1 of 20
TI: Chernobyl radionuclides in a Black Sea sediment trap.
AU: Buesseler,-K.O.; Livingston,-H.D.; Honjo,-S.; Hay,-B.J.; Manganini,-S.J.; Degens,-E.; Ittekkot,-V.; Izdar,-E.; Konuk,-T.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: NATURE. 1987. vol. 329, no. 6142, pp. 825-828
LA: English
ER: M (Marine)
AB: The Chernobyl nuclear power station accident released large quantities of vaporized radionuclides, and, to a lesser extent, mechanically released small (< 1-10 mu m) aerosol particles. The total release of radioactivity is estimated to be of the order of 1-2 x 10 super(18) Bq (3-5 x 10 super(7) Ci) not allowing for releases of the xenon and krypton gases. The super(137)Cs releases of 3.8 x 10 super(16) Bq from Chernobyl can be compared to 1.3 x 10 super(18) Bq super(137)Cs released due to atmospheric nuclear weapons testing. Chernobyl-derived radionuclides can be used as transient tracers to study physical and biogeochemical processes. Initial measurements of fallout Chernobyl radionuclides from a time-series sediment trap at 1,071 m during June-September 1986 in the southern Black Sea are presented. The specific activities of super(137)Cs, super(144)Ce and super(106)Ru in the trap samples (0.5-2, 4-12 and 6-13 Bq g super(-1)) are independent of the particle flux while their relative activities reflect their rates of scavenging in the order Ce > Ru > Cs.
AN: 1623826
2 of 20
TI: Suspended matter distributions and fluxes related to the Hudson-Raritan estuarine plume.
AU: Young,-R.A.; Hillard,-B.F.
CA: National Ocean Serv., Rockville, MD (USA). Off. of Oceanogr. and Mar. Assess.
SO: NOAA-TECH.-MEMO. 1984. 39 pp
NT: NTIS Order No.: PB87-131140/GAR.
RN: NOAA/TM/NOS/OMA-8 (NOAATMNOSOMA8)
LA: English
ER: B (Brackish)
AB: Particle flux through the New York Bight apex was calculated using current meter and suspended matter concentration data obtained from March to September 1979, to gain insight into the particle dynamics within the Hudson-Raritan estuarine plume discharged on the shelf. Suspended particulate matter (SPM) concentrations show the expected rapid decrease seaward (10 to 1 mg/l), but high concentrations often extended seaward around Shrewsbury Rocks on the New Jersey shore.
AN: 1541242
3 of 20
TI: Biogenic siliceous particle flux in Antarctic waters and its palaeoecological significance.
AU: Gersonde,-R.
AF: Alfred-Wegener-Inst. Polarforsch., Columbus-Cent., 2850, Bremerhaven, FRG
SO: S.-AFR.-J.-SCI.-S.-AFR.-TYD-SKR.-WET. 1986. vol. 82, no. 9, pp. 500-501
LA: English
ER: M (Marine)
AB: Siliceous hardparts of planktonic microorganisms such as diatoms, silicoflagellates and radiolarians, which are preserved in the sediment record, can be used as "palaeoecological indicators" to reconstruct environmental conditions during the depositions of the sediments. Little is known about alteration processes affecting the biogenic particles during their settlement throughout the water column, the mechanisms of vertical and horizontal transport, and time-specific vertical transport. Knowledge of these three parameters in essential for the evaluation of the palaeoecological indicators found in the sediments. Since the austral summer of 1980-81, four moorings with sediment traps have been deployed at three sites in the western Atlantic sector of the Antarctic Ocean. The data retrieved are being used for studies of alteration processes and transport mechanisms.
AN: 1468089
4 of 20
TI: The supply and the transformation of organic material at the deep-sea floor in the Tropical Atlantic Ocean.
OT: Les apports organiques et leur transformation en milieu abyssal a l'interface eau sediment dans l'ocean atlantique tropicale
AU: Khripounoff,-A.; Rowe,-G.T.
AF: IFREMER, Cent. Brest, BP 337, 29273 Brest Cedex, France
SO: OCEANOL.-ACTA. 1985. vol. 8, no. 3, pp. 293-301
LA: French
ER: M (Marine)
AB: On the Cape Verde abyssal plain, an intensive sampling of superficial sediments was carried out using a 0.25 m super(2) box corer. The total particle flux varied from 372 to 87.7 mg dry weight/m super(2)/day. The average concentration of organic carbon was 40 mg/g of material collected. In the surface sediment this was only 4 mg/g. A direct relationship existed between the intensity of the flux of organic matter and the richness of the organic matter of the deposited sediment. More than 90% of the organic matter arriving at the bottom is consumed by the abyssal benthos and only 1% is lost to permanent sediment deposits. The biochemical composition of the particles is characterized by a predominance of "humic" material in the total organic matter (more than 55%).
AN: 1358785
5 of 20
TI: The fecal pellet fraction of oceanic particle flux.
AU: Pilskaln,-C.H.
CA: Harvard Univ., Cambridge, MA (USA)
SO: DISS.-ABST.-INT.-PT.-B-SCI.-and-ENG. 1986. vol. 46, no. 7, 262 pp
NT: Diss. Ph.D.: Order No.: FAD DA8520269.
LA: English
ER: M (Marine)
AB: The objectives of this study are to quantify the mass flux of pelagic zooplankton fecal pellets, determine their contribution to the total biogeochemical fluxes of oceanic particulate matter, and to examine such fluxes as a function of time and depth. Fecal pellet samples were obtained from five open-ocean stations, 389m to 5068m, located in the north central Pacific (P sub(1)), the western tropical Atlantic (E), the eastern tropical Pacific (CL II), and in the Pacific Panama Basin(PB sub(1), PB sub(2) sites). The fecal pellet data presented show that contrary to previous assumptions, these ubiquitous biogenic particles represent < 5% of the total mass flux of particulate material through the open-ocean. Despite the fact that large numbers of intact pellets are collected at abyssal depths, they contribute an average of only 1-10%, 0.5-4%, 1-3%, and 0.5-4% to the total measured deep-sea fluxes of particulate organic, carbonate, opaline silica, and lithogenic silica material, respectively. However, the pelletal organic carbon may provide up to 66% of the calculated energy requirements of the deep-sea benthos. The absence of pellets from the sites' cores indicates that they are rapidly remineralized at the oxic sediment-water interface.
AN: 1236592
6 of 20
TI: Sedimentation processes on continental shelves.
AU: Sternberg,-R.W.
AF: Univ. Washington, Seattle, WA, 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. 137-157
NT: Incl. bibliogr. 54 ref.
LA: English
ER: M (Marine)
AB: Shelf sedimentologists are extending the growing body of knowledge accumulated by physical oceanographers and boundary-layer scientists to encompass sediment transport processes on continental shelves. Field studies from various shelf environments have documented significant sediment response to fluid flows generated by wind stress, tides, surface gravity waves, and intruding oceanic currents. Sediment response is measured in terms of frequency of grain motion, mode of transport, particle flux, sediment transport routes, accumulation rates, and total sediment budgets. Research trends, based on recently developed instrumentation and techniques, are expanding shelf sedimentology into important new subject areas such as grain motion under combined oscillatory and steady flows; effects of biological activity on sediment entrainment; flow-sediment-organism interactions; the conditions leading to strata formation and sediment mixing; and computer modeling of sediment transport systems. Major problems of shelf sedimentology would be best studied from a multidisciplinary point of view. (Publ. in coop. with: Minist. Sci. and Technol. (Pakistan))
AN: 1198718
7 of 20
TI: Pb-210 and Pu-239,240 in nearshore Gulf of Mexico sediments.
AU: Rotter,-R.J.
CA: Texas A&M Univ., College Station, TX (USA). Dep. Oceanogr
SO: 1985. 158 pp
NT: NTIS Order No. DE85007269/GAR; ORO-3852-56; Contract AS05-76EV03852.
RN: DOE/EV/03852-56 (DOEEV0385256)
LA: English
ER: M (Marine)
AB: Pb-210, Ra-226, and Pu-239,240 activities were measured in nearshore Gulf of Mexico sediments. Sediment cores were collected from the Mississippi Delta, and the western Gulf of Mexico shelf. Mississippi Delta cores which exhibit significantly higher sedimentation rates show larger inventories of Pb-210. The measured Pu levels from the western shelf are lower than from the delta at comparable depths. In three of the western shelf cores, the observed Pu inventory is considerably less than predicted from atmospheric flux. Therefore, Pu is not being removed to the sediment. A sub-surface Pu maximum has been observed. Excess Pb-210 and Pu levels correlate well with sedimentation rates. This suggests that particle flux is important in removal of Pb-210 and Pu to the sediment. The flux of Mn out of the sediment is correlated with inventory data, suggesting that redox cycling of Mn may play a role in increasing Pb-210 and Pu sediment inventories.
AN: 1123986
8 of 20
TI: Metal transport and metal/biota interactions in lakes.
AU: Baccini,-P.
AF: Swiss Fed. Inst. Water Resour. and Water Pollut. Control, CH-8600 Duebendorf, Switzerland
CO: Workshop on Contaminated Sediments in Aquatic Systems, Delft (Netherlands), Dec 1984
SO: ENVIRON.-TECHNOL.-LETT. 1985. vol. 6, no. 8, pp. 327-334
LA: English
ER: F (Freshwater)
AB: The master variable in the transport of copper and zinc in lakes is the particle flux. The autochthonous contribution to this particle flux stems primarily from the primary producers. The bioavailability of copper and zinc is strongly influenced by the proton activity in the lake water. Since this property is also a function of primary production, a negative feed-back mechanism can be postulated for the biota/metal interaction. If the two metals exceed a certain threshold value, the biota adapts itself primarily on the level of the primary producers. This adaption results in a phytoplankton community having a reduced capacity to assimilate trace metals.
AN: 1022923
9 of 20
TI: Seasonal variations in natural abundance of super(15)N in particles sinking to the deep Sargasso Sea.
AU: Altabet,-M.A.; Deuser,-W.G.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: NATURE. 1985. vol. 315, no. 6016, pp. 218-219
LA: English
ER: M (Marine)
AB: Temporal variations in super(15)N natural abundance have been used to study both nitrogen cycling and particle dynamics in the ocean. Changes in the delta super(15)N (1,000 x ( super(15)N/ super(14)N) sub(sample)/( super(15)N/ super(14)N) sub(atmospheric) sub(N2)-1)) of particulate matter are related, in part, to variations in the input of nitrogen to the euphotic zone that have been observed to regulate the downward transport of particles. Here the authors report the first long-term data set for seasonal variations in the delta super(15)N of sinking particulate matter sampled using a sediment trap. These variations co-vary with the magnitude of the particle flux. The delta super(15)N of sinking particles is a monitor for NO super(-)@)d3 flux into the euphotic zone during the formation of these particles on a timescale directly related to the magnitude of the particle flux.
AN: 1015249
10 of 20
TI: The effect of tilt on sediment trap efficiency.
AU: Gardner,-W.D.
AF: Lamont/Doherty Geol. Obs., Columbia Univ., Palisades, NY 10964, USA
SO: DEEP-SEA-RES. 1985. vol. 32, no. 3A, pp. 349-361
LA: English
AB: Cylindrical traps with an aspect ratio of 5.2 were tilted from 0 degree to 70 degree upstream and downstream in the Hudson River with currents ranging between 2 and 62 cm s super(-1). Particle flux in the tilted traps increased with tilt up to about 45 degree where overcollection reached a maximum factor of three but decreased beyond 45 degree when traps were tilted downstream. There was no discernible velocity effect on the total flux collected with tilted traps. In a recirculating flume, dye used as a water tracer revealed the existence of boundary layers within traps. The exchange of particles across the boundaries appears to play an important role in controlling the collection rate of particles and the conditions during which traps over- and under-collect particles. The tilt effect on traps is important, not only where high velocities can cause a mooring to lean, but also where high-frequency internal waves might pass either moored or freefloating traps since the vertical velocity component of an internal wave can cause an effective tilt of the traps.
AN: 0960904
11 of 20
TI: Seasonality in the flux of natural radionuclides and plutonium in the deep Sargasso Sea.
AU: Bacon,-M.P.; Huh,-C.-A.; Fleer,-A.P.; Deuser,-W.G.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES. 1985. vol. 32, no. 3A, pp. 273-286
LA: English
ER: M (Marine)
AB: A record of radionuclide fluxes at a deep-ocean station near Bermuda (32 degree 05'N, 64 degree 15'W) was obtained from analysis of a 3-year collection of sediment-trap samples. The trap was placed at a depth of 3,200 m, 1,000 m above the sea floor, and the samples were recovered at 2-month intervals. Concentrations of super(238)U, super(234)U, super(232)Th, super(230)Th, super(228)Th, super(231)Pa, super(210)Pb, super(210)Po, and super(239, 240)Pu were measured in the trapped material. Most of the radionuclide activity was found in the <37- mu m sieved fraction. All of the radionuclide fluxes showed seasonal variations that were in phase with the variations in total sediment flux, which were shown in earlier work to be closely tied to the annual cycle of primary production in the overlying surface water. The seasonal variations are especially noteworthy for super(230)Th and super(231)Pa, considering that most of their production occurs in the water column below the euphotic zone. Evidently the seasonal influence is transmitted downward by the varying particle flux so that radionuclide scavenging rates at depth, as well as at the surface, are affected.
AN: 0960827
12 of 20
TI: Particle flux and trace metal residence time in natural waters.
AU: Santschi,-P.H.
AF: Inst. Aquat. Sci., Swiss Fed. Inst. Technol., CH-8600 Duebendorf, Switzerland
SO: LIMNOL.-OCEANOGR. 1984. vol. 29, no. 5, pp. 1100-1108
LA: English
ER: M (Marine); F (Freshwater)
AB: A simple inverse relationship between trace metal residence time and particle flux through the water column is tested on the trace metals Zn super(2+) in freshwater and Th(IV) in ocean water systems with a available data on the vertical flux and concentration of particulate matter and of Zn super(2+) in lakes or on the disequilibrium of U/Th nuclides in the ocean. Natural or model aquatic ecosystems with different chemical compositions and particle fluxes confirm the concept that the particle flux through the water column is the major factor regulating trace metal concentrations in natural waters.
AN: 0812926
13 of 20
TI: Rare earth element fluxes and geochemical budget in the eastern Equatorial Pacific.
AU: Murphy,-K.; Dymond,-J.
AF: Coll. Oceanogr., Oregon State Univ., Corvallis, OR 97331, USA
SO: NATURE. 1984. vol. 307, no. 5950, pp. 444-447
LA: English
ER: M (Marine)
AB: Rare earth element (REE) patterns and flux measurements of sediment traps, sediments, and nodules from the eastern Tropical Pacific demonstrate the dominance of REE supply to the sea floor by particle settling. Quantitative partitioning of the particle flux reveals that biogenic debris is the major REE carrier in shallow depths; however, the labile particles at greater depths. Regeneration of biogenic-associated REE appears responsible for La/Ce variations in the particle flux with depth, and provides the primary source of REE accreted by nodules.
AN: 0791622
14 of 20
TI: Sediment in seagrasses near Link Port, Indian River, Florida.
AU: Hoskin,-C.M.
AF: Mar. Geol. Dep., Harbor Branch Foundation, Inc., R.R. 1, Box 196, Fort Pierce, FL 33450, USA
CO: Future of the Indian River System. FIRST Symposium, Melbourne, FL (USA), 20 Nov 1981
SO: FUTURE-OF-THE-INDIAN-RIVER-SYSTEM. Taylor,-W.K.;Whittier,-H.O.-eds. 1983. vol. 46, no. 3-4 pp. 153-161
ST: FLA.-SCI. vol. 46, no. 3-4
LA: English
ER: M (Marine); B (Brackish)
AB: Grain size analyses have been made for 34 samples of the upper 5 cm of sediment cores from seagrass beds. Sieves were used for gravel and sand; the SEDIGRAPH was used for silt and clay. Thalassia (13 samples), Halodule (3), Syringodium (3) and bare sand areas (15) within seagrass beds were sampled in the summers of 1979 and 1980. Generally, these sediments are sands, with small admixtures of gravel, silt and clay. The average particle size is about 0.25 mm with grain size modes at 0.3 and 0.1 mm. These sediments are poorly sorted (large standard deviation), positively skewed (excess fine particles) and are leptokurtic (excessive peakedness). Sand content is greater than 90% by weight, and is mostly guartz. Gravel consists of carbonate shells and shell fragments. Preliminary results from late summer sediment trap measurements give a particle flux of 10-20 g m super(-2) day super(-1) during ordinary weather, which doubled during passage of storm Dennis.
