mar. Stud., Univ. Delaware, Newark, DE 19716, USA
CO: 8. International Symposium on the Chemistry of the Mediterranean, Primosten (Yugoslavia), May 1984
SO: 8th-INTERNATIONAL-SYMPOSIUM-ON-THE-CHEMISTRY-OF-THE-MEDITERRANEAN,-PRIMOSTEN,-YUGOSLAVIA,-MAY,-1984. Branica,-M.-ed. 1986. vol. 18, no. 2-4 pp. 393-406
ST: MAR.-CHEM. vol. 18, no. 2-4
LA: English
ER: M (Marine)
AB: Evidence is drawn from the Delaware estuary to illustrate biogeochemical estuarine reaction processes using salinity distribution data and mass balance calculations. The Delaware retains some of its estuarine trace elements as sedimented estuarine particles, while others are more conservative and largely exported. Those retained by sedimenting processes include trace elements in primarily geochemical (particle reactive) chemistries, while those exported appear recycled by biochemical (nutrient reactive) chemistries. Often, the behavior of trace elements (e.g., Fe, Cd) and nutrients (e.g., PO sub(4)) appear biogeochemically linked. Other examples are drawn from mixing studies to illustrate particle interaction, and benthic flux measurements to illustrate limited diagenetic reflux.
AN: 1230895

                                                                      96 of 369  
TI: Deep-sea biological activity: In situ biochemical transformation of organic     matter labelled with carbon-14 at the water sediment interface at 2,000 m depth in the Bay of Biscay.
OT: Activite biologique en domaine profond: Transformations biochimiques in situ de composes organiques marques au carbone-14 a l'inte    rface eau-sediment par 2,000 m de profondeur dans le golfe de Gascogne 
AU: Cahet,-G.; Sibuet,-M.
AF: Univ. Pierre et Marie Curie, Lab. Arago, F-66650 Banyuls sur mer, France
SO: MAR.-BIOL. 1986. vol. 90, no. 2, pp. 307-315
LA: English
ER: M (Marine)
AB: In June 1983, in situ water-sediment interface experiments were conducted with the submersible Cyana  at 2,000 m depth in the Bay of Biscay. Dissolved or particulate  super(14)C-labelled organic compound was injected into a compartment of a box-corer specifically adapted for use with the submersible. After incubation, the biochemical reactions were stopped by addition of Formalin. In the laboratory, the pathways of the labelled molecules in the various extracts were followed by means of chemical and granulometric fractionation and isolation of meiofauna. Various experiments run at 1 atm and at in situ pressures, for incubation times of between 3 and 144 h, revealed in situ biochemical transformation. After recovery of the samples, activity at 1 atm was low, with only 4% of the radioactivity being recovered in the macromolecules against 84% for the in situ experiments. Results comprise new evidence of the existence of a rapid biochemical transformation at great depth in the ocean.
AN: 1230568

                                                                      97 of 369  
TI: Biogeochemical cycling of lignocellulosic carbon in marine and freshwater ecosystems: Relative contributions of procaryotes and eucaryotes.
AU: Benner,-R.; Moran,-M.A.; Hodson,-R.E.
AF: Dep. Microbiol., Univ. Georgia, Athens, GA 30602, USA
SO: LIMNOL.-OCEANOGR. 1986. vol. 31, no. 1, pp. 89-100
LA: English
ER: M (Marine); F (Freshwater)
AB: The relative contributions of procaryotes and eucaryotes to the degradation of the lignin and polysaccharide components of lignocellulosic detritus in two marine and two freshwater wetland ecosystems were determined. Two independent methods-physical separation of bacteria from fungi and other eucaryotes by size fractionation, and antibiotic treatments-were used to estimate procaryotic and eucaryotic contributions to the degradation of ( super(14)C-lignin)lignocelluloses and ( super(14)C-polysaccharide)lignocelluloses in samples of water and decaying plant material from each environment. Both methods yielded similar results. The results indicate a basic difference between the microbial degradation of lignocellulosic material in terrestrial and aquatic environments. Fungi have long been considered the predominant degraders of lignocellulose in terrestrial systems; the present results indicate that in aquatic systems bacteria are the predominant degraders of lignocellulose.
AN: 1199627

                                                                      98 of 369  
TI: Accumulation of some monoaromatic compounds during the degradation of crude oil by marine bacteria.
AU: Rontani,-J.F.; Bertrand,-J.-C.; Blanc,-F.; Giusti,-G.
AF: Cent. Oceanol. Marseille, U.R.A. 41, Fac. Sci. Luminy, 13288 Marseille Cedex 9, France
SO: MAR.-CHEM. 1986. vol. 18, no. 1, pp. 1-7
LA: English
ER: M (Marine)
AB: In continuous culture of a marine mixed bacterial population, the different fractions of crude petroleum strongly degraded. Analysis of the aromatic fraction by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) reveals the accumulation, during degradation, of some monoaromatic compounds probably initially trapped in asphaltenic structures.
AN: 1199306

                                                                      99 of 369  
TI: Comparison of the structures of humic acids from marine sediments and degraded field diatoms by  super(13)C- and  super(1)H-NMR spectroscopy.
AU: Poutanen,-E.-L.; Morris,-R.J.
AF: Inst. Mar. Res., P.O. Box 33, SF-00931 Helsinki, Finland
SO: MAR.-CHEM. 1985. vol. 17, no. 2, pp. 115-126
LA: English
ER: M (Marine)
AB: Humic acids isolated from marine sediments of the Peru continental shelf and from a degraded field diatom population dominated by the diatoms Skeletonema costatum, Nitzschia seviata  and Thalassiosira  sp. were characterized on the basis of infrared spectra and  super(13)C- and proton-NMR spectra. Aliphatic structures were found to constitute the major fraction of humic acids and they appear to be highly branched. Carbohydrates and to a lesser extent aromatic materials, carbonyl-, ether-, alcohol- and amino groups are important contributors to the structure of marine humic acids. A close relationship was observed between the chemical structure of the sedimentary humic acid and the plankton humic acid.
AN: 1199278

                                                                     100 of 369  
TI: Comparison of the lipid composition of sediments from three sites in the Venezuela Basin.
AU: Shaw,-P.M.; Johns,-R.B.
AF: Dep. Org. Geochem., Univ. Melbourne, Parkville, Vic. 3052, Australia
SO: MAR.-GEOL. 1985. vol. 68, no. 1-4, pp. 205-216
LA: English
ER: M (Marine)
AB: Solvent extractable and bound lipids from pelagic (site 1), turbidite (site 2) and hemipelagic (site 3) sediments of the Venezuela Basin have been analysed to indicate input sources of sedimentary lipids. Acids consist mainly of normal, branched, monoenoic and cyclopropyl components less than 24 carbons long with concentration and distribution indicating bacterial inputs of a similar level to each site. Long-chain acids, alcohols and 24-ethylcholest-5-en-3 beta -ol represent an input of higher plant-derived organics, which maximizes at sites 2 and 3. The source of this material is likely to be the Orinoco and Amazon river systems. Algal input is suggested by the distribution of sterols comprising diatoms and coccolithophores (24-methyl sterols), and dinoflagellates (dinosterol and other 4-methyl sterols).
AN: 1199189

                                                                     101 of 369  
TI: Wax esters and triacylglycerols in sinking particulate matter in the Peru upwelling area (15 degree S, 75 degree W).
AU: Wakeham,-S.G.
AF: Dep. Chem., Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: MAR.-CHEM. 1985. vol. 17, no. 3, pp. 213-235
LA: English
ER: M (Marine)
AB: The flux and composition of wax esters and triacylglycerols were measured in particulate matter collected by free-drifting sediment traps in the Peru upwelling area to assess diurnal variations in sources and vertical transport of these lipids. Traps were deployed for periods of 8-12 h during both day and night at the base of the euphotic zone (10-14 m) and at  approximately equals  50 m. Although the flux of total particulate organic carbon varied 4x, the flux of wax esters varied by 84x and triacylglycerols by 30x. POC, was esters, and triacylglycerols also showed different temporal patterns. The highest wax ester flux was measured in shallow traps at night and is attributed to increased inputs from zooplankton which feed near the surface at night. Triacylglycerol flux was high in both shallow and deep nocturnal traps, consistent with inputs of both phytoplankton and zooplankton lipids.
AN: 1199115

                                                                     102 of 369  
TI: Depletion of  super(13)C in Cretaceous marine organic matter: Source, diagenetic, or environmental signal?.
AU: Dean,-W.E.; Arthur,-M.A.; Claypool,-G.E.
AF: U.S. Geol. Surv., P.O. Box 25046, Federal Cent., Denver, CO 80225, USA
SO: MAR.-GEOL. 1986. vol. 70, no. 1-2, pp. 119-157
NT: Special issue: Deep ocean black shales.
LA: English
ER: M (Marine)
AN: 1199009

                                                                     103 of 369  
TI: The ecological and biogeochemical roles of the bacterioplankton in coastal marine ecosystems.
AU: Azam,-F.
AF: Scripps Inst. Oceanogr., La Jolla, CA 920939, USA
CO: U.S.-Pakistan Workshop on Marine Science in the Arabian Sea and Coastal Pakistan, Karachi (Pakistan), Nov 1982
SO: MARINE-GEOLOGY-AND-OCEANOGRAPHY-OF-ARABIAN-SEA-AND-COASTAL-PAKISTAN. Haq,-B.U.;Milliman,-J.D.-eds. National-Science-Found.,-Washington,-DC-USA 1984. pp. 317-326
NT: Incl. bibliogr.: 51 ref.
LA: English
ER: M (Marine)
AB: Bacterial abundance and growth are strongly correlated with phytoplankton biomass, suggesting a tight coupling between the production of organic matter by algae and its utilization by bacteria. The bacterioplankton are likely to be a major route for energy and material fluxes in marine foodwebs, consuming one-third or more of the primary production. Recent evidence suggests that heterotrophic flagellates consume a significant fraction of the bacterial production, though many other organisms also eat bacteria. This predation probably aids in nutrient recycling by releasing the nitrogen and phosphorus sequestered by the bacteria. Since bacteria account for about 80% of the living surface in seawater, they are also likely to be important in the absorption and transformation of dissolved pollutants. Therefore, it is clear that any study of coastal marine ecosystems should consider the role of the bacterioplankton. (Publ. in coop. with: Minist. Sci. and Technol. (Pakistan)).
AN: 1198970

                                                                     104 of 369  
TI: Biogeochemical cycle in marine systems.
AU: Hattori,-A.
AF: Ocean Res. Inst., Univ. Tokyo, Tokyo, Japan
CO: 20. Gen. Assem. International Council of Scientific Unions. ICSU Symp. on Global Change, Ottawa (Canada), 25 Sep 1984
SO: GLOBAL-CHANGE.-THE-PROCEEDINGS-OF-A-SYMPOSIUM-SPONSORED-BY-THE-INTERNATIONAL-COUNCIL-OF-SCIENTIFIC-UNIONS-ICSU-DURING-ITS-20TH-GENERAL-ASSEMBLY-IN-OTTAWA,-CANADA-ON-SEPTEMBER-25,-1984. Malone,-T.F.;Roederer,-J.G.-eds. ICSU,-Paris-France 1985. no. 5 pp. 278-286
ST: ICSU-PRESS-SYMP.-SER. no. 5
NT: Incl. bibliogr.: 33 ref.
LA: English
ER: M (Marine)
AB: Biogeochemical cycles in marine ecosystems are discussed with special reference to the behavior of nitrogen. Some research recommendations are presented which should be considered in the framework of the proposed International Geosphere and Biosphere Program (IGBP).
AN: 1198439

                                                                     105 of 369  
TI: The science of global change -- an overview.
AU: Friedman,-H.
AF: Natl. Res. Counc., 2101 Constitution Ave. NW, Washington, DC 20418, USA
CO: 20. Gen. Assem. International Council of Scientific Unions. ICSU Symp. on Global Change, Ottawa (Canada), 25 Sep 1984
SO: GLOBAL-CHANGE.-THE-PROCEEDINGS-OF-A-SYMPOSIUM-SPONSORED-BY-THE-INTERNATIONAL-COUNCIL-OF-SCIENTIFIC-UNIONS-ICSU-DURING-ITS-20TH-GENERAL-ASSEMBLY-IN-OTTAWA,-CANADA-ON-SEPTEMBER-25,-1984. Malone,-T.F.;Roederer,-J.G.-eds. ICSU,-Paris-France 1985. no. 5 pp. 20-52
ST: ICSU-PRESS-SYMP.-SER. no. 5
LA: English
ER: B (Brackish)
AB: Various areas of interdisciplinary research in the Sun-Earth system are discussed in detail: 1) sun and climate; 2) oceans and atmosphere; 3) the interannual variability of the tropical ocean and the global atmosphere (TOGA); 4) ocean and atmosphere chemistry and biogeochemical cycles; 5) the hydrological cycle; 6) ozone chemistry and dynamics; 7) CO sub(2) and agriculture; 8) remote sensing of global metabolism; 9) lithospheric processes; 10) sun and earth; 11) atmospherical catastrophes.
AN: 1198315

                                                                     106 of 369  
TI: The influence of microtopographic heterogeneity on carbon dioxide efflux from a subarctic bog.
AU: Luken,-J.O.; Billings,-W.D.
AF: Dep. Biol. Sci., Northern Kentucky Univ., Highland Heights, KY 41076, USA
SO: HOLARCT.-ECOL. 1985. vol. 8, no. 4, pp. 306-312
LA: English
ER: F (Freshwater)
AB: Soil carbon dioxide efflux was measured in hummock and hollow microhabitats of a subarctic peat bog near fairbanks, Alaska, during the 1983 growing season. Regardless of the presence of permafrost, hummocks showed a late June or early July peak in soil respiration followed by a gradual decrease. Hollows and wet Carex  Lawns showed a gradual increase in soil respiration with no mid-season peaks. Regression equations using soil temperature and soil moisture as independent variables explained 76% of the variance associated with soil carbon dioxide efflux. Sucrose (100 g m super(-2)) applied to a field plot caused a significant increase in soil respiration but nitrogen (5 g m super(-2)) did not. Sequential effects of nitrogen and phosphorus on peat respiration were demonstrated in a laboratory experiment.
AN: 1192401

                                                                     107 of 369  
TI: Hydrocarbons in water and suspended matter from the Pacific Ocean and Bering Sea.
OT: Uglevodorody vody i vzvesi tikhogo okeana i Beringova morya 
AU: Nemirovskaya,-I.A.
AF: Inst. Okeanol. AN S.S.S.R., Moscow, USSR
SO: OKEANOLOGIYA-OCEANOLOGY-MOSC.. 1985. vol. 25, no. 5, pp. 761-767
LA: Russian
ER: M (Marine)
AB: In surface water from the Tsugarustrait, Shatsky Rise and Bering Sea the concentration of organic compounds (mainly hydrocarbons) averaged 8  mu g/l, which is close to the background level in the Atlantic and Indian Oceans. In the Bering Sea the concentrations of dissolved and suspended particulate organic matter in surface water were 26 and 58  mu g/l respectively, in the near bottom layer the corresponding values were 42 and 52  mu g/l. The anomalously high (exceeding 50  mu g/l) concentrations of both forms in near bottom layers in some cases are assumed to be associated with intensive biochemical processes.
AN: 1192269

                                                                     108 of 369  
TI: A steady-state model for two humic fractions.
AU: Frisk,-T.; Pennanen,-V.
AF: Natl. Board Waters, Finland, P.O. Box 250, SF-00101 Helsinki, Finland
SO: VESIENTUTKIMUSLAIT.-JULK.,-HELSINKI-PUBL.-WATER-RES.-INST.,-HELSINKI. 1985. no. 65, pp. 98-107
LA: English
ER: F (Freshwater)
AB: A steady-state mass balance model for two humic fractions is presented. In the model the input of humus to the lake and the output from the lake, the loss reaction of humus including decay and sedimentation, and the possible transfer reactions between the two fractions are taken into account. The loss coefficients of the fractions are linearly interdependent. The absolute values of the coefficients cannot, however, be determined using the steady-state approach of this study. The characteristic coefficients of the interdependence of the coefficients as well as the loss coefficients of total humus were calculated for three lakes: Hakojaeryi, Kalaejaeryi, and Seinaejaeryi.
AN: 1174993

                                                                     109 of 369  
TI: Nutrient regeneration by zooplankton in southern Lake Huron.
AU: Korstad,-J.
AF: Dep. Nat. Sci., Oral Roberts Univ., 7777 S. Lewis, Tulsa, OK 74171, USA
SO: J.-GREAT-LAKES-RES. 1983. vol. 9, no. 3, pp. 374-388
LA: English
ER: F (Freshwater)
AB: Rates of nutrient regeneration by zooplankton ( mu mol/mg dry wt/hr) in southern Lake Huron from April to August 1975 ranged from undetectable to 2.6 for total phosphorus (TP), undetectable to 0.8 for total soluble phosphorus (TSP), undetectable to 0.12 for soluble reactive phosphorus (SRP), undetectable to 0.97 for ammonia (NH sub(3)), undetectable to 3.8 for nitrate plus nitrite (NO sub(3) + NO sub(2)), and undetectable to 2.9 for silica (SiO sub(2)). Two diel experiments were conducted. Times of highest rates of regeneration varied for the different nutrients on these dates. Using the average concentration of zooplankton in the surface waters during this study, the calculated average concentration of nutrients regenerated by zooplankton was 0.012  mu mol P/L/hr for TP, 0.0046  mu mol P/L/hr for TSP, 0.0016  mu mol P/L/hr for SRP, 0.0146  mu mol N/L/hr for NH sub(3), 0.043  mu mol N/L/hr for NO sub(3) + NO sub(2), and 0.058  mu mol Si/L/hr for SiO sub(2). The contribution of nutrient regeneration by zooplankton to the turnover time of the various nutrients in the surface waters was calculated to be 212 hr for TSP, 69 hr for SRP, 62 hr for NH sub(3), 505 hr for NO sub(3) + NO sub(2), and 531 hr for SiO sub(2).
AN: 1170937

                                                                     110 of 369  
TI: Sediments and sedimentation.
AU: Mothes,-G.; Proft,-G.
AF: Akad. Wiss. DDR, Inst. Geogr. und Geooekol., Ber. Hydrol., Jena, GDR
SO: LAKE-STECHLIN:-A-TEMPERATE-OLIGOTROPHIC-LAKE. Casper,-S.J.-ed. 1985. vol. 58 pp. 375-399
ST: MONOGR.-BIOL. vol. 58
LA: English
ER: F (Freshwater)
AB: This contribution summarizes the findings on sediments and the sediment process in the Lake Stechlin area, and compares them with other regions, discussing open questions.
AN: 1169898

                                                                     111 of 369  
TI: The chemical environment.
AU: Mothes,-G.; Koschel,-R.; Proft,-G.
AF: Akad. Wiss. DDR, Inst. Geogr. und Geooekol., Ber. Hydrol., Jena, GDR
SO: LAKE-STECHLIN:-A-TEMPERATE-OLIGOTROPHIC-LAKE. Casper,-S.J.-ed. 1985. vol. 58 pp. 87-125
ST: MONOGR.-BIOL. vol. 58
LA: English
ER: F (Freshwater)
AB: Changes in the chemical features of Lake Stechlin, Nehmitz and Dagow as a result of the cooling water circuit of the nuclear power plant must be expected both spatially and temporally. In the following sections the authors will give basic data about the phosphorus, carbon, nitrogen, silicium and oxygen content of the water characterizing the chemical state of the lake system before and during the operation of the nuclear power plant. The results give an insight into the temporal and spatial concentration gradients, the long-term changes and the external loads of these elements (import and export). This is intended to contribute to a deeper understanding of the main features of lake metabolism, such as primary production, secondary production, microbial activities, and sedimentation which will be described in other chapters of this volume.
AN: 1169771

                                                                     112 of 369  
TI: Stable sulfur isotope ratios as a tool for interpreting ecosystem sulfur dynamics.
AU: Fuller,-R.D.; Mitchell,-M.J.; Krouse,-H.R.; Wyskowski,-B.J.; Driscoll,-C.T.
AF: Dep. Civ. Eng., Syracuse Univ., Syracuse, NY 13210, USA
SO: WATER-AIR-SOIL-POLLUT. 1986. vol. 28, no. 1-2, pp. 163-171
LA: English
ER: F (Freshwater)
AB: Stable isotope ratios ( delta  super(34)S) were evaluated in soil solution leachates, soluble plus absorbed soil SO sub(4) super(2-), soil organic S, precipitation, and in stream solutions along an elevational gradient at the Hubbard Brook Experimental Forest in the White Mts. of New Hampshire, U.S.A. The  delta  super(34)S of soil organic S varied with soil horizon and vegetation type, but was generally more negative than adsorbed or soil solution SO sub(4) super(2-1). In the Bh horizon,  delta  super(34)S of organic S was typically more negative than the Oa horizon or lower mineral soil (Bs1). The patterns suggest a combination of plant and microbial fractionation processes. Stream  delta  super(34)S values decreased with decreasing elevation and were correlated with decreases in SO sub(4) super(2-1) concentration, suggesting an additional S source in higher elevation coniferous sites with a unique  delta  super(34)S.
AN: 1155855

                                                                     113 of 369  
TI: Nitrification, nitrate reduction, and nitrogen immobilization in a tidal freshwater marsh sediment.
AU: Bowden,-W.B.
AF: Yale Univ., Sch. For. and Environ. Stud., New Haven, CT 06511, USA
SO: ECOLOGY. 1986. vol. 67, no. 1, pp. 88-99
LA: English
ER: F (Freshwater)
AB: The dominant microbial transformations of ammonium and nitrate in the sediments of a tidal freshwater marsh were estimated from measured rates of isotope dilution of ammonium( super(15)N) added to sediment and litter samples, reduction of nitrate( super(15)N) to ammonium( super(15)) in fresh sediments, and net exchange of ammonium and nitrate between the marsh and river water in flumes built in the field. In two separate laboratory experiments, nitrification in mixed, fresh, surface sediments was 2.8 and 3.4 nmol multiplied by cm super(-3) multiplied by h super(-1). In undisturbed field sediments, nitrification rates are probably <1 nmol multiplied by cm super(-3) multiplied by h super(-1). Additions of nitrate( super(15N) to fresh sediments showed that nitrate produced from ammonium by nitrification was reduced very quickly. Less than 10% of this nitrate was reduced back to ammonium by dissimilation. The net transfer of nitrate in this marsh is to the sediments, and since nitrate does not accumulate in these sediments, the remaining nitrate produced by nitrification must be reduced by denitrification or by assimilatory nitrate reduction.
AN: 1153536

                                                                     114 of 369  
TI: Mineralization of organic carbon on and in the sediment of Lake Grevelingen.
AU: Londeboom,-H.J.; Klerk,-H.A.J.,de; Sandee,-A.J.J.
AF: North Sea Dir., Minist. Transp. and Public Works, P.O. Box 5807, 2280 HV Rijswijk, Netherlands
SO: NETH.-J.-SEA-RES. 1984. vol. 18, no. 3-4, pp. 492-510
LA: English
ER: B (Brackish)
AB: Within the framework of a research project on the carbon cycle in saline Lake Grevelingen a study of the mineralization on and in the sediment was made. The oxygen uptake by the sediment was measured using the bell jar method at 6 sampling stations. Applying a C over O sub(2) conversion factor of 0.29, it was calculated that 330 g  multiplied by  m super(-2) is mineralized in the sediment of the lake annually. By means of biomass estimates of the macroflora and fauna inside the bell jars and regression analysis, the contribution of these organisms to the carbon mineralization rate was calculated to be 70 and 95 g  multiplied by  m super(-2)  multiplied by  a super(-1), respectively. The effect of oxygen gradients and apparent diffusion coefficients up the oxygen uptake rate was studied with microelectrodes. This indicated that bioturbation is a major factor influencing the oxygen uptake rate. A good correlation between this rate and temperature was found.
AN: 1151993

                                                                     115 of 369  
TI: The carbon balance of a saline lake (Lake Grevelingen, The Netherlands).
AU: Vries,-I.,de
AF: Delft Hydraulics Lab., P.O. Box 177, 2600 MH Delft, Netherlands
SO: NETH.-J.-SEA-RES. 1984. vol. 18, no. 3-4, pp. 511-528
LA: English
ER: B (Brackish)
AB: An annual carbon balance is presented for Lake Grevelingen, a former shallow estuary in the SW part of The Netherlands. Planktonic primary production is the main source of organic material, with an estimated contribution of at least 60%. From a comparison of the carbon balance with oxygen consumption measurements, the efficiency of the planktonic auto- and microheterotrophic community in producing particulate organic material is estimated at 44%. The pelagic and benthic compartment of the lake are tightly coupled by the filtering activity of benthic macrofauna, causing a high grazing pressure on phytoplankton (estimated at 55% of net production) and a transport of suspended organic particles to the sediment by deposition of faeces and pseudofaeces, exceeding passive sinking with a factor 3 to 4.
AN: 1151633

                                                                     116 of 369  
TI: Carbon fixation and chlorophyll in bottom sediments of brackish Lake Grevelingen, The Netherlands.
AU: Nienhuis,-P.H.; de-Bree,-B.H.H.
AF: Delta Inst. Hydrobiol. Res., Vierst. 28, 4401 EA Yerseke, Netherlands
SO: NETH.-J.-SEA-RES. 1984. vol. 18, no. 3-4, pp. 337-359
LA: English
ER: B (Brackish)
AB: Lake Grevelingen in the SW Netherlands is a former estuary and since 1971 a brackishwater lake, connected with the North Sea by sluices. Chlorophyll a concentrations in the upper 10 cm (sliced per cm) of Lake Grevelingen sediments are given for the years 1977-1980. Chlorophyll a in the upper cm of the bottom varied between 20-400 mg  multiplied by  m super(-2). Average values in 1-3 m deep sandy and silty-sandy stations amounted to 67.5-82.2 mg  multiplied by  m super(-2) in the upper cm. A restricted number of phaeopigment data for 1977 revealed an average phaeopigment-chlorophyll a ratio of 0.03 (sand) to 0.39 (silt). POC measured in 1977 and 1978 in the top cm of the sediment showed annual average values ranging between 0.2 and 0.7% of sediment dry weight.  super(14)C fixation data in the light, as measured in a laboratory incubator, are given for 1979 and 1980, with highest values during summer (200-500 mg C  multiplied by  m super(-2)  multiplied by  d super(-1)) and lower values in winter. Integrated annual values give average  super(14)C fixation estimates per station, ranging between 47 g C  multiplied by  m super(-2)  multiplied by  a super(-1), with a variation coefficient of 35 to 49% of the mean. Average  super(14)C dark fixation values varied between 13 and 27% of average hight fixation values.
AN: 1151579

                                                                     117 of 369  
TI: Sediment-water exchange in Lake Grevelingen under different environmental conditions.
AU: Kelderman,-P.
AF: Inst. Hydraulic and Environ. Eng., P.O. Box 3015, 2601 DA Delft, Netherlands
SO: NETH.-J.-SEA-RES. 1984. vol. 18, no. 3-4, pp. 286-311
LA: English
ER: B (Brackish)
AB: The impact of various environmental factors on the phosphate and silicate sediment-water exchange in Lake Grevelingen has been investigated in a series of laboratory experiments under aerobic conditions. Silicate mobilization from the sediment showed a strong temperature dependence, with fluxes ranging from 5  plus or minus  3.2 mg Si  multiplied by  m super(-2)  multiplied by  d super(-1) at 5 degree C to 85  plus or minus  18 mg Si  multiplied by  m super(-2)  multiplied by  d super(-1) at 20 degree C. Phosphate mobilization fluxes ranged from 0.5  plus or minus  0.7 mg PO sub(4)-P  multiplied by  m super(-2)  multiplied by  d super(-1) at 5 degree C to 11  plus or minus  3.4 mg P  multiplied by  m super(-2)  multiplied by  d super(-1) at 20 degree C. The phosphate exchange fluxes showed a significantly linear negative correlation with the phosphate concentrations in the overlying water, in accordance with Fick's first law of diffusion. Based on the results of 4 different sediment types, general relationships have been derived for the phosphate sediment-water exchange as a function of water temperature and phosphate concentration in Lake Grevelingen. The results have successfully been applied in a simulation model for the phosphate concentration in Lake Grevelingen for the years 1974-1977.
AN: 1151334

                                                                     118 of 369  
TI: A new method for the recovery of ammonium from natural waters for measurement of  super(15)N composition in isotope dilution experiments.
AU: Fisher,-T.R.; Morrissey,-K.M.
AF: Univ. Maryland-CEES, Horn Point Environ. Lab., Cambridge, MD 21613, USA
SO: MAR.-CHEM. 1985. vol. 16, no. 1, pp. 11-21
LA: English
ER: M (Marine)
AB: Efforts to measure the rate of nitrogen recycling in natural waters have depended on estimates of ammonium production using the  super(15)N isotope dilution method. This technique requires the removal of dissolved ammonium from the water sample for analysis of the  super(15)N content. Steam distillation or micro-diffusion methods have been most commonly used, but these techniques are labor intensive and time consuming. The authors have attempted to simplify the measurement of the planktonic regeneration of ammonium by presenting a mercury precipitation technique which is simple, practical, and easily used at sea.
AN: 1134182

                                                                     119 of 369  
TI: Organic matter in sediments from the Bay of Cadiz and its salt-ponds areas.
OT: Materia organica en los sedimentos de la bahia de Cadiz y sus zonas de marismas y salinas 
AU: Establier,-R.; Blasco,-J.; Gomez,-A.; Escolar,-D.
AF: Inst. Invest. Pesq., Puerto Pesquero s/n, Cadiz, Spain
SO: INVEST.-PESQ.-BARC.. 1984. vol. 48, no. 2, pp. 285-301
LA: Spanish
ER: M (Marine)
AB: Analysis of the concentrations of organic matter, phosphates and other complementary parameters in scdiments of 62 sampling stations from the Bay of Cadiz (Spain) and surrounding salt-pond areas showed enrichment of organic matter and phosphates in the surface. This may be partly attributed to urban effluents flowing in the area studied. The low values obtained in the carbon/nitrogen relation suggest that the incorporation of these materials in the sediments is produced by phytoplankton assimilation of nutrients, originating from the microbiological descomposition of the organic matter in the environment. The vertical trends of the sedimentary column at various stations showed intense bottom activity as well as marked sedimentary progression. Grain-size distribution of the sediments is a significant factor in the accumulation levels of the organic matter and phosphates in the different sectors of the study area.
AN: 1130624

                                                                     120 of 369  
TI: The isotopic mass balance of sulphur in oceanic sediments (the Pacific Ocean as an example).
AU: Lein,-A.Yu.
AF: Inst. Biochem. and Physiol. Microorg., U.S.S.R. Acad. Sci., Pushchino, Moscow 142292, USSR
SO: MAR.-CHEM. 1985. vol. 16, no. 3, pp. 249-257
LA: English
ER: M (Marine)
AB: Dissimilatory sulphate reduction is the main biogeochemical reaction responsible for the cycle of sulphur and its isotopic composition in modern oceanic sediments. The maximal intensity of this process, measured with the help of radioactive isotopes, is typical of sediments in the peripheral regions of the ocean to a depth of 1,000 m and makes up 10-60  mu g S/kg wet silt/day. The minimal enrichment with  super(32)S of the buried, reduced sulphur and the maximal accumulation of heavy isotopes in sulphate sulphur of pore waters are observed under conditions of the most intensive biogeochemical processes. Further away from continents the intensity of bacterial sulphate reduction diminishes to a fraction of 1  mu g S/kg wet silt/day, and the reduced sulphur becomes enriched in  super(32)S (up to - 50.0 ppt.). The amount of reduced sulphur in the total sulphur buried in modern sediments of the Pacific Ocean is twice the amount of sulphate sulphur.
AN: 1130548

                                                                     121 of 369  
TI: Cycling of transuranic radionuclides in the Columbia River, its estuary and the Northeast Pacific Ocean. Progress Report, January-December 1984.
AU: Beasley,-T.M.
CA: Oregon State Univ., Newport, OR (USA). Marine Science Cent
SO: 1984. 22 pp
NT: NTIS Order No.: DE85011485/GAR; Contr. AT06-77EV70030.
RN: DOE-EV-70030-13 (DOEEV7003013)
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: This report summarizes progress from 1 January 1984 to 31 December 1984 in research dealing with the behavior of transuranic and other long-lived radionuclides in the Columbia River downstream from the Hanford Reservation and in the northeast Pacific Ocean. Goals achieved include: The analysis of thirteen continental slope cores for sup 137 Cs,/sup 239, 240/Pu and sup 241 Am is complete; while sup 210 Pb, C, and P analyses continue. The analysis of composite river sediment samples for sup 63 Ni inventory in lower river reaches was done. Mass spectrometry analysis of fish, mussels, and plankton determined the isotopic composition of plutonium during 1962 to 1980.
AN: 1125226

                                                                     122 of 369  
TI: A tentative assessment of the balance of heavy and transition metals in the Caspian Sea.
OT: Predvaritel'naya otsenka balansa tyazhelykh i perekhodnykh metallov v Kaspijskom more 
AU: Morozov,-N.P.; Petukhov,-S.A.
AF: VNIRO, Moscow, USSR
SO: METEOROL.-GIDROL. 1985. no. 9, pp. 75-81
LA: Russian
ER: M (Marine)
AB: The balance of Fe, Mn, Zn, Cu, Ni, Co, Cr, Pb and Cd in the Caspian Sea was analysed on the basis of field hydrological observations and literature data. 68-87% of Fe, Mn, Ni and Pb are shown to be discharged with eolian material. Rivers contribute the major proportion of Zn, Cu, and Cd (36-48%) in solution and of Mn, Pb, cd and Co (24, 26, 28 and 69% respectively) in suspension, Zn, Cu and Cd are added into the Sea with atmospheric precipitation (27, 12 and 14% respectively). 66 and 52% of Fe and Mn load were in particulate form. 98.2-99.9% of metals are buried in bottom sediments. The input from sewage constituted from 0.03 (Co) to 1.3-1.9% (Cd and Cu) which is 10 times lower than in the Baltic Sea.
AN: 1124601

                                                                     123 of 369  
TI: Hydrocarbons in marine sediments from eastern Taiwan.
AU: Jeng,-W.-L.
AF: Inst. Oceanogr., Natl. Taiwan Univ., Taipei, Taiwan
SO: ACTA-OCEANOGR.-TAIWAN. 1984. no. 15, pp. 31-38
LA: English
ER: M (Marine)
AB: Hydrocarbons in marine sediments taken from the continental margin of eastern Taiwan have been analyzed by gas chromatography. Total n-alkane contents in the sediments range from 21 to 1213 ng/g dry wt. with a mean of 307 ng/g dry wt.. Generally speaking, higher n-alkane levels were found in offshore sediments and lower n-alkane levels in near-shore sediments. Carbon preference indices for 42 samples range from 1.0 to 7.9 with an average of 2.4. This average is higher than those (2.0 and 1.7) found in Taiwan Strait sediments, suggesting larger inputs of land-derived organic matter from the Central Range and Coastal Range. In addition, the pentacyclic aromatic hydro-carbon perylene has been detected in offshore sediments (9-50 ng/g dry wt.) exclusively. An in situ formation rather than a deposition of perylene directly into the sediments is discussed.
AN: 1123650

                                                                     124 of 369  
TI: (Microbiological processes involved in carbon and nitrogen cycles in lakes.).
OT: Mikrobiologicheskie protsessy krugovorota ugleroda i azota v ozerakh 
AU: Kuznetsov,-S.I.; Saralov,-A.I.; Nazina,-T.N.
SO: MOSKVA-USSR-NAUKA 1985. 213 pp
NT: Incl. bibliogr.: 720 ref.
LA: Russian
ER: F (Freshwater)
AN: 1121346

                                                                     125 of 369  
TI: A carbon budget for South West Arm, Port Hacking.
AU: Cuff,-W.R.; Sinclair,-R.E.; Parker,-R.R.; Tranter,-D.J.; Bulleid,-N.C.; Giles,-M.S.; Godfrey,-J.S.; et-al.
AF: Maritimes Forest Res. Cent., Can. For. Serv., P.O. Box 4000 Fredericton, N.B., E3B 5P7, Canada
SO: SYNTHESIS-AND-MODELLING-OF-INTERMITTENT-ESTUARIES.-A-CASE-STUDY-FROM-PLANNING-TO-EVALUATION. Cuff,-W.R.;Tomczak,-M.,Jr.-eds 1983. vol. 3 pp. 193-232
ST: LECT.-NOTES-COAST.-ESTUAR.-STUD. vol. 3
LA: English
ER: B (Brackish)
AB: A multidisciplinary study of the structure and dynamics of a small ( similar to  78 ha) Australian marine embayment (South West Arm of Port Hacking, New South Wales) was conducted during 1973-1978. Compatible data were obtained by studying processes in terms of the flow of carbon. The carbon budget developed in this paper represents an attempt at a synthesis of that information. The chemical and biological species contained in each of 10 compartments are described; as data allows, the average carbon mass within each compartment and the average flow rates between the compartments, with variances, are estimated. This information is used to piece together the distribution of carbon among the compartments and to ascertain the major flow paths of carbon into, within, and out of South West Arm.
AN: 1116394

                                                                     126 of 369  
TI: Regeneration rate and extent of phosphorus and silicon from decomposing phytoplankton assemblages.
AU: Kamatani,-A.; Ueno,-Y.
AF: Tokyo Univ. Fish., Konan, Minato-ku, Tokyo 108, Japan
SO: BULL.-JAP.-SOC.-SCI.-FISH.-NISSUISHI. 1980. vol. 46, no. 5, pp. 537-542
LA: Japanese
AB: A study of the aerobic decomposition of two different phytoplankton assemblages from Tokyo Bay was conducted under the thermostated-dark condition in an attempt to study the rate and extent of regeneration of phosphorus and silicon. In the first stage 70-80% of the biogenous-P regenerated and the remaining which was considered to be refractory and resistant, underwent slow biochemical oxidation in the second stage. Silica dissolution rate constant at the first stage was 0.5 - 8 x 10 super(-2) day super(-1), which was 10 to 30 times smaller than that for the acid-cleaned silica walls. The silica dissolution rate constant at the first stage increased about 2.3 times corresponding to a rise in temperature of 10 degree C and the activation energy was estimated to be about 14.1 kcal mol super(-1). The ratio of reactive Si to P increased exponentially as regeneration proceeded.
AN: 1111930

                                                                     127 of 369  
TI: The distribution of cadmium, copper, nickel, manganese, and aluminium in surface waters of the open Atlantic and European shelf area.
AU: Kremling,-K.
AF: Inst. Meereskunde, Duesternbrooker Weg 20, D-2300 Kiel, FRG
SO: DEEP-SEA-RES. 1985. vol. 32, no. 5A, pp. 531-555
LA: English
ER: M (Marine)
AB: A total of 232 surface water samples (6 m depth) was collected in the open Atlantic Ocean and in the Brazilian and northwest European shelf areas during three transects between 23 degree S and 59 degree N in October/November 1980, August/September 1981, and March/April 1982. The open Atlantic cadmium, copper, and nickel concentrations increase towards higher latitudes with averages (nmol kg super(-1)  plus or minus  1 s) and ranges of 0.002 to 0.10 (0.040  plus or minus  0.026) Cd; 0.86  plus or minus  0.34 (1.28  plus or minus  0.26) Cu; and 1.88  plus or minus  0.66 (3.40  plus or minus  0.61) Ni in the regions 7 degree S to 35 degree N and 35 degree  to 59 degree N, respectively. These elevations are probably the result of the biogeochemical cycles of these elements and of the hydrographical regimes in those regions. The manganese and aluminium distributions show a different geographical pattern with maximum concentrations in the region between around 10 degree N to 30 degree N which probably originate from aeolian input (Sahara dust).
AN: 1111119

                                                                     128 of 369  
TI: Biological principles of pond culture: Sediment and benthos.
AU: White,-D.
SO: PRINCIPLES-AND-PRACTICES-OF-POND-AQUACULTURE:-A-STATE-OF-THE-ART-REVIEW. Lannan,-J.E.;Smitherman,-R.O.;Tchobanoglous,-G.-eds. 1983. pp. 33-37
NT: Incl. bibliogr.: 38 ref. Grant No. AID/DSAN-G-0264.
LA: English
ER: F (Freshwater)
AB: The greatest contribution of benthic organisms to aquaculture is their ability to modify sediments and enhance release of nutrients. Where algae serve directly to provide a food source for fish, nutrient transfer may be immediate. Benthic bacteria and the large benthic invertebrates are most important in reworking soils and in facilitating release of nutrients from the soil by assimilating compounds and keeping the topo few centimeters in constant movement. Production of fish will be directly proportional to the fertility and type of soils present.
AN: 1110183

                                                                     129 of 369  
TI: Minipellets: A new and abundant size class of marine fecal pellets.
AU: Gowing,-M.M.; Silver,-M.W.
AF: Cent. Mar. Stud., Univ. California, Santa Cruz, CA 95064, USA
SO: J.-MAR.-RES. 1985. vol. 43, no. 2, pp. 395-418
LA: English
ER: M (Marine)
AB: Minipellets, fecal pellets from 3 to 50  mu m in diameter, were found on detritus collected by a particle interceptor trap array in the upper 2,000 m of the eastern tropical Pacific. The fluxes of minipellets reached 5 x 10 super(6) m super(-2)/day, and exceeded fluxes of larger (> 50  mu m diameter) fecal pellets by 3 orders of magnitude. Carbon flux of minipellets was 11-49% that of larger pellets; however, carbon flux of ultrastructurally intact cells (microalgae and bacteria) in minipellets was equal to that of intact cells in the larger pellets. Minipellets appear ubiquitous; the authors have found them in all their samples of particulates from other cruises from surface waters to bathypelagic depths. Minipellets are probably wastes of protozoans and small invertebrates that consume marine snow and larger fecal pellets throughout the water column, thereby maintaining the high numbers of minipellets from the surface to 2,000 m.
AN: 1094914

                                                                     130 of 369  
TI: Global Ocean Flux Study. Proceedings of a workshop held at Woods Hole, Massachusetts on September 10-14, 1984.
CA: National Research Counc., Washington, DC (USA)
CO: Global Ocean Flux Study, Woods Hole, MA (USA), 10-14 Sep 1984
SO: 1984. 378 pp
NT: NTIS Order No.: PB85-203800/GAR; Grant NSF-OCE84-17920.
LA: English
ER: M (Marine)
AB: A major goal for Ocean Sciences is to gain an understanding of the processes controlling marine biogeochemical cycling at regional, basin-wide, and global spatial scales, and at time scales from interannual through decadal. The physical, chemical, and biological processes governing the production and fate of biogenic materials in the sea need to be understood well enough to predict their influences on, and responses to, global-scale perturbations, whether natural or anthropogenic, since these perturbations can have a significant impact on human populations. To achieve this goal, a long-term multidisciplinary study of the flux of material through the global ocean environment is needed. (Sponsored by Off. Nav. Res., Arlington, VA., NASA, Washington, DC., and NOAA, Washington, DC).
AN: 1084571

                                                                     131 of 369  
TI: The contribution of bacterioplankton to productivity and organic matter cycle in the southeastern Pacific Ocean.
AU: Sorokin,-Yu.I.; Mamayeva,-T.I.
AF: South Dep., Shirshov Inst. Oceanol., USSR Acad. Sci., Gelendzhik, USSR
SO: DOKL.-EARTH-SCI.-SECT. 1985. vol. 275, no. 1-6, pp. 214-218
LA: English
ER: M (Marine)
AB: In the southeastern pacific there are several large quasipermanent zones of upwelling, divergence, as well as frontal zones. For this reason, this is a region of high biological productivity. Much of the total biological resources of the oceans are present here, and as much as 20 percent of the world fish landings are made in this region. Previous investigations have shown the important combination of bacterioplankton to the food resources of the pelagic zone of the oceans. During the 34th cruise of the RV Akademik kurchatov , the authors investigated the function of the bacterioplankton.
AN: 1081531

                                                                     132 of 369  
TI: Biogeochemical influence of vegetation and soils in the ILWAS watersheds.
AU: Cronan,-C.S.
AF: Dep. Bot. and Plant Pathol., Univ. Maine, Orono, ME 04469, USA
SO: WATER-AIR-SOIL-POLLUT. 1985. vol. 26, no. 4, pp. 355-371
NT: Special issue: Integrated Lake-Watershed Acidification.
LA: English
ER: F (Freshwater)
AB: The Integrated Lake-Watershed Acidification Study (ILWAS) was initiated to develop a quantitative mechanistic understanding of the relationship between atmospheric deposition and surface water quality and acidity. The study was conducted using three forested watersheds (Panther, Sagamore, and Woods) in the central Adirondack Park of New York State. Although these catchments receive similar loadings of acidic deposition, the three systems exhibit distinct differences in lake water pH and alkalinity (Panther Lake = pH 6.2, Sagamore Lake = pH 5.6, and Woods Lake = pH 4.7). By comparing the biogeochemical behavior of these watersheds, the ILWAS investigators hoped to elucidate and to quantify the major ecosystem parameters controlling the fate of strong acids introduced from the atmosphere to lake-watershed systems.
AN: 1080137

                                                                     133 of 369  
TI: Speciation of chemical elements in sediments of an eutrophicated and polluted lake basin in southern Finland.
AU: Alhonen,-P.; Vuorinen,-A.; Suksi,-J.
AF: Dep. Geol., Univ. Helsinki, Helsinki, Finland
CO: 7. International Symposium on Environmental Biogeochemistry, Viterbo (Italy). Rome (Italy), 8-13 Sep 1985
SO: 7th-INTERNATIONAL-SYMPOSIUM-ON-ENVIRONMENTAL-BIOGEOCHEMISTRY. 1985. p. 5
NT: Abstract only.
LA: English
ER: F (Freshwater)
AB: A sediment profile of an eutrophicated and polluted lake, Lake Lippajaervi was investigated for lithostratigraphy, lake productivity (including subfossil diatoms) and speciation of chemical elements. Sedimentation rate was on an average 10.5 mm/yr during the last twenty years, being ca. 8 mm/yr between 1963 and 1970 and ca. 13 mm/yr between 1970 and 1982. Biogeochemical cycles and processes have led to dissolution of remarkable amounts of elements from mineral matter and their binding in more loosely bound forms. The elements seem to be present as sorbed, as sulphides, and in association with Fe oxyhydroxides and with organic matter (Fe and Cu). As a consequence of eutrophication and pollution many elements were enriched in the upper parts of the sediment profile.
AN: 1073150