AN: 0692113
15 of 20
TI: Biological control of the removal of abiogenic particles from the surface ocean.
AU: Deuser,-W.G.; Brewer,-P.G.; Jickells,-T.D.; Commeau,-R.F.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: SCIENCE-WASH.. 1983. vol. 219, no. 4583, pp. 388-391
LA: English
ER: M (Marine)
AB: Concurrent measurements of particle concentrations in the near-surface water and of particle fluxes in the deep water of the Sargasso Sea show a close coupling between the two for biogenic components. The concentrations of suspended matter appear to follow an annual cycle similar to that of primary production and deepwater particle flux. Although the concentration of particulate aluminum in the surface water appears to vary randomly with respect to that cycle, the removal of aluminum to deep water is intimately linked to the rapid downward transport of organic matter.
AN: 0593527
16 of 20
TI: An instrument system for the investigation of particle fluxes.
AU: Baker,-E.T.; Milburn,-H.B.
AF: Pacific Mar. Environ. Lab., NOAA, 7600 Sandy Point Way N.E., Seattle, WA 98115, USA
SO: CONT.-SHELF-RES. 1983. vol. 1, no. 4, pp. 425-435
LA: English
ER: M (Marine)
AB: The rationale, design, and use of an instrument system to measure the variability of vertical and horizontal particle fluxes is presented. The system features a new sequentially sampling sediment trap which collects and seals 10 separate samples during a single deployment. Horizontal particle fluxes are simultaneously monitored with a beam transmissometer interfaced to a standard Aanderaa current meter. Results from a 10-week deployment of instruments at several depths in a deep fjord estuary indicate that the trapping rate increases from similar to 0.5 g m super(-1) day super(-1) at 20 m to similar to 150 g m super(-2) day super(-1) at 200 m (5 m above bottom) because of frequent erosion in the deep waters. Periodic flushing of the deep water by intrusions of marine water over the seaward sill markedly enhances erosion and causes an up-estuary particle transport comparable to the vertical particle flux originating at the surface.
AN: 0517522
17 of 20
TI: Particle resuspension in the benthic boundary layer induced by flow around polychaete tubes.
AU: Carey,-D.A.
AF: Earth Environ. Sci., Wesleyan Univ., Middletown, CT 06457, USA
CO: Symposium on the Dynamics of Turbid Coastal Environments, Dartmouth, N.S. (Canada), 29 Sep 1981
SO: PROCEEDINGS-OF-THE-SYMPOSIUM-ON-THE-DYNAMICS-OF-TURBID-COASTAL-ENVIRONMENTS. 1983. vol. 40, no. suppl.1 pp. 301-308
ST: CAN.-J.-FISH.-AQUAT.-SCI. vol. 40, no. suppl.1
LA: English
ER: M (Marine)
AB: The effect of the projecting tubes of Lanice conchilega (Terebellidae) on particle flux in the benthic boundary layer was studied in laboratory flume experiments. Intact tubes, worms, and flume sediment were collected from an ebb channel of the Tay Estuary. Experiments were performed with dye and high contrast, near-neutral density particles to determine flow patterns and net particle movement in individual tube wakes. Projecting tubes produced characteristic vortex patterns which may increase resuspension of sediment particles. These vortex patterns were not strongly dependent on obstacle shape or flow regime and resulted in pronounced upward motion of fluid from the bed. Particle velocities within the wake were lower than ambient free stream velocity. Results of flume observations reported are consistent with detailed visualization studies of small-scale disturbances within a laminar boundary layer.
AN: 0446965
18 of 20
TI: Chemical composition of suspended particles in an estuarine turbidity maximum zone.
AU: Loring,-D.H.; Rantala,-R.T.T.; Morris,-A.W.; Bale,-A.J.; Howland,-R.J.M.
AF: Atlantic Oceanogr. Lab., BIO, Dartmouth, N.S. B2Y 4A2, Canada
CO: Symposium on the Dynamics of Turbid Coastal Environments, Dartmouth, N.S. (Canada), 29 Sep 1981
SO: PROCEEDINGS-OF-THE-SYMPOSIUM-ON-THE-DYNAMICS-OF-TURBID-COASTAL-ENVIRONMENTS. 1983. vol. 40, no. suppl.1 pp. 201-206
ST: CAN.-J.-FISH.-AQUAT.-SCI. vol. 40, no. suppl.1
LA: English
ER: M (Marine); B (Brackish)
AB: The detrital and nondetrital elemental compositions of suspended particles in the Tamar Estuary, U.K., have been examined when the estuarine turbidity maximum was well developed and also when high river flow restricted the development of a turbidity maximum. Correlation matrices and "r"-mode factor analyses were used to identify significant relationships within and between the variances in the fractionated particulate compositions and in the ambient physico-chemical conditions. Marked temporal and spatial differences in the elemental composition of suspended particles were found. At high river flow, suspended particulate compositions throughout the estuary were dominated by dilution and dispersion of an over-whelming flux of riverborne material. Under normal conditions of low riverine particle flux, internal cycling of particles, especially within the turbidity maximum region, controlled the spatial distributions of suspended particle compositions and subsidiary inputs were of greater significance.
AN: 0446752
19 of 20
TI: The chemistry, biology, and vertical flux of particulate matter from the upper 1500 m of the Panama Basin.
AU: Bishop,J.K.B.; Collier,R.W.; Ketterns,D.R.; Edmond,J.M.-(Lamont-Doherty-Geol.-Observ.,-Palisades,-NY-10964,-USA)
SO: Deep-Sea-Res., ISSN:-0198-0149 1980 27(8A), 615-640
LA: English
ER: M (Marine)
AB: Particulate matter divided into <1-, 1, to 53-, and >53-m size fractions was obtained. Samples collected at 045'N, 8610'W were analyzed for major and minor element, organism, and large particle size distributions. Vertical fluxes of fecal matter, fecal pellets, foraminifera, and diatoms were calculated from size distribution data and two settling models. Estimates of the vertical mass, organic carbon, carbonate, and opal fluxes were compared with mean particle collection rates by sediment traps. The productivity of the surface layer at this station is controlled by the north-south poisition of the Equatorial Front, which separates low productivity Tropical Surface Water (TSW) from a mixture of warm Suptropical Surface Water and cool, nutrient-rich water upwelled along the Peruvian coast. At the time of sampling the front was south of the station, with the lower productivity TSW dominating the surface water. Particle distributions and fluxes indicated lower than average productivity and highly efficient zooplankton grazing. Variability in productivity at the station was indicated by weekly sea surface temperature data and was manifested by an anomalous centrate diatom maximum centered at 400 m and by the indication that the particle flux through 1500 m was 1/40th of the rates particles were collected by the sediment traps at 2500 m. The depth of the nitrite maximum corresponded to that of strongest rate of decrease of the organic carbon flux. Fluxes of particulate opal and carbonate decreased markedly in the upper water column although it was supersaturated with respect to calcite.
AN: 0009880
20 of 20
TI: Electron density in the south Atlantic anomaly region.
AU: Noor-Sheikh,M.; Rawer,K.; Neske,E.-(Dep.-Elect.-Eng.,-Univ.-Eng.-Technol.,-Lahore,-Pakistan)
SO: J.-Geophys.-Z.-Geophys., 1979 45(2), 113-117
LA: English
ER: M (Marine)
AB: Since an increased particle flux was found in a well-defined region in the South Atlantic, AEROS-B electron density measurements of August 1974 were checked for a similar effect. During daylight no particular influence could be found, for quiet as well as for disturbed conditions. During night the Atlantic longitude sector shows greater electron densities, but there is no well-defined disturbance area as found for the particle flux.
AN: 9115890
No. Records Request
1: 71 JGOFS
Searches and records above from: ASFA 1997-1998/09
3: 200 #1
4: 14252 INDIA
5: 1 #3 and INDIA
6: 200 #3
Searches and records above from: ASFA 1988-1996
8: 0 #6
9: 1797 PARTICLE
10: 2284 FLUX
11: 20 PARTICLE FLUX
Searches and records above from: ASFA 1978-1987
13: 126 #11
1 of 126
TI: Seasonal reproduction in deep-sea sponges -- triggered by vertical particle flux?
AU: Witte,-U.
AF: GEOMAR Forschungszentrum fuer Marine Geowissenschaften, Wischhofstrasse 1-3, Geb. 15, D-241 48 Kiel, FRG
SO: MAR.-BIOL. 1996 vol. 124, no. 4, pp. 571-581
NT: Bibliogr.: 77 ref.
LA: English
ER: M (Marine)
AB: The examination of oogenesis and reproductive pattern in three deep-sea demosponge species from the foot of the Barents Sea continental slope (Norwegian Sea, similar to 2300 m, similar to 75 degree 18'N; 9 degree 55'E), Thenea abyssorum, Trichostemma sol and Tentorium semisuberites, suggests that sexual reproduction is triggered by the vertical flux of particulate organic carbon at least in one species. All three species examined reproduce sexually and proved to be oviparous and gonochoristic. A considerable number of asexually produced reproductive units was found in Thenea abyssorum, but owing to morphological details the origin of these buds is equivocal, and asexual reproduction is therefore judged to be of minor importance. Oogenesis in the three species can be divided into two developmental periods and does not differ greatly from processes known from shallow water species, except for the almost complete absence of nurse cells. For Thenea abyssorum a distinct seasonal reproductive cycle was found. The onset of yolk accumulation coincides precisely a with a maximum in vertical particle flux as detected in sediment trap studies (von Bodungen et al. 1994). In addition, prior to yolk accumulation the sponge tissue appears almost "empty", without storage units. Once yolk accumulation (i.e. the second growth period) has started, gamete development and release are completed within a few weeks. Thus sexual reproduction is an important reproductive mode in deep-sea sponges, which may be triggered by the pulsed input of POC to this food-limited environment, the energy-dependent process of yolk accumulation being the most sensitive process.
AN: 3967614
2 of 126
TI: Chlorophenolic and isotopic tracers of pulp mill effluent in sedimenting particles collected from southern Lake Saimaa, Finland
AU: Kukkonen,-J.V.K.; Eadie,-B.J.; Oikari,-A.; Holmbom,-B.; Lansing,-M.B.
AF: Lab. Aquatic Toxicol., Dep. Biol., Univ. Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland
SO: SCI.-TOTAL-ENVIRON. 1996 vol. 188, no. 1, pp. 15-27
LA: English
ER: F (Freshwater)
AB: Sediment traps were used to collect settling particles at two stations upstream of a pulp and paper mill and at four stations along the effluent gradient in Southern Lake Saimaa. The particle samples were collected monthly from May to October 1991. Trap materials were analyzed for concentration and stable isotopic composition of organic carbon and nitrogen. The May 1991 trap samples and water and surface sediment samples from the trap locations were also analyzed for chlorophenolics. The trapped particle flux in May was 6.4 g(dry wt.)/m super(2)/day at the station closest to the pulp mill (3.3 km) and decreased to 2.6 g(dry wt.)/m super(2)/day at the farthest station (16.1 km). The organic carbon content of the particles varied from 10.5% to 22.1% and was the highest at the station nearest to the mill. There was a strong point source signal in the nitrogen isotope composition of effluent material. The other sampling times revealed a similar pattern. The total concentration of chlorophenols, chloroguaiacols and chlorocatechols was 0.8, 17.1 and 16.3 mu g/g (dry wt.) particles, respectively, at the nearest station and decreased downstream. The total extractable organic halogens in particles exhibited a similar concentration pattern to the identified chlorinated compounds. While about 60% of chloroguaiacols and about 90% of chlorocatechols are removed by sedimentation or degradation processes in the recipient area, most of the chlorophenols and adsorbable organic halogens are transported through the system.
AN: 3966411
3 of 126
TI: Seasonal and interannual variability in primary production and particle flux at Station ALOHA
AU: Karl,-D.M.; Christian,-J.R.; Dore,-J.E.; Hebel,-D.V.; Letelier,-R.M.; Tupas,-L.M.; Winn,-C.D.
AF: Dep. Oceanogr., Sch. Ocean and Earth Sci. and Technol., Univ. Hawaii, 1000 Pope Rd., Honolulu, HI 96822, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 539-568
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
ER: M (Marine)
AB: A 5-year time-series study of primary production and euphotic-zone particle export in the subtropical North Pacific Ocean near Hawaii (Sta. ALOHA, 22 degree 45'N, 158 degree W) with measurements collected at approximately monthly intervals has revealed significant variability in both ecosystem processes. Depth-integrated (0-200 m) primary production averaged 463 mg C m super(-2) day super(-1) (s = 156, n = 54) or 14.1 mol C m super(-2) year super(-1). This mean value is greater than estimates for the North Pacific Ocean gyre made prior to 1984, but conforms to data obtained since the advent of trace metal-clean techniques. Daily rates of primary productivity at Sta. ALOHA exhibited interannual variability including a nearly 3-year sustained increase during the period 1990-1992 that coincided with a prolonged El Nino-Southern Oscillation (ENSO) event. Export production, defined as the particulate carbon (PC) flux measured at the 150 m reference depth, also varied considerably during the initial 5 years of the ongoing field experiment. The PC flux averaged 29 mg C m super(-2) day super(-1) (s = 11, n = 43) or 0.88 mol C m super(-2) year super(-1). A 5-fold variation between the minimum and maximum fluxes, measured in any given year, was observed. During the first 3 years of this program (1989-1991), a pattern was resolved that included two major export events per annum one centered in late winter and the other in late summer. After 1991, export production exhibited a systematic decrease with time during the prolonged ENSO event. When expressed as a percentage of the contemporaneous primary production, PC export ranged from 2 to 16.9%, with a 5-year mean of 6.7% (s = 3.3, n = 40). Contrary to existing empirical models, contemporaneous primary production and PC flux were poorly correlated, and during the ENSO period they exhibited a significant inverse correlation. This unexpected decoupling of particle production and flux has numerous implications for oceanic biogeochemical cycles and for the response of the ocean to environmental perturbations.
AN: 3965261
4 of 126
TI: Particles in surface waters: Coagulation and transport
AU: Culkin,-G.W.; Lawler,-D.F.
AF: Center for Research in Water Resources, Bureau of Engineering Research, The University of Texas at Austin, Austin, Texas 78758-4497, USA
SO: TECH.-REP.-TEXAS-WATER-RESOUR.-INST. 1991 no. 152, 392pp
LA: English
AB: Conventional water quality assessment and simulation of particles in natural waters focus on bulk concentrations of the suspended solid phase. These analyses rely directly or indirectly on a linear, `average particle' approach to describe processes that are nonlinear and highly size-dependent. Size-dependent transport and transformation mechanisms were simulated in this research to identify conditions in which coagulation is important. Explicit finite difference schemes for two-dimensional, laterally-averaged, unsteady particle transport were developed to approximate the size-dependent particle transport processes, which included advection, dispersion, and settling. Coupled exchange of discrete particles between the water column and sediment bed was modeled using size-dependent particle sedimentation and resuspension. Simultaneous particle-particle flocculation was integrated over time in parallel with transport. Model simulations of systems with idealized morphometry and forcing provided greater insight to competing processes that drive particle behavior in natural systems. Application of the model to a real system gave plausible results and suggested explanations for observed conditions. (DBO)
AN: 3944807
5 of 126
TI: super(210)Pb-derived chronology and the fluxes of super(210)Pb and super(137)Cs isotopes into continental shelf sediments, East Chukchi Sea, Alaskan Arctic
AU: Baskaran,-M.; Naidu,-A.S.
AF: Dep. Oceanogr., Texas A&M Univ. at Galveston, Galveston, TX 77551, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA 1995 vol. 59, no. 21, pp. 4435-4448
LA: English
ER: M (Marine)
AB: Eleven sediment cores and eight sediment trap samples from the continental shelf of the Eastern Chukchi Sea were analyzed for super(210)Pb, super(137)Cs, and super(226)Ra. In selected samples, the organic carbon content and stable carbon isotope ratios were also determined. The excess super(210)Pb ( super(210)Pb sub(xs)) concentrations in the 1-cm core tops are generally lower than those of surficial sediments of subarctic shelves and arctic lakes. The sediment inventory-derived depositional fluxes of super(210)Pb vary between 0.09 and 0.38 dpm cm super(-2) y super(-1), with a mean of 0.18 dpm cm super(-2) y super(-1). The apparent mass sediment accumulation rates, which vary between 31 and 324 mg cm super(-2) y super(-1) with a mean value of 133 mg cm super(-2) y super(-1), are about an order of magnitude lower than the yearly particle flux obtained from the sediment trap experiments. This difference between the relatively long-term and short-term yearly accumulation rates is likely due to the occasional resuspension of fine particles in the continental shelf areas and their advective transport to sites other than their initial deposition.