                                                                     134 of 369  
TI: The effects of natural water level fluctuations on N and P cycling in a Great Lakes marsh.
AU: Kelley,-J.C.; Burton,-T.M.; Enslin,-W.R.
AF: Dep. Fish. and Wildl., Michigan State Univ., East Lansing, MI 48824, USA
SO: WETLANDS. 1984. vol. 4, pp. 159-175
LA: English
ER: F (Freshwater)
AB: The water depth in marshes occurring along Lake Michigan is largely controlled by fluctuations of the Lake Michigan water level. The role of water level in controlling the distribution and cycling of N and P in emergent (Sparganium eurycarpum, Scirpus validus , and Typha latifolia ) and wet meadow (Calamagrostis canadensis, Carex stricta , and Carex aquatilis ) communities of a Lake Michigan river mouth marsh was studied. Nutrient uptake was determined from biomass sampling and tissue analysis. Community distribution at various lake stages was determined from aerial photographs.
AN: 1046531

                                                                     135 of 369  
TI: Arsenic transport, reactivity, and toxicity in the Chesapeake Bay.
AU: Sanders,-J.G.
CO: The Fate and Effects of Pollutants: A Symposium, (College Park, MD) (USA), 26-27 Apr 1985
SO: THE-FATE-AND-EFFECTS-OF-POLLUTANTS:-A-SYMPOSIUM. Maryland-Univ.,-College-Park-USA.-Sea-Grant-Program 1985. p. 55
ST: TECH.-REP.-MD.-UNIV.-SEA-GRANT-PROGRAM. 
NT: Summary only.
RN: UM-SG-TS-85-02 (UMSGTS8502)
LA: English
ER: M (Marine); B (Brackish)
AB: Arsenate, the primary inorganic form of arsenic in oxidized natural waters, is highly reactive in productive estuaries, actively taken up by phytoplankton, transformed into reduced and methylated forms, then released into the surrounding water column. The degree of arsenic methylation that takes place is proportional to the rate of primary production and the chemical form of arsenic produced is dependent on the species of phytopolankton present. The various chemical forms of arsenic differ in their stability, reactivity, and toxicity; thus, the observed variations have considerable geochemical and ecological significance. Algal incorporation of arsenic and subsequent transformation of chemical form leads to an increase in reduced and methylated arsenicals which are less available (and, therefore, less toxic) to phytoplankton, but are much more toxic to higher organisms.
AN: 1046215

                                                                     136 of 369  
TI: A global biogeochemical cycle and the system organization.
OT: Global'nyj biogeokhimicheskij krugovorot khimicheskikh ehlementov i ego sistemnaya organizovannost' 
AU: Norozov,-N.P.
AF: VNIRO, Moscow, USSR
SO: BIOGEOCHEMICAL-AND-TOXICOLOGICAL-STUDIES-OF-WATER-POLLUTION..  BIOGEOKHIMICHESKIE-I-TOKSIKOLOGICHESKIE-ISSLEDOVANIYA-ZAGRYAZNENIYA-VODOEMOV.- Patin,-S.A.-ed.1984. pp. 9-21
ST: SB.-NAUCH.-TR.-VNIRO. 
LA: Russian
AB: A global biogeochemical embraces all migrations of chemical elements governed by biological, geological and physico-chemical processes and by human activities. However, the leading role is played by migrations of nutrients with live organisms, their metabolites and detritus. A multi-purpose approach to investigations of biogeochemical cycles in ecosystems will contribute to the solution of problems related to rational exploitation and protection of natural resources.
AN: 1037723

                                                                     137 of 369  
TI: The transport of major dissolved matter in Changjiang Estuary.
AU: Wang,-Z.-F.; Yuan,-X.-Z.; Yao,-L.-K.
AF: Second Inst. Oceanogr., Natl. Bur. Oceanogr., Hangzhou, People's Rep. China
SO: OCEANOL.-LIMNOL.-SIN. 1985. vol. 16, no. 3, pp. 222-230
LA: Chinese
ER: B (Brackish)
AB: The average concentrations (ppm) of major dissolved matter in Changjiang River are: SiO sub(2), 6.2, Ca 35.0, Mg 5.5, Na 9.0, K 2.2, Cl 20, SO sub(4) 13.5, HCO sub(3) 127, among them the most concentrated species are Ca and HCO sub(3). In the area studied, major dissolved elements are controlled by the physical mixing because they are linearly related with C1ppt, which also indicates a behavir of conservation. The correlations are: Na = -1.6 + 540 Cl Clppt.  less than or equal to 1; Na = -64.8 + 539.5 Cl Clppt >1; K = 1.53 + 23.7 Cl; Ca = 34.8 + 19.6 Cl; Mg = 2.75 + 68.5 Cl; SO sub(4) = 9.43 + 140.1 Cl; HCO sub(3) = 126.5 + 0.69 Cl; and SiO sub(2) = 6.24-0.17S. The fluxes of the major dissolved matter in the Changjiang Estuary were also estimated as follows: Na 8.4 x 10 super(6)t/a; K 2.0 x 10 super(6)t/a; Ca 31.9 x 10 super(6)t/a; SO sub(4) 12.3 x 10 super(6)t/a; Mg 5.2 x 10 super(6)t/a; HCO sub(3) 116.4 x 10 super(6)t/a; SiO sub(2) 5.7 x 10 super(6)t/a; and Cl 18.5 x 10 super(6)t/a sub(o).
AN: 1035841

                                                                     138 of 369  
TI: Extraction and cleanup procedures for determination of diarylphosphates in fish, sediment, and water samples.
AU: Muir,-D.C.G.; Grift,-N.P.
AF: Freshwat. Inst., Dep. Fish. and Oceans, 501 University Crescent, Winnipeg, Man. R3T 2N6, Canada
SO: J.-ASSOC.-OFF.-ANAL.-CHEM. 1983. vol. 66, no. 3, pp. 684-690
LA: English
AB: Methods for determination of triaryl/alkylphosphates (TAPs) in water, fish, and sediment have been extended to determination of the diarylphosphate (DAP) degradation products. DAPs were extracted from water (adjusted to pH 0.5) by use of XAD-2 resin and determined by gas-liquid chromatography as butyl esters. Recovery of diphenylphosphate (DPP) and o-, m-, p-dicresylphosphates (DoCP, DmCP, DpCP) were >95% in water samples fortified at 1, 10, and 50  mu g/L. DAPs were extracted from fish with methanol and the extracts were cleaned up on reverse phase (C18) silica cartridges. Recoveries were >87% for DPP, DoCP, DmCP, and DpCP in fish muscle fortified at 50, 100, and 500 ng/g. Sediments were refluxed with aqueous methanol and DAPs were recovered by use of XAD-2 resin. Recoveries of DAPs from sediments fortified at 50 and 100 ng/g were >76%. Interferences (1-10 ng/g) from phosphorus or nitrogen-containing GLC peaks prevented sub-ng/g level analysis for DAPs in sediment and fish extracts.
AN: 1033824

                                                                     139 of 369  
TI: Cycling of fluoride in a mangrove community near a fluoride emission source.
AU: Murray,-F.
AF: Dep. Biol. Sci., Univ. Newcastle, Newcastle, N.S.W. 2308, Australia
SO: J.-APPL.-ECOL. 1985. vol. 22, no. 1, pp. 277-285
LA: English
ER: B (Brackish)
AB: A comparison of stands of immature grey mangroves, Avicennia marian  growing near a fluoride emission source (Kooragang Island, Australia) and a relatively unpolluted area (Gosford) showed that A. marina  and accumulate high concentrations of fluoride, particularly in leaves, generally without visible injury. Fluoride input to the Kooragang Island ecosytem as bulk deposition of fluoride was found to be 0 multiplied by 31 g m super(-2) year super(-1) and this varied with the distance and direction of each site in relation to fluoride emission sources. Most of the input at Kooragang Island was gaseous fluoride, but a small particulate fluoride input occurred. Mangrove communities may export up to 25 kg ha super(-1) day super(-1) of detritus to estuarine food webs of commercial and ecological importance, so the fluoride retentive capacity of mangrove communities is of potential significance when industrial emission sources establish in these estuarine areas.
AN: 1031386

                                                                     140 of 369  
TI: Composition of alkanes and fatty acids of lipids in suspended organic matter and sediments from the Northwest Indian Ocean.
OT: Sostav alkanov i zhirnykh kislot lipidov vzvesi i osadkov severo-zapadnoj chasti Indijskogo okeana 
AU: Nemirovskaya,-I.A.; Verkhovskaya,-Z.I.
AF: Inst. Okeanol. AN SSSR, Moscow, USSR
SO: GEOKHIMIYA. 1985. no. 6, pp. 891-898
LA: Russian
ER: M (Marine)
AB: Based on samples collected during the 32nd cruise of the R/V Akademik Kurchatov  in March and April 1981 an analysis was made of the composition of alkanes in suspended matter obtained by separation and filtration and of alkanes and fatty acids from the upper bottom sediments in the Mozambique Channel and the Seychelles area. The alkanes were mainly C sub(16) - C sub(35) compounds. In individual samples the alkane spectrum was characterized by 2 maxima: n - C sub(17) and n C sub(25) - C sub(31). C sub(13) - C sub(20) enter into fatty acids with saturated C sub(16), C sub(18) and unsaturated C sub(18), C sub(20) predominating. It is shown that alkanes and fatty acids are of both of terraneous and marine origin at various ratios of allochthonic and antochthonous components, the latter playing a more important role at the stations located in the immediate vicinity of oil- and gas-bearing formations.
AN: 1023877

                                                                     141 of 369  
TI: Biogeochemical processes and climate modelling.
AU: Bolin,-B.
AF: Dep. Meteorol., Univ. Stockholm, Stockholm, Sweden
SO: THE-GLOBAL-CLIMATE. Houghton,-J.T.-ed. 1984. pp. 213-224
LA: English
ER: M (Marine)
AB: Some basic steady state features of the global biogeochemical cycles are reviewed, particularly with regard to turnover times for carbon in terrestrial and marine reservoirs, and the means for their determination. The processes of evapo-transpiration, the dependence of surface albedo on type of vegetation and moisture supply photosynthesis and gaseous exchange between the atmosphere and plants are analysed as is their possible role in modelling long-term changes of climate. Similarly, the role of the nutrient balance of the sea for climate change is discussed.
AN: 1021455

                                                                     142 of 369  
TI: Effects of benthic macroinvertebrates on the exchange of solutes between sediments and freshwater.
AU: Matisoff,-G.; Fisher,-J.B.; Matis,-S.
AF: Dep. Geol. Sci., Case Western Reserve Univ., Cleveland, OH 44106, USA
SO: HYDROBIOLOGIA. 1985. vol. 122, no. 1, pp. 19-33
LA: English
ER: F (Freshwater)
AB: Infaunal macrobenthos (tubificid oligochaetes, chironomid larvae, and unionid bivalves) were studied in laboratory microcosms to determine their effects on freshwater sediment diagenesis and the exchange of solutes between sediments and water. Tubificids enhanced the flux of ammonium, bicarbonate, and silica from sediments. After the onset of anoxia, they decreased the flux of iron and phosphate. Chironomids increased the flux of nitrate, bicarbonate, and silica, but did not affect the flux of phosphate. Pore water concentrations were low within the irrigated burrowed zone for chemical species normally high in reduced sediments. Concentration gradients were less steep in the actively irrigated burrow zone, but radial diffusion to and from burrows, increased rates of organic decomposition, and enhanced diatom frustule dissolution rates result in enhanced mass transport from sediments.
AN: 1019837

                                                                     143 of 369  
TI: Particulates and the cycling of lead in Ullswater, Cumbria.
AU: Everard,-M.; Denny,-P.
AF: Sch. Biol., Queen Mary Coll., Mile End Rd., London E1 4NS, UK
SO: FRESHWAT.-BIOL. 1985. vol. 15, no. 2, pp. 215-226
LA: English
ER: F (Freshwater)
AB: Ullswater has been affected by former lead mining in the catchment area. This paper investigates how lead in the lake is re-distributed within the littoral zones. Concentrations in the lakewater are low. Particulates including phytoplankton, seston and gelatinous ooze overlying lead-enriched sediments can have values from 1.3 to > 6.0 and 26 mg Pb g super(-1) dry weight respectively.
AN: 1016232

                                                                     144 of 369  
TI: Prospects for global ocean pollution monitoring.
CA: UNEP, Geneva (Switzerland)
SO: UNEP-REG.-SEAS-REP.-STUD. GENEVA-SWITZERLAND-UNEP 1984. no. 47, 58 pp
LA: English
ER: M (Marine)
AB: The oceans cover 70% of the earth's surface and are thus a major component of the environment. They play a significant role in biogeochemical cycles, in stabilising climate, and in providing marine resources. Therefore it is important that man's polluting activities are not allowed to impair this system. It is necessary for man to obtain a fundumental understanding of marine systems and to monitor the levels and effects of pollutants.
AN: 0977423

                                                                     145 of 369  
TI: Wetland research and NASA: Towards a planetary ecological perspective.
AU: Bartlett,-D.S.
AF: NASA Langley Res. Cent., Hampton, VA, USA
CO: 8. Biennial International Estuarine Research Conf., Durham, NH (USA), 28 Jul 1985
SO: ESTUARIES. 1985. vol. 8, no. 2B, p. 4A
NT: Abstract only.
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: The National Aeronautics and Space Administration (NASA) has begun a "Global Biospheric Research Program", which attempts to bring a planetary perspective to ecological studies. The objective of the program is to apply NASA technology and expertise from a number of relevant areas to establish a greater understanding of the influence of the biota on global material cycling. Investigations of wetlands have been chosen for particular emphasis because of their potentially important role in global nutrient cycling and of the active body of biogeochemical research taking place in wetland environments.
AN: 0976292

                                                                     146 of 369  
TI: (Role of circulation in the Alboran Sea in the vicinity of the Strait of Gibraltar, on the production-regeneration system (MEDIPROD cruise IV of Jean Charcot ).).
OT: Role de la circulation en mer d'Alboran au voisinage du detroit de Gibraltar, sur le systeme production-regeneration (Campagne MEDIPROD IV du Jean-Charcot ) 
AU: Minas,-M.; Coste,-B.; le-Corre,-P.; Minas,-H.J.; Packard,-T.T.; Raimbault,-P.
AF: Fac. Sci. Luminy, 13288 Marseille Cedex 09, France
SO: RAPP.-P.-V.-REUN.-CIESM. 1983. vol. 28, no. 7, pp. 59-61
LA: French
ER: M (Marine)
AB: Two phenomena can explain the nutrient enrichment leading to the high chlorophyll area off the Spanish coast in the northwestern Alboran Sea: A the turbulent mixing in the Strait of Bigraltar; - the Spanish coastal upwelling, associated with the anticyclonic gyre. The high productivity area produces, by organic sedimentation, a well-formed oxygen minimum and a regeneration layer in the Alboran Sea.
AN: 0964532

                                                                     147 of 369  
TI: (Comparison of the chemical composition of particles and plankton of the Liguro-Provencal Basin.).
OT: Comparaison de la composition chimique des particules et du plancton du Bassin Liguro-Provencal 
AU: Haerdstedt-Romeo,-M.; Copin-Montegut,-C.
AF: Lab. Phys. et Chim. Mar., Univ. Pierre et Marie Curie, B.P. 8, La Darse, 06230 Villefranche-sur-Mer, France
SO: RAPP.-P.-V.-REUN.-CIESM. 1983. vol. 28, no. 7, pp. 63-65
LA: French
ER: M (Marine)
AB: The concentrations of C, N, P, Al, Fe and Si have been determined in plankton and particulate matter in the Liguro-Provencal Basin during March 80. Trace metals: Mn, Zn, Cu and Cd have been also analyzed in the plankton. C, N, Al, Fe and Si exhibit parallel variations in plankton and particulate matter.
AN: 0964166

                                                                     148 of 369  
TI: (Origin, distribution and evolution of organic matter in deposits of two Mediterranean lagoon ecosystems.).
OT: Origine, distribution et evolution de la matiere organique dans les depots de deux ecosystems lagunaires mediterraneens 
AU: Gadel,-F.; Martin,-R.; Dumas,-J.P.
AF: Lab. Sedimentol. et Geochim. Mar., Univ. de Perpignan, France
SO: RAPP.-P.-V.-REUN.-CIESM. 1983. vol. 28, no. 7, pp. 115-118
LA: French
AB: The study of the organic matter determined the main factors responsible for the sedimentation of two Mediterranean lagoons composition of the organic matter results from its origin (phanerogamic, algal). It is distributed according to the dynamic and chemical environmental conditions. The evolution proceeds from the presedimentary alteration phenomena in freewater environment and diagenetic effects after deposition.
AN: 0964163

                                                                     149 of 369  
TI: The distribution of cadmium, copper, nickel, manganese, and aluminum, in surface waters of the open Atlantic and European shelf area.
AU: Kremling,-K.
AF: Inst. Meereskd., Duesternbrooker Weg 20, D-2300 Kiel, FRG
SO: DEEP-SEA-RES. 1985. vol. 32, no. 5A, pp. 531-555
LA: English
ER: M (Marine)
AB: A total of 232 surface water samples (6 m depth) was collected in the open Atlantic Ocean and in the Brazilian and northwest European shelf areas during three transects between 23 degree S and 59 degree N in October/November 1980, August/September 1981, and March/April 1982. The open Atlantic cadmium, copper, and nickel concentrations increase towards higher latitudes. These elevations are probably the result of the biogeochemical cycles  of these elements and of the hydrographical regimes in those regions. A significant increase of all metals studied is observed at the northwest European shelf edge area. A comparison with waters of the central North Sea indicates enrichment factors of about 3 to 5 for the metals investigated here. The mechanisms that potentially may affect the shelf water concentrations are discussed on the basis of their relations with salinity.
AN: 0959453

                                                                     150 of 369  
TI: Experimental study of long-lived radionuclides transfers (americium, plutonium, technetium) between labelled sediments and Annelidae (Nereis diversicolor, Arenicola marina ).
AU: Germain,-P.; Miramand,-P.; Masson,-M.
AF: Comm. Energ. At., IPSN-DERS-SERE Lab. Radioecol. Mar., Cent. La Hague, B.P. 270, 50107 Cherbourg, France
CO: International Symposium on the Behavior of Long-lived Radionuclides in the Marine Environment, La Spezia (Italy), 28-30 Sep 1983
SO: INTERNATIONAL-SYMPOSIUM-ON-THE-BEHAVIOR-OF-LONG-LIVED-RADIONUCLIDES-IN-THE-MARINE-ENVIRONMENT. Cigna,-A.;Myttenaere,-C.-eds. Commission-of-the-European-Communities,-Luxembourg-Luxembourg 1984. pp. 327-340
ST: RADIAT.-PROT.-SER. 
NT: ISBN 92-825-5089-3.
RN: EUR-9214-EN (EUR9214EN)
LA: English
ER: M (Marine)
AB: Laboratory experiments were conducted to determine the bioavailability of sediments labelled by  super(241)Am,  super(238)Pu,  super(239)Pu and  super(95m)Tc to two marine benthic annelidae: N. diversicolor  and A. marina . Channel coastal sediments and atlantic sediments originating from Abyssal plain of Cape Verde were contaminated. The biological availability was expressed in terms of a transfert factor (T.F.) defined as the activity in the organisms (cpm.g super(-1) wet weight) relative to the activity in the sediment (cpm.g super(-1) wet weight). For both species and the three radionuclides, the transfer factors were lower than unity. In the case of reduced sediment, T.F. of  super(95m)Tc (< 0.5) were higher than those of Am and Pu(< 0.01). The bounding of Tc with oxidative sediments is low and reversible, and T.F. are not significant, which is not the case with Am and Pu. Transfer modalities, indirect transfer via interstitial water and/or direct transfer from sediments, were discussed.
AN: 0958515

                                                                     151 of 369  
TI: Microbial sterility and salinity effects on  super(241)americium distribution and biological transfer coefficients, in sandy marine and freshwater sediments.
AU: Vanderborght,-O.L.J.; van-Puymbroeck,-S.; Gerits,-J.; Vangenechten,-J.; Bierkens,-J.
AF: Belgian Nucl. Cent. SCK/CEN, Radionuclides Metab. Lab., B 2400 Mol, Belgium
CO: International Symposium on the Behavior of Long-lived Radionuclides in the Marine Environment, La Spezia (Italy), 28-30 Sep 1983
SO: INTERNATIONAL-SYMPOSIUM-ON-THE-BEHAVIOR-OF-LONG-LIVED-RADIONUCLIDES-IN-THE-MARINE-ENVIRONMENT. Cigna,-A.;Myttenaere,-C.-eds. Commission-of-the-European-Communities,-Luxembourg-Luxembourg 1984. pp. 317-325
ST: RADIAT.-PROT.-SER. 
NT: ISBN 92-825-5090-3.
RN: EUR-9214-EN (EUR9214EN)
LA: English
ER: M (Marine)
AB: Microbial activity in sediments is often called upon as a factor that could change the mobility and the biological availability of transuranics. Experimental data on  super(241)Am are scarce. The authors' former data indicated low K sub(d) values for  super(241)Am in sandy marine and freshwater sediments (9.1 x 10 super(4)), values that did not significantly change by  gamma -sterilization. In contrast, most reported k sub(d) values are situated at about 1.10 super(4) to 50.10 super(4). The authors report an extensive experiment to check in controlled conditions, the effect of microbial sterility of sediments, on  super(241)Am K sub(d) and on its bioaccumulation by detritus feeders. A first approach to the situation in which a continental radioactive sediment would be flooded by seawater was also simulated by adding seawater to freshwater sediments.
AN: 0958452

                                                                     152 of 369  
TI: Behaviour of tritium in the marine environment: Studies with the macroalgae Laurencia obtusa  and Cystoseira compressa .
AU: Cinelli,-F.; Belcari,-P.; De-Ranieri,-S.; Arapis,-G.; Bonotto,-S.; Gerber,-G.B.; Kirchmann,-R.
AF: Ist. Zool. e Anat. Comp., Univ. Pisa, I-56100 Pisa, Italy
CO: International Symposium on the Behavior of Long-lived Radionuclides in the Marine Environment, La Spezia (Italy), 28-30 Sep 1983
SO: INTERNATIONAL-SYMPOSIUM-ON-THE-BEHAVIOR-OF-LONG-LIVED-RADIONUCLIDES-IN-THE-MARINE-ENVIRONMENT. Cigna,-A.;Myttenaere,-C.-eds. Commission-of-the-European-Communities,-Luxembourg-Luxembourg 1984. pp. 271-282
ST: RADIAT.-PROT.-SER. 
NT: ISBN 92-825-5089-3.
RN: EUR-9214-EN (EUR9214EN)
LA: English
ER: M (Marine)
AB: Kinetic experiments with tritium water have shown that in the marine pluricellular algae L. obtusa  and C. compressa , water equilibrates rapidly with external tritium water (5  mu Ci ml super(-1)). Two components were found in uptake, having respectively a half life of 0.2-0.4 and of 3.3.-22 min. In release, three components could be discerned, with half lives of 0.25, 4 and  approximately equals  75-500 min. Incorporation of  super(3)H into the total organic matter of Cystoseira), incubated in tritium water (50  mu Ci ml super(-1)) for 8-11 days, is small (0.6 to 2.5  mu Ci g super(-1) or 1-5% only). Selective extraction of freeze-dried Cystoseira  has shown that 32% and 36% of tritium was bound respectively to small organic molecules and to lipids and pigments, whereas 20%, 11% and 0.4% of total organic tritium was present respectively in nucleic acids, protein and residual material.
AN: 0958361

                                                                     153 of 369  
TI: The chemical behavior of long-lived radionuclides in the marine environment.
AU: Edgington,-D.N.; Nelson,-D.M.
AF: Cent. Great Lakes Stud., Univ. Wisconsin, Milwaukee, WI 53204, USA
CO: International Symposium on the Behavior of Long-lived Radionuclides in the Marine Environment, La Spezia (Italy), 28-30 Sep 1983
SO: INTERNATIONAL-SYMPOSIUM-ON-THE-BEHAVIOR-OF-LONG-LIVED-RADIONUCLIDES-IN-THE-MARINE-ENVIRONMENT. Cigna,-A.;Myttenaere,-C.-eds. Commission-of-the-European-Communities,-Luxembourg-Luxembourg 1984. pp. 19-66
ST: RADIAT.-PROT.-SER. 
NT: ISBN 92-825-5089-3.
RN: EUR-9214-EN (EUR9214EN)
LA: English
ER: M (Marine)
AB: Measurements of long-lived radionuclides in the marines environment have provided a wealth of information regarding the physical, biological, and chemical processes which control the behavior of these and many other pollutants in the oceans. Their value as tracers for the dispersion, transport, and fate of pollutants in the oceans is largely dependent on the chemical properties of each individual radioelement. Differences in these properties, particularly in relation to their interaction with biotic or abiotic particulate matter, result in the separation of parent-daughter radioisotopes in the natural radioelement series or in changes in the ratios of fission and activation products. Such differences have provided the means to provide time scale for a variety of transport processes and to determine sedimentation rates. the properties of these radionuclides in the oceans can, in general, be predicted from the chemical properties of the stable elements.
AN: 0957859

                                                                     154 of 369  
TI: The environmental behavior of long-lived radionuclides: Radiological protection requirements.
AU: Preston,-A.
AF: Minist. Agric., Fish. Food Fish. Lab., Lowestoft, Suffolk NR33 0HT, UK
CO: International Symposium on the Behavior of Long-lived Radionuclides in the Marine Environment, La Spezia (Italy), 28-30 Sep 1983
SO: INTERNATIONAL-SYMPOSIUM-ON-THE-BEHAVIOR-OF-LONG-LIVED-RADIONUCLIDES-IN-THE-MARINE-ENVIRONMENT. Cigna,-A.;Myttenaere,-C.-eds. Commission-of-the-European-Communities,-Luxembourg-Luxembourg 1984. pp. 3-15
ST: RADIAT.-PROT.-SER. 
NT: ISBN 92-825-5089-3.
RN: EUR-9214-EN (EUR9214EN)
LA: English
ER: M (Marine)
AB: Radiological protection concern with long-lived radionuclides in the environment is examined and requirements in relation to the behaviour of such radionuclides in the environment are considered.
AN: 0957839

                                                                     155 of 369  
TI: International Symposium on the Behavior of Long-lived Radionuclides in the Marine Environment.
AU: Cigna,-A.; Myttenaere,-C.-(eds.)
AF: ENEA, Dip. Prot. Ambientale e Salute, Uomo Cent. Ric. Energ. Ambiente, Forte di Santa Teresa, La Spezia, Italy
CA: Commission of the European Communities, Luxembourg (Luxembourg)
CO: International Symposium on the Behavior of Long-lived Radionuclides in the Marine Environment, La Spezia (Italy), 28-30 Sep 1983
SO: RADIAT.-PROT.-SER. 1984. 471 pp
NT: ISBN 92-825-5089-3.
RN: EUR-9214-EN (EUR9214EN)
LA: English
ER: M (Marine)
AB: Abstracts of the 27 papers presented at the conference are cited. A brief discussion follows each paper. A round table discussion follows the proceedings.
AN: 0957796

                                                                     156 of 369  
TI: Arsenic in marine organisms. A minireview.
AU: Maher,-W.A.
AF: Dep. Phys. and Inorg. Chem., Univ. Adelaide, Adelaide, S.A., Australia
SO: BIOL.-TRACE-ELEM.-RES. 1984. vol. 6, no. 2, pp. 159-164
LA: English
ER: M (Marine)
AB: A review of the nature and accumulation of arsenic in marine organisms is presented. A study of the literature has revealed a lack of information about the mechanisms of uptake, molecular transformations, and biochemical associations of arsenic within organisms, and it remains unclear whether a few forms of arsenic are ubiquitous. The arsenic forms present in marine sediments and their role in the biogeochemical cycling of arsenic are also largely unknown.
AN: 0953546

                                                                     157 of 369  
TI: Accumulation of sediment organic matter in a hardwater lake with reference to lake ontogeny.
AU: Godshalk,-G.L.; Wetzel,-R.G.
AF: Dep. Biol. Sci., Univ. Southern Mississippi, Southern Station Box 5018, Hattiesburg, MS 39406, USA
CO: Symposium on Detritus Dynamics in Aquatic Ecosystems, Savannah, GA (USA), Nov 1983
SO: SYMPOSIUM-ON-DETRITUS-DYNAMICS-IN-AQUATIC-ECOSYSTEMS. 1984. vol. 35, no. 3 pp. 576-586
ST: BULL.-MAR.-SCI. vol. 35, no. 3
LA: English
ER: F (Freshwater)
AB: The occurrence and quality of detrital organic matter was investigated in sediments of a small hardwater lake. The objective of the study was to examine the interactions between plant productivity and growth form, water depth, sediment depth and potential erosion and deposition processes in the lake and their mutual impact on accumulation of detritus in the sediments. Of particular interest are the potential effects such accumulation has on sediment dynamics and lake ontogeny. Sediment core samples were taken on a transect from the water's edge to the deepest part of the lake. Samples of surficial, intermediate and deep sediments from all water depths were analyzed for content of coarse particulate matter, organic matter, solvent-extractable humins and fulvic and humic acids. The observed occurrence of sedimentary detrital carbon is explained in terms of hypothesized synergistic effects of increasing production and succession of littoral vegetation, differential decomposition rates controlled by properties of both the substrate and the microenvironment and the influence of water movements and basin morphology on sediment erosion and deposition. Results are discussed.
AN: 0947896

                                                                     158 of 369  
TI: Alternate fate of planktonic detritus: Organic deposition and the geological record.
AU: Porter,-K.G.
AF: Dep. Zool., Univ. Georgia, Athens, GA 30602, USA
CO: Symposium on Detritus Dynamics in Aquatic Ecosystems, Savannah, GA (USA), Nov 1983
SO: SYMPOSIUM-ON-DETRITUS-DYNAMICS-IN-AQUATIC-ECOSYSTEMS. 1984. vol. 35, no. 3 pp. 587-600
ST: BULL.-MAR.-SCI. vol. 35, no. 3
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Extensive deposits of amorphous and fine grained organic matter called black shale are found in the geological record. These deposits were formed in open water marine and freshwater systems as evidenced by the presence of planktonic microfossils including zooplankton fecal pellets. Fecal pellets are easily identifiable particles found among sedimenting planktonic material. An examination of morphometric and ecological conditions favoring pellet deposition today allows one to reconstruct the paleoecological environments at the time black shale formed. Loss of organic matter from the pellets through microbial degradation and coprophagy is reduced by cool water temperatures and brief residence time in the water column. Pellet preservation in sediments is enhanced in areas with minimal physical disturbance, bioturbation, and microbial activity. These conditions are generally well met in anoxic, silled marine basins, trenches, fjords, and permanently anoxic lakes.
AN: 0947765

                                                                     159 of 369  
TI: Symposium on Detritus Dynamics in Aquatic Ecosystems, sponsored by the Oceanography Section of the National Science Foundation, Center for Environmental and Estuarine Studies of the University of Maryland, and Skidaway Institute of Oceanography of the University of Georgia, Savannah, Georgia, November 1983.
CO: Symposium on Detritus Dynamics in Aquatic Ecosystems, Savannah, GA (USA), Nov 1983
SO: BULL.-MAR.-SCI. 1984. vol. 35, no. 3, 356 pp
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Twenty-eight papers from this conference are published in this issue.
AN: 0947322

                                                                     160 of 369  
TI: Ecology of Indian estuaries.10. Distribution of total phosphorus, total nitrogen and total potassium in the sediments of Ashtamudi Estuary.
AU: Balakrishnan-Nair,-N.; Abdul-Azis,-P.K.; Arunachalam,-M.; Krishnakumar,-K.; Dharmaraj,-K.
AF: Dep. Aquat. Biol. and Fish., Univ. Kerala, Trivandrum-695 007, India
SO: MAHASAGAR. 1984. vol. 17, no. 1, pp. 33-39
LA: English
ER: B (Brackish)
AB: The distribution of total phosphorus, total nitrogen and total potassium in the sediments of Ashtamudi, a tropical estuarine system (8 degree 53'-9 degree 2'N latitude and 76 degree 31'-76 degree 41'E longitude) has been studied from riverine to marine area in relation to the texture of the sediment and hydrographical features of the bottom waters. The values of total phosphorus, total nitrogen and total potassium are in the range 0.63-7.32 mg.g super(-1), 1.49-13.78 mg.g super(-1) and 0.4-3.1 mg.g super(-1) respectively. The pattern of distribution of total P with the textural relationship is discussed. The input of allochthonous phosphates from sewage is traced in the system. The reason for the higher values for total nitrogen in the riverine area is attributable to the admixture of industrial and agricultural wastes.
AN: 0947309

                                                                     161 of 369  
TI: Ecology of Indian estuaries. 8. Inorganic nutrients in the Ashtamudi Estuary.
AU: Balakrishnan-Nair,-N.; Dharmaraj,-K.; Abdul-Azis,-P.K.; Arunachalam,-M.; Krishnakumar,-K.; Balasubramanian,-N.K.
AF: Dep. Aquat. Biol. and Fish., Univ. Kerala, Trivandrum-695 007, India
SO: MAHASAGAR. 1984. vol. 17, no. 1, pp. 19-32
LA: English
ER: B (Brackish)
AB: Ashtamudi Backwater is the second largest estuarine system of the southwest coast of India. Surface and bottom waters from 52 stations covering the entire watershed from the lower reaches of the Kallada River to the mouth of estuary have been analysed. Data pertaining to temperature, salinity, transparency, pH, dissolved oxygen, phosphate-phosphorus, silicate-silicon, nitrate-nitrogen and nitrite-nitrogen are presented and discussed. Various sources of pollution, deposition and filling and their impact on the exosystem are also discussed. All parameters exhibited wide spatial and zonal variations governed mainly by mixing, nature and intensity of water pollution and other human interference. Results of the analyses are statistically compared. Phosphate-phosphorus and slicate-silicon are available throughout the watershed. Depletion of nitrate-nitrogen and nitrite-nitrogen has been observed in certain heavilly polluted regions.
AN: 0947219

                                                                     162 of 369  
TI: Contribution of gaseous sulphur from salt marshes to the global sulphur cycle.
AU: Steudler,-P.A.; Peterson,-B.J.
AF: Ecosyst. Cent., Mar. Biol. Lab., Woods Hole, MA 02543, USA
SO: NATURE. 1984. vol. 311, no. 5985, pp. 455-457
LA: English
ER: B (Brackish)
AB: The authors report here a synthesis of the results of an annual set of monthly flux measurements of hydrogen sulphide (H sub(2)S), dimethyl sulphide (DMS), carbonyl sulphide (COS), carbon disulphide (CS sub(2)) and dimethyl disulphide (CMDS) from a Spartina) marsh and an adjacent tidal creek. Dimethyl sulphide and H sub(2)S were the predominant gases released from the Spartina) marsh (49% and 35% of the total, respectively) while H sub(2)S was the major gas (71%) emitted from the creek site. They suggest that the short-lived sulphur gases released from marshes may have an important role in local atmospheric sulphur budgets. Globally, saline marshes may release a total of 1.7 Tg S yr super(-1) (1 Tg = 10 super(12) g) in the atmosphere, which includes more than double the quantity of two important long-lived sulphur gases, COS and CS sub(2), needed to sustain the stratospheric sulphate layer.
AN: 0942365

                                                                     163 of 369  
TI: Metals analysis in aquatic sediments. A review.
AU: Boniforti,-R.
AF: Lab. Stud. Ambiente Mar., CNEN-EURATOM, Fiascherino, La Spezia, Italy
SO: THALASSIA-JUGOSL. 1978. vol. 14, no. 3-4, pp. 281-301
NT: Incl. bibliogr.: 68 ref.
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: In environmental pollution studies it is of great importance to know the distribution of metals in sediments, water, and biological material in order to evaluate the stresses imposed on the environment by anthropogenic activity. The availability of elements to organisms depends on their physicochemical state which in turn depends on the overall biogeochemical cycle. An important step of this cycle is the accumulation and/or release of elements by the sediments. Extraction methods used to investigate the distribution of metals in aquatic sediments are reviewed.
AN: 0938746

                                                                     164 of 369  
TI: Some aspects of biogeochemical cycles in the Red Sea with special reference to new observations made in summer 1982.
AU: Poisson,-A.; Morcos,-S.; Souvermezoglou,-E.; Papaud,-A.; Ivanoff,-A.
AF: Lab. Phys. Chim. Mar., Univ. Pierre et Marie Curie, Tour 24, 4 Place Jussieu, 75230 Paris Cedex 05, France
CO: Mabahiss/John Murray  International Symposium, Alexandria (Egypt), 3 Sep 1983
SO: MARINE-SCIENCE-OF-THE-NORTH-WEST-INDIAN-OCEAN-AND-ADJACENT-WATERS. Angel,-M.V.-ed. 1984. vol. 31, no. 6-8A pp. 707-718
ST: DEEP-SEA-RES. vol. 31, no. 6-8A
LA: English
ER: M (Marine)
AB: Recent data of some parameters of the carbon dioxide system in the Red Sea are presented and discussed in relation to the distribution of nutrients, water budget and general circulation in the Red Sea. Special attention is focussed on the variation of distribution of these parameters from winter to summer, and on the two regimes of circulation in the straits of Bab-el-Mandab. This is based mainly on the measurements made on the Meteor  in December 1964 and the new data collected during two recent cruises on the R/V. Maeio-Dufresne  in June and October 1982.
AN: 0926544

                                                                     165 of 369  
TI: Biogeochemistry of particulate organic matter in the oceans: Results from sediment trap experiments.
AU: Wakeham,-S.G.; Lee,-C.; Farrington,-J.W.; Gagosian,-R.B.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES. 1984. vol. 31, no. 5A, pp. 509-528
LA: English
ER: M (Marine)
AB: Particulate organic matter collected in sediment traps from various oceanic regimes-Sargasso Sea, equatorial North Atlantic, central North Pacific, California Current, and Peru coastal upwelling-have been analyzed for their lipid and amino acid composition and flux. Despite rapid settling of the large particles through the water column and a relatively small depth gradient for total organic carbon flux, there are major changes in the composition and flux of lipids and amino acids associated with the particles. The rapid disappearance of the more labile compounds, such as amino acids and polyunsaturated fatty acids, with increasing depth indicates that the major sources of such compounds are in the upper part of the water column and that they are readily degraded as the particles sink. On the other hand, the intermittent appearance of large amounts of wax ester, along with the changing fatty acid composition of the particles, points to deep-water sources for some of these compounds.
AN: 0920865

                                                                     166 of 369  
TI: Antarctic freshwater algae.
AU: Wharton,-R.A.,Jr.
AF: NASA-Ames Res. Cent., Moffett Field, CA 94035, USA
CO: Annual Meeting of the Phycological Society of America, Fort Collins, CO (USA), 5-9 Aug 1984
SO: ABSTRACTS.-ANNUAL-MEETING-OF-THE-PHYCOLOGICAL-SOCIETY-OF-AMERICA,-1984. 1984. vol. 20, no. suppl. p. 11
ST: J.-PHYCOL. vol. 20, no. suppl.
NT: Summary only.
LA: English
ER: F (Freshwater)
AB: Less than 10% of Antarctica contains regions favorable to the growth and reproduction of algae. These regions included coastal areas of the Antarctic Peninsula and several ice free valleys along the margin of the continent. Directions of future research will likely include year-round field studies, laboratory studies of physiological-ecology, the role of algae in biogeochemical cycles, including sedimentation, mineral deposition, stromatolite formation, and understanding the paleoecology of antarctic freshwater ecosystems.
AN: 0909798

                                                                     167 of 369  
TI: Suspended sediments and nutrients in water ebbing from seagrass-covered and denuded tidal mudflats in a southern Australian embayment.
AU: Bulthuis,-D.A.; Brand,-G.W.; Mobley,-M.C.
AF: Mar. Sci. Lab., P.O. Box 114, Queenscliff, Vic. 3225, Australia
SO: AQUAT.-BOT. 1984. vol. 20, no. 3-4, pp. 257-266
LA: English
ER: M (Marine)
AB: The concentrations of suspended solids, nitrogen (NH sub(4)@)u+, NO sub(3)@)u-, NO sub(2)@)u-), phosphorus (total phosphorus, PO sub(4)@)u- super(3)) and silicate were measured in water ebbing from seagrass-covered tidal mudflats and from adjacent ungrassed mudflats in Western Port, Victoria, Australia. Ebb water was collected on six occasions during January and February (summer) and once during July (winter). From both types of mudflats the concentrations of suspended solids, phosphorus and silicate increased during the last hour of ebb tide with maxima in concentrations reached 0.5 to 1 h before slack water ebb. During the last 1.5-2.5 h of ebb tide the suspended solids, phosphorus and silicate concentrations were higher in water ebbing from denuded mudflats than from seagrass-covered mudflats. The concentration of nitrogen remained low in water ebbing from both types of mudflats during the day, but increased significantly during a night-time ebb; light-dependent biological uptake of nitrogen is implicated.
AN: 0887251

                                                                     168 of 369  
TI: The supersaturation of carbonyl sulfide in surface waters of the Pacific Ocean off Peru.
AU: Ferek,-R.J.; Andreae,-M.O.
AF: Dep. Oceanogr., Florida State Univ., Tallahassee, FL 32206, USA
SO: GEOPHYS.-RES.-LETT. 1983. vol. 10, no. 5, pp. 393-396
LA: English
ER: M (Marine)
AB: Carbonyl sulfide (COS) was found to be supersaturated by a factor averaging 2.6 with respect to the atmosphere in surface waters of the continental shelf of Peru. The degree of supersaturation was correlated with dissolved dimethyl sulfide (MDS) concentrations indicating a possible biogenic source of atmospheric COS. The oceanic source of COS could account for a substantial fraction of the COS flux to the atmosphere.
AN: 0876961

                                                                     169 of 369  
TI: Imitation study of spring phytoplankton bloom in the coastal "pelagial" of the Gulf of Finland.
OT: Imitatsionnoe modelirovanie vesennego tsveteniya fitoplanktona v "pelagiali" pribrezhnykh vod Finskogo zaliva 
AU: Savchuk,-O.P.; Kolodochka,-A.A.
AF: Address not stated
SO: STATISTICAL-ANALYSIS-AND-MODELLING-OF-OCEANOLOGICAL-PROCESSES..  VEROYATNOSTNYJ-ANALIZ-I-MODELIROVANIE-OKEANOLOGICHESKIKH-PROTSESSOV.- Rozhkov,-V.A.-ed.LENINGRAD-USSR-GIDROMETEOIZDAT 1984. pp. 130-146
LA: Russian
ER: M (Marine)
AB: A one-dimensional model is formulated describing cycle of N and dynamics of O sub(2) caused by vertical transport and translocation of matter within the components of the model (phytoplankton, zooplankton, detritus, dissolved organic N, ammonium, nitrites, nitrates and O sub(2)) is presented. The model was calibrated and verified with reference to observations carried out in 2 areas of the Gulf. It is concluded that the model simulates large-scale evolutionary regularities of vertical structure of ecosystem during spring phytoplankton bloom and can be used to study inner mechanisms of the matter cycle in relation to changes in ecological factors.
AN: 0869148

                                                                     170 of 369  
TI: Monitoring carbon in world rivers.
AU: Degens,-E.; Kempe,-S.; Ittekkot,-V.
AF: Inst. Geol. and Paleontol., Univ. Hamburg, Hamburg, FRG
SO: ENVIRONMENT-WASH.-DC. 1984. vol. 26, no. 9, pp. 29-33
LA: English
ER: F (Freshwater)
AB: Riverine systems play a major role in the transport of nutrients from the planet's land masses and atmosphere to its oceans, and frequently serve as reservoirs for numerous compounds. This project report outlines the activities and initial results of a unique research effort to measure the transport of nutrients--especially organic carbon--in major world rivers. Many scientists believe that the results of this study may aid them in determining some unknown parameters of the global carbon dioxide budget and in understanding how human actions have complicated the biogeochemical cycling of elements.
AN: 0865926

                                                                     171 of 369  
TI: Resistance of estuarine bacteria to organotin compounds.
AU: Pettibone,-G.W.; Cooney,-J.J.
AF: Univ. Massachusetts, Boston, MA 02125, USA
CO: 84. Annual Meeting of the American Society for Microbiology, St. Louis, MO (USA), 4-9 Mar 1984
SO: ABSTRACTS-OF-THE-ANNUAL-MEETING-OF-THE-AMERICAN-SOCIETY-FOR-MICROBIOLOGY-1984. 1984. p. 186
NT: Summary only.
LA: English
ER: B (Brackish)
AB: Pure cultures of estuarine bacteria were isolated and screened to determine resistance to increasing concentrations of (CH sub(3)) sub(2)SnCl sub(2). MIC's for 100 isolates ranged from 2.5 to  greater than or equal to 200 ppm Sn as (CH sub(3)) sub(2)SnCl sub(2) and most (68%) had MIC's in the range of 15-50 ppm Sn. All pure cultures isolated on media containing 15 ppm Sn as (CH sub(3)) sub(2)SnCl sub(2) were resistant to (CH sub(3)) sub(3)SnCl. This suggests that resistance to one methyltin confers resistance to other methyltins. These results are consistent with the proposal that estuarine microflora can participate in biogeochemical cycling of tin.
AN: 0864848

                                                                     172 of 369  
TI: Detritus processing and mineral cycling in seagrass (Zostera ) litter in an Oregon salt marsh.
AU: Gallagher,-J.L.; Kibby,-H.V.; Skirvin,-K.W.
AF: Coll. Mar. Stud., Univ. Delaware, Lewes, DE 19958, USA
SO: AQUAT.-BOT. 1984. vol. 20, no. 1-2, pp. 97-108
LA: English
ER: B (Brackish)
AB: In estuaries where seagrass beds adjoin marshes, the import and decomposition of seagrass litter in the marsh provide a mechanism for retaining nutrients within the wetlands and preventing loss to adjacent oceanic waters. Several aspects of the influence of seagrass litter on an Oregon salt marsh were studied. The quantity of Zostera  litter in the marsh vegetation depended on elevation and on the marsh-plant canopy structure. Litter decomposition was most complete in the seagrass bed and in the highest marsh area. Seagrass litter contributed between 14 and 31% as much dead material to the total litter in the marsh as did the marsh plants. Decomposition of this litter could release 6-8% of the nitrogen required for the growth of the marsh plants.
AN: 0862591

                                                                     173 of 369  
TI: Abstracts of the Annual Meeting of the American Society for Microbiology 1984.
CA: American Soc. for Microbiology, Washington, DC (USA)
CO: 84. Annual Meeting of the American Society for Microbiology, St. Louis, MO (USA), 4-9 Mar 1984
SO: WASHINGTON,-DC-USA-ASM 1984. 386 pp
NT: Summaries only.
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: The papers included from this conference deal with the role of microorganisms in aquatic ecosystems, microbial contamination of shellfish, waters, and sediments, and the physiology and metabolism of bacteria and viruses.
AN: 0862414