AN: 3927278
6 of 126
TI: Fluid flow and suspended particulates as determinants of polychaete feeding behavior
AU: Bock,-M.J.; Miller,-D.C.
AF: Grad. Coll. Mar. Stud., Univ. Delaware, Lewes, DE 19958-1298, USA
SO: J.-MAR.-RES. 1996 vol. 54, no. 3, pp. 565-588
LA: English
ER: M (Marine)
AB: We examined the interactive effects of fluid flow, bed characteristics and suspended load on the feeding behavior of four species of marine polychaetes. Two species of obligate deposit feeders (Marenzelleria viridis and Ampharete parvidentata) and two species of palp-coiling facultative suspension feeders (Spiochaetopterus oculatus and Spio setosa) were exposed to flow and sediment-bed treatments that served to decouple fluid flow and particle flux. We employed low (no particle transport), medium (transport of flocs only) and high (transport of sand) flow speeds in factorial treatments of natural sediment, winnowed bed (flocs removed), armored bed (no sand transport at high flows), and armored bed plus fines (flocs added). For each species, worms were exposed to an increasing (low, medium and high) and then decreasing (high, medium and low) flow leg for each bed treatment. We recorded visual observations of animal behavior of the four polychaete species. We found little systematic response to flow and bed differences in the two obligate deposit feeders. When fine material was present, one of the two species exhibited higher variability in time spent deposit feeding, possibly responding to small-scale depositional pockets enriched with fine particles and organic matter. For both facultative suspension feeders, there was an increase in time spent suspension feeding with increasing flow and suspended particle concentrations. Percent suspension feeding was also greater on the decreasing flow legs in treatments with fine material available for suspension. Exploratory analyses of the data reveal a direct relationship between time spent suspension feeding and the flux of suspended high quality organic matter. For both species, compositional parameters of particulate nitrogen and enzymatically available amino acid concentrations were the best correlates of suspension feeding behavior.
AN: 3917784
7 of 126
TI: Sediment redistribution versus paleoproductivity change: Weddell Sea margin sediment stratigraphy and biogenic particle flux of the last 250,000 years deduced from super(230)Th sub(ex), super(10)Be and biogenic barium profiles
AU: Frank,-M.; Eisenhauer,-A.; Bonn,-W.J.; Walter,-P.; Grobe,-H.; Kubik,-P.W.; Dittrich-Hannen,-B.; Mangini,-A.
AF: Heidelberger Akademie der Wissenschaften, INF 366, 69120 Heidelberg, Germany
SO: EARTH-PLANET.-SCI.-LETT. 1995 vol. 136, no. 3-4, pp. 559-573
LA: English
ER: M (Marine)
AB: High resolution super(230)Th sub(ex) and super(10)Be and biogenic barium profiles were measured at three sediment gravity cores (length 605-850 cm) from the Weddell Sea continental margin. Applying the super(230)Th sub(ex) dating method, average sedimentation rates of 3 cm/kyr for the two cores from the South Orkney Slope and of 2.4 cm/kyr for the core from the eastern Weddell Sea were determined and compared to delta super(18)O and lithostratigraphic results. Strong variations in the radionuclide concentrations in the sediments resembling the glacial/interglacial pattern of the delta super(18)O stratigraphy and the super(10)Be stratigraphy of high northern latitudes were used for establishing a chronostratigraphy. Biogenic Ba shows a pattern similar to the radionuclide profiles, suggesting that both records were influenced by increased paleoproductivity at the beginning of the interglacials. However, super(230)Th super(0) sub(ex) fluxes (0 stands for initial) exceeding production by up to a factor of 4 suggest that sediment redistribution processes, linked to variations in bottom water current velocity, played the major role in controlling the radionuclide and biogenic barium deposition during isotope stages 5e and 1. The correction for sediment focusing makes the 'true' vertical paleoproductivity rates, deduced from the fluxes of proxy tracers like biogenic barium, much lower than previously estimated. Very low super(230)Th super(0) sub(ex) concentrations and fluxes during isotope stage 6 were probably caused by rapid deposition of older, resedimented material, delivered to the Weddell Sea continental slopes by the grounded ice shelves and contemporaneous erosion of particles originating from the water column.
AN: 3916144
8 of 126
TI: Distribution of super(230)Th and super(231)Pa in the water column in relation to the ventilation of the deep Arctic basins
AU: Scholten,-J.C.; Rutgers-Van-Der-Loeff,-M.M.; Michel,-A.
AF: Geologisch-Palaeontologisches Institut und Mus., Universitaet Kiel, Olshausenstr. 40, D-24118 Kiel, Germany
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 6, pp. 1519-1531
NT: Special issue: Arctic radioactivity and related transport processes.
LA: English
ER: M (Marine)
AB: Distribution of super(230)Th and super(231)Pa in the water column was measured in the Eurasian basins of the Arctic Ocean, i.e. the Makarov, Amundsen and Nansen basins. The profiles obtained were compared to one previously published from the Alpha Ridge. The Amundsen and Nansen basins are similar in their super(230)Th and super(231)Pa distribution, whereas in the Makarov Basin and at the Alpha Ridge these radionuclides are comparatively enriched in the deep basin. This may be due to low particle flux in conjunction with low water mass renewal rates. The super(230)Th concentration in water depth < 1000 m in the Makarov Basin is relatively low compared with the Alpha Ridge, which may be caused by an exchange of water masses between the Amundsen and Makarov basins. In the Eurasian Basin Deep Water, super(230)Th profiles can be explained both by a scavenging model and by a mixing-scavenging model. Enhanced particle load caused by resuspension may explain the increased scavenging in the Eurasian Basin Bottom Water. The differences in scavenging between the Norwegian-Greenland Sea and the Eurasian basins at present are not large enough to cause significant fractionation between super(230)Th and super(231)Pa.
AN: 3910916
9 of 126
TI: The vertical and regional distribution of the mesozooplankton in the northeast Atlantic with special reference to copepods
OT: Vertikale und regionale Verteilung des Mesozooplanktons im Nordostatlantik unter der besonderen Beruecksichtigung von Copepoden
AU: Morales-R,-A.
CA: Christian-Albrechts-Univ., Kiel (FRG).
SO: BER.-INST.-MEERESKD.-CHRISTIAN-ALBRECHTS-UNIV.-KIEL 1993 no. 239, 126 pp.
NT: Bibliogr.: 33 pages ref.
LA: German
ER: M (Marine)
AB: This work aims to study and characterize the mesozooplankton population (0.2-20 mm) and to follow the development of a zooplankton population with special emphasis on copepods. A further aim is to estimate the potential grazing activity of the mesozooplankton and its resulting effect on phytoplankton. The vertical migration of copepods and their potential contribution to particle flux was also studied. The study was conducted in May (14 days) and June (10 days), 1989 at two different areas in the Northeast Atlantic (47 degree N 20 degree W and 58 degree N 21 degree W) using Lagrange Drift experiments and was designed to be able to observe the development of the spring phytoplankton bloom from the north to the south. In an accompanying programme, the mesozooplankton were collected from depths standardized at 500-200 m, 200-100 m, 100-50 m and 25-0 m on a day-night basis. The dry weight and the ash-free dry weight were determined and the carbon content calculated from the latter. The chlorophyll content in the zooplankton samples was also analysed to correct the zooplankton biomass. The mesozooplankton abundance was determined and for the analysis of copepods distribution a community analysis was done using multivariate procedure. Size fractionated samples from night and day hauls were also studied size classes being: 200-5OO mu m, 500-75 mu m, 750-1000 mu m and 1000-2000 mu m. High biomass was found in both areas studied. Generally the biomass values from night hauls were higher than those from day hauls, the differences ranging from 4-8%. These differences were caused mainly by the interzonally wandering species Metridia and Pleuromamma at 47 degree N and 58 degree N as well as Euchaeta norvegica at 58 degree N.The species Calanus finmarchicus contributed to most of the biomass. The highest biomass concentration was found in the upper 100 m. The high biomass measured from 2 stations at 47 degree N (day haul) was comprised mainly of the exoskeleton of planktonic organisms. This was also reflected in the low organic content on the dry material.
AN: 3897820
10 of 126
TI: Distinct year-to-year particle flux variations off Cape Blanc during 1988-1991: Relation to delta super(18)O-deduced sea-surface temperatures and trade winds
AU: Fischer,-G.; Donner,-B.; Ratmeyer,-V.; Davenport,-R.; Wefer,-G.
AF: Fachbereich Geowissenschaften, Universitaet Bremen, Klagenfursterstr., 28359 Bremen, FRG
SO: J.-MAR.-RES. 1996 vol. 54, no. 1, pp. 73-98
LA: English
ER: M (Marine)
AB: Particle fluxes measured from 1988 to 1991 adjacent to a coastal upwelling site off Cape Blanc showed significant interannual variability of fluxes and sea-surface temperatures (SST) deduced from stable oxygen isotope analysis of the planktonic foraminifera Globigerinoides ruber and, partly, of the pteropod Limacina inflata. For the duration of the study period, a decrease in the seasonality of SST's was observed, as well as a significant decrease in the average annual SST from 24.4 degree to 20.8 degree C. In comparison, the winter-spring SST decreased only slightly from 20.3 degree in 1988 to 19.8 degree C in 1991. Our data set does not yet provide conclusive evidence that the observed year-to-year flux and SST variations represent larger-scale, periodically occurring climatic variations in the eastern Atlantic but it offers insight into the prevailing large variability in biochemical cycles and processes in the eastern Atlantic.
AN: 3890150
11 of 126
TI: Dissolved and particulate nutrient transport through a coastal watershed-estuary system
AU: Smith,-S.V.; Chambers,-R.M.; Hollibaugh,-J.T.
AF: De. Oceanogr., Univ. Hawaii, Honolulu, HI 96822, USA
SO: J.-HYDROL.-AMST. 1996 vol. 176, no. 1-4, pp. 181-203
LA: English
ER: B (Brackish)
AB: Tomales Bay and its adjacent watershed are the location of integrated research on the C-N-P-Si biogeochemical coupling between the land and coastal ocean and cycling of these materials within the bay. In the present paper, budgets have been constructed to describe the rainfall delivery of dissolved nutrients to the watershed and export of dissolved and particulate nutrients from the watershed, mostly in runoff. The quantity of dissolved materials, especially dissolved organic materials, delivered to the watershed by rainfall is about the same as the export: Suspended load transport represents the major net removal of C, N, and P from the watershed, and this flux shows large interannual variation. Runoff-adjusted particle flux from the watershed is small at present in comparison with estimates based on sedimentation rate in the bay over the past 130 years. This difference apparently cannot be explained by natural or managed interannual variation in runoff or by other obvious aspects of water management. We believe that changes in agricultural land use have led to recent decreases in erosion and removal of particulate materials from the watershed. Even though the watershed has been disturbed by agricultural practices over the past 130 years, the system as a whole appears largely to have recovered to steady-state conditions.
AN: 3881216
12 of 126
TI: super(26)Al- super(10)Be systematics in deep-sea sediments
AU: Wang,-Lei; Ku,-T.L.; Luo,-S.; Southon,-J.R.; Kusakabe,-M.
AF: Dep. Earth Sci., Univ. Southern California, Los Angeles, CA 90089-0740, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA 1996 vol. 60, no. 1, pp. 109-119
LA: English
ER: M (Marine)
AB: We report the development of a NaOH-leaching technique to extract the authigenic Al and Be in marine sediments, which should allow the sedimentary signals of cosmogenic super(26)Al and super(10)Be to be more effectively studied as geochemical/geophysical tracers. The technique has been applied to the study of super(26)Al and super(10)Be in opal-rich sediments from the North Pacific. The super(26)Al/ super(27)Al and super(10)Be/ super(9)Be ratios of similar to 3 x 10 super(4) and 1 x 10 super(7) leached from the sediments are higher than those in the total sediments by factors of 3-10 and 2-3, respectively. The authigenic super(10)Be/ super(9)Be ratios are similar to those in deep waters at the study site, pointing to the potential usefulness of the ratios in paleoceanographic studies. The fractions of total Be and Al in the sediment studied that are of authigenic origin average about 40 and 17%, respectively. Estimated super(26)Al/ super(27)Al ratios in detrital sediments are less than or equal to 10 super(-15), low enough to indicate that the source of super(26)Al in the ocean mainly comes from atmospheric production. In the study area, the deposition flux of super(26)Al is comparable to its atmospheric supply. However, the deposition flux of super(10)Be is about threefold higher than the atmospheric input, signifying lateral transport of super(10)Be from the open ocean to this area of relatively high particle flux. The super(26)Al/ super(10)Be ratio, being insensitive to the oceanic influx of lithogenic particles, may serve as a valuable proxy for paleoproductivity. Both the authigenic and total-sediment super(26)Al/ super(27)Al and super(10)Be/ super(9)Be ratios decreased significantly at similar to 6 ka, which could reflect an enhanced input of windblown lithogenic particles to the North Pacific. While the enhanced dust input did not significantly alter the deep-water super(9)Be concentration, it contributed to the observed increase of authigenic super(9)Be flux to the sediment.
AN: 3881125
13 of 126
TI: Experimental study of bioturbation in shallow and deep environment
OT: Etude experimentale de la bioturbation en milieux littoral et profond
AU: Gerino,-M.
CA: Aix-Marseille-2 Univ., (France). Station marine d'Endoume
SO: MARSEILLE-FRANCE STATION-MARINE-D'-ENDOUME 1992
LA: French
ER: M (Marine); B (Brackish)
AB: The main objectives were to determine the potential for bioturbation by the macrobenthos, to quantify the bioturbation structures, to modelise and estimate biological sediment mixing on the selected sites, and to provide evidence of the impact of bioturbation incidence on flux through the water-sediment interface. Research has been carried out both in shallow environment (the Gulf of Fos - Mediterranean sea) and in deep environment: the Mediterranean canyons of Toulon, Grand Rhones and Lacaze Duthiers, and the canyon of Cap-Ferret in Atlantic Ocean. There is a positive relation between density of structures and macrobenthos abundance, hut in the upper layer of sediment the structures are rapidly destroyed by biological mixing. On the basis of the results of in vitro experiments, the organisms of a benthic community can be grouped into 3 classes according to their mode of bioturbation: the biodiffusives, the conveyor-belts, and the regenerators. Models of biological sediment mixing have one term for biodiffusive mixing and another for non-local mixing. Biological sediment mixing has been quantify by in situ experiments based on signal introduction of tracers: the luminophores and/or the radionuclides. In shallow environment the intensity of mixing is 10 times higher than in deep environment. In coastal sediment, the solute fluxes from sediment into underlying water are increased by rnacrofauna activity by a factor ranging between 1.5 and 2. Bioturbation occurs in the stockage, the transformation and exportation of deposited rnatter. It enhances the possibility of solute exchange and generates intensive particle flux through the sediment water interface.
AN: 3869523
14 of 126
TI: Abundance and feeding ecology of larger protozooplankton in the ice edge zone of the Weddell and Scotia Seas during the austral winter
AU: Gowing,-M.M.; Garrison,-D.L.
AF: Inst. Mar. Sci., Univ. California, Santa Cruz, CA 95064, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP. 1992 vol. 39, no. 5, pp. 893-919
LA: English
ER: M (Marine)
AB: Biomasses, abundances and feeding ecology of larger (>50 mu m diameter) protozooplankton were studied in the upper 210 m in the ice edge zone of the Weddell/Scotia Sea area in the austral winter of 1988. Sixty-liter water samples were taken at five depths at 17 stations, and organisms were concentrated by reverse-flow filtration. Mean abundances of the total assemblage of larger protozooplankton (radiolarians, formaminiferans, acantharians, the heliozoan Sticholonche, tintinnid and aloricate ciliates, and thecate and athecate dinoflagellates) ranged from 2040 to 3745 m super(-3) in the upper 210 m. Biomass ranged from 33 to 48 mu g C m super(-3) in the upper 85 m, and from 32 to 54 mu g C m super(-3) from 115 to 210 m. Phaeodarian radiolarians larger than 1.6 mm (sampled with plummet nets) contributed an additional 3 mu g C m super(-3) in the upper 100 m and an additional 7 mu g C m super(-3) from 100 to 200 m. These abundances and biomasses are lower than for other seasons in the Antarctic, but are comparable to abundances reported for several of these groups in lower latitude waters. We attribute the low winter abundances to slower growth and reduced food, rather than to increased mortality. The large protozooplankton are trophically diverse; in addition to heterotrophy on a variety of organisms, we found apparent evidence of mixotrophy and symbiosis in some of the groups. The large protozooplankton fed on both autotrophic and heterotrophic organisms in winter, although the biomass of smaller forms is dominated by heterotrophs. Feeding on detrital particles also was indicated by the presence of siliceous fragments in vacuoles. The larger protozooplankton in the winter ice edge zone may be important in reducing particle flux to the deep sea and as a food source for larger zooplankton, especially from the base of the euphotic zone to 210 m. (DBO)
AN: 3854997
15 of 126
TI: Oceanic trace metal scavenging: The importance of particle concentration
AU: Honeyman,-B.D.; Balistrieri,-L.S.; Murray,-J.W.