                                                                     174 of 369  
TI: Composition and origin of temperate skeletal carbonate sediments on South Maria Ridge, northern New Zealand.
AU: Nelson,-C.S.; Hancock,-G.E.
AF: Dep. Earth Sci., Univ. Waikato, Hamilton, New Zealand
SO: N.Z.-J.-MAR.-FRESHWAT.-RES. 1984. vol. 18, no. 2, pp. 221-239
LA: English
ER: M (Marine)
AB: South Maria (34 degree S) is a 1500 km super(2) submarine ridge and bank system, less than 500 m deep, slowly accumulating photic and subphotic, clean skeletal carbonate gravels and sands having over 80%, and generally over 95%, CaCO sub(3), mainly calcite. Contributing factors include the negligible supply of terrigenous sediment, the availability of stable rocky substrates for colonisation by epibenthos, and the prominent upwelling of nutrient-rich waters, stimulating organic growth. Sediments mainly comprise fragmental remains of diverse bryozoan colonies (10-74%), with lesser amounts of mainly infaunal bivalves (2-20%), gastropods (2-10%), ahermatypic corals (0-18%), calcareous red algae (1-16%), and benthic foraminifers (3-15%). Major species are identified. The distribution of skeletal types is controlled initially by substrate, bathymetry, and energy level, and subsequently by topographically influenced tidal flow dispersal. However, the present sediment distribution pattern has been complicated by eustatic sea level changes. Modern zones of carbonate production are centered mainly on the shallower portions of the ridge, in the vicinity of Three Kings and Middlesex Banks. Below 150-200 m depth the skeletal sediments become increasingly relict.
AN: 0837273

                                                                     175 of 369  
TI: The role of sulphide in the formation of dimethyl mercury in river and estuary sediments.
AU: Craig,-P.J.; Moreton,-P.A.
AF: Sch. Chem., Leicester Polytech., P.O. Box 143, Leicester, LE1 9BH, UK
SO: MAR.-POLLUT.-BULL. 1984. vol. 15, no. 11, pp. 406-407
LA: English
ER: B (Brackish); F (Freshwater)
AB: The role of sulphide-containing species in sediments in the mobilization of mercury in the environment is demonstrated. The mobile species is the volatile hydrophobic dimethyl mercury. Transport to atmosphere in this form may account for a loss of about 12% annually of methyl mercury from sediments and may therefore be a substantive part of the biogeochemical cycling of mercury in the environment.
AN: 0836766

                                                                     176 of 369  
TI: Biogeochemical behaviour of nitrate and phosphate in the ocean.
OT: Taiheiyo kaisui-chu no shosan-ion oyobi rinsan-ion no seikagakuteki kyodo 
AU: Sagi,-T.; Miyake,-Y.; Saruhashi,-K.
AF: Nagasaki Mar. Obs., Minamiyamate-cho, Nagasaki, 850 Japan
SO: OCEANOGR.-MAG.-KISHO-CHO-OBUN-KAIYOHO. 1983. vol. 33, no. 1-2, pp. 1-18
LA: English
ER: M (Marine)
AB: Concentrations of nitrate and phosphate in sea water can be expressed as a sum of a constant term (primary concentration) and a variable term (plus or minus). In the upper layer from surface to 1 km, variation in concentration is caused mainly by organic production, while in the deeper layer, by decomposition of organic matters. Primary concentration is defined as concentration when biological production and AOU are zero. Calculations using observed values of nitrate ion concentration (N) and AOU at 54 stations in the Pacific showed that the relation between and AOU is linear, the ratio of their rates of change is 0.043 and the primary concentration is 20.2  mu g atoms liter super(-1). For phosphorus, ratio between rates of change of phosphate ion concentration (P) and AOU is 0.0029 and primary concentration is 1.58  mu g atoms liter super(-1) . Using these values, N and P were calculated below 1 km depth. Results agreed well with observations. N/P ratio in sea water is determined by difference between primary N/P ratio (12.8) and  Delta N/ Delta P ratio (15). N/P ratio near the surface is lower than 12.8 due to biological production and higher in the deep layer up to 14.
AN: 0836580

                                                                     177 of 369  
TI: The vertical profiles of carbon, nitrogen, phosphorous and biogenic silica in sediment from the Bering Sea.
AU: Kamatani,-A.
AF: Tokyo Univ. Fish., Konan-4, Minatoku, Tokyo 108, Japan
SO: UMI-LA-MER. 1983. vol. 21, no. 4, pp. 198-206
LA: English
ER: M (Marine)
AB: A biogenic silica-rich core sample from the central Bering Sea was analyzed for total nitrogen and phosphorus, organic carbon and biogenic silica contents, and the results studied to evaluate the decomposition rates of these bioelements during diagenesis. Organic carbon, biogenic silica and total nitrogen contents decreased with depth. The content of total phosphorus was roughly constant throughout the core sediment, suggesting that phosphorus released to the overlying waters by way of the interstitial waters was sufficiently small to be considered negligible. The dissolution rate constants of biogenic silica were in the range of 1.2-2.8 x 10 super(-4) yr super(-1). The mineralization rate constants of organic carbon, calculated on biogenic silica-free basis, were 0.43-1.0 x 10 super(-4) yr super(-1). This can be ascribed to the high efficiency of the poor adsorption capacity of the biogenic silica-rich content of the Bering Sea sediment. Based on primary production in the euphotic zone, organic carbon flux was only 2%, whereas biogenic silica was 32-40%.
AN: 0833709

                                                                     178 of 369  
TI: Cycle of organic matter in deep water.
OT: Yukibutsu no dotai 
AU: Tanoue,-E.
AF: Grad. Sch. Sci. Technol., Kobe Univ., Rokkodai, Nada-ku, Kobe, 657, Japan
CA: Soc. Franco-Japonaise Oceanogr., Tokyo (Japan)
Oceanogr. Soc. Japan (Japan)
CO: Carbohydrates, Proteins, Lipids, Nucleic Acids and other Organic Compounds of Phytoplankton in Aquatic Environments, Tokyo (Japan), 6 Apr 1983
SO: UMI-LA-MER. 1983. vol. 21, no. 4, pp. 241-248
LA: Japanese
AB: Fatty acid and monosaccharide compositions of sinking particles collected with sediment traps and particulate matter collected by filtration of seawater were compared and discussed. Organic materials in sinking particles from 0.1 through 5.25 km depths were mainly derived from phytoplankton in euphotic layers. These organic materials were highly susceptible to biological degradation and played a major active role in biological cycles even in intermediate and deep water layers. Rates of degradation of organic matter in the deep water layer estimated by the sediment trap method were found to be almost comparable to those obtained from the dissolved oxygen consumption rates reported in deep waters of various oceanic areas.
AN: 0832266

                                                                     179 of 369  
TI: Carbonate cycles in Aptian-Albian "black shales" of the Falkland Plateau.
AU: Parker,-M.E.; Arthur,-M.A.; Wise,-S.W.,Jr.
AF: Dep. Geol., Florida State Univ., Tallahassee, FL 32306, USA
SO: ANTARCT.-J.-U.S. 1983. vol. 18, no. 5, pp. 153-154
LA: English
ER: M (Marine)
AB: Cretaceous cores from Deep Sea Drilling Project (DSDP) leg 71, site 511, drilled on the eastern Falkland Plateau (51 degree 00.28'S 46 degree 58.30'W), were examined via carbonate, organic carbon, stable isotope, nannofloral, and ultrastructural analysis in an attempt to determine the mode of origin of thin but discrete pelagic limestone beds intercalated among the black mudstones (figure 2) near the top of the extensive Mesozoic "black-shale" sequence of the Falkland Plateau. The "black shales" are of interest because of their paleoenvironmental significance and their potential as a source rock for petroleum in and around the South Atlantic Basin. This article is a synopsis of a more extended work that has been submitted for publication elsewhere (Parker et al. in press).
AN: 0813098

                                                                     180 of 369  
TI: The association of iron and manganese with bacteria on marine macroparticulate material.
AU: Cowen,-J.P.; Silver,-M.W.
AF: Cent. Coastal Mar. Stud., Univ. California, Santa Cruz, CA 95064, USA
SO: SCIENCE-WASH.. 1984. vol. 224, no. 4655, pp. 1340-1342
LA: English
ER: M (Marine)
AB: Evidence of in situ metal (iron and manganese) deposition onto bacteria associated with rapidly sinking particles in the open ocean is reported. Below 100 meters, bacteria are found with extracellular capsules containing metal precipitates; the frequency of these capsules increases with depth. The capsular metal deposits appear to contribute a major portion of the weakly bound fraction of the particulate iron flux.
AN: 0800216

                                                                     181 of 369  
TI: Carbon production and export from Biscayne Bay, Florida. 1. Temporal patterns in primary production, seston and zooplankton.
AU: Roman,-M.R.; Reeve,-M.R.; Froggatt,-J.L.
AF: Univ. Maryland Cent. Environ. and Estuar. Stud., HPEL, P.O. Box 775, Cambridge, MD 21613, USA
SO: ESTUAR.-COAST.-SHELF-SCI. 1983. vol. 17, no. 1, pp. 45-59
LA: English
ER: M (Marine)
AB: Five stations along a transect from the western shore of Biscayne Bay, Florida to the Florida Current were sampled monthly for one year. The variability and amount of seston particulate organic carbon, adenosine triphosphate, chlorophyll a, primary production and zooplankton decreased along the seaward transect. The greater inshore biomass and variability of seston were the result of the allochthonous input of detritus and inorganic nutrients via terrestrial runoff. Annual primary production in this subtropical coastal lagoon ranged from 13 to 46 g C m super(-2)yr super(-1). In this clear, shallow (2 to 3 m), oligotrophic lagoon, over 90% of total primary production is by submerged macrophytes and benthic algae. The high zooplankton biomass in the bay in most likely sustained by macrophyte detritus and the resuspension of benthic diatoms by the high winds associated with summer squalls and winter cold fronts.
AN: 0798247

                                                                     182 of 369  
TI: Toward an International Geosphere-Biosphere Program: A study of Global Change. Report of a workshop held at Woods Hole, Massachusetts July 25-29, 1983.
CA: National Research Counc., Washington, DC (USA)
CO: Workshop Toward an International Geosphere-Biosphere Program: A study of Global change, Woods Hole, MA (USA), 25-29 Jul 1983
SO: 1983. 94 pp
NT: NTIS Order No.: PB84-161769.
LA: English
AB: Progress in fundamental areas of ocean-atmosphere interactions, biogeochemical cycles, and solar-terrestrial relationships has come far more slowly than in specialized fields, in spite of the obvious practical importance of such studies. If, however, we could launch a cooperative interdisciplinary program in the earth sciences, on an international scale, the authors might hope to take a major step toward revealing the physical, chemical and biological workings of the Sun-Earth system and the mysteries of the origins and survival of life in the biosphere. The concept of an International Geosphere-Biosphere Program (IGBP), as outlined in this report, calls for this sort of bold, "holistic" venture in organized research.
AN: 0792082

                                                                     183 of 369  
TI: The asphyxiation technique: An approach to distinguishing between molecular diffusion and biologically mediated transport at the sediment-water interface.
AU: van-der-Loeff,-M.M.R.; Anderson,-L.G.; Hall,-P.O.J.; Iverfeldt,-Aa.; Josefson,-A.B.; Sundby,-B.; Westerlund,-S.F.G.
AF: Neth. Inst. Sea Res., P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands
SO: LIMNOL.-OCEANOGR. 1984. vol. 29, no. 4, pp. 675-686
LA: English
ER: M (Marine); B (Brackish)
AB: On the assumption that lack of oxygen will cause the activity of benthic infauna to cease and thereby limit solute transport to that accomplished by molecular diffusion, the authors have measured the flux of dissolved silicate across the sediment-water interface of sediments incubated in situ under parallel benthic flux chambers. In one chamber the oxygen concentration was allowed to go to zero, and in the other the oxygen and pH remained at ambient values. As long as oxygen was present in the chambers, the measured summer and fall fluxes were 2-10 times those calculated from porewater profiles assuming one-dimensional molecular diffusion. After oxygen depletion, the silicate fluxes decreased and approached the values calculated on the basis of molecular diffusion.
AN: 0791945

                                                                     184 of 369  
TI: Depositional fluxes of metals and phytoplankton in Windermere as measured by sediment traps.
AU: Hamilton-Taylor,-J.; Willis,-M.; Reynolds,-C.S.
AF: Dep. Environ. Sci., Univ. Lancaster, Lancaster LA1 4YQ, UK
SO: LIMNOL.-OCEANOGR. 1984. vol. 29, no. 4, pp. 695-710
LA: English
ER: F (Freshwater)
AB: Monthly sediment trap samples collected from a deep water station (42 m) in Windermere for a period of 1 year were analyzed for 0.5 M HCl extractable and total Fe, Mn, Al, Pb, Cu, Zn, total C, N, and total solids. Concomitant algal counts showed the year to be fairly typical in terms of the known sequence of phytoplankton. The annual depositional fluxes are compared with previously determined values based on sediment studies. The ratio of the annual trap to sediment flux for Al ( less than or equal to 1) indicates the absence of local sediment resuspension. The ratios for Fe, Pb, and Zn (1.1, 1.4, and 1.5, but not significantly > 1) suggest some possible biogeochemical cycling at the sediment-water inerface. The deposition of Fe, Al, and Pb is predominantly associated with detrital material and occurs mainly during winter.
AN: 0791506

                                                                     185 of 369  
TI: (Vertical distribution of metals in marine particles in the western Mediterranean Sea: Role of biogeochemical processes.).
OT: La distribution verticale des metaux dans les particules marines en Mediterranee Occidentale: Role de processus biogeochimiques 
AU: Risler,-N.; Lambert,-C.E.; Buat-Menard,-P.; Chesselet,-R.
AF: Cent. Faibles Radioact., Lab. Mixte CNRS-CEA, Gif-sur-Yvette, France
CO: 10. Reunion Annuelle des Sciences de la Terre, Bordeaux (France), 2 Apr 1984
SO: TENTH-ANNUAL-MEETING-ON-EARTH-SCIENCES.-BORDEAUX.-2-6-APRIL-1984..  10e-REUNION-ANNUELLE-DES-SCIENCES-DE-LA-TERRE.-BORDEAUX.-2-6-AVRIL-1984.- Institut-Geologie-Bassin-Aquitaine,-Talence-France;-S.G.F.,-Paris-France1984. vol. 10 p. 474
ST: RESUMES-COMMUN.-REUN.-ANNU.-SCI.-TERRE. vol. 10
NT: Summary only.
LA: French
ER: M (Marine)
AB: The behavior of elements, the role of living organisms (Fe, Mn, Co, Zn) and the sources, atmosphere and continental slopes, has been studied in the Western Mediterranean. Results are: the euphotic zone is influenced by living organisms and atmospheric input; between 100 and 500 m is the zone of utilization of organic detritus where Fe, Co, Mn are recycled; in deep waters, vertical distributions are more uniform, and result from the combined effect of absorption-desorption processes and the bursting of faecal pellets; near the bottom, a resuspension of the clay fraction occurs.
AN: 0791390

                                                                     186 of 369  
TI: Dynamic patterns of dissolved nitrogen in the Southern Bight of the North Sea.
AU: Baeyens,-W.; Mommaerts,-J.-P.; Dehairs,-L.G.F.
AF: Lab. Anal. Scheikd., Vrije Univ., Brussels, Belgium
SO: ESTUAR.-COAST.-SHELF.-SCI. 1984. vol. 18, no. 5, pp. 499-510
LA: English
ER: M (Marine)
AB: Spatial and temporal variations of dissolved inorganic nitrogen (DIN) have been assessed in onshore and offshore areas of the Southern Bight on the basis of several years' measurements. They indicate that both the residual flow lines and DIN isoconcentration lines run parallel with the coast excpt in the vicinity of imporant freshwater discharge points such as the Scheldt estuary. Evidence was found that the seasonal DIN oscillations are not created through fluctuations in input conditions at the lateral boundaries, despite considerable fluctuations in these inputs which include the English Channel and also rivers such as the Scheldt estuary. In both the onshore and offshore areas the sum of daylight phytoplanktonic nitrogen intake and sediment release of nitrogen corresponds to the observed DIN variations during most of the year.
AN: 0780807

                                                                     187 of 369  
TI: Denitrification rates and availability of organic matter in marine environments.
AU: Liu,-K.-K.; Kaplan,-I.R.
AF: Inst. Geophys. and Planet. Phys., Univ. California, Los Angeles, CA 90024, USA
SO: EARTH-PLANET.-SCI.-LETT. 1984. vol. 68, no. 1, pp. 88-100
LA: English
ER: M (Marine)
AB: Relationships between denitrification rates and availability of organic matter in three types of marine environments - water column, water-sediment interface and sediments - were delineated. Correlation between supply and demand of organic matter for denitrificaiton in the first two types of environments suggests that denitrifation is mainly supported by organic matter provided as macroparticles from the euphotic zone. Decomposition of organic matter during denitrification in the water column of certain high productivity areas is at a minimum 1/4 to 1/2 as effective as the respiratory processes which use dissolved oxygen.
AN: 0780669

                                                                     188 of 369  
TI: The microbial manganese cycle.
AU: Nealson,-K.H.
AF: Univ. California at San Diego, Scripps Inst. Oceanogr., MBRD, A-002, La Jolla, CA 92093, USA
SO: MICROBIAL-GEOCHEMISTRY. Krumbein,-W.E.-ed. 1983. pp. 191-221
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AN: 0758347

                                                                     189 of 369  
TI: The microbial silica cycle.
AU: Krumbein,-W.E.; Werner,-D.
AF: Geomicrobiol. Div., Univ. Oldenburg, D-2900 Oldenburg, FRG
SO: MICROBIAL-GEOCHEMISTRY. Krumbein,-W.E.-ed. 1983. pp. 125-157
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AN: 0758331

                                                                     190 of 369  
TI: The microbial sulphur cycle.
AU: Joergensen,-B.B.
AF: Inst. Ecol. and Genet., Univ. Aarhus, Ny, Munkegarde, DK-8000 Aarhus C, Denmark
SO: MICROBIAL-GEOCHEMISTRY. Krumbein,-W.E.-ed. 1983. pp. 91-124
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AN: 0758328

                                                                     191 of 369  
TI: Microbial geochemistry.
AU: Krumbein,-W.E.-(ed.)
SO: OXFORD-UK-BLACKWELL-SCIENTIFIC-PUBLICATIONS 1983. 342 pp
NT: Price: $60.00.
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AN: 0757958

                                                                     192 of 369  
TI: A nonlinear model of the carbon cycle in the ocean.
AU: Kagan,-B.A.; Ryabchenko,-V.A.
AF: Leningrad Dep., Inst. Oceanol., USSR Acad. Sci., Leningrad, USSR
SO: DOKL.-EARTH-SCI.-SECT. 1981. vol. 258, no. 1-6, pp. 208-211
LA: English
ER: M (Marine)
AB: A model of the carbon cycle in the ocean that would be an adequate representation of reality should describe the interrelated variations of the temperature, total carbon content, the decomposition and production of organic matter that are the source and sink for organic carbon, the behavior of CO sub(2) in solution, gas exchange with the atmosphere, the thickness of the upper quasihomogeneous layer (UQL), exchange processes between the UQL and the deep layer (DL), as well as between the regions of generation of cold deep water and the rest of the ocean. Existing models do not satisfy this requirement. Their deficiencies are overcome to some degree in the model discussed below.
AN: 0743939

                                                                     193 of 369  
TI: Role of marine phytoplankton in determining the chemical speciation and biogeochemical cycling of arsenic.
AU: Sanders,-J.G.
AF: Univ. Maryland, Solomons, MD, USA
CO: 6. Biennial International Estuarine Research Conference, Gleneden Beach, OR (USA), 1-5 Nov 1981
SO: ESTUARIES. 1981. vol. 4, no. 3, p. 283
NT: Summary only.
LA: English
ER: B (Brackish)
AB: Phytoplankton take up arsenate readily via the phosphate transport system, incorporating a small percentage into the cell. The majority of the arsenic is released in reduced (as arsenite) and methylated (as monomethylarsonic and dimethylarsinic acids) form, causing substantial changes in arsenic speciation. Experiments performed in controlled marine ecosystems correlate well with field sampling; Results indicate that rates of arsenic reduction and methylation are proportional to the primary productivity of the ecosystem. In highly productive ecosystems, up to 80% of the total arsenic pool may undergo reduction and methylation. Large differences in the rate of arsenic uptake and incorporation exist within algal groups.
AN: 0712502

                                                                     194 of 369  
TI: Interactions of marine plankton with transuranic elements. 3. Biokinetics of americium in euphausiids.
AU: Fisher,-N.S.; Bjerregaard,-P.; Fowler,-S.W.
AF: Int. Lab. Mar. Radioact., Mus. Oceanogr., MC-98000 Monaco
SO: MAR.-BIOL. 1983. vol. 75, no. 2-3, pp. 261-268
LA: English
ER: M (Marine)
AB: In a series of laboratory experiments, the biokinetics of  super(241)Am, an important transuranium element, was studied in Meganyctiphanes norvegica . The euphausiids accumulated Am from water by passive adsorption onto exoskeletons, achieving wet weight concentration factors on the order of 10 super(2) after 1 wk exposure; concentration factors varied inversely with the size of the euphausiids and linearly with their surface area:wet weight ratios. Essentially all (96  plus or minus  10%) of the Am taken up from water was associated with the exoskeleton, so that negligible Am was retained by the euphausiids after molting. The retention half-time of Am in molts was 2.9 d. Euphausiids could also concentrate Am from feeding suspensions by ingesting Am-labelled diatom cells. After passage through the gut, virtually all ( approximately equals  99%) of the ingested Am was defecated within 1 wk. The retention half time of Am in fecal pellets was 41 and 51 d at 13 degree  and 5 degree C respectively.
AN: 0697443

                                                                     195 of 369  
TI: Polonium-210: Its relative enrichment in the hepatopancreas of marine invertebrates.
AU: Cherry,-R.D.; Hayraud,-M.; Higgo,-J.J.W.
AF: Mus. Oceanogr., Int. Lab. Mar. Radioact., Monaco
SO: MAR.-ECOL.-PROG.-SER.. 1983. vol. 13, no. 2-3, pp. 229-236
LA: English
ER: M (Marine)
AB: The alpha-radioactive nuclide  super(210)Po is known to be enriched in many components of the marine biosphere. Particularly high concentrations of  super(210)Po are found in the hepatopancreas of many marine invertebrates, making this organ one of the highest known natural radiation dose domains. Concentrations of many other elements in the hepatopancreas have been reported in the literature, and these are summarised and compared with those for  super(210)Po. The enrichment factor concept is used, and a simple marine biogeochemical classification of the elements results. The enrichment factors for Ag. Cd and Se in the marine hepatopancreas are found to be even higher than that for  super(210)Po; those for Cu, Hg, Sb and Zn are an order of magnitude lower, and those for all other elements for which data are available are at least one order of magnitude lower still.
AN: 0678619

                                                                     196 of 369  
TI: General discussion. Biogeochemical cycling.
AU: Furtado,-J.I.; Mori,-S.
SO: TASEK-BERA,-THE-ECOLOGY-OF-A-FRESHWATER-SWAMP. Furtado,-J.I.;Mori,-S.-eds. 1982. vol. 47 p. 359
ST: MONOGR.-BIOL. vol. 47
LA: English
ER: F (Freshwater)
AB: The macrophytes in the forested and non-forested littoral regions appear important in purifying the waters and being able to cope with organic loading. The capacity of the swamp-forest needs to be examined further as it has implications in pollution control.
AN: 0677246

                                                                     197 of 369  
TI: Cycling of toxic organics in the Great Lakes: A 3-Year status report.
AU: Eadie,-B.J.; Robbins,-J.A.; Landrum,-P.F.; Rice,-C.P.; Simmons,-M.S.
CA: NOAA, Ann Arbor, MI. Great Lakes Environmental Research Lab
SO: 1983. 176 pp
NT: NTIS Order No.: PB83-256792; NOAA-83090104.
RN: NOAA/TM/ERL/GLERL-45 (NOAATMERLGLERL45)
LA: English
ER: F (Freshwater)
AB: This interim 3-year status report describes the results of GLERL's studies on the cycling of toxic organics in the Great Lakes. A hierarchy of models has been developed. These modeling efforts have identified process research needs, some of which have been supported. Reported here are results of the authors' work on 1) air-water exchange; 2) photolysis; 3) sorption and partitioning; 4) particle settling and transport; 5) early diagenetic processes in lake sediments; 6) interaction of sediments, contaminants, and benthic organisms; and 7) simulation studies of organic contaminants.
AN: 0676973

                                                                     198 of 369  
TI: Balance of the biogenic calcium carbonate production in an oligotrophic lake (Lake Attersee, Salzkammergut - Austria).
OT: Bilanzierung der biogenen Karbonatproduktion eines oligotrophen Sees. (Attersee, Salzkammergut-Oesterreich) 
AU: Schroeder,-H.G.; Windolp,-H.; Schneider,-J.
AF: Goldschmidtst. Geol.-Palaentol. Inst., und Mus., 3, 3400 Goettingen, FRG
SO: ARCH.-HYDROBIOL. 1983. vol. 97, no. 3, pp. 356-372
LA: German
ER: F (Freshwater)
AB: Biogenic carbonate precipitation has been determined quantitatively at Lake Attersee (Salzkammergut/Austria). Epilimnetic and benthic decalcification cause changes in water chemistry during 24 hours and also seasonal changes have been observed. Epilimnetic decalcification is dominant in the southern and central part of the lake while in the north benthic decalcification plays an important role in the shallow sublittoral areas. The whole biogenic calcium carbonate production reaches about 11,000 to 12,000 metric tons a year or 250 metric tons per km a year.
AN: 0655549

                                                                     199 of 369  
TI: Mathematical modelling of estuaries and coastal waters.
AU: James,-A.
AF: Dep. Civ. Eng., Univ. Newcastle-upon-Tyne, Newcastle-upon-Tyne, UK
CO: 11. Biennial Conference of the International Association on Water Pollution Research and Control, Cape Town (South Africa), 29 Mar-2 Apr 1982
SO: WATER-POLLUTION-RESEARCH-AND-CONTROL.-PART-4. Jenkins,-S.H.-ed. 1982. vol. 14, no. 8 pp. 1109-1123
ST: WATER-SCI.-TECHNOL. vol. 14, no. 8
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Mathematical modelling has contributed significantly to our ability to handle pollution problems in estuaries and coastal water. The complexities of the hydraulics and biogeochemical cycles precluded the use of simple empirical approaches which are satisfactory in rivers and lakes. Although physical modelling is an alternative not all the phenomena concerned may be simulated physically; there are problems of scaling and the cost is very high. In these circumstances mathematical models are an essential tool in the control of pollution. Estuaries and coastal waters are physically contiguous and share many hydraulic characteristics but there are important differences which have made the modelling approaches to the two environments fundamentally different.
AN: 0642233

                                                                     200 of 369  
TI: Effect of the biogenic factor upon the sedimentation and bottom morphology in the Sea of Azov.
OT: Vliyanie biogennogo faktora na osadkonakoplenie i morfologiyu dna Azovskogo moryo 
AU: Artyukhin,-Yu.V.; Grudinova,-L.Ya.; Marynich,-A.G.; Badenko,-A.E.
AF: Address not stated
SO: IZV.-VSES.-GEOGR.-O-VA. 1983. vol. 115, no. 2, pp. 149-154
LA: Russian
ER: M (Marine)
AB: A high productivity of zoobenthos is shown to affect bottom and coastal sedimentation in the Sea of Azov. Bottom mollusks affect bottom topography and sediment accumulation by assimilating carbonates from sea water to be transformed into solid shells. Common cockle Cardium edule to accelerate sedimentation rates considerably. In the areas of the "primary" and "secondary" biogenic matter discharge the sedimentation rate may reach 10-15 om per year.
AN: 0621721

                                                                     201 of 369  
TI: Uptake and conversion of selenium by a marine bacterium.
AU: Foda,-A.; Vandermeulen,-J.H.; Wrench,-J.J.
AF: Mar. Ecol. Lab., BIO, Dartmouth, N.S. B2Y 4A2, Canada
CO: Conference on Pollution in the North Atlantic Ocean, Halifax, N.S. (Canada), 19-23 Oct 1981
SO: CONFERENCE-ON-POLLUTION-IN-THE-NORTH-ATLANTIC-OCEAN. 1983. vol. 40, no. suppl.2 pp. 215-220
ST: CAN.-J.-FISH.-AQUAT.-SCI. vol. 40, no. suppl.2
LA: English
ER: M (Marine)
AB: Bio-conversion of Se was examined by incubating Pseudomonas marina  in seawater containing either selenite (Na sub(2)Se super(IV)O sub(3)) or selenate (Na sub(2)Se super(VI)O sub(4)). At the concentrations of selenite and selenate used (10 super(-4)-10 super(-7) mol/L), the growth of P. marina  was not inhibited. Under these conditions, selenite was taken up by P. marina , but selenate was not found to enter the cells. Pseudomonas marina  incorporated selenite from filtered seawater into subcellular fractions, primarily protein (30-50%) and amino acids (44-70%). When incubated in marine broth, P. marina  incorporated  super(75)selenite primarily into protein (up to 75%), with a lesser amount into the amino acid fraction (approx. 25%). Insignificant amounts were associated with the bacterial lipid fraction. Se super(75) was found in the protein and amino acid fractions within 10 min of incubation in medium containing selenite.
AN: 0614339

                                                                     202 of 369  
TI: Role of marine phytoplankton in determining the chemical speciation and biogeochemical cycling of arsenic.
AU: Sanders,-J.G.
AF: Acad. Nat. Sci., Benedict Estuarine Res. Lab., Benedict, MD 20612, USA
CO: Conference on Pollution in the North Atlantic Ocean, Halifax, N.S. (Canada), 19-23 Oct 1981
SO: CONFERENCE-ON-POLLUTION-IN-THE-NORTH-ATLANTIC-OCEAN. 1983. vol. 40, no. suppl.2 pp. 192-196
ST: CAN.-J.-FISH.-AQUAT.-SCI. vol. 40, no. suppl.2
LA: English
ER: M (Marine)
AB: Biological mediation of arsenic speciation in marine systems is substantial and significant. Phytoplankton reduce and methylate arsenic, thus altering its geochemical cycle. Rates of arsenic reduction and methylation are proportional to the primary productivity of the ecosystem. In highly productive ecosystems, up to 80% of the total arsenic pool may undergo reduction and methylation. Experiments detailing rates of reduction have been performed in controlled marine ecosystems. Predictions of arsenic speciation based on these results agree well with actual samples taken from coastal areas. The form of reduced arsenic present varies between regions and temporally within regions, probably because of differences in phytoplankton community structure.
AN: 0604705

                                                                     203 of 369  
TI: The role of zooplankton in the accumulation and deposition of DuPont Edgemoor waste (an acid-iron waste) at a deepwater dumpsite in the Northwest Atlantic.
AU: Capuzzo,-J.M.
AF: Woods Hole Oceanographic Inst., Woods Hole, MA 02543, USA
CO: Conference on Pollution in the North Atlantic Ocean, Halifax, N.S. (Canada), 19-23 Oct 1981
SO: CONFERENCE-ON-POLLUTION-IN-THE-NORTH-ATLANTIC-OCEAN. 1983. vol. 40, no. suppl.2 pp. 242-247
ST: CAN.-J.-FISH.-AQUAT.-SCI. vol. 40, no. suppl.2
LA: English
ER: B (Brackish)
AB: DuPont Edgemoor waste derived from titanium dioxide production is a highly acidic solution of ferric chloride containing relatively high levels of several trace metals including Cr, V, Pb, Ni, Cu, and Cd. Approximately 3 x 10 super(5) t multiplied by yr super(-1) are dumped at Deepwater Dumpsite 106,  similar to  160 km southeast of Ambrose Light, New York. Chemical dispersion studies at the dumpsite indicate that ferric oxide precipitates in the waste plume and that other trace metals may become associated with this particulate phase. Ingestion of this particulate phase by copepods is a significant route of uptake for the waste-derived metals in the laboratory. Accumulation of the various metals by exposed copepods ranged from 10.8% above control values for Fe to 54.7% for Cu. The ratios of the various trace metals relative to Fe were only slightly enhanced in exposed copepods in comparison with control copepods but 1 to 2 orders of magnitude higher than the metal ratios of a 20 super(5) waste dilution.
AN: 0604636

                                                                     204 of 369  
TI: Uptake and conversion of selenium by a marine bacterium.
AU: Foda,-A.; Vandermeulen,-J.H.; Wrench,-J.J.
AF: Marine Ecol. Lab., BIO, Dartmouth, N.S. B2Y 4A2, Canada
CO: Conference on Pollution in the North Atlantic Ocean, Halifax, N.S. (Canada), 19-23 Oct 1981
SO: CONFERENCE-ON-POLLUTION-IN-THE-NORTH-ATLANTIC-OCEAN. 1983. vol. 40, no. suppl.2 pp. 215-220
ST: CAN.-J.-FISH.-AQUAT.-SCI. vol. 40, no. suppl.2
LA: English
ER: M (Marine)
AB: Bio-conversion of Se was examined by incubating Pseudomonas marina  in seawater containing either selenite (Na sub(2)Se super(IV)O sub(3)) or selenate (Na sub(2)Se super(VIO)d4). At the concentrations of selenite and selenate used (10 super(-4) - 10 super(-7) mol/L), the growth of P. marina  was not inhibited. Under these conditions, selenite was taken up by P. marina , but selenite was not found to enter the cells. Pseudomonas marina  incorporated selenite from filtered seawater into sub-cellular fractions, primarily protein (30-50%) and amino acids (44-70%). When incubated in marine broth, P. marina  incorporated  super(75)selenite primarily into protein (up to 75%), with a lesser amount into the amino acid fraction (approximately 25%). Insignificant amounts were associated with the bacterial lipid fraction. Se super(IV) was found in the protein and amino acid fractions within 10 min of incubation in medium containing selenite.
AN: 0604520

                                                                     205 of 369  
TI: Session 2 --- summary and overview: Heavy metals.
AU: Farrington,-J.W.; Vandermeulen,-J.H.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
CO: Conference on Pollution in the North Atlantic Ocean, Halifax, N.S. (Canada), 19-23 Oct 1981
SO: CONFERENCE-ON-POLLUTION-IN-THE-NORTH-ATLANTIC-OCEAN. 1983. vol. 40, no. suppl.2 pp. 221-225
ST: CAN.-J.-FISH.-AQUAT.-SCI. vol. 40, no. suppl.2
LA: English
ER: M (Marine)
AB: A wide variety of papers were presented at this conference on marine pollution on the subject of trace metal studies, the problem of contamination in sampling and in the precision and accuracy of analyses, notably the analyses of seawater. Despite the progress in sampling and analyses, standardization of basic data still requires more attention via the use of standard reference materials and intercalibration exercises.
AN: 0604511

                                                                     206 of 369  
TI: Trace metal remobilization in the interstitial waters of red clay and hemipelagic marine sediments.
AU: Sawlan,-J.J.; Murray,-J.W.
AF: Mobil Explor. and Prod. Serv. Inc., P.O. Box 900, Dallas, TX 75221, USA
SO: EARTH-PLANET.-SCI.-LETT. 1983. vol. 64, no. 2, pp. 213-230
LA: English
ER: M (Marine)
AB: Interstitial water samples from the Guatemala Basin and the coast of Baja California have been analyzed for manganese, iron, copper, nickel and nitrate. The data provide a systematic look at changes in trace metal diagenesis proceeding from red clay to highly reducing nearshore sediments. In red clay sediments, the nitrate concentrations suggest that only aerobic respiration is occurring. Manganese and iron are below detection. Nickel concentrations remain the same as in bottom seawater but copper shows a pronounced maximum just at the sediment/water interface. Proceeding to hemipelagic sediments, denitification becomes increasingly important and manganese and iron remobilization occur in the sediments. The linear manganese and nitrate profiles suggest regions of production or consumption separated by zones of diffusion. This differs from the conventional picture of a continuous series of reactions within the sediments. Manganese reduction always occurs before iron reduction.
AN: 0603895

                                                                     207 of 369  
TI: Deep circulation of the North Atlantic over the last 200,000 years: Geochemical evidence.
AU: Boyle,-E.A.; Keigwin,-L.D.
AF: Dep. Earth and Planet. Sci., Massachusetts Inst. Technol., Cambridge, MA 02139, USA
SO: SCIENCE-WASH.. 1982. vol. 218, no. 4574, pp. 784-787
LA: English
ER: M (Marine)
AB: Variations in the cadmium/calcium ratio of North Atlantic Deep Water are recorded in the fossil shells of benthic foraminifera. The oceanic distribution of cadmium is similar to that of the nutrients, hence the cadmium/calcium ratio in shells records temporal variations in nutrient distributions. Data from a North Atlantic sediment core show that over the past 200,000 years there has been a continuous supply of nutrient-depleted waters into the deep North Atlantic. The intensity of this source relative to nutrient-enriched southern waters diminished by about a factor of 2 during severe glaciations. This evidence combined with carbon isotope data indicates that the continental carbon inventory may have been less variable than previously suggested.
AN: 0589652

                                                                     208 of 369  
TI: Mass balance of carbon and phosphorus in Shark Bay, Western Australia.
AU: Smith,-S.V.; Atkinson,-M.J.
AF: Hawaii Inst. Mar. Biol., P.O. Box 1346, Kaneohe, HI 96744, USA
SO: LIMNOL.-OCEANOGR. 1983. vol. 28, no. 4, pp. 625-639
LA: English
ER: M (Marine)
AB: Deviations of total CO sub(2), total alkalinity, and reactive P from conservative evaporation lines are used to quantify nonconservative fluxes of these materials in a negative estuary; the fluxes are then partitioned among CaCO sub(3) production, net community organic carbon production, and CO sub(2) gas evasion. The rate of organic metabolism for the system is controlled by nutrient delivery, although individual communities within the system support higher local metabolic rates than the bay-wide average by exchange of materials between autotrophic and heterotrophic components. The three CO sub(2) flux processes act in concert to keep pH and PCo sub(2) relatively constant.
AN: 0586406

                                                                     209 of 369  
TI: Phosphorus dynamics in a woodland stream ecosystem: A study of nutrient spiralling.
AU: Newbold,-J.D.; Elwood,-J.W.; O'-Neill,-R.V.; Sheldon,-A.L.
AF: Stroud Water Res. Cent., Acad. Natl. Sci. Philadelphia, R.D. 1, Box 512, Avondale, PA 19311, USA
SO: ECOLOGY. 1983. vol. 64, no. 5, pp. 1249-1265
LA: English
ER: F (Freshwater)
AB: The term spiralling refers to the interdependent processes of cycling and downstream transport of nutrients in a stream ecosystem. To describe spiralling in Walker Branch, a first-order woodland stream in Tennessee, the authors released  super(32)PO sub(4) to the stream water and measured its uptake from the water and then followed its dynamics in coarse particulate organic matter (CPOM), fine particulate organic matter (FPOM), aufwuchs, grazers, shredders, collectors, net-spinning filter feeders, and predators over a 6-wk period. Rates of transfer among compartments and rates of downstream transport were estimated by fitting a partial differential equation model of the ecosystem to the data. With the resulting coefficients, the model was run to steady state to estimate standing stocks and fluxes of exchangeable phosphorus.
AN: 0570766

                                                                     210 of 369  
TI: Organic matter transfer during diurnal vertical migrations of pelagic animals in the tropical oceanic areas.
OT: Perenos organicheskogo veshchestva pri sutochnykh vertikal'nykh migratsiyakh pelagicheskikh zhivotnykh v tropicheskikh rajonakh okeana 
AU: Tsejtlin,-V.B.
AF: Inst. Okeanol. AN S.S.S.R, Moscow, USSR
SO: OKEANOLOGIYA. 1982. vol. 22, no. 5, pp. 827-832
LA: Russian
ER: M (Marine)
AB: Organic matter can be transfered to deeper layers in the bodies or with excretions of migrating animals. In the first case the transfer is determined as a difference between the consumption of migrants by predators at the lowest depth of occurrence and the proportion of their own diet consumed at this depth. It is shown that even insignificant feeding at the lower depth results in a very small or zero organic matter transfer. In the second case the organic matter can transfered with the excretions of macroplanktonic animals only and it constitutes a very small proportion in the detritus supply from the upper layers.
AN: 0569438

                                                                     211 of 369  
TI: Biogeochemical approach to the study of the World Ocean pollution.
AU: Morozov,-N.P.
AF: VNIRO, Moscow, USSR
CA: International Counc. for the Exploration of the Sea, Copenhagen (Denmark)
CO: Council Meeting, 1982, of the International Council for the Exploration of the Sea (Copenhagen (Denmark)) (11 Oct 1982)
SO: COPENHAGEN-DENMARK-ICES 1982. 13 pp
ST: ICES-COUNCIL-MEETING-1982-COLLECTED-PAPERS. 
RN: ICES-CM-1982/E:21 (ICESCM1982E21)
LA: English
ER: M (Marine)
AN: 0567368

                                                                     212 of 369  
TI: The importance of measuring microbial enzymatic functions while assessing and predicting long-term anthropogenic perturbations.
AU: Griffiths,-R.P.
AF: Dep. Microbiol., Oregon State Univ., Corvalis, OR 97331, USA
SO: MAR.-POLLUT.-BULL. 1983. vol. 14, no. 5, pp. 162-165
LA: English
ER: M (Marine)
AB: The studies outlined were an attempt to quantify the impact of a pollutant (crude oil) on the microbial activities associated with major nutrient cycling in arctic and subarctic sediments. In addition, an assessment was made concerning the potential impact of this pollutant in a prospective lease area for offshore drilling. The general approach taken and a brief summary of the results are described to illustrate the feasibility of this approach in application to other pollution impact studies.
AN: 0565853

                                                                     213 of 369  
TI: Modeling in estuaries and coastal lagoons.
OT: L'utilisation de modeles dans l'etude des estuaires et des lagunes cotiers 
AU: Nixon,-S.W.
AF: Univ. Rhode Island, Kingston, RI, USA
CO: Workshop on the Coastal Ecosystems of West Africa, Dakar (Senegal), 11 Jun 1979
SO: THE-COASTAL-ECOSYSTEMS-OF-WEST-AFRICA:-COASTAL-LAGOONS,-ESTUARIES-AND-MANGROVES.-A-WORKSHOP-REPORT,-DAKAR,-11-15-JUNE-1979.  LES-ECOSYSTEMES-COTIERS-DE-L'-AFRIQUE-DE-L'-OUEST:-LAGUNES,-ESTUAIRES-ET-MANGROVES.-RAPPORT-D'-UN-ATELIER,-DAKAR,-11-15-JUIN-1979.- UNESCO-Div.-of-Marine-Sciences,-Paris-France1981. no. 17 p. 57
ST: UNESCO-REP.-MAR.-SCI.-RAPP.-UNESCO-SCI.-MER. no. 17
NT: Fr. ed. pp. 55-56.
LA: English
ER: M (Marine); B (Brackish)
AB: There are 3 major types of models of use to study the ecology of estuaries and lagoons. One is the standard statistical model, such as the multivariate repression models used in fisheries work. While these are often quite useful and require a relatively small data input, they are not very applicable to ecosystems analysis. For systems analysis a more mechanistic sort of model is meeded in which a mathematical synthesis of a great deal of reductionist data can be obtained. Such models may have stochastic as well as deterministic formulations and provide a holistic point of view for exploring the consequences of a great deal of "autecological" or physiological research on individual species. For experimental problems concerning the probable response of natural ecosystems to perturbations, living models or microcosms should be developed as small scale analogues of larger nature. It is possible to maintain complex marine systems in replicate containers for long periods to study the biological effects of various pollutants as well as biomagnification, inter- and intra-species interactions, and biogeochemical cycling of the pollutant.
AN: 0554836

                                                                     214 of 369  
TI: A layer-by-layer analysis of seasonal and long-term dynamics of phosphorus in the Baltic Sea, using the data on the Gotland Deep as an example.
AU: Yurkovskiy,-A.K.; Khozioskiy,-S.A.
AF: Address not stated
SO: OCEANOL.-ACAD.-SCI.-USSR. 1982. vol. 22, no. 4, pp. 429-433
LA: English
ER: M (Marine)
AB: The main points of phosphorus dynamics in the Baltic Sea are examined. The long-term pattern of phosphorus exchange between the water column and the bottom sediments in the Gotland Deep is discussed. It is shown that a large increase in phosphorus concentration in deep water, weakening of the halocline and stratification of the upper layer in summer have contributed to a gradual shift of the P metabolic cycle of the phosphorus to a new quantitative level, thereby promoting eutrophication of the sea. The vertical distribution and seasonal phosphorus cycles are approximated by polynomial expressions written in terms of sppt, O sub(2), H sub(2)S concentrations, 1 degree C chlorophyll a content, and annual runoff of nutrients from land. A biogeochemical mechanism for the eutrophying effect of phosphorus in the central Baltic Sea is outlined.
AN: 0550446

                                                                     215 of 369  
TI: Bacterial biomass and productivity in sediments, stromatolites, and water of Hamelin Pool, Shark Bay, Western Australia.
AU: Moriarty,-D.J.W.
AF: Div. Fish. Res., CSIRO Mar. Lab., Cleveland, Queensl. 4163, Australia
SO: GEOMICROBIOL.-J. 1983. vol. 3, no. 2, pp. 121-133
LA: English
ER: M (Marine)
AB: Heterotrophic bacterial biomass and growth rates were examined in stromatolites formed from four different types of benthic cyanobacteria. Pustular mat, which occurs in the upper intertidal zone, contained relatively few bacteria in the surface layers (0-5 mm), having about 0.2 x 10 super(6) cells mm super(-3), or 20 mgC m super(-2) per millimetre depth. Other mats in the lower intertidal and subtidal zones had from 1 x 10 super(6) cells mm super(-3) to 8 x 10 super(6) cells mm super(-3). Heterotrophic bacterial productivities were 2.1 to 5.0 mgC m super(-2) h super(-1). Turnover times were an average of 1 day in the sandy sediment and 5 days in the colloform mat. Although these results are minimum estimates, they indicate that heterotrophic bacteria contribute substantially to the carbon cycle in stromatolites, by utilizing about 20 to 30% of primary production.
AN: 0541739