AF: Swiss Federal Inst. for Water Resour. and Water Pollut. Control (EAWAG), CH-8600 Duebondorf, Switzerland
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP. 1988 vol. 35, no. 2, pp. 227-246
LA: English
ER: M (Marine)
AB: Adsorption (surface complexation) has long been considered to be the dominant process involved in the oceanic scavenging of many trace metals. Much of what we know about metal removal in the ocean (i.e. rate and extent) is based on measurements of U and Th decay series isotopes. However, the scavenging equations developed from radioactive parent-daughter relationships presume no specific metal removal process and cannot be directly used to verify a particular one. In this paper we examine and compare the phenomenological model of adsorption and oceanic scavenging observations. The formalisms of surface coordination and colloid chemistry are linked to the mechanism-free observations of oceanic trace metal scavenging by the strong similarities in the description of the reaction rates and the influence of particle concentration on those rates and the equilibrium distributions. The correspondence between laboratory sorption data and field scavenging observations as well as the consistency of the hypothesis over a wide range of environmental systems successfully link oceanic trace metal scavenging with surface coordination and colloid aggregation reactions. The merging of descriptions of surface and colloid chemistry and field observations of scavenging provide a framework for interpreting field data and understanding how master variables (e.g. reaction rate, particle concentration, or particle flux) influence metal removal from the oceans. (DBO)
AN: 3854983
16 of 126
TI: Variations in nitrogen isotopic composition between sinking and suspended particles: Implications for nitrogen cycling and particle transformation in the open ocean
AU: Altabet,-M.A.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP. 1988 vol. 35, no. 4, pp. 535-554
LA: English
ER: M (Marine)
AB: Significant and consistent differences in nitrogen isotopic ratio (measured as delta super(15)N relative to atmospheric N sub(2)) are observed between suspended and sinking particles in the Sargasso Sea. Suspended particles in the euphotic zone have an annual average of -0.2ppt while particles sinking out of the euphotic zone average 3.7ppt. This latter value is equivalent to the average delta super(15)N value for the sources of new nitrogen to the euphotic zone. The delta super(15)N of NO sub(3) super(-) below the euphotic zone is similar, confirming that this is the major source. The downward particle flux acts to preferentially export super(15)N out of the euphotic zone, with the result that suspended particles are depleted in super(15)N relative to new nitrogen sources. The observed difference in delta super(15)N is evidence that the net transformation of suspended into sinking particles in this region is a result of active processes such as macrozooplankton feeding, as opposed to passive physical effects. Suspended particles below 200 m are 6ppt higher in delta super(15)N relative to those within the euphotic zone. This observation reflects, in part, the origin of suspended particles below the euphotic zone from the larger, faster sinking particles which are enriched in delta super(15)N. Since these suspended particles are also higher in delta super(15)N relative to sinking particles by 3ppt, isotopic fractionation must occur during the disaggregation of sinking particles and/or the subsequent degradation of suspended particles. (DBO)
AN: 3854960
17 of 126
TI: The effects of bioturbation on particle redistribution in Mediterranean coastal sediment. Preliminary results
AU: Gerino,-M.
AF: Cent. Oceanol. Marseille, U.R.A. 41, Stn. Mar. d'Endoume, Rue de la Batterie des Lions, 13007 Marseille, France
CO: Conf. on Limnology and Oceanography, , 26-29 Jun 1989
SO: FLUXES-BETWEEN-TROPHIC-LEVELS-AND-THROUGH-THE-WATER-SEDIMENT-INTERFACE. Bonin,-D.J.;Golterman,-H.L.-eds. 1990 vol. 207 pp. 251-258
ST: HYDROBIOLOGIA vol. 207
LA: English
ER: M (Marine)
AB: In order to quantify bioturbation processes in a coastal Mediterranean ecosystem, experiments were performed to determine sediment mixing rates resulting from macrobenthos activity. Particle flux was measured in situ for 22 days using luminophores, which are colored sediment particles with sizes ranging from 10 to 200 mu m. In sediment depths from 0-5 cm, particle mixing was intensive due to high macrobenthos abundance. A small quantity of luminophores was transported down to a depth of 14 plus or minus 2 cm, where the macrofauna was represented principally by Polychetes. In a control experimental structure - without benthic fauna - no transfer of luminophores into the sediment was recorded. Sediment particle mixing measured in the ecosystem studied is intensive, and is the result of high macrobenthos activity. Different mixing modes occur with scales and rates depending on the organisms present. The luminophore profile resulting from bioturbation processes is explained by an intensive bioadvection sediment mixing added to a biodiffusive mixing with an order of magnitude of 10 super(-6) cm super(2)/s. Tracer accumulations between 1 and 2 plus or minus 1 cm and between 4 and 5 plus or minus 1 cm are attributed to bioadvection activity of two or more distinct populations. Studies over a larger time scale have been undertaken to monitor developments in the observed subsurface maxima (DBO).
AN: 3854912
18 of 126
TI: Vertical particle flux in outer shelf waters of the southern Bay of Biscay in summer 1993
AU: Fernandez,-E.; Maranon,-E.; Cabal,-J.; Alvarez,-F.; Anadon,-R.
AF: Dep. Recursos Naturais e Medio Ambiente, Univ. de Vigo, Campus Lagoas-Marcosende, 36200 Vigo, Spain
SO: OCEANOL.-ACTA 1995 vol. 18, no. 3, pp. 379-384
LA: English
ER: M (Marine)
AB: Export of particulate matter out of the euphotic zone was measured in the southern Bay of Biscay in summer 1993 using shallow (50 m) sediment traps deployed for a short period in outer shelf waters. The sedimented material consisted of intact and degraded faecal pellets, diatom frustules, coccolithophorid cells, detached coccoliths and zooplankton remains. Measured vertical fluxes were 173-236 mg C m super(-2) day-l, 18-20 mg N m super(-2) day-l and 3.8-4.5 mg C m super(-2) day super(-l), respectively for particulate organic carbon (POC), particulate organic nitrogen (PON) and particulate inorganic carbon (PIC). The downward flux of POC represented 24 -37 % of the estimated primary production. Export of PIC accounted for only 2 % of the total carbon flux. A large proportion (50-70 %) of the material retained in the traps originated from phytoplankton. The contribution of 'living' phytoplankton to organic carbon fluxing out of the fertile zone was, however, less than 10 %.
AN: 3851041
19 of 126
TI: Bank-derived carbonate sediment transport and dissolution in the Hawaiian Archipelago
AU: Sabine,-C.L.; MacKenzie,-F.T.
AF: Atmos. Ocean Sci. Program, Dep. Geol. Geophys. Sci., Princeton Univ., Princeton, NJ 08544, USA
SO: AQUAT.-GEOCHEM. 1995 vol. 1, no. 2, pp. 189-230
LA: English
ER: M (Marine)
AB: This investigation used two approaches to examine the flux of bank-derived carbonate particles and determine the potential influence of benthic carbonate particle dissolution on the carbon chemistry of the waters around the Hawaiian Archipelago. First, the particle flux near several representative carbonate banks in the Hawaiian Archipelago was measured and compared with the flux at a distal site (ALOHA) approximately 100 km north of Oahu, Hawaii. The results of four sediment trap deployments on three carbonate banks in the Hawaiian Archipelago demonstrate that the flux of bank-derived carbonate particles are consistently one to two orders of magnitude higher than the fluxes at the distal station. Furthermore, the mineralogy of the carbonate flux near the banks, which includes very soluble bank-derived aragonite and magnesian calcite particles, is distinctly different from that of the distal fluxes. Second, the chemistry of the waters at each bank station along the archipelago was characterized and compared with the chemistry of the distal waters to determine if differences in the particle flux were reflected in the carbon chemistry. Higher alkalinity and carbonate ion concentrations were observed around all of the banks studied. The saturation state of these waters suggests that the dissolution of some magnesian calcite and aragonite phases could explain the higher alkalinity values. Calculations suggest that the dissolution of benthically-derived aragonite and magnesian calcite may be an important component of the North Pacific alkalinity budget and a potential sink for anthropogenic CO sub(2).
AN: 3827979
20 of 126
TI: Tracing, particle cycling in the upper ocean with super(230)Th and super(228)Th: An investigation in the Equatorial Pacific along 140 degree W
AU: Luo,-Shangde; Ku,-Teh-Lung; Kusakabe,-M.; Bishop,-J.K.B.; Yang,-Yong-Liang
AF: Dep. Earth Sci., Univ. Southern California, Los Angeles, CA 90089-0740, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 805-829
LA: English
ER: M (Marine)
AB: Vertical distributions of super(230)Th and super(228)Th were measured in large-volume (2000 to 3000 liter) seawater samples collected with the Multiple Unit In-Situ Large-Volume Filtration System (MULVFS) and in-situ Fe/Mn-fiber enrichment technique. The samples were from the upper similar to 800 m of the water column in the Central Equatorial Pacific along similar to 140 degree W during two survey cruises of JGOFS EqPac in February/March (Survey I) and August/September (Survey II) 1992. Significantly lower activities of super(230)Th and super(228)Th relative to those of their parent isotopes exist in the upper-ocean water column due to their particle-reactive behavior. The activities of these thorium isotopes also show large temporal variations, in response to surface productivity changes. During Survey I, a period of the El Nino, the super(230)Th and super(228)Th activities were higher than those measured during Survey II (a non-El Nino period), reflecting a depressed ocean productivity and particle flux under El Nino conditions. Vertical profiles of super(230)Th show a minimum at about 50 to 100 m, suggesting maximal particle scavenging in this depth range. Below this depth interval is a super(230)Th chemocline (rapid increase in super(230)Th activities with depth) and a super(228)Th activity maximum. The occurrence of the super(230)Th chemocline and the super(228)Th maximum just below the euphotic zone is a manifestation of active particle regeneration. Based on the extent of radioactive disequilibria between super(228)Th and super(228)Ra and between super(230)Th and super(234)U, we have estimated vertical fluxes of the two Th isotopes and of the particle mass. The export particle flux reaches a maximum in the lower portion of the euphotic zone, followed by a rapid decrease resulting from intensive particle remineralization in the super(230)Th chemocline/ super(228)Th maximum region. The scavenging rates of super(228)Th and super(230)Th are not balanced by their in-situ production and radioactive decay. The imbalance is attributable to their diffusional and advective transport. From the vertical profiles of particle fluxes derived from super(228)Th and super(230)Th, export fluxes of particulate organic carbon (POC) at the base of the euphotic zone are estimated to be 0.6-1.3 mmol C m super(-2)day super(-1) during El Nino, and 1.5-5.0 mmol C m super(-2)day super(-1) during the non-El Nino period. These values are small compared to the new production, indicating that much of the organic matter must be removed from the euphotic zone in dissolved form. Deeper at similar to 800 m, the POC fluxes are reduced to 0.14-0.50 mmol C m super(-2)day super(-1) (El Nino) and 0.5-1.1 mmol C m super(-2)day super(-1) (non-El Nino).
AN: 3822076
21 of 126
TI: Export production of particles to the interior of the Equatorial Pacific Ocean during the 1992 EqPac experiment
AU: Honjo,-S.; Dymond,-J.; Collier,-R.; Manganini,-S.J.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 831-870
LA: English
ER: M (Marine)
AB: Twenty-four time-series, moored sediment traps were deployed between 2/2/92 and 1/27/93 along 140 degree W at 9 degree N, 5 degree N, 2 degree N, 0 degree , 2 degree S, 5 degree S and 12 degree S at water depths of approximately 1200 m and 2200 m, and 700 m above the bottom. The opening/closing of the traps was synchronized at 17-day periods, for 21 events, covering a total of 357 days. The average annual particle flux in the ocean's interior (2.2 to 4.4 km deep) from 5 degree N to 5 degree S was 28.5 g m super(-2) year super(-1), with 34.8 g super(-2) year super(-1) the maximum annual flux at the equator. Sixty-six per cent of settling particles were carbonate; 24% biogenic SiO sub(2) and 5% organic carbon. The onset of tropical instability waves, marking the year's El Nino/post-El Nino boundary, was associated with a succession of intervals with greater organic carbon and opal at 5 degree N, 2 degree S and 5 degree S that occurred synchronously with a meridional oscillation of instability waves, while net carbon flux during El Nino and post-El Nino periods did not change. Although organic carbon flux increased at 5 degree N, 2 degree S and 5 degree S during the post-El Nino period, it was counterbalanced by decreases at the upwelling stations (2 degree N and the equator), resulting in no net carbon flux increase across the 5 degree N to 5 degree S region. In February/March 1992, only 0.34% of the organic carbon fixed by primary production over the 5 degree N to 5 degree S zone arrived in the ocean's interior. In August/September that year, zonal average of organic carbon flux increased slightly to 0.5% of primary production. Very little carbon reached the interior depths of the upwelling stations; however, the fraction of export was higher at the 5 degree N, 2 degree S and 5 degree S stations. The pattern of variability of particle flux at the shallow depths was observed also in deeper traps, without temporal offsets, suggesting a settling particle residence time shorter than the 17-day time- series resolution during most of this experiment.
AN: 3821995
22 of 126
TI: Spatial variability in sediment composition and evidence for resuspension in a large, deep lake
AU: Lebo,-M.E.; Reuter,-J.E.
AF: California Univ. Inst. Ecol., Davis, CA 95616, USA
CO: 6. International Symposium. International Association for Sediment Water Sciences Santa Barbara, CA (USA)
SO: MAR.-FRESHWAT.-RES. 1995 vol. 46, no. 1, pp. 321-326
LA: English
ER: F (Freshwater)
AB: Spatial variability in the composition of sediments in Pyramid Lake, Nevada, was assessed by collecting surficial samples at 32 sites. For those sites, organic fractions were highest in the centre of the lake and low near the single inflow to the system. The spatial patterns for organic carbon, nitrogen and phosphorus in lake sediments indicated that small organic-rich particles are preferentially deposited in the centre of the lake. This sorting of particles by water depth was supported by a corresponding decrease in the particle size distribution of sediments with station depth and by limited sediment-trap data. Further, a comparison of sediment-trap particle flux rates with the net sediment accumulation rate for the centre of the lake based on 210-Pb decay indicated that the resuspension of bottom sediments in Pyramid Lake must occur throughout the lake.
AN: 3815252
23 of 126
TI: Patterns in the distribution of demersal fishes on the upper continental slope off central California with studies on the role of ontogenetic vertical migration in particle flux
AU: Wakefield,-W.W.,II
CA: California Univ., San Diego (USA)
SO: DISS.-ABST.-INT.-PT.-B-SCI.-and-ENG. 1991 vol. 51, no. 11, 301 pp
NT: Diss. Ph.D.: Order No.: DA9110731.