                                                                     216 of 369  
TI: The geochemistry of plutonium in fresh and marine water environments.
AU: Sholkovitz,-E.R.
AF: Address not stated
SO: EARTH-SCI.-REV. 1983. vol. 19, no. 2, pp. 95-161
LA: English
ER: M (Marine); F (Freshwater)
AB: The chemical behaviour of plutonium in the hydrosphere is a subject of both great practical and intrinsic importance. The production and eventual disposal of Pu and other artificial radionuclides dictates that this be the case. The main objective of this paper is to provide a synthesis and critical examination of currently published data and interpretations of the geochemistry of Pu in natural waters and sediments. Where appropriate, an attempt is made to reinterpret published data with the aim of establishing the relationships between geochemical and biological processes and the distribution, concentration and speciation of Pu. Particular attention is paid to the question of the potential for the chemical remobilization of Pu from the solid to the aqueous phase. Approximately one third of the text deals with freshwater (mostly lakes) while two thirds discusses the estuarine, coastal and open ocean environments.
AN: 0535236

                                                                     217 of 369  
TI: The review of the health of the oceans.
CA: Joint Group of Experts on the Scientific Aspects of Marine Pollution (GESAMP)
SO: REP.-STUD.-GESAMP. PARIS-FRANCE-UNESCO 1982. no. 15, 108 pp
NT: Also as: UNEP Reg. Seas Rep. Stud. No. 16. Incl. Glossary: 33 terms. 50 ref.
LA: English
ER: M (Marine); B (Brackish)
AB: This report assesses the condition of the marine environment ten year   s after the United Nations Conference on Human Environment, Stockholm    1972. The aim of the report is to evaluate the conditions and qualit   y of the marine environment in relation to man's various uses of the    ocean. The report is divided into the following main sections: 1) bas   ic properties of the ocean system; 2) biogeochemical cycles: 3) pollu   tants in the marine environment; 4) uses of the marine environment in    relation to pollution; 5) specific problems of regional significance   ; 6) methodology for the assessment and control of marine pollution.    The report is addressed to scientific administrators and decision mak   ers concerned with the state of the marine environment and its protection.
AN: 0534928

                                                                     218 of 369  
TI: Perspectives on the importance of the oceanic particulate flux in the global carbon cycle.
AU: Peterson,-B.J.
AF: Exosystems Cent., Mar. Biol. Lab., Woods Hole, MA 02543, USA
SO: OCEAN-SCI.-ENG. 1981. vol. 6, no. 1, pp. 71-108
LA: English
ER: M (Marine)
AB: The atmospheric CO sub(2) concentration is increasing in part in response to combustion of fossil fuels. The author examines the hypothesis that "the sedimentation of plankton into the deep-sea and into coastal sediments may provide a sink for carbon that would help resolve this apparent discrepancy in the global carbon balance". The resulting calculations suggest that the "baseline" rate of particulate carbon sinking out of the surface ocean mixed layer is 2-3 billion metric tons (BMT) C per year. However, the recent increment in this flux due to nitrogen and phosphorus loading resulting from human activities is not likely to be greater than 0.1-0.2 BMT/year. The discrepancy between the estimated CO sub(2) sources and sinks in the global balances is several BMT/year. Thus, the hypothesis is rejected and the author guestions either or both (1) the terrestrial carbon balance calculations and (2) the oceanic CO sub(2) uptake and mixing models.
AN: 0505144

                                                                     219 of 369  
TI: Inorganic controls on the biogeochemical cycling of the elements in the oceans.
AU: Turner,-D.R.; Whitfield,-M.
AF: Mar. Biol. Assoc. UK, Citadel Hill, Plymouth PL1 2PB, UK
CO: 5. International Symposium on Environmental Biogeochemistry, Stockholm (Sweden), 1-5 Jun 1981
SO: ENVIRONMENTAL-BIOGEOCHEMISTRY. Hallberg,-R.-ed. 1983. vol. 35 pp. 9-37
ST: ECOL.-BULL. vol. 35
LA: English
ER: M (Marine)
AB: The geochemical cycling of an element through the seawater reservoir can be characterised on a global scale by its residence time in seawater (t@u- sub(y)) and by the ratio of its concentrations in seawater and crustal rock, the partition coefficient (K sub(y)(CR)). These parameters summarise the chemical reactivity of the elements in seawater and hence encompass the influence of a variety of chemical processes, some of which may be biologically mediated. In recent years considerable effort has been devoted to identifying elemental parameters suitable for this task, employing both theoretical and empirical approaches. Parameters proposed include electrostatic properties (ionic potential Z sub(i)/r sub(i) and ionic electrostatic energy Z super(2)@)di/r sub(i)), more empirical parameters which take account of covalency (electronegativity  chi  and "softness" parameters) and a screening loss parameter R sub( xi ) derived from Slater atomic orbitals. The use of such parameters can be shown to provide (1) some rationalisation of the observed K sub(y)(CR) and t@)u- sub(y) values, (2) a useful summary of the speciation of the elements in natural waters and (3) a concise means of classifying the biological functions of the elements.
AN: 0501412

                                                                     220 of 369  
TI: Environmental biogeochemistry.
AU: Hallberg,-R.-(ed.)
CO: 5. International Symposium on Environmental Biogeochemistry, Stockholm (Sweden), 1-5 Jun 1981
SO: ECOL.-BULL. 1983. vol. 36, 576 pp
LA: English
ER: M (Marine)
AB: This volume is based on papers presented at the 5th International Symposium on Environmental Biogeochemistry, held in Stockholm, Sweden, during July 1-5, 1981. On two session days the subjects pertained to the biogeochemical cycles of natural reservoirs. The presentations focused on reservoir component pool-size variability, chemical transformation mechanisms, and the impact of these factors on the interpretation of field data. On a third session day the topics related to the effects of man-made emissions on the biosphere. The final day of the symposium was reserved for a case-study of the Baltic Sea.
AN: 0501382

                                                                     221 of 369  
TI: The flux of carbon, nitrogen and phosphorus between coastal lagoons and offshore waters.
AU: Nixon,-S.W.; Lee,-V.
AF: Grad. Sch. of Oceanogr., Univ. Rhode Island, Kingston, RI 02881, USA
CO: Seminar on Coastal Lagoon Research, Present and Future, Beaufort, NC (USA), 29 Aug 1978
SO: COASTAL-LAGOON-RESEARCH,-PRESENT-AND-FUTURE.-PROCEEDINGS-OF-A-SEMINAR,-DUKE-UNIVERSITY-MARINE-LABORATORY,-BEAUFORT,-NC,-U.S.A.,-AUGUST-1978-UNESCO,-IABO. UNESCO,-Paris-France;-Int.-Assoc.-of-Biol.-Oceanogr.,-Paris-France PARIS-FRANCE-UNESCO 1981. no. 33 pp. 325-348
ST: UNESCO-TECH.-PAP.-MAR.-SCI. no. 33
LA: English
ER: B (Brackish)
AB: Data on the concentrations of a variety of ecologically important materials in Green Hill Pond, Charlestown, Rhode Island, USA, are presented in order to make a preliminary estimate of the magnitude and direction of the flux between this lagoon complex and Block Island Sound. The net fluxes of carbon, nitrogen and phosphate were estimated.
AN: 0477263

                                                                     222 of 369  
TI: Nickel, copper, cadmium and zinc in the Northwest Atlantic Ocean.
AU: Yeats,-P.A.; Campbell,-J.A.
AF: Atl. Oceanogr. Lab., Bedford Inst. Oceanogr., P.O. Box 1006, Dartmouth, N.S., Canada
SO: MAR.-CHEM. 1983. vol. 12, no. 1, pp. 43-58
LA: English
ER: M (Marine)
AB: The concentrations of nickel, copper, zinc and cadmium have been determined in the water of the northwest Atlantic Ocean between 45 degree  and 60 degree N. The vertical distributions of Ni, Zn and Cd show depletion in surface waters and a general correlation with nutrients indicative of biogeochemical cycling of these metals. The profiles are complicated by the effects of other processes such as advection and aeolian inputs. At one station close to the Gibbs Fracture Zone, maxima in the nickel and copper concentrations are observed. This feature centered at 3200m is deeper than the core of the Gibbs Fracture Zone Water. Elevated near-bottom concentrations are observed for cadmium, but not copper.
AN: 0472619

                                                                     223 of 369  
TI: Initial effects of the Mount St. Helens eruption on nitrogen cycle and related chemical processes in Ryan Lake.
AU: Dahm,-C.N.; Baross,-J.A.; Ward,-A.K.; Lilley,-M.D.; Sedell,-R.
AF: Dep. Fish. & Wildlife, Oregon State Univ., Corvallis, OR 97331, USA
SO: APPL.-ENVIRON.-MICROBIOL. 1983. vol. 45, no. 5, pp. 1633-1645
LA: English
ER: F (Freshwater)
AB: Ryan Lake, a 1.6-hectare basin lake near the periphery of the tree blowdown area in the blast zone 19 km north of Mount St. Helens, was studied from August to October 1980 to determine the microbial and chemical response of the lake to the eruption. Nutrient enrichment through the addition of fresh volcanic material and the organic debris from the surrounding conifer forest stimulated intense microbial activity. Concentrations of such nutrients as phosphorus, sulfur, manganese, iron, and dissolved organic carbon were markedly elevated. Nitrogen cycle activity was especially important to the lake ecosystem in regulating biogeochemical cycling owing to the limiting abundance of nitrogen compounds. Nitrogen fixation, both aerobic and anaerobic, was active from aerobic benthic and planktonic cyanobacteria. A general scenario for the microbial cycling of nitrogen, carbon, sulfur, and metals is presented for volcanically impacted lakes. The important role of nitrogen as these lakes recover from the cataclysmic eruption and proceed back towards their prior status as oligotrophic alpine lakes is emphasized.
AN: 0459374

                                                                     224 of 369  
TI: Benthic response to sedimentation of a spring phytoplankton bloom: Process and budget.
AU: Graf,-G.; Bengtsson,-W.; Diesner,-U.; Schulz,-R.; Theede,-H.
AF: Univ., Sonderforschungsbereich 95, Olhausenst. 40/60, D-2300 Kiel 1, FRG
SO: MAR.-BIOL. 1982. vol. 67, no. 2, pp. 201-208
LA: English
ER: M (Marine)
AB: The response of benthos to sedimentation of the spring phytoplankton bloom in the Kiel Bight (Western Baltic Sea) is described in terms of biomass (ATP) and activity (heat production and ETS-activity). Input of the bloom (11.5 g C m super(-2)) over a period from March 25 to April 19, 1980 to the sediment surface was in the form of cells and fresh phytodetritus as indicated by low C/N ratios ( less than or equal to  7) and high energy charge values (0.78). Benthic microbial activity was immediately stimulated by this input as heat production doubled and the activity of ETS tripled over winter values within 12 d in the absence of a significant increase in ambient temperature. A comparison of the two activity parameters suggests that anaerobic metabolism is more important during the winter (February and March) than after input of the bloom. Preliminary estimations for an annual budget suggest that the vertical transport of particulate organic matter via sedimentation can only explain 25% (15%) of the benthic activity in the shallow water ecosystem of the Kiel Bight. This indicates the presence of other sources of organic carbon such as benthic primary production or other transport processes providing carbon to the sediments.
AN: 0442935

                                                                     225 of 369  
TI: Manganese cycling in northeast Pacific equatorial waters.
AU: Martin,-J.H.; Knauer,-G.A.
AF: Moss Landing Mar. Lab., P.O. Box 223, Moss Landing, CA 95039, USA
SO: J.-MAR.-RES. 1982. vol. 40, no. 4, pp. 1213-1225
LA: English
ER: M (Marine)
AB: Sea water samples collected above, within and below a pronounced oxygen minimum (0-5  mu mol liter super(-1)) were analyzed for their Mn content. Amounts of dissolved Mn slowly decreased with depth and little, if any, relationship with oxygen was found. In contrast, suspended particulate Mn values increased markedly at the top of the oxygen minimum. Labile Mn fluxes, measured with particle interceptor traps at depths of 125, 275, 525 and 900 m slowly increased with depth from 270 at 125 m to 450  mu g Mn cm super(-2) 1000 yr super(-1) at 900 m. These rates are the same order of magnitude as those estimated for excess Mn accumulating in open-ocean sediments, which implies that biogenic transport is a major factor in the oceanic cycling of Mn.
AN: 0442052

                                                                     226 of 369  
TI: The global troposphere: Biogeochemical cycles, chemistry, and remote sensing.
AU: Levine,-J.S.; Allario,-F.
AF: NASA Langley Res. Cent., Hampton, VA 23665, USA
SO: ENVIRON.-MONIT.-ASSESS. 1982. vol. 1, no. 3, pp. 263-306
LA: English
AB: The chemical composition of the troposphere is controlled by various biogeochemical cycles that couple the atmosphere with the oceans, the solid Earth and the biosphere, and by atmospheric photochemical/chemical reactions. These cycles and reactions are discussed and a number of key questions concerning tropospheric composition and chemistry for the carbon, nitrogen, oxygen and sulfur species are identified. Next, the authors review various remote sensing techniques and instruments capable of measuring and monitoring tropospheric species from the ground, aircraft and space to address some of these key questions. They also consider future thrusts in remote sensing of the troposphere.
AN: 0435522

                                                                     227 of 369  
TI: Analysis of vertical, seasonal and long-term dynamics of phosphorus in the Baltic Sea with special reference to the Gotland Deep.
OT: Analiz poslojnoj sezonnoj i mnogoletnej dinamiki fosfora v Baltijskom more na primere Gotlandskoj vpadiny 
AU: Yurkovskij,-A.K.; Khozioskij,-S.A.
AF: BaltNIRKh, Riga, USSR
SO: OKEANOLOGIYA. 1982. vol. 22, no. 4, pp. 584-589
LA: Russian
ER: M (Marine)
AB: The dynamics of phosphorus in the Baltic Sea and long-term variations in exchange with the bottom are considered. A considerable increase in the amount of P in deep water, the weakening of the halocline and the summer stratification of the upper layer are shown to have gradually moved the metabolic cycle of P to a new quantitative level contributing to eutrophication of the sea. The vertical distribution and the seasonal cycles of P are approximated by polynomials relationships with S ppt., O sub(2), H sub(2)S, t degree C, chlorophyll and nutrient runoff from land. The biogeochemical mechanism of the eutrophicating effect of P in the central Baltic Sea is discussed.
AN: 0426582

                                                                     228 of 369  
TI: Heterotrophic bacteria associated with the degradation of zooplankton fecal pellets in Lake Michigan.
AU: Ferrante,-J.G.; Ptak,-D.J.
AF: Environmental Impact Stud. Div., Argonne Natl. Lab., IL 60439, USA
SO: J.-GREAT-LAKES-RES. 1978. vol. 4, no. 2, pp. 221-225
LA: English
ER: F (Freshwater)
AB: Heterotrophic microbes decompose most of the calanoid copepod fecal pellets produced in Lake Michigan before they reach the sediment. Rod-shaped nonfermenters isolated from copepod and Mysis relicta  fecal pellets were identified as Pseudomonas maltophilia  and Pseudomonas fluorescens  species. No enterobacteriaceae or fungal hyphae were found on or in any pellets. This investigation suggests that Pseudomonas  species are attached to and may degrade Mysis relicta  and calanoid copepod fecal pellets in the water column of Lake Michigan.
AN: 0426532

                                                                     229 of 369  
TI: Dissolved and particulate hydrocarbons in water from a spring sampling of the Var River Estuary (S. France).
AU: Burns,-K.A.; Villeneuve,-J.-P.
AF: Int. Lab. Mar. Radioactivity, Int. Atomic Energy Agency, c/o Mus. Oceanogr., Monaco
CO: Workshop on the Chemistry and Analysis of Hydrocarbons in the Environment, Barcelona (Spain), Nov 1981
SO: TOXICOL.-ENVIRON.-CHEM. 1982. vol. 5, no. 3-4, pp. 195-203
LA: English
ER: M (Marine); B (Brackish)
AB: To address questions of water quality monitoring and to investigate processes controlling the biogeochemical cycling of organics in estuarine and marine systems, the authors have used a resin adsorption apparatus with in-line glass fiber filter for sampling "dissolved" and "particulate" organics. Analyses of water samples collected from the Var River and coastal Mediterranean show rivers are important sources of soluble pesticides and some PCB's. Petroleum products discharged to rivers and the sea surface plus atmospheric inputs of combustion products add to level of biogenic sources making distributions highly variable. The authors note an increase in relative importance in new unidentified halogenated hydrocarbon contaminants in coastal systems.
AN: 0425492

                                                                     230 of 369  
TI: The effect of hippopotamuses on potassium and phosphate ion concentrations in an African lake.
AU: Kilham,-P.
AF: Div. Biol. Sci., Univ. Michigan, Ann Arbor, MI 48109, USA
SO: AM.-MIDL.-NAT. 1982. vol. 108, no. 1, pp. 202-205
LA: English
ER: F (Freshwater)
AB: Anomalously high potassium:sodium and phosphate:sodium molar ratios are found in Hippo Pool (Uganda). These unusual ratios are consistent with the hypothesis that the leaching and partial decomposition of hippopotamus (Hippopotamus amphibius ) dung strongly affects the ionic composition of the water in this lake.
AN: 0413612

                                                                     231 of 369  
TI: Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 1. Northeast Pacific pelagic red clay.
AU: Schmidt,-R.L.
CA: Battelle Pacific Northwest Labs., Richland, WA (USA)
SO: RICHLAND,-WA-USA-BPNL 1982. 45 pp
NT: NTIS Order No.: DE82012251. Contract AC06-76RL01830.
RN: PNL-3466-Pt.1 (PNL3466Pt1)
LA: English
ER: M (Marine)
AB: To provide information useful for determining the biogeochemical cycling of corrosion products in the benthic boundary layer of the deep ocean, neutron-activated stainless steel was exposed to seawater and to Northeast Pacific red clay under aerobic and non-oxygenated conditions. This report describes the trace metal geochemistry of the sediment and the chemical speciation of the corrosion products. The distribution of exp 60 Co released from the stainless steel exposed to aerated seawater show that almost 70% of exp 60 Co activity became associated with suspended particulate matter. No detectable exp 60 Co activity was present in the soluble, readily dissolved, or inorganic or weakly complexes fractions of aerated sediment which had been used to treat neutron-activated stainless steel. Almost 50% of the exp 60 Co activity was extracted in the combined soluble, easily dissolved, adsorbed, and organically complexed fractions from the non-oxgenated sediment treatment indicating that this much of the corrosion products may be initially released in ionic form.
AN: 0413432

                                                                     232 of 369  
TI: Volatile fatty acid cycling in organic-rich marine sediments.
AU: Sansone,-F.J.; Martens,-C.S.
AF: Dep. Oceanogr., Hawaii Inst. Geophys., Univ. Hawaii Manoa, Honolulu, HI 96822, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA. 1982. vol. 46, no. 9, pp. 1575-1589
LA: English
ER: M (Marine)
AB: Volatile fatty acid (VFA) apparent turnover rates were determined by   measuring whole sediment VFA concentrations and the corresponding rea  ction rate constants. The following ranges of VFA concentrations were   measured in Cape Lookout Bight, N.C. sediments ( mu mole multiplied by l sub(s) super(-1)):   acetate 54-660, propionate 1-24, butyrate <0.5-22, iso-butyrate <0.5  -6. Apparent turnover rates measured over a one-year period ranged fr  om 18-600  mu mole multiplied by l sub(s) super(-1) multiplied by h super(-1) for acetate and 0.7-7  mu mole multiplied by l   sub(s) super(-1) multiplied by h super(-1) for the carboxyl carbon of propionate. Methane production was observed only with acetate and only in sulfate depleted sediments; total acetate turnover attained approximately the same maximum value   in both sulfate-reducing and sulfate-depleted sediments.
AN: 0413243

                                                                     233 of 369  
TI: Biogeochemical cycling in an organic-rich coastal marine basin--3. Dissolved gas transport in methane-saturated sediments.
AU: Kipphut,-G.W.; Martens,-C.S.
AF: Inst. Mar. Sci., Univ. North Carolina, Morehead City, NC 28557, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA. 1982. vol. 46, no. 11, pp. 2049-2060
LA: English
ER: M (Marine)
AB: The transport of dissolved gases in the anoxic sediments of Cape Lookout Bight, North Carolina, is controlled by diffusion and bubble ebullition and exhibits a distinct seasonal cycle. Detailed seasonal profiles of CH sub(4), N sub(2) and  super(222)Rn and direct gas flux measurements indicate the ebullition dominates the flux of all dissolved gases across the sediment-water interface during summer months, and is of major importance on an annual basis. Transport within the upper 6-8 cm of sediment appears to be controlled by molecular diffusion of gases. Transport at greater depths is controlled by diffusion in winter and ebullition in summer. Rn-222 profiles were used to estimate the rate of stripping of dissolved gases within the CH sub(4) production zone (10-30 cm); rates averaged 3-5 percent per day and agreed with estimates derived from N sub(2) profiles. As a result of summer ebullition, the sediments of the bight are never at saturation with respect to the major gases present in seawater. Evidence from other sites suggests that ebullition may be an important transport process in many coastal sediments, and may provide mechanism for the transport of volatile reduced compounds between anoxic sediments and the atmosphere.  super(222)Rn is a useful tracer for quantifying this transport.
AN: 0413220

                                                                     234 of 369  
TI: Cycling of xenobiotics through marine and estuarine sediments.
AU: D'-Asaro,-C.N.; Wilkes,-F.G.
AF: Univ. West Florida, Dep. Biol., Pensacola, FL, USA
CA: University of West Florida, Pensacola (USA). Dep. of Biology
SO: 1982. 51 pp
NT: NTIS Order No.: PB82-239252.
LA: English
ER: M (Marine); B (Brackish)
AB: The results of five broadly defined projects are reported. Cycling of xenobiotics was studied with a photobioassay system that used time-lapse photography to evaluate effects of Kepone and sodium pentachlorophenate on feeding activity of the lugworm, Arenicola cristata . Radio-labeled methyl parathion was used to demonstrate fate and effect in microcosms inhabited by lugworms. Uptake and depuration of chrysene by lugworms was evaluated in a flow-through system. A toxic sediment bioassay system was developed to provide a means to test effects of dredge spoil. Keponesorbed sediment and dredge spoil from James River and Houston Ship Channel were tested for 28 days. Long-term tests (100 days), with the same systems, were used to evaluate effects of a specific drilling mud from an  an active exploratory platform. Predator-prey tests of sublethal effects of xenobiotics demonstrated effect in one-prey and two-prey systems. Evaluation of sublethal effects, such as avoidance of pollution gradients, was studied in a trough-type avoidance-response system. Tests with pinfish demonstrated that they will avoid chlorine-produced oxidants. Usefulness of small-scale microcosms was evaluated by developing methods to culture polychaetes and crustaceans. Various aspects of the biology of selected species were studied.
AN: 0413144