LA: English
ER: M (Marine)
AB: Patterns in the distribution and abundance of upper continental slope demersal fishes off central California were studied using a bottom trawl and newly-developed camera sled. From May 1984 through May 1985, seven cruises were conducted off Point Sur, California (36 degree 15-31' N, 122 degree 4-26' W). The camera sled permitted accurate quantification of the distribution and abundance of fishes as well as direct observation of the slope habitat. Sampling was conducted along bathymetric contours at 200-m intervals from 200 to 1,600 m. The number of species identified from trawls was relatively constant at ca. 20 for four 200-m depth intervals from 400 to 1,000 m, but decreased below 1,000 m to a minimum at 1,600 m. A faunal break between 400 and 600 m corresponds to a transition between shelf- and slope-dwelling species. The sediment-covered sea floor off Point Sur is characterized by a number of sharp environmental boundaries that in some instances correspond to marked changes in the abundance of a given species of fish. On a slope-wide basis, Sebastolobus altivelis, was the numeric and gravimetric dominant. Other important taxa, either in terms of numbers or biomass, included Eptatretus deani, Sebastolobus alascanus, Microstomus pacificus, Coryphaenoides acrolepis, Albastrossia pectoralis, Anoplopoma fimbria, Antimora microlepis, and Lycenchelys spp. Total fish biomass was relatively constant between 400 and 1,000 m, and decreased below 1,000 m to a minimum at 1,600 m. Specific emphasis was placed on the life-history of Sebastolobus altivelis and the importance of this dominant species in the vertical transport of particulate matter along the continental margin during its ontogenetic vertical migration. Studies on reproduction in adult S. altivelis and settlement in their juveniles were conducted. The production of particulate organic matter (POM) in buoyant masses of eggs and the recruitment of POM by settling juveniles were determined as measures of the passive upward flux of POM and active transport of POM back to the sea floor. Fluxes of particulate organic carbon associated with planktonic development and ontogenetic migration of S. altivelis were 4.1 to 5.8 and 3.0 to 5.5 mg/C m super(2)/yr, respectively. These upward and downward fluxes are lower by a factor of about 10 and 10 super(4), respectively, than reported passive upward and active downward fluxes measured with particle interceptor traps in the eastern North Pacific. (DBO)
AN: 3808047
24 of 126
TI: Biological mixing intensity and rates of organic carbon accumulation in North Carolina slope sediments
AU: DeMaster,-D.J.; Pope,-R.H.; Levin,-L.A.; Blair,-N.E.
AF: Dep. Mar., Earth, Atmos. Sci., North Carolina State Univ., Raleigh, NC 27695-8208, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1994 vol. 41, no. 4-6, pp. 735-753
LA: English
ER: M (Marine)
AB: Sediment accumulation rates and biological mixing intensities were determined at three sites on the North Carolina slope based on profiles of naturally occurring super(14)C, super(210)Pb and super(234)Th. The three sites all were at a water depth of 850 m with a spacing of 150-180 km between sites. Sediment accumulation rates increase from south to north from values of 7 cm ky super(-1) at Site I, to 160 cm ky super(-1) at Site II, to 1100 cm ky super(-1) at Site III. The organic carbon burial rate at these sites also increases in the northward direction from 0.65 (Site I) to 20 (Site II) to less than or equal to 150 g C sub(org) m super(-2) year super(-1) (Site III). These data indicate that continental margin environments can exhibit highly variable carbon fluxes over relatively small distances on the seafloor. The rate of organic carbon accumulation at Site III is one of the highest values reported for the marine environment. For the three study sites off North Carolina, a strong correlation exists between macrofaunal abundance and the organic carbon deposition rate. An equally strong correlation occurs between macrofaunal abundance and the super(234)Th inventories (index of 100-day particle flux). Fine-sand size glass tracer beads were dispersed at these three sites by submersible and then the field plots were sampled similar to 1 year later. The vertical distributions of beads at the three sites are consistent with a higher mixing intensity at Site III than at the other two sites, but the estimated mixing coefficients generally are lower than those determined from the profiles of super(234)Th. The slower mixing of the glass beads may be the result of their low food value and/or their relatively large size (compared to the surrounding fine-grained sediments).
AN: 3740003
25 of 126
TI: On the trophic fate of Phaeocystis pouchetii (Hariot): 6. Significance of Phaeocystis-derived mucus for vertical flux
AU: Riebesell,-U.; Reigstad,-M.; Wassmann,-P.; Noji,-T.; Passow,-U.
AF: Alfred-Wegener-Inst. Polar and Mar. Res., Am Handelshafen 12, D-27515 Bremerhaven, FRG
SO: NETH.-J.-SEA-RES. 1995 vol. 33, no. 2, pp. 193-203
LA: English
ER: M (Marine)
AB: The development and decline of a phytoplankton spring bloom dominated by the prymnesiophyte Phaeocystis pouchetii were studied in Balsfjord, northern Norway between 30 March and 27 May 1992. At a fixed station, the concentration and composition of suspended particulate matter was monitored and compared to the particulate matter collected in sediment traps at six different depths. Direct sedimentation of phytoplankton contributed a minor fraction to particle flux and was confined to a few diatom genera. No evidence was found for pronounced aggregation of Phaeocystis colonies during bloom decline or direct sedimentation of either Phaeocystis colonies or single cells. Particle flux was dominated by faecal-pellet sedimentation during most of the study period, suggesting zooplankton grazing to be a main loss factor. Despite an abrupt decrease in faecal-pellet sedimentation after the decline of the bloom, particulate-carbon sedimentation rates remained high. High post-bloom sedimentation rates were characterized by elevated C/N and C/Chl a ratios of largely amorphous sedimented material. Post-bloom sedimentation coincided with a decrease in transparent exopolymeric particles (TEP) in the surface layer, suggesting that this change resulted from aggregation and sedimentation of carbon-rich exopolymeric material accumulated in the surface layer in the course of the bloom. While organic-carbon accumulation indicates the significance of disintegration of Phaeocystis colonies, post-bloom mucilage sedimentation could be a secondary pathway for the vertical flux of Phaeocystis-derived organic matter.
AN: 3736230
26 of 126
TI: Fluxes of material in the Arabian Sea and Bay of Bengal -- sediment trap studies
AU: Ramaswamy,-V.; Nair,-R.R.
AF: NIO, Dona Paula, Goa 403 004, India
SO: BIOGEOCHEMISTRY-OF-THE-ARABIAN-SEA:-PRESENT-INFORMATION-AND-GAPS Lal,-D.-ed. BANGALORE-INDIA INDIAN-ACAD.-OF-SCI. 1994 pp. 189-210
ST: PROC.-INDIAN-ACAD.-SCI.-EARTH-PLANET.-SCI.
LA: English
ER: M (Marine)
AB: In order to investigate how monsoons influence biogeochemical fluxes in the ocean, twelve time-series sediment traps were deployed at six locations in the northern Indian Ocean. In this paper we present particle flux data collected during May 1986 to November 1991 and November 1987 to November 1992 in the Arabian Sea and Bay of Bengal respectively. Particle fluxes were high during both the SW and NE monsoons in the Arabian Sea as well as in the Bay of Bengal. The mechanisms of particle production and transport, however, differ in both the regions. In the Arabian Sea, average annual fluxes are over 50 g m/2 y/1 in the western Arabian Sea and less than 27 g m/2 y/1 in the central part. Biogenic matter is dominant at sites located near upwelling centers, and is less degraded during peak flux periods. High particle fluxes in the offshore areas of the Arabian Sea are caused by injection of nutrients into the euphotic zone due to wind-induced mixed layer deepening. In the Bay of Bengal, average annual fluxes are highest in the central Bay of Bengal (over 50 g m/2 y1) and are least in the southern part of the Bay (37 g m/2 y1). Particle flux patterns coincide with freshwater discharge patterns of the Ganges-Brahmaputra river system. Opal/carbonate and organic carbon/carbonate carbon ratios increase during the SW monsoon due to variations in salinity and productivity patterns in the surface waters as a result of increased freshwater and nutrient input from rivers.
AN: 3732831
27 of 126
TI: Clay-mineral flux in the Fram Strait and Norwegian Sea
AU: Berner,-H.; Wefer,-G.
AF: Geowiss., Univ. Bremen, Klagenfurter Str., 28359 Bremen, FRG
SO: MAR.-GEOL. 1994 vol. 116, no. 3-4, pp. p. 327-348
LA: English
ER: M (Marine)
AB: Since 1983 time-series traps have been deployed in the Fram Strait and the Norwegian Sea to study sedimentation processes in open ocean and ice-covered areas. The seasonal and regional variability of clay minerals is used to decipher the effect of current systems on particle flux and particle producing processes. Toward this end the occurrence of the clay mineral kaolinite can be used to identify transported material. High koalinite/illite ratios are related to distinct sedimentation events caused by particularly high plankton productivity. In the various current systems, the following types of sedimentation can be distinguished: a "polar" type, characterized by low total flux, high lithogenic content and a kaolinite/illite-ratio of <0.3, in the region of the predominantly ice-covered East Greenland Current (EGC), and an "arctic-atlantic" type, characterized by very high total flux, high lithogenic content and a kaolinite/illite-ratio of >0.3, in the area of the West Spitsbergen Current. The type of sedimentation in the region of the drift-ice margin is referred to as "ice-margin" type, characterized by medium total flux, medium lithogenic content and a kaolinite/illite-ratio of >0.3. Additionally, in the near-shore sediments of the Norwegian Sea, a "continental" influence from resuspended material with high contents of terrigenous material in the otherwise characteristically pelagic sediments is apparent.
AN: 3715001
28 of 126
TI: Grazing of natural particulates by the mussel, Mytilus edulis: A spatial and temporal perspective
AU: Newell,-C.R.
AF: Great Eastern Mussel Farms, Inc., Tenants Harbor, ME 04860, USA
CO: 1994 Annu. Meet. of the National Shellfisheries Assoc., Charleston, SC (USA), 24-28 Apr 1994
SO: J.-SHELLFISH-RES. 1994 vol. 13, no. 1, p. 301
NT: Abstract only.
LA: English
ER: M (Marine)
AB: The production of suspension feeders such as mussels may be limited by processes ranging from cm to km scales, and time periods ranging from seasonal changes in temperature to tidal cycle changes in the flux of seston. Field observations have shown that the processing of phytoplankton, organic detritus and inorganic particulates by shellfish beds results in kilometer scale effects of particle concentration (depletion) which may be simulated by computer modelling. Over 4 years (1986-1990), biological and oceanographic processes were examined at 4 commercial mussel bottom leases in Maine, USA, in order to build and test mussel production models and determine the optimal seeding density. Several key factors examined during the study include: height of the mussel feeding zone; fine vertical gradients in the food (seston) supply; spatial variations in benthic boundary layer particle flux; temporal variations in feeding rates on natural particulates; and estuary-scale variations in food supply. The data suggest that the estuary-scale processes of tidally-supplied diatom blooms are a major forcing function in the production of benthic filter-feeders such as the mussel, Mytilus edulis. The implications of these studies on site selection and the management of shellfish bottom leases are discussed.
AN: 3712022
29 of 126
TI: Seasonal patterns of ocean biogeochemistry at the U.S. JGOFS Bermuda Atlantic Time-series Study Site
AU: Michaels,-A.F.; Knap,-A.H.; Dow,-R.L.; Gundersen,-K.; Johnson,-R.J.; Sorensen,-J.; Close,-A.; Knauer,-G.A.; Lohrenz,-S.E.; Asper,-V.A.; et-al.
AF: Bermuda Biol. Stn. Res., Inc., St. Georges, GE-01, Bermuda, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP. 1994 vol. 41, no. 7, pp. 1013-1038
LA: English
ER: M (Marine)
AB: Seasonal patterns in hydrography, oxygen, nutrients, particulate carbon and nitrogen and pigments were measured on monthly cruises at the Bermuda Atlantic Time-series Study Site, 80 km Southeast of Bermuda. Between October 1988 and September 1990, the annual cycle was defined by the creation of 160-230 m-deep mixed layers in February of each year and a transition to strong thermal stratification in summer and fall. The 230 m mixed layer in February 1989 resulted in mixed-layer nitrate concentrations of 0.5-1.0 mu mole/kg, carbon fixation rates over 800 mg C/m super(2)/day, and a phytoplankton bloom with chlorophyll concentrations over 0.4 mg m super(-3). Chlorophyll a, particulate organic matter, inorganic nutrients and primary production had returned to pre-bloom levels the following month with the exception of a chlorophyll maximum layer at 100 m. Particle fluxes at 150 m in February 1989 reached 56 mg C/m super(2)/day and 11 mg N/m super(2)/day (0.77 mmole N/m super(2)/day). Estimates of new production during the bloom period calculated from changes in oxygen and nitrate profiles ranged from 100 to 240 mmoles N/m super(2), significantly higher than the sediment trap fluxes and approaching the measured total production rates. In spring of 1990, mixed layer depths did not exceed 160 m, nitrate was rarely detectable in the upper euphotic zone, chlorophyll a concentrations were similar to 1989, and particulate organic matter concentrations were lower. The period of elevated biomass lasted for 3 months in 1990, and phytoplankton pigment composition varied between cruises. The average rates of primary production and particle flux were higher in 1990 than those measured in the spring of 1989, despite the differences in mixed layer depth. Throughout both years, NO sub(3):PO sub(4) ratios in the upper thermocline exceeded Redfield ratios. The maintenance of this pattern requires a net uptake of PO sub(4) between 150 and 250 m, a depth range usually associated with net remineralization. The exact mechanism that maintains elevated PO sub(4) uptake and its implication for the nutrient supply to the euphotic zone remain unknown.
AN: 3693257
30 of 126
TI: Dynamics of the downward flux of particles and carbon in the open northwestern Mediterranean Sea
AU: Miquel,-J.C.; Fowler,-S.W.; La-Rosa,-J.; Buat-Menard,-P.
AF: IAEA Mar. Environ. Lab., P.O. Box 800, MC98012 Monaco Cedex, Monaco
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP. 1994 vol. 41, no. 2, pp. 243-261
LA: English
ER: M (Marine)
AB: Downward fluxes and the elemental composition of settling particles at 80, 200 and 1000 m depth measured during an 18-month sediment trap experiment are presented, together with associated hydrographic and biological data, in order to assess the relative importance of these factors in controlling particle flux. Mass, carbon and nitrogen fluxes were generally higher during the first half of the year. Mass flux maxima occurred at different times of the year depending on trap depth, whereas the peak carbon flux was measured in late June. Most of the total carbon flux was composed of organic carbon. On an annual basis the total particle flux was 32.9, 40.6 and 8.1 g/m super(2)/year at 80, 200 and 1000 m depth, respectively. The organic carbon flux decreased from 4.8 and 5.0 g/m super(2)/year at 80 and 200 m, respectively to 1.2 g/m super(2)/year at 1000 m, and the corresponding nitrogen flux from 0.7 and 0.8 to 0.2 g/m super(2)/year. Organic carbon and nitrogen content of sinking particles decreased with depth, whereas the carbonate carbon content remained constant. The contribution of zooplankton feces to the carbon flux was highly variable throughout the year, ranging from 1.6 to 62%. Swimmers, including fish, that entered the traps in the upper 200 m were abundant and, on average, were twice the weight of the sinking particle flux. Pelagic production was the main source of particles during the late spring and mid-summer sedimentation pulses; however physical forcing, particularly the winter mixing of the water column, was partially responsible for the high sedimentation during the earlier part of the year. Wind gusts and concomitant vertical mixing appeared responsible for the carbon rich particle flux in summer. Separation of data for the mixed and stratified water column periods clearly indicated that most of the downward flux occurred in mixed waters whereas the organic carbon content was higher in particles sedimenting through stratified waters. The export of organic carbon from the euphotic zone (upper 200 m) represented only 5-7% of the estimated phytoplankton production in this region. Furthermore time-series measurements of POC flux averaged on an annual basis were only 14-42% of indirect estimates of carbon export or "new production" for this region. This discrepancy suggests that a good portion of the total downward carbon flux occurs through advection and/or diffusion of DOC.
AN: 3687952
31 of 126
TI: Swimmers: A recapitulation of the problem and a potential solution
AU: Karl,-D.M.; Knauer,-G.A.
SO: OCEANOGRAPHY 1989 vol. 2, no. 1, pp. 32-35
LA: English
ER: M (Marine)
AB: We read, with great interest, the article by Lee et al. (1988) concerning the effects of "swimmers" on the measurement of particulate organic matter flux in the marine environment. Generally swimmers are either: (1) acknowledged and their impact reduced by manually removing the carcasses ("picking") before further sample processing, (2) acknowledged, but trap contents analyzed unaltered, or (3) totally ignored. None of these three options is acceptable, if the desired outcome is to obtain accurate particle flux estimates. As Lee et al. (1988) discuss in their review, the swimmer problem is exacerbated in near-surface waters ( less than or equal to 500 m). Unfortunately, the measurement of particulate organic matter flux in the upper water column is crucial to our understanding of biogenic element cycles, including the rates and mechanisms of nutrient regeneration and, consequently, crucial to addressing the Global Ocean Flux Study (GOFS) program objectives. Because sediment traps are now recognized as the only method for estimating the passive downward flux of organic matter in the sea (SCOR WG-71 report on "Particulate Biogeochemical Processes," S. Krishnaswami, chairman), our progress toward a resolution of these important oceanic processes is stalled at this time. So, to provide a brief answer to the rhetorical question posed in their title, "Are 'Swimmers' a Problem?," we believe the reply is an overwhelming affirmative. (DBO)
AN: 3663177
32 of 126
TI: Particle deposition in the Present and Holocene Black Sea
AU: Hay,-B.; Honjo,-S.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: OCEANOGRAPHY 1989 vol. 2, no. 1, pp. 26-31
LA: English
ER: M (Marine)
AB: The Black Sea represents a fascinating environment for detailed particle deposition studies. The basin is comparatively small, yet over 2,000 m deep. It is nearly completely enclosed and only connected through the shallow Bosporus to the world's oceans. The hydrography and the sediment input parameters from the surrounding rivers are comparatively well known. The seasonal changes in sedimentation are preserved in the bottom sediments in the form of laminated sequences, since the absence of oxygen in the deep water interface prohibits bioturbation. Once deposited, the sediments in the abyssal Black Sea remain in place; redistribution processes on the basin floor are comparatively insignificant. Recently, we investigated the seasonal particle flux in the water column in a feasibility study in the southwestern Black Sea with time-series sediment traps from 1982-1988 in collaboration with Dokuz Eyluel University in Izmir, Turkey, the University of Hamburg, and Woods Hole Oceanographic Institution. Sediment traps were moored consecutively at two sites at a water depth of 250m and 1200m. Conclusions from these first sediment trap studies, integrated in the discussion below, provided new insights into the particle deposition processes in that region of the Black Sea. (DBO)
AN: 3663174
33 of 126
TI: Particle flux, and composition of sedimenting matter, in the Greenland Sea
AU: Bauerfeind,-E.; Bodungen,-B.V.; Arndt,-K.; Koeve,-W.
AF: Sonderforschungsbereich 313, Univ. Kiel, Heinrich Hecht Platz 10, D 24118 Kiel, FRG
SO: J.-MAR.-SYST. 1994 vol. 5, no. 6, pp. 411-423
LA: English
ER: M (Marine)
AB: Vertical flux of particulate material was recorded with moored sediment traps during 1988/1989 in the Greenland Sea at 72 degree N, 10 degree W. This region exhibits pronounced seasonal variability in ice cover. Annual fluxes at 500 m water depth were 22.79, 8.55, 2.39, 3.81 and 0.51 g/m super(2) for total flux (dry weight), carbonate, particulate biogenic silicate, particulate organic carbon and nitrogen, respectively. Fluxes increased in April, maximum rates of all compounds occurred in May-June, and consistently high total flux rates of around 100 mg/m super(2)/d prevailed during the summer. The increasing flux of biogenic particles measured in April is indicative of an early onset of algal growth in spring. Small pennate diatoms dominated in the trap collections during April, and were still numerous during the high flux period when Thalassiosira species were the most abundant diatoms. During May-June, up to 22% of the Thalassiosira cells collected were viable-looking cells. The faecal pellet flux increased after the May-June event. Therefore we conclude that the diatoms settled as phytodetritus, most likely in rapidly sinking aggregates. From seasonal nutrient profiles it is concluded that diatoms contribute 25% to new production during spring and 50% on an annual basis. More than 50% of newly produced silicate particles are dissolved above the 500 m horizon. High new production during spring does not lead to a pronounced sedimentation pulse of organic matter during spring but elavated vertical export is observed during the entire growth period.
AN: 3660533
34 of 126
TI: The measurement of oceanic particle flux - Are "swimmers" a problem?
AU: Lee,-C.; Wakeham,-S.G.; Hedges,-J.I.
AF: Mar. Sci. Res. Cent., SUNY, Stony Brook, NY 11794-5000, USA
SO: OCEANOGRAPHY 1988 vol. 1, no. 2, pp. 34-36
LA: English
ER: M (Marine)
AB: About 10 years ago, the use of sediment traps to measure oceanic particle fluxes and composition began to proliferate. This technique has now become widespread. Research on particle composition and flux using sediment-trap and other large-particle sampling technologies has clearly shown the importance of particulate matter in global biogeochemical cycles. It has become a major goal within the oceanographic community to understand the processes controlling particle production, transport and destruction on both small and large scales. Particularly important to these studies is an accurate estimate of particle production and flux in surface waters. Initially, sediment traps were used to collect particles without careful regard to in-situ bacterial decay of material in the traps. As it became clear that organic material in particles could be significantly degraded during the two-week and longer periods over which traps were deployed, poisons and preservatives became more commonly used to prevent decomposition. Typical poisons currently used are HgCl sub(2) and NaN sub(3), while common preservatives are formalin and salt. We are currently investigating the effectiveness of these and other compounds in preventing decomposition and alteration of particulate organic compounds collected in sediment traps. However, with the use of poisons and preservatives, another potentially more significant bias is introduced to sediment trap collections. This is the collection of "swimmers": zooplankton and other marine animals that swim into the trap and die. Under some circumstances, particularly in shallow traps placed in coastal areas, much of the material collected can be swimmers. We observed this in trap samples collected in the California Current during the VERTEX V experiments. (VERTEX was a multidisciplinary study of VERtical Transport and EXchange of material in the upper ocean.) Even in deeper or less productive waters, swimmers can be present in trap samples. (DBO)
AN: 3655147
35 of 126
TI: Particle fluxes, South Central Black Sea: 1982-1985 (Black Sea sedimentation data file, volume 1)
AU: Honjo,-S.; Manganini,-S.J.; Asper,-V.L.; Hay,-B.J.; Karowe,-A.
CA: Woods Hole Oceanographic Inst., MA (USA)
SO: 1987 113 pp
RN: WHOI-87-25 (WHOI8725)
LA: English
ER: M (Marine)
AB: Annual particle fluxes were measured by sediment traps deployed at a station about 40 km north of Amasra, Southern Black Sea, by an international team of oceanographers from Germany, Turkey, and the United States. This experiment continuously monitored oceanic particle flux for two and a half years at approximately two-week intervals at 250 m and 1200 m below the surface using 1.2 sq.m Mark 5-12 time-series sediment traps. The water depth at this station was about 2,000 m and both traps were situated within the anoxic layer of the Black Sea. The collected flux samples were analyzed at the Wood Hole Oceanographic Institution to document the basic sedimentary characteristics using a quarter of each sample split. In the first data file from the experiment, total mass, carbonate, noncombustible, combustible, opal (biogenic silica), organic carbon, and organic nitrogen fluxes data are presented in bar graphs and detailed tables, in unit samples covering a two-week period at each depth. The Black Sea Sedimentation Data File is intended to provide source data on particle fluxes from this unique ocean environment for further investigation and for planning advanced research program. (DBO)
AN: 3639081
36 of 126
TI: Annual flux of dissolved organic carbon from the euphotic zone in the northwestern Sargasso Sea
AU: Carlson,-C.A.; Ducklow,-H.W.; Michaels,-A.F.
AF: Horn Point Environ. Lab., Univ. Maryland, P.O. Box 775, Cambridge, MD 21613, USA
SO: NATURE 1994 vol. 371, no. 6496, pp. 405-408
LA: English
ER: M (Marine)
AB: The export of biogenic carbon from the upper ocean is responsible for maintaining the vertical gradient of dissolved inorganic carbon and thus indirectly for regulating the level of atmospheric CO sub(2). Large, rapidly sinking particles are thought to dominate this export, and this sinking flux has been thought to balance new production. Recent measurements of particle export and estimates of new production have questioned this picture, however. Here we report measurements of dissolved organic carbon (DOC) off Bermuda, which provide strong support for the idea that this component of oceanic carbon is also an important and dynamic part of the ocean carbon cycle. We find that DOC accumulates in the early spring owing to increased primary production, and is partially consumed in the summer and autumn. The DOC that escapes remineralization is exported from the surface ocean the following winter, and we estimate this export to be equal to or greater than the measured particle flux, allowing us to close the annual vertical carbon budget for this site to within a factor of two. Our observations should be applicable to other temperate, sub-polar and continental-shelf regions of the world ocean which exhibit convective mixing and vernal restratification.
AN: 3627395
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TI: Atmospheric deposition of organic contaminants to the Chesapeake Bay
AU: Leister,-D.L.; Baker,-J.E.*
AF: Chesapeake Biol. Lab., Cent. Environ. and Estuar. Stud., Univ. Maryland Syst., P.O. Box 38, Solomons, MD 20688, USA
SO: ATMOS.-ENVIRON. 1994 vol. 28, no. 8, pp. 1499-1520
LA: English
ER: M (Marine)
AB: To estimate loadings of contaminants from the atmosphere to the Chesapeake Bay, ambient atmospheric concentrations and wet deposition fluxes of several polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were measured at a shore-based station between June 1990 and December 1991. Geometric mean concentrations of individual PAHs in air ranged from 0.003 (dibenz[ah]anthracene) to 1.4 ng/m super(-3) (phenanthrene) and the observed temporal variability in PAH levels in the air ranged from 0.1 to 41% about the respective geometric mean concentrations. The mean ambient atmospheric PCB concentration over the Chesapeake Bay during the study period was 0.21 ng/m super(-3), with a relative standard deviation of 56%. PCB concentrations in the air were slightly correlated with air temperature. Volume-weighted mean (VWM) concentrations of individual PAHs in precipitation ranged from 1.1 (dibenz[ah]anthracene) to 17 ng/l (pyrene). The VWM t-PCB concentration was 1.6 ngl super(-1). The temporal variability of HOC concentrations in rainfall was as large as one order of magnitude, with no apparent seasonal trend, suggesting highly variable HOC scavenging processes. Assuming a dry deposition velocity of 0.49 plus or minus 0.23 cm/s super(m) dry particle fluxes of PAHs ranged from 1 plus or minus 0.4 (anthracene) to 16 plus or minus 7 (fluoranthene) mu g m super(-2)/yr. The dry deposition velocity was derived using monthly average wind speeds and temperature differentials derived for the Chesapeake Bay area from climatological compilations [Quinn T. L., Ondov J. M. and Holland J. Z. (1992) Dependence of deposition velocity on the frequency of meteorological observations for the Chesapeake Bay. J. Aerosol Sci. 23, S973-S976; Wu Z. Y., Ondov J. M., Holland J. Z. and Lin Z. C. (1992) Dry deposition fluxes of elements in Chesapeake Bay aerosol. J. Aerosol Sci. 23, S969-S972]. Wet fluxes of PAHS ranged from 1 (anthracene) to 20 (pyrene) mu g m super(-2) yr super(-1). Total (wet + dry) fluxes ranged from 2 plus or minus 0.4 (anthracene) to 35 plus or minus 7 (pyrene) mu g m super(-2) yr super(-1). The t-PCB wet flux was 1.9 mu g m super(-2) yr super(-1), with the estimated dry particle flux accounting for 75% of the total flux (3.3 plus or minus 0.6 mu g m super(-2) yr super(-1)). The t-PCB wet flux in Chesapeake Bay is similar to that of rural Minnesota [2 mu g m super(-2) yr super(-1), Franz T. P., Eisenreich S. J. and Swanson M. B. (1991) Evaluation of precipitation samplers for assessing atmospheric fluxes of trace organic contaminants. Chemo 23, 343-361]. Annual atmospheric loadings of individual PAHs to the surface waters of the Chesapeake Bay were calculated by extrapolating the total flux to the surface area of the Chesapeake Bay. Individual PAH loadings range from 23 plus or minus 5 (anthracene) to 403 plus or minus 81 (pyrene) kg yr super(-1) and the t-PCB annual atmospheric loading is 38 plus or minus 7 kg yr super(-1).
AN: 3603326
38 of 126
TI: Late Quaternary palaeoenvironments in the Lake Barombi Mbo (West Cameroon) deduced from pollen and carbon isotopes of organic matter
AU: Giresse,-P.; Maley,-J.; Brenac,-P.
AF: Lab. Sedimentol. Mar., Univ. Perpignan, 66025 Perpignan, France
SO: PALAEOGEOGR.,-PALAEOCLIMATOL.,-PALAEOECOL. 1994 vol. 107, no. 1-2, pp. 65-78
LA: English
ER: F (Freshwater)
AB: A sediment core, 23.5 m long, was recovered from a water depth of ca. 110 m in Lake Barombi Mbo, a maar crater of the Cameroon volcanic chain. This paper presents a carbon isotopic curve of organic matter linked to the main results of the pollen analysis. Interpretation of this carbon isotopic curve is simplified (1) because of the weak role played by the phytoplankton in the balance of the organic particle flux, and (2) because of the presumed absence of diagenetic alteration of the isotopic composition. The carbon isotopic curve exhibits an almost linear correlation with that of total grass pollen which form the main part of the C4 biomass. The major fluctuations of isotopic and pollen curves allow four main phases to be distinguished: -from ca. 25,000 to 20,000 yr B.P., delta super(13)C values of -25 to -30ppt (PDB) are related to a forest environment associated with a montane floral element; -from 20,000 to 13,000 yr B.P., the delta super(13)C values are between -23 and -28ppt and are linked to openings of landscape with a mosaic of forest and savanna and a fall of lake level with colonization of the shores by Cyperaceae and other aquatic plants; -from 13,000 to 10,000 yr B.P., the forest extended again reaching a maximum density during the period from 9500 until 3000 yr B.P. and with an average delta super(13)C value of -32ppt; -a new dry phase occurred at around 2500-2000 yr B.P., with temporary openings in the forest, marked by a delta super(13)C excursion above -30ppt, but during the last 2 millennia, the forest developed again with delta super(13)C values of -32ppt.
AN: 3591287
39 of 126
TI: In situ time-series measurement of ingestion and absorption rates of suspension-feeding bivalves: Placopecten magellanicus
AU: Cranford,-P.J.; Hargrave,-B.T.
AF: Dep. Fish. and Oceans Habitat Ecol. Div., Bedford Inst. Oceanogr., P.O. Box 1006, Dartmouth, N.S. B2Y 4A2, Canada
SO: LIMNOL.-OCEANOGR. 1994 vol. 39, no. 3, pp. 730-738
LA: English
ER: M (Marine)
AB: An adaptation of available methods is described for quantifying the ingestion and absorption rates of suspension-feeding bivalve molluscs exposed in situ to natural food sources and flow conditions. This new approach was used to follow the feeding response of the sea scallop Placopecten magellanicus (Gmelin) to short-term tidal cycle effects on current speed and seston quality in Lunenburg Bay, Nova Scotia. Unlike traditional methods, sampling is continuous and measurements of food uptake and utilization are averaged over selected time intervals (minutes to days). Scallop feeding activity varied markedly over a tidal cycle and periodic feeding activity accounted for a large proportion of food intake. Ingestion rates were not closely coupled with seston quantity, horizontal particle flux, or nutritional value as inferred from pigments, total organic and organic carbon and nitrogen content. The scallops did not alter absorption efficiency to adapt to short-term variations in diet quality.
AN: 3584519
40 of 126
TI: Bacterioplankton distributions and production in the northwestern Indian Ocean and Gulf of Oman, September 1986
AU: Ducklow,-H.W.
AF: Horn Point Environ. Lab., Univ. Maryland CEES, Box 775, Cambridge, MD 21613, USA
SO: BIOGEOCHEMICAL-CYCLING-IN-THE-NORTHWESTERN-INDIAN-OCEAN. Burkill,-P.H.;Mantoura,-R.F.C.;Owens,-N.J.P.-eds. 1993 vol. 40, no. 3 pp. 753-771
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 3
LA: English
ER: M (Marine)
AB: Bacterial abundance and super(3)H-thymidine incorporation were measured throughout the water column during September-October 1986, along transects in the north western Arabian Sea and Gulf of Oman. Bacterial abundances and production estimated from incorporation rates were high (>1 x 10 super(9) cells/l and 30-92% of primary production, respectively) along the oceanic portions of the transects. These elevated levels may indicate a response to the decline of summer phytoplankton blooms stimulated by monsoonal deepen of the mixed layer. Bacterial production and abundance profiles had complex vertical structure with multiple subsurface maxima related to chlorophyll and oxygen distributions. Production and abundance both declined exponentially with depth below 100-200 m. Rates of dissolved organic carbon (DOC) release from the sinking particle flux may have been adequate to support bacterial production in the Gulf of Oman, but in the open Arabian Sea this source appeared to be insufficient to meet the bacterial demand. The bacterial production estimates reported herein are very conservative because very low conversion factors were used. In general these results suggest that the carbon sources usually assumed to support bacterial production (e.g., phytoplankton exudation, particle breakdown) supply only a fraction of the bacterial demand in the northwest Indian Ocean.