                                                                     235 of 369  
TI: Excretion of total phosphorus, dissolved reactive phosphorus, ammonia, and urea by Lake Michigan Mysis relicta .
AU: Madeira,-P.T.; Brooks,-A.S.; Seale,-D.B.
AF: Cent. Great Lakes Stud., Univ. Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
CA: Wisconsin Univ., Milwaukee, (USA). Sea Grant Inst.
SO: REP.-WIS.-UNIV.-SEA-GRANT-COLL.-PROGRAM. 1982. (10 pp)
NT: Reprinted from Hydrobiologia 93: 145-154, 1982.
RN: WIS-SG-82-736 (WISSG82736)
LA: English
ER: F (Freshwater)
AB: Rates of nutrient release by Mysis relicta  in Lake Michigan were measured on five nights at a 45-m station near Milwaukee, Wisconsin, U.S.A., in the summer of 1977. Nocturnal vertical migrations of the mysids were monitored with both echosounder tracings and vertical net tows. Estimates of the total areal dry mass of the mysids ranged from 600 to 1,820 mg m super(-2). The depths of maximum mysid densities corresponded approximately with a deep phytoplankton peak located in the vicinity of the thermocline. Semiquantitative "demands" for N and P by phytoplankton within this peak were obtained from  super(14)C estimates of primary production from a previous study, assuming a constant C:N:P ratio for the algae. These algal nutrient "demands" were compared to potential N and P release by the mysids to obtain a first approximation of the relative rates of nutrient supply and demand for the field phytoplankton populations. Analysis indicates that mysids may directly supply about 1-10% of the daily N and P "demands" of the phytoplankton in the deep peak. However, indirect interactions between Mysis relicta  and other organisms, such as small zooplankton and fishes, could be major factors in nutrient recycling within the metalimnion and subthermocline region of Lake Michigan.
AN: 0410193

                                                                     236 of 369  
TI: (Organic matter of lagoon sediments (Etang de Berre). Carbohydrates as indicators of the origin and the evolution of the organic matter.).
OT: Matiere organique de sediments lagunaires (Etang de Berre). Etude des glucides en tant qu'indicateure de l'origine et de l'evolution de la matiere organique 
AU: Delmas,-D.
CA: Marseille Univ. (France). Faculte des Sciences de Luminy
SO: LUMINY-FRANCE-UNIV.-MARSEILLE 1981. 107 pp
NT: These Doctorat 3e cycle - Oceanologie.
LA: French
ER: B (Brackish)
AB: This thesis deals with the organic matter carbohydrates in the sediments, their evolution during the driving in the soil and determination of marine or terrestrial origin of the organic substances especially in the Berre Lagoon. The qualitative and quantitative evolution is investigated and the biological or chemical mechanisms of accumulation and transformation are identified. At the sediment-water interface, the carbohydrates can be incorporated in some organo-metallic complexes, absorbed by the particulate matter, associated with other humic matter or combined with amines. Theses biochemical and geochemical reactions are analysed and the methodology is described.
AN: 0390482

                                                                     237 of 369  
TI: Geochemical functions of zooplankton at the stage of sedimentogenesis in the Sea of Azov.
OT: Geokhimicheskie funktsii zooplanktona na stadii sedimentogeneza v Azovskom more 
AU: Khrustalev,-Yu.P.; Sevast'-yanova,-N.V.; Myrzoyan,-I.A.
AF: Gos. Univ., Rostov-na-Donu, USSR
SO: DOKL.-AN-S.S.S.R. 1982. vol. 264, no. 5, pp. 1239-1241
LA: Russian
ER: M (Marine)
AB: Active participation of pelagic organisms in the formation of geochemical characteristics of suspended sedimentary material in shallow inland seas and shelf zones is demonstrated. Zooplankton assimilates mineral components of the suspended matter removing from it vitally important chemical elements. This conclusion supported by experimental work is essential for understanding the geochemistry of sedimentation. The geochemical function of zooplankton includes transformation of the suspended form of elements into organic compounds, transport thereof to the bottom and enrichment of the water by dissolved forms during gradual desintegration of the skeletons.
AN: 0374997

                                                                     238 of 369  
TI: Remineralization and nutrient cycling in coastal marine ecosystems.
AU: Nixon,-S.W.
AF: Grad. Sch. Oceanogr., Univ. Rhode Island, Kingston, RI 02881, USA
CO: International Conference on the Effects of Nutrient Enrichment in Estuaries, Williamsburg, VA (USA), 29 May 1979
SO: ESTUARIES-AND-NUTRIENTS. Nielson,-B.J.;Cronin,-L.E.-eds. 1981. pp. 111-138
LA: English
ER: M (Marine); B (Brackish)
AB: Views of remineralization and nutrient cycling in coastal marine ecosystems have changed considerably over the last 30 years. The major trend has been an increasing appreciation for the complexity of processes involved, including some marked changes in our assessment of the importance of bacteria with respect to smaller animals and in our perception of the association between bacteria and particulate matter in the sea. Among the more recent developments in this area is a growing awareness of the importance of the coupling between benthic and pelagic communities in coastal waters. There appears to be a strong linear correlation between the organic matter produced in the overlaying water and the amount of organic matter consumed on the bottom in almost all of the coastal environments for which annual data are available.
AN: 0369027

                                                                     239 of 369  
TI: (Contribution of vegetation to heavy metal dynamics in a salt marsh in the north-east of the United States of America.).
OT: Contribution de la vegetation a la dynamique des metaux lourds dans un marais maritime du nord-est des Etats Unis d'Amerique 
AU: Bourg,-A.
AF: Inst. Chimie, Univ. Berne, Freiestrass 3, 3 000 Berne 9, Switzerland
CO: 24. National Congress of the French Association of Limnology, Marseille (France), 28 May 1979
SO: FRENCH-ASSOCIATION-OF-LIMNOLOGY-24.-NATIONAL-CONGRESS,-MARSEILLE,-28-31-MAY-1979..  ASSOCIATION-FRANCAISE-DE-LIMNOLOGIE-24.-CONGRES-NATIONAL,-MARSEILLE,-28-31-MAI-1979.- Association-Francaise-de-Limnologie,-Paris-France1979. vol. 6, no. 3-4 pp. 205-210
ST: ANN.-UNIV.-PROVENCE-BIOL.-ECOL.-MEDITERR. vol. 6, no. 3-4
LA: French
ER: B (Brackish); F (Freshwater)
AB: The experimental addition of heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) on a Massachusetts salt marsh increases the exports of these metals outside of the marsh as detritus of the plant Spartina alterniflora  (except for Fe). However, for the quantities added, it seems that, except for Mn, the exports are negligible (< 1%) compared to the additions.
AN: 0353440

                                                                     240 of 369  
TI: The Biogeochemical Cycle of Barium in the Open Ocean. An Evaluation.
AU: Dehairs,-F.
AF: Vrije Univ. Brussel, Lab. Analyt. Scheikd., Belgium
CA: International Counc. for the Exploration of the Sea, Copenhagen (Denmark)
CO: Council Meeting, 1980, of the International Council for the Exploration of the Sea, Copenhagen (Denmark), 6 Oct 1980
SO: COPENHAGEN-DENMARK-ICES 1980. 20 pp
ST: ICES-COUNCIL-MEETING-1980-COLLECTED-PAPERS. 
RN: ICES-CM--1980/C:23 (ICESCM1980C23)
LA: English
ER: M (Marine)
AN: 0350618

                                                                     241 of 369  
TI: Nitrogen cycling in sea waters.
AU: Fogg,-G.E.
AF: Dep. Mar. Biol., University Coll. North Wales, Mar. Sci. Lab., Menai Bridge, Anglesey, Gwynedd LL59 5EH, UK
CO: The Nitrogen Cycle, London (UK), 17 Jun 1981
SO: PHILOS.-TRANS.-R.-SOC.-LONDON-SER.-B. 1982. vol. 296, no. 1082, pp. 511-520
LA: English
ER: M (Marine)
AB: An attempt to quantify the cycling of N in the oceans suggests that losses of combined N greatly exceed gains, a discrepancy that points to the inadequacy of our knowledge of the processes involved. Combined N in particulate matter sedimenting into deep water is partly returned to the euphotic zone in the form of nitrate, the rate of this upward flux of new nitrogen being the main determinant of the upper limit of biomass in any given area. Within the euphotic zone combined N is rapidly recycled by bacteria and animals and in oligotrophic areas the ammonium, urea, and perhaps organic, N that they make available is the main source maintaining phytoplankton growth.
AN: 0348767

                                                                     242 of 369  
TI: Phosphorus Solubilization by Some Marine Fungi.
AU: Araujo,-A.; D'-Souza,-J.; Karande,-A.A.
AF: Goa Coll. Pharm., Panaji, Goa-403 001, India
SO: MAHASAGAR. 1981. vol. 14, no. 1, pp. 67-70
LA: English
ER: M (Marine)
AB: Ten marine fungi were qualitatively screened for phosphorus solubilizing ability. The organisms were then tested quantitatively in liquid media containing tricalcium phosphate as a phosphorus source. The optimum pH for phosphorus solubilizing activity of fungi was from 6 to 6.5. An incubation period of 6 days was required for an appreciable quantity of phosphorus to be leached into the medium. A maximum amount of 18% phosphorus was obtained in the culture filtrate and about 54% phosphorus was found in the total cell mass with Penicillium funiculosum .
AN: 0348114

                                                                     243 of 369  
TI: (Organic Geochemistry of the Deep Marine Sediments. Orgon 4 , Aden Gulf, Oman Sea. November 1978.).
OT: Geochimie Organique des Sediments Marin Profonds. Orgon 4 . Golfe d'Aden, Mer d'Oman. November 1978 
CA: CEPM-CNEXO, Comite d'Etudes Geochimiques Marines (France)
SO: PARIS-FRANCE-EDITIONS-DU-CENTRE-NATIONAL-DE-LA-RECHERCHE-SCIENTIFIQUE 1981. 547 pp
LA: French
ER: M (Marine)
AB: This report presents the results of the laboratory analysis undertaken by the scientific teams from the material collected during the Orgon 4 cruise in the Arabian Sea and Aden Gulf. 23 contributions describe the biological and biochemical aspects of the sedimentation and the organic geochemistry of the superficial and deep-sea marine sediments.
AN: 0337509

                                                                     244 of 369  
TI: Biogeochemistry and Geomicrobiology of Lagoons and Lagoonary Environments.
AU: Krumbein,-W.E.
CO: Seminar on Coastal Lagoon Research, Present and Future, Beaufort, NC (USA),  29 Aug 1978
SO: COASTAL-LAGOON-RESEARCH,-PRESENT-AND-FUTURE.-PROCEEDINGS-OF-A-SEMINAR.-DUKE-UNIVERSITY-MARINE-LABORATORY,-BEAUFORT,-NC,-U.S.A.,-AUGUST-1978-UNESCO,-IABO. UNESCO,-Paris-France;-Int.-Assoc.-of-Biol.-Oceanography,-Paris-France PARIS-FRANCE-UNESCO 1981. no. 33 pp. 97-109
ST: UNESCO-TECH.-PAP.-MAR.-SCI. no. 33
LA: English
ER: B (Brackish)
AB: In geochemical terms the lagoon is the centrepoint of 2 constantly changing and developing energy flows, one from the continent and one from the open sea. The biogeochemistry of lagoons can be described as the ephemeral upheaval of reduced organic compounds and speeding up of biochemcial reactions as a consequence of the constant exchange of lagoons with the open sea in cases of hypersaline systems and with the sea and continent in the case of brackish and freshwater lagoons. Productivity and nutrient cycles in lagoons is also discussed; it is believed future work on coastal lagoons should focus on : 1) plant adaptation to salt water; 2) biogeochemical cycles; 3) polluting influences from the mainland; and 4) comparative studies on tropical arid areas. Some findings from studies carried out on coastal lagoons along the Gulf of Aqaba in 1971-77 are presented.
AN: 0321516

                                                                     245 of 369  
TI: An Oxygen Model for Lake Haukivesi.
AU: Frisk,-T.
AF: Natl. Board of Waters, P.O. Box 250, 00101 Helsinki 10, Finland
CO: 30 Years Jubilee Symposium of the Finnish Limnological Society: Lakes and Water Management, Helsinki (Finland), 22-23 Sep 1980
SO: HYDROBIOLOGIA. 1982. vol. 86, no. 1-2, pp. 133-139
LA: English
ER: F (Freshwater)
AB: A simple water quality model for Lake Haukivesi, heavily loaded by pulp and paper mill effluents, has been developed. The main purpose of the model is to predict the concentration of dissolved oxygen in the hypolimnion. The lake is divided into seven sub-basins, and also into epilimnion and hypolimnion. Transfers between sub-basins are calculated using water balance equations. The state variables of the model are dissolved oxygen concentration, biochemical oxygen demand, phytoplankton biomass, and total phosphorus concentration. The effect of temperature on reaction rate coefficients has been taken into account. Temperature is calculated in the model using a second degree polynomial function. The processes affecting hypolimnetic oxygen consumption are BOD decay, decomposition of phytoplankton, benthic oxygen demand, and decomposition of slowly decaying organic matter.
AN: 0321499

                                                                     246 of 369  
TI: Joint FAO (GFCM)/UNEP Coordinated Project on Pollution in the Mediterranean. Report Number 2.
OT: Projet Commun Coordonne FAO (CGPM) PNUE sur la Pollution en Mediterranee. Rapport Numero 2 
CA: FAO Gen. Fisheries Counc. for the Mediterranean, Rome, (Italy)
SO: CIRC.-CGPM. 1977. no. 6, 38 pp
LA: French
ER: M (Marine)
AB: The report contains results obtained from the 4 pilot projects carried out on pollution in the Mediterranean. The first 2 present data on the quantity of pollutants (heavy metals, chlorinated hydrocarbons) which accumulate in the bodies of the organisms occurring in the areas studied. The other 2 enable an understanding of the relations which exist between the levels of contaminants in the water and the organisms, a clarification of the biogeochemical cycle of the pollutants and the obtaining of data concerning not only the safety levels but also the effects of environmental factors on toxic reactions of the organisms.
AN: 0321399

                                                                     247 of 369  
TI: Sorption and Desorption of Trace Elements by Spartina alterniflora  Detritus.
AU: Drifmeyer,-J.E.; Cross,-F.A.; Zieman,-J.C.
AF: Preventive Med. Activity, Letterman Army Med. Cent., Presidio of San Francisco, CA 94129, USA
SO: PLANT-AND-SOIL. 1982. vol. 66, no. 1, pp. 69-80
LA: English
ER: M (Marine)
AB: Element and extractant-specific desorption of Mn, Fe, Cu, and Zn from Spartina alterniflora  detritus was observed. Desorption of a substantial fraction of the total detrital Mn, Fe, Cu and Zn occurred rapidly when the detritus was treated with 0.1 N HCl or 1 MgCl sub(2). This treatment removed precipitated/coprecipitated and adsorbed trace elements, respectively, suggesting that a large fraction of detritus-bound trace elements are in readily exchangeable, surface reaction sites. The carboxylic acid functional group cation exchange capacity of the detritus also suggests an important role of surface exchange reactions in the dynamics of trace elements during decomposition. The rate and magnitude of changes in the trace elements content of detritus has important implications for estuarine biogeochemical cycling of these elements including the potential for biological uptake of trace elements by detritus-consuming fauna.
AN: 0313233

                                                                     248 of 369  
TI: Marine Microcosms in Ecological Research.
AU: Pilson,-M.E.Q.; Nixon,-S.W.
AF: Grad. Sch. Oceanogr., Univ. Rhode Island, Kingston, RI 02881, USA
CO: Savannah River Ecology Laboratory Symposium, Augusta, Georgia (USA), 8-10 Nov 1978
SO: MICROCOSMS-IN-ECOLOGICAL-RESEARCH. Giesy,-J.P.,Jr.-ed. WASHINGTON,-D.C.-USA-TECHNICAL-INFORMATION-CENTER,-U.S.-DEPARTMENT-OF-ENERGY 1980. vol. 52 pp. 724-741
ST: DOE-SYMPOSIUM-SERIES. vol. 52
LA: English
ER: M (Marine)
AB: A major recent trend in marine research is the use of microcosms as living models of specific natural ecosystems or types of systems. Microcosms have always been used in research dealing with species succession, predator--prey interactions, etc., and much work has emphasized their use to explore the biogeochemical cycling of various materials, especially pollutants, and the effects of these materials on the biology and chemistry of marine ecosystems. This approach has generated interest in the problems involved with microcosm design and operation and the interpretation of complex multiparameter data sets obtained from supposedly replicate microcosms over long periods of time, Attempts have been made to design experimental systems in which light, flushing, surface-to-volume ratios, and turbulence are scaled appropriately and to evaluate the consequences, if any, of the exclusion of larger animals.
AN: 0266596

                                                                     249 of 369  
TI: Methane Flux in the Great Dismal Swamp.
AU: Harriss,-R.C.; Sebacher,-D.I.; Day,-F.P.,Jr.
AF: Mail Stop 270, NASA Langley Res. Cent., Hampton, VA 23665, USA
SO: NATURE. 1982. vol. 297, no. 5868, pp. 673-674
LA: English
ER: F (Freshwater)
AB: Methane is an important component of the biogeochemical cycle of carbon with potentially critical roles in both atmospheric chemical and radiation transfer processes. Limited evidence is available which suggests an increase in global tropospheric methane during the last decade. To understand and assess the possibility and implications of temporal variations in atmospheric methane requires improved quantitative knowledge of methane sources and sinks. The authors report methane flux measurements made over a 17-month period in the Great Dismal Swamp, Virginia. These flux measurements indicate that Great Dismal Swamp soils can act as both a source and sink for atmospheric methane. In a waterlogged condition, swamp soils are a net source of methane to the atmosphere with seasonal variations in emission rates from < 0.001 to 0.02 g CH sub(4) m super(-2) day super(-1). During drought conditions, swamp soils consume atmospheric methane at rates of < 0.001 to 0.005 g CH sub(4) m super(-2) day super(-1). While these results should not be extrapolated to all swamp soils, they illustrate the potential complexity of processes which regulate net flux of methane between wetland soils and the atmosphere.
AN: 0262008

                                                                     250 of 369  
TI: Effect of Different Nitrogen and Phosphate Sources on the Calcification in Gloeotaenium .
AU: Prasad,-P.V.D.; Chowdary,-Y.B.K.
AF: Dep. Bot., Banaras Hindu Univ., Varanasi-221005, Inida
SO: PHYKOS. 1981. vol. 20, no. 1&2, pp. 8-15
LA: English
ER: F (Freshwater)
AB: The effect of different nitrogen and phosphate sources on the calcification of G. loitlesbergarianum  Hansgirg has been studied. Ammonia-nitrogen inhibited the calcification at very low concentrations (0.0006%) while nitrate-nitrogen and sulphate had no effect. This inhibitory effect of ammonia may be through the inhibition of photosynthesis. Both ortho and glycero phosphates inhibited the calcification even at 0.0001% concentration of the salt used, without affecting the alga.
AN: 0258924

                                                                     251 of 369  
TI: The Chemistry of Suspended Matter in Esthwaite Water, a Biologically Productive Lake With Seasonably Anoxic Hypolimnion.
AU: Sholkovitz,-E.R.; Copland,-D.
AF: Dep. Chem., Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA. 1982. vol. 46, no. 3, pp. 393-410
LA: English
ER: F (Freshwater)
AB: Ten vertical water column profiles were taken Apr. - Nov. 1979, in Esthwaite Water, a lake with high biological productivity and a seasonally anoxic hypolimnion. Measurements of the major-element particle composition (organic C, P, S, Si, Al, Ti, K, Mg, Ca, Fe, Mn, and Ba) and hydrochemical constituents (temp., pH, Do, total suspended load, dissolved Fe, Mn, P, and Ba) were carried out. These revealed new information on mechanisms and kinetics of biogeochemical cycles in lake. Pronouned seasonal cycles exist in which large excess concentrations (those unsupported by detrital components) of particulate organic C, Fe, Mn, P, S, Mg, K, Ba, and Ca are being generated and lost in situ in the water column (15 m). In the epilimnion these elements (excepting Fe and Mn) are incorporated into the organic components of growing phytoplankton during spring and summer. As the hypolimnion becomes anoxic, dissolved ferrous Fe is released from the sediments and large concentrations of excess particulate iron (III) oxides accumulate; these oxides act as adsorbing substrates for the above-mentioned elements. Adsorption equations are derived from the field data which relate the concentration of excess particulate Fe to those of POC, P, S, Ca, Mg, Ba, and K. At the last stages of anoxia (before the lake overturns) large populations of bacteria and the formation of iron sulfide particles control the concentrations of excess particulate C, S, P, Mg, K, and Ca.
AN: 0257396

                                                                     252 of 369  
TI: On the Mineralization of Organic Materials in the Coastal Marine Sediments.
AU: Yamada,-H.; Murakami,-A.; Kayama,-M.
AF: Nansei Regional Fisheries Research Lab., Ohno-cho, Hiroshima 739-04, Japan
SO: BULL.-JAP.-SOC.-SCI.-FISH. 1981. vol. 47, no. 2, pp. 171-177
LA: English
ER: M (Marine)
AB: The mineralization rate in the marine sediments was estimated in the coastal areas of Beppu Bay, Osaka Bay and Hiuchi Nada in the Seto Inland Sea by the kinetic approach method described by M.J. Harrison et al. The highest mineralization rate of sediments was measured on the surface in Hiuchi Nada, the second in Osaka Bay and the lowest in Beppu Bay. Vilable counts of heterotrophic bacteria on the surface of sediments of Osaka Bay and Hiuchi Nada were larger than those of Beppu Bay. Since the C/N ratio in Beppu Bay was larger than those in Hiuchi Nada and Osaka Bay, the activity of microorganisms was lower in Beppu Bay than  that in the other two areas As the mineralization rate and the number of heterotrophs decrease significantly with the column depth of sediments, the surface of the important for the mineralization of organic materials. Comparing the mineralization rate on the surface of the sediments with that in the overlaying water, the percentage of the mineralization in the shallow waters like Osaka Bay was larger than that at the relatively deep waters of Beppu Bay.
AN: 0241655

                                                                     253 of 369  
TI: Environmental Quality Criteria: Some Considerations.
AU: Babich,-H.; Davis,-D.L.; Trauberman,-J.
AF: Environmental Law Inst., Washington, D.C., USA
SO: ENVIRON.-MANAGE. 1981. vol. 5, no. 3, pp. 191-205
LA: English
AB: The use of the term, ecological dosage 50% or EcD50, is recommended for the quantification of adverse effects of pollutants on microbe-mediated processes such as biogeochemical cycling, litter decomposition, and mineralization. This information was not considered in EPA's development of water quality criteria. Although few complete studies have been done in this field, a broad S-shaped curve can be plotted for respiration rate vs. concentration of pollutant. EcD50 values could be computed for individual pollutants, environments (such as a soil type), or processes. The advantages of EcD50 over LC50 are: (1) EcD50 from one ecosystem may be correlated with the same processes in a different ecosystem, and (2) a given EcD50 value reflects a group of mixed organisms and may be better applied to the total environment. The interactions between pollutant toxicity and abiotic factors justify setting different water quality standards for different regions. These physiochemical factors (such as pH, temperature, aeration state, and many others) affect a pollutant's chemical speciation form, mobility, and bioavailability. Cadmium and phenol are used as examples in the discussion of high risk environments, the partition between water column and sediments, and invisible injury to aquatic life.
AN: 0241499

                                                                     254 of 369  
TI: Biological Processes Affecting the Distribution of Pollutants in Marine Sediments. Part 1: Accumulation, Trophic Transfer, Biodegradation and Migration.
AU: Swartz,-R.C.; Lee,-H.,II
AF: U.S. EPA, Mar. Sci. Cent., OR 97365, USA
SO: CONTAMINANTS-AND-SEDIMENTS.-VOLUME-2:-ANALYSIS,-CHEMISTRY,-BIOLOGY. Baker,-R.A.-ed. ANN-ARBOR,-MI-USA-ANN-ARBOR-SCIENCE-PUBLISHERS-INC. 1980. vol. 2, pp. 533-553
LA: English
ER: M (Marine)