AN: 3567033
41 of 126
TI: Utilization, cycling and vertical transport of particulate organic matter in the coastal marine environment. Final project report, November 15, 1987--May 14, 1992
AU: Landry,-M.R.
CA: Hawaii Univ. Manoa, Honolulu (USA). Dep. of Oceanography
SO: REP.-U.S.-DEP.-ENERGY 1992 6 pp
RN: DOE/ER/60628-3 (DOEER606283)
LA: English
ER: M (Marine)
AB: This project was funded as part of the California Basin Study (CaBS), a DOE-funded regional program investigating production, cycling, transport, and fate of organic matter, chemical tracers, and pollutants in the Southern California Bight. The study area, adjacent to Los Angeles, was of programmatic interest due to its heavy concentration of energy-related activities, including offshore oil drilling and natural seeps, shipping, nuclear power facilities, and industrial and municipal ocean waste disposal. It was also of scientific interest because the wide continental margin in the region, potmarked with natural sediment traps in the form of deep basins with restricted inputs and outputs, was ideal for integrating water-column and benthic studies and tracing the fates of in situ production and introduced pollutants. Our role in the CABS Program was to investigate the flux of particulate matter through the water column, emphasizing the relationship between macrozooplankton feeding and particle flux.
AN: 3551577
42 of 126
TI: Field evaluation of a valved sediment trap
AU: Peterson,-M.L.; Hernes,-P.J.; Thoreson,-D.S.; Hedges,-J.I.; Lee,-C.; Wakeham,-S.G.
AF: Sch. Oceanogr., WB-10, Univ. Washington, Seattle WA 98195, USA
SO: LIMNOL.-OCEANOGR. 1993 vol. 38, no. 8, pp. 1741-1761
LA: English
ER: M (Marine)
AB: An internally valved sediment trap designed to isolate sinking particulate matter from free-swimming animals, temporally subsample particle flux, and minimize washout of solid and dissolved material is described. The trap is controlled by a single microprocessor capable of supporting multiple traps as well as other instrumentation on a single array. Test deployments of valved and nonvalved control traps, along with three other conventional cylindrical trap designs, were undertaken during a series of six 1-week experiments in Dabob Bay, Washington. Treated traps containing biocide-spiked (HgCl sub(2) or Formalin) bottom brine layers (80ppt NaCl brine), brine layers alone, and only seawater (untreated) were deployed on multitrap arrays. Fluxes of material >850 mu m in size (almost exclusively large zooplankton) caught in biocide- and brine-treated valved traps were reduced by an average of 88% relative to non-valved control traps; all other open traps collected >850- mu m fluxes equivalent to controls. The type of treatment had a significant effect on the >850- mu m mass flux, with Formalin-treated traps >HgCl sub(2) similar to NaCl brine >> untreated. Fluxes of <850- mu m material were reduced in treated valved traps and averaged 39% less than fluxes caught in VERTEX-style particle interceptor traps. Organic C:total N ratios were higher in material caught in valved traps than in all other types, primarily due to reduced nitrogen fluxes. Reduced fluxes of the primarily autochthonous biochemicals (pigments, amino acids, and lipids) measured by valved relative to control traps indicate significant exclusion (>80%) of zooplankton <850 mu m from valved traps.
AN: 3547242
43 of 126
TI: Hydrodynamic impediments to settlement of marine propagules, and adhesive-filament solutions
AU: Loya,-Y.; Weihs,-D.; Abelson,-A.*
AF: Hopkins Mar. Stn., Stanford Univ., Pacific Grove, CA 93950-3094, USA
SO: LIMNOL.-OCEANOGR. 1994 vol. 39, no. 1, pp. 164-169
LA: English
ER: M (Marine)
AB: "Protruding bodies," such as kelp stems, seagrasses filiform algae, artificial reefs, and engineered structures, constitute substrata for proliferation of benthic communities of great ecological and economical importance. Unfortunately, very little is known of hydrodynamic aspects of settlement in such habitats. Based on flow-tank experiments and theoretical considerations, we discuss hydrodynamic interference with settlement of larvae on protruding-body habitats. We suggest that larvae may overcome these interferences by producing mucous threads up to 100 body lengths in size. These adhesive threads enable propagules of suspension feeders to settle in environments of high food-particle flux and flow sedimentation rate. The results suggests that hydrodynamic impediments to encounter play a major role in determining the spatial distribution of benthic species on protruding bodies by favoring propagules of species with such adhesive devices.
AN: 3545324
44 of 126
TI: [North Atlantic 92 Cruise No. 21, 16 March - 31 August 1992.]
OT: Nordatlantik 92 Reise Nr. 21, 16. Maerz - 31. August 1992
AU: Pfannkuche,-O.; Duinker,-J.C.; Graf,-G.; Henrich,-R.; Thiel,-H.; Zeitzschel,-B.-(eds.)
SO: METEOR-BER. HAMBURG-FRG LEITSTELLE-METEOR.-INST.-FUER-MEERESKUNDE 1993 no. 93-4, 281 pp
LA: German
ER: M (Marine)
AB: The 21 super(st) expedition of RV METEOR led into the eastern North Atlantic. Research was carried out between Madeira and the Svalbard Archipelago. The expedition was divided into 6 legs. The main objective on four legs which concentrated on the area between Madeira and Iceland was the investigation of the oceanic flux of greenhouse gases. The investigations carried out by the German groups of the Joint Global Ocean Flux Study (JGOFS) will provide data for the creation and verification of models for climatic changes. Physical, chemical, and biological investigations were concentrated to a transect along 20 degree W and to a time series station in the BIOTRANS area at 47 degree N, 20 degree W. The investigations focussed on the fluxes of greenhouse gases between the ocean's upper mixed layer and the atmosphere, the chemical and biological carbon dioxide fixation on the cycling of carbon in the epipelagial as well as the flux of sedimented particulate organic carbon in the deep-sea benthic boundary zone. Two legs were restricted to investigations in the Norwegian, Greenland and Barents Sea. The programmes were carried out by the Sonderforschungsbereich 313 of the Kiel University. Apart from investigations on the vertical particle flux influenced by pelagic processes, station work focussed on studies of the lateral particle transport, on processes in the bottom near nepheloid layer, and on fluxes in the benthic boundary layer. On the basis of already available data on recent sediment formation processes and partly in analogy with these investigations, it is intended to reconstruct the history of the marine environment.
AN: 3536674
45 of 126
TI: Effects of spatial and temporal scale on the relationship of surface pigment biomass to community structure in the deep-sea benthos
AU: Watts,-M.C.; Etter,-R.J.; Rex,-M.A.
AF: Dep. Biol., Univ. Massachusetts, Boston, MA 02125, USA
CO: NATO Advanced Research Workshop, College Station, TX (USA), 2-6 Apr 1991
SO: DEEP-SEA-FOOD-CHAINS-AND-THE-GLOBAL-CARBON-CYCLE. Rowe,-G.T.;Pariente,-V.-eds. DORDRECHT-NETHERLANDS KLUWER-ACADEMIC-PUBLISHERS 1992 vol. 360 pp. 245-254
ST: NATO-ASI-SER.-SER.-C:-MATH.-PHYS.-SCI. vol. 360
LA: English
ER: M (Marine)
AB: A problem of fundamental importance in deep-sea ecology has been to quantify the relationship between surface production and benthic community structure over spatial and temporal scales that include major variation in both surface and benthic ecosystems. Recent experimental and observational research on particle flux has suggested that benthic and surface communities may be directly coupled on short-term local scales. How small-scale effects become integrated into large-scale patterns of benthic community structure is still unclear. In this paper, we examine the relationship between large-scale variability in deep-sea benthic community structure and mesoscale surface pigment biomass estimated by the Nimbus-7 Coastal Zone Color Scanner. Measures of benthic community structure included macrofaunal density and biomass, and species diversity of four important macrofaunal taxa (the Polychaeta, Gastropoda, Cumacea and Bivalvia). Surface pigment biomass directly above the benthic sampling stations was averaged monthly and seasonally over a three-year period at three spatial scales corresponding to square areas of 1, 9 and 121 pixels (0.83, 7.43 and 99.83 km super(2) respectively). Benthic biomass and density are significantly and positively correlated with surface pigment biomass. Species diversity is significantly predicted by second degree polynomial regression models indicating a parabolic relationship with peak diversity at intermediate values of surface pigment biomass. Relationships between community structure and surface pigment biomass closely resemble those between community structure and depth. When we statistically remove the effect of depth by partial correlation analysis, measures of benthic community structure become either uncorrelated or only weakly correlated with surface pigment biomass. The results suggest that surface and benthic communities are largely decoupled by depth-related processes in the water column or within bottom communities.
AN: 3531310
46 of 126
TI: Annual biogenic particle fluxes to the interior of the North Atlantic Ocean; studied at 34 degree N 21 degree W and 48 degree N 21 degree W
AU: Honjo,-S.; Manganini,-S.J.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02453, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 587-607
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: In order to clarify the annual quality, quantity and export process of biogenic particles from the euphotic zone to the deep ocean interior, an array of automated time-series sediment traps were deployed for 1 year from 4 April 1989 to 17 April 1990 at 34 degree N 21 degree W and 48 degree N 21 degree W as part of the Joint Global Ocean Flux Program (JGOFS) North Atlantic Bloom Experiment (NABE). Three sediment traps with 13 time-series sediment collectors were placed at both stations approximately 1 and 2 km below the surface and 0.7 km above the bottom. They collected settling particles during 26 14-day intervals for 376 days with an 20-day hiatus in September-October 1989 for changeover of the trap moorings. The collection periods of the six traps were synchronized, forming a spatio-temporal matrix of 156 samples. The annual mass flux at about 2 km deep during this experiment was 22 and 27 g/m super(2)/y at the 34 and 48 degree N stations, consisting of biogenic particles with traceable quantities of lithogenic particle flux. The spring particle bloom, characterized by the sedimentation of particles relatively enriched by N sub(org), began in January at the 34 degree N station and in March at the 48 degree N station. The bloom continued for 4.5 and 3 months and provided 62 and 50% of the annual biogenic particle mass flux at 2 km at the 34 and 48 degree N stations. The surface bloom penetrated to the ocean interior within a few weeks, with apparently accelerated settling speed at deeper layers. The order of susceptibility of biogenic elements to mineralization while settling in the 1-0.7 km a.b. water column was, from least to most resistant: P, N sub(org), C sub(org), Si and Ca. The C/N/P ratio at 0.7 km a.b. was 154 : 18 : 1 at the 34 degree N station and 148 : 18 : 1 at the 48 degree N station.
AN: 3530699
47 of 126
TI: The role of plankton in particle flux: Two case studies from the Northeast Atlantic
AU: Passow,-U.; Peinert,-R.
AF: Mar. Sci. Inst., Univ. California, Santa Barbara, CA 93106-6150, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 573-585
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: The relationship between the vertical flux of microplankton and its standing stock in the upper ocean was determined in the subtropical (33 degree N, 21 degree W) and tropical (18 degree N, 30 degree W) northeast Atlantic in spring 1989 as part of the North Atlantic Bloom Experiment. In the subtropical area specific sedimentation rates at all depths were low (0.1% of standing stock) and 10-20% of settled particulate organic carbon (POC) was viable diatoms. The high contribution of viable diatoms, their empty frustules and tintinnid loricae to settled material characterized a system in transition between a diatom bloom sedimentation event and an oligotrophic summer situation. In the tropical area specific sedimentation rates were similar, but absolute rates (3 mg C/m super(2)/day) were only about a third of those in the subtropical area. Microplankton carbon contributed only 2-6% to POC. Hard parts of heterotrophs found embedded in amorphous detrital matter suggest that particles had passed through a complex food web prior to sedimentation. Coccolithophorids, not diatoms dominated the autotrophic fraction in traps, and a shift in the composition of autotrophs may indicate a perturbation of the oligotrophic system.
AN: 3530698
48 of 126
TI: Mesozooplankton standing stock during the North Atlantic spring bloom study in 1989 and its potential grazing pressure on phytoplankton: A comparison between low, medium and high latitudes
AU: Lenz,-J.; Morales,-A.; Gunkel,-J.
AF: Inst. Meereskd., Univ. Kiel, Duesternbrooker Weg 20, 2300 Kiel 1, FRG
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 559-572
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Within the framework of the JGOFS Pilot Study in 1989 mesozooplankton (0.2-20 mm) was sampled by means of a Hydro-Bios multinet in five depth strata (0-25, 25-50, 50-100, 100-200, 200-500 m) during four Lagrangian drift experiments of 8-14 days' duration at 18, 33, 46 and 58 degree N, to follow the seasonal progress of the phytoplankton spring bloom development in the northeast Atlantic. Mesozooplankton standing stock, measured as dry weight and ash-free dry weight, increased by a factor of about 6 from 18 to 58 degree N. Day/night differences amounted to 10-20% of the average and were-with one exception at 18 degree N-not statistically significant. Using the data on weight-specific respiration rates measured by colleagues on the same cruise, the ingestion rates and potential community grazing of mesozooplankton on phytoplankton within the upper 100 m of the water column were calculated. During all four drift experiments, quasi-steady-state conditions were observed in phyto- and zooplankton standing stock, primary production and daily sedimentation at 100 m depth. The maximum potential grazing rate by mesozooplankton accounted for about half of the daily primary production. Since sedimentation of fresh phytoplankton was negligible, it is concluded that the grazing pressure exercised by mesozooplankton together with micro- and nanozooplankton was responsible for keeping the phytoplankton standing stock at a more or less constant level during the investigated spring bloom in the four areas. Particle flux was thus dominated by zooplankton faecal material.
AN: 3530697
49 of 126
TI: Biogenic flux of A1 to sediment in the central equatorial Pacific Ocean: Evidence for increased productivity during glacial periods
AU: Murray,-R.W.; Leinen,-M.; Isern,-A.R.
AF: Dep. Earth Sci., Boston Univ., Boston, MA, USA
SO: PALEOCEANOGRAPHY 1993 vol. 8, no. 5, pp. 651-670
LA: English
ER: M (Marine)
AB: We examined the flux of A1 to sediment accumulating beneath the zone of elevated productivity in the central equatorial Pacific Ocean, along a surface sediment transect at 135 degree W as well as downcore for a 650 kyr record at 1.3 degree N, 133.6 degree W. Across the surface transect, a pronounced, broadly equatorially symmetric increase in A1 accumulation is observed, relative to Ti, with A1/Ti ratios reaching values 3-4 times that of potential detrital sources. The profile parallels biogenic accumulation and the modeled flux of particulate super(234)Th, suggesting rapid and preferential adsorptive removal of A1 from seawater by settling biogenic particles. Normative calculations confirm that most A1 is unsupported by the terrigenous fraction. The observed distributions are consistent with previous observations of the relative and absolute behavior of A1 and Ti in seawater, and we can construct a reasonable mass balance between the amount of seawater-sourced A1 retained in the sediment and the amount of seawater A1 available in the overlying column. The close tie between A1/Ti and biogenic accumulation (as opposed to concentration) emphasizes that biogenic sedimentary A1/Ti responds to removal-transport phenomena and not bulk sediment composition. Thus, in these sediments dominated by the biogenic component, the bulk A1/Ti ratio reflects biogenic particle flux, and by extension, productivity of the overlying seawater.
AN: 3525974
50 of 126
TI: Seasonal patterns of vertical particle flux in equatorial and coastal upwelling areas of the eastern Atlantic
AU: Wefer,-G.; Fischer,-G.
AF: Fachbereich Geowissenschaft., Klagenfurter Str., Univ. Bremen, 28359 Bremen, FRG
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1993 vol. 40, no. 8, pp. 1613-1645
LA: English
ER: M (Marine)
AB: Eight time-series sediment traps were deployed on moored arrays of Mauritania (Cap Blanc), in the northern and southern Guinea Basin, and off Namibia (Walvis Ridge). The highest total fluxes, as well as carbonate and biogenic opal fluxes were recorded at the two coastal sites, off Mauritania and off Namibia, respectively. Intermediate rates were recorded north and low rates south of the equator. Surprisingly, carbonate-producing organisms dominated total fluxes at all sites, whereas biogenic opal was only a minor contributor. The most distinct flux maxima were in July-August both at the Cap Blanc and the northern Guinea Basin site (2 degree N). Carbonate fluxes also peaked during that period. In contrast, highest opal fluxes were measured there in late winter/early spring.
AN: 3509979
51 of 126
TI: Reply to the comment by Jackson (zooplankton and particle flux below the euphotic zone)
AU: Najjar,-R.G.; Toggweiler,-J.R.
AF: Natl. Cent. Atmos. Res., P.O. Box 3000, Boulder, CO 80307, USA
SO: LIMNOL.-OCEANOGR. 1993 vol. 38, no. 6, pp. 1331-1332
LA: English
ER: M (Marine)
AB: In his comment concerning zooplankton and their relationship to the particle flux below the euphotic zone, Jackson (1993) suggests that the assumption of a constant remineralization length scale is important with regard to the conclusions of these modeling studies. In particular, he suggests that a shorter remineralization length scale in regions of higher productivity (where animal populations are greater) would improve simulation of the nutrient distribution. We disagree.
AN: 3034866
52 of 126
TI: Growth and competitive ability of an encrusting bryozoan in the Gulf of Maine: Effects of current speed and particle concentration
AU: Genoyese,-S.J.; Wjtman,-J.D.
AF: Mar. Sci. Cent., Northeastern Univ., Nahant, MA 01908, USA
CO: Annu. Meet. of the American Soc. of Zoology, American Microscopical Soc., Animal Behavior Soc., the Crustacean Soc., and the Int. Assoc. of Astacology, Atlanta, GA (USA), 27-29 Dec 1991
SO: AM.-ZOOL. 1991 vol. 31, no. 5, p. 144A
NT: Summary only.
LA: English
ER: M (Marine)
AB: Parasmitina jeffreysi is an encrusting bryozoan commonly found on deep ( greater than or equal to 30m) subtidal, rock walls throughout the Gulf of Maine, This facultatively active suspension feeder appears to be a top competitor for space (via overgrowth) in these epifaunal communities, reaching local densities of 28 colonies per 0.04 m super(2), with 25% cover. Colonies were measured photographically over a two-year period to test the hypothesis that differences in growth rate for this bryozoan correspond to differences in either of the two components of particle flux, current velocity and particle concentration. Two offshore sites characterized by high flow speed (x = 24 cm/s) and comparitively low phytoplankton concentration will be compared to two coastal sites with low current velocity (x = 8 cm/s) and high phytoplankton concentration. In addition, sediment load on vertical walls and sedimentation rates at the study sites were measured to determine if a negative correlation exists between either of these factors and growth rate. Finally, competitive interactions between P. jeffreysi and other community members will be compared at both coastal and offshore sites.
AN: 3030231
53 of 126
TI: Primary ocean production: Carbon and particle flux.
OT: Production primaire oceanique: Flux de carbone et de particules
AU: Morel,-A.
CA: Paris-6 Univ. (France)
SO: 1990 8 pp
NT: NTIS Order No.: N91-23596/0/GAR.
LA: French
ER: M (Marine)
AB: The role of the ocean and its vegetation with regard to the carbon and other cycles is discussed. Comprehension of the flux between the atmosphere and the ocean in stationary conditions at the interface and at the interior of the ocean is considered. Present incertitudes with regard to the marine biomass carbon content, the flux entering, the net carbon flux at the base of the superficial layer, and the flux in a column of water down to the sediment are presented. Possible progressions are given. (In Esa, Space and Sea p 233-240.)
AN: 3023004
54 of 126
TI: Enhanced particle flux through the biodeposition by the Antarctic suspension-feeding bivalve Laternula elliptica in Marian Cove, King George Island
AU: Ahn,-In-Young
AF: Polar Ecol. Lab., Polar Res. Cent., Korea Ocean Res. and Dev. Inst., Ansan, P.O. Box 29, Seoul 425-600, South Korea
SO: J.-EXP.-MAR.-BIOL.-ECOL. 1993 vol. 171, no. 1, pp. 75-90
LA: English
ER: M (Marine)
AB: The infaunal lamellibranch Laternula elliptica (Laternulidae), one of the most Antarctic bivalves, is widely distributed in shallow waters around the Antarctic Continent. In order to evaluate the contribution of this species to organic carbon flux in an Antarctic coastal ecosystem, biodeposition rates by L. elliptica were measured and compared with sedimentation without this bivalve species in laboratory experiments during one austral summer. The amount of deposited material increased in the presence of L. elliptica. Weight-specific biodeposition rates varied from 0.26 to 2.17 mg dry wt/g wet wt/d and the rate decreased with increase in body weight. Due to massive inflows of terrigenous sediment through coastal meltwater stream into the coastal water, fecal and pseudofecal material contained a considerable amount of mineral particles and only a small percentage of organic carbon (1.6-5.2%). Estimated particulate organic carbon flux through the biodeposition of L. elliptica is [95 mg C/m super(2)/d, an amount comparable to that of a typical suspension-feeding bivalve, Mytilus edulis, L. elliptica is apparently an important agent for sedimentation of both lithogenic particles and organic particles. Thus, this study suggests that L. elliptica play an important role in enhancing particle flux from water column to sea bed through biodeposition and possibly nourishing other benthic fauna, particularly in phytoplankton-impoverished nearshore waters.
AN: 3018639
55 of 126
TI: Marine and terrigenous origin of organic matter in modern sediments of the Equatorial East Atlantic: The delta super(13)C and molecular record.
AU: Westerhausen,-L.; Poynter,-J.; Eglinton,-G.; Erlenkeuser,-H.; Sarnthein,-M.
AF: Geol.-Palaeontol. Inst., Univ., Olshausenstr. 40, D-2300 Kiel, FRG
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP.. 1993. vol. 40, no. 5, pp. 1087-1121
LA: English
ER: M (Marine)
AB: The contributions of marine and terrigenous organic carbon in modern organic sediments from the equatorial East Atlantic was quantified, based on the stable carbon isotope composition standardized for sea surface temperature and water depth. In our binary delta super(13)C mixing model, the marine end member (-21.5 ppt) is redefined at 23 degree C and 0 m water depth and the terrigenous end member, independent of SST and water depth, at -26 ppt. Terrigenous carbon fractions account for more than 60% of total organic carbon (TOC) on the shelf off East Liberia and the Ivory Coast and off Gabon. On the upper slope the land-derived fraction decreases in general to less than 20% of the high TOC concentrations, which can reach 3.5 wt%. The distribution of plant wax n-alkanes (C sub(27), C sub(29), C sub(31)) and C:N ratios do not parallel those of land-derived organic carbon, but may be controlled largely by carbon degradation and aeolian/aquatic sorting. The ratio of n-alkanols vs n-alkanes (HPA index) varies with water depth in a non-linear mode. Since both groups of compounds stem from the same source, plant waxes, it is proposed that the HPA index is controlled mainly by degradation and to a lesser extent by sorting prior to degradation. Enhanced n-alkane concentrations (up to 580 mu g/gTOC) in the Gambia Basin and in the central Guinea Basin clearly reflect the influx of aeolian organic matter from northeasterly trades near and below the Inter Tropical Convergence Zone (ITCZ). The particle flux from marine plankton is traced by high concentrations of both dinosterol, long-chain unsaturated methyl and ethyl ketones (C sub(37)-C sub(39)), and alkandiols in marine organic matter. Whereas alkenones, synthesized by prymnesiophyte algae generally, reflect upwelling-related productivity off-shore, dinosterol, synthesized by dinoflagellates, is enriched in near-shore areas of high marine productivity linked to fluvial fertilization. All marine biomarker groups show a surprisingly low concentration below the equatorial high productivity belt.
AN: 2989127
56 of 126
TI: Boundary scavenging and deep-sea sediment dating: Constraints from excess super(230)Th and super(231)Pa.
AU: Lao,-Yong; Anderson,-R.F.; Broecker,-W.S.
AF: Lamont-Doherty Geol. Obs., Columbia Univ., Palisades, NY 10027, USA
SO: PALEOCEANOGRAPHY. 1992. vol. 7, no. 6, pp. 783-798
LA: English
ER: M (Marine)
AB: Apparent sedimentation rates derived from excess super(230)Th and super(231)Pa in deep-sea sediments accumulated during the last 25,000 years in the Pacific Ocean are mostly lower than the average rates determined by other independent (such as super(14)C and partial differential super(18)O) dating methods, which may be a consequence of generally higher accumulation rates of aluminosilicate and carbonate during the last glacial that diluted the excess super(230)Th and super(231)Pa activities in glacial sediments. The pattern of enhanced scavenging of nuclides in ocean margin areas (i.e., boundary scavenging) also changed from the glacial to the Holocene. Fluxes of super(230)Th and super(231)Pa throughout the ocean varied over time responding to changes in the nature and intensity of boundary scavenging which, in turn, were influenced by changes in particle flux and particle composition. The lower intensity of boundary scavenging of super(231)Pa during the last glacial may also have contributed to the lower apparent sediment accumulation rates based on excess super(231)Pa for cores in ocean margin areas.
AN: 2987884
57 of 126
TI: Interactions between metazoans and large, agglutinating protozoans: Implications for the community structure of deep-sea benthos.
AU: Levin,-L.A.
AF: Dep. Mar., Earth, and Atmos. Sci., North Carolina State Univ., Raleigh, NC 27695-8208, USA
CO: Symposium on New Perspectives in Soft-Sediment Ecology at Annual Meeting of the American Society of Zoologists, San Antonio, TX (USA), 27-30 Dec 1990
SO: AM.-ZOOL. 1991. vol. 31, no. 6, pp. 886-900
LA: English
ER: M (Marine)
AB: Large, agglutinating protozoans belonging to the Foraminiferida (suborder Astrorhizina) and the Xenophyophorea are conspicuous, often dominant faunal elements in the deep sea. A review of known and suspected interactions between these forms and metazoans reveals a potentially significant role for the protozoans in structuring deep-sea metazoan assemblages. Direct interactions include provision to metazoans of (a) hard or stable substratum, (b) refuge from predators or physical disturbance, and (c) access to enhanced dietary resources. In some instances, rhizopod tests may provide a nursery function. Xenophyophore modification of flow regimes, particle flux, bottom skin friction and sediment characteristics appear likely and are believed to account for altered composition and abundance of meiofauna and macrofauna in the vicinity of rhizopod tests. Some analogous interactions are observed between metazoans and biogenic sediment structures in shallow water. However, metazoan-rhizopod associations are hypothesized to be more highly developed and complex in the deep sea than are comparable shallow-water associations, due to rhizopod abilities to enhance scarce food resources and to low rates of disturbance in much of the deep sea. Agglutinating rhizopods appear to be a significant source of heterogeneity on the deep-sea floor and large tests often represent "hotspots" of metazoan activity. As such, they are hypothesized to have contributed to the origin and maintenance of metazoan diversity in the deep sea by providing distinct microenvironments in which species can specialize.
AN: 2953420
58 of 126
TI: Enhanced deposition to pits: A local food source for benthos.
AU: Yager,-P.L.; Nowell,-A.R.M.; Jumars,-P.A.
AF: Sch. Oceanogr., WB-10, Univ. Washington, Seattle, WA 98195, USA
SO: J.-MAR.-RES. 1993. vol. 51, no. 1, pp. 209-236
LA: English
ER: M (Marine)
AB: Particle deposition experiments using mimics of biogenous negative relief ("pits") and low-excess-density particles in a small annular flume indicate a significantly enhanced deposition rate (number of particles per time) compared to smooth, flat patches of the same diameter. This study included flow visualizations as well as observations of particle residence times, particle concentrations in the pits, and particle fluxes to the pits from the main flow. Experimental conditions of particle concentration, shear velocity, and particle settling velocity mimicked the dynamic characteristics (low excess density and large size) of organic-rich flocs and flow conditions in the subtidal and deep sea where biogenous pits are common features. Results suggest that pits provide benthic organisms an important capture mechanism for such flocs. Flow visualizations concur qualitatively with previously reported results for two-dimensional cavity flow, with unique features due to the conical shape of the pits. When the Rouse number (settling velocity/shear velocity) was much less than 1, pit deposition rate increased with increasing pit aspect ratio (AR = depth/diameter; ranging from 0.25 to 2) and always exceeded deposition to a flat patch of comparable diameter. For the single aspect ratio tested (AR = 0.5) under conditions of increasing turbulence, deposition to the pit increased under transitional flow, but then decreased to near zero when conditions reached fully rough flow. Relative enhancement of deposition to this pit decreased with increased ambient bed roughness since gravel beds also effectively collect particles. Particle concentration inside pits decreased weakly with pit aspect ratio but greatly increased with increasing roughness Reynolds number. Particle residence time increased somewhat with pit aspect ratio but decreased significantly with increasing roughness Reynolds number. Particle flux into pits from the main flow increased with both increasing aspect ratio and increasing roughness Reynolds number. Enhancement of food supply to pit inhabitants thus depends on the flow regime.
AN: 2933142
59 of 126
TI: Boundary scavenging and deep-sea sediment dating: Constraints from excess super(230)Th and super(231)Pa.
AU: Lao,-Y.; Anderson,-R.F.; Broecker,-W.S.
AF: Lamont-Doherty Geol. Obs., Columbia Univ., Palisades, NY, USA
SO: PALEOCEANOGRAPHY. 1992. vol. 7, no. 6, pp. 783-798
LA: English
ER: M (Marine)
AB: Apparent sedimentation rates derived from excess super(230)Th and super(231)Pa in deep-sea sediments accumulated during the last 25,000 years in the Pacific Ocean are mostly lower than the average rates determined by other independent (such as super(14)C and partial differential super(18)O) dating methods, which many be a consequence of generally higher accumulation rates of aluminosilicate and carbonate during the last glacial that diluted the excess super(230)Th and super(231)Pa activities in glacial sediments. The pattern of enhanced scavenging of nuclides in ocean margin areas (i.e., boundary scavenging) also changed from the glacial to the Holocene. Fluxes of super(230)Th and super(231)Pa throughout the ocean varied over time responding to changes in the nature and intensity of boundary scavenging which, in turn, were influenced by changes in particle flux and particle composition. The lower intensity of boundary scavenging of super(231)Pa during the last glacial may also have contributed to the lower apparent sediment accumulation rates based on excess super(231)Pa for cores in ocean margin areas.
AN: 2927797
60 of 126
TI: super(231)Pa/ super(230)Th ratios in sediments as a proxy for past changes in Southern Ocean productivity.
AU: Kumar,-N.; Gwiazda,-R.; Anderson,-R.F.; Froelich,-P.N.
AF: Lamont-Doherty Earth Obs., Columbia Univ., Palisades, NY 10964, USA
SO: NATURE. 1993. vol. 362, no. 6415, pp. 45-48
LA: English
ER: M (Marine)
AB: The biological productivity of the oceans is sensitive to changes in climate, which can affect essential factors such as nutrient and light availability. In turn, ocean productivity may influence climate by regulating the partitioning of carbon dioxide, a greenhouse gas, between the ocean and the atmosphere. Investigators have attempted to link variations in atmospheric CO sub(2) content, recorded in ice cores, to the productivity of the Southern Ocean, but an unambiguous means of assessing past changes in ocean productivity has been lacking. Here we exploit established relationships between super(231)Pa/ super(230)Th ratios and particle flux to infer, from the analysis of dated sediment cores, variability through time of fluxes of particulate biogenic material exported from surface waters. Records from two cores in the Atlantic sector of the Southern Ocean indicate that ocean productivity during glacial periods was lower than at present south of the Antarctic polar front, and support earlier conclusions that the zone of maximum productivity migrated northwards during glacial conditions. Although further work at other sites is needed for an assessment of changes in total Antarctic productivity, our technique has the potential to provide this information while avoiding some of the limitations of other productivity proxies.
AN: 2906515
61 of 126
TI: Suspended sediment transport in the surf zone: Response to incident wave and longshore current interaction.
AU: Beach,-R.A.; Sternberg,-R.W.
AF: Sch. Oceanogr., WB-10, Univ. Washington, Seattle, WA 98195, USA
SO: MAR.-GEOL. 1992. vol. 108, no. 3-4, pp. 275-294
LA: English
ER: M (Marine)
AB: This paper reports the results of a field experiment carried out in the inner surf zone of a dissipative beach at San Marine, Oregon, in 1984. Observations were made at a location 70 m seaward of the mean high water line (mean depth 1.3 m) during a period when significant offshore wave heights were 3-5 m and the surf zone was 500 m wide. Instruments were deployed in a closely spaced array and measurements included cross-shore and longshore velocity, sea surface fluctuations, and sediment concentration profiles. The results reported in this paper are from a particular 44-min data run characterized by high waves and strong longshore currents. In the first section of this paper the field measurements are summarized to provide insight into the resuspension process and observed sediment concentrations and fluxes on time scales including incident and infragravity bands, and mean values for the entire data set. In the second section a numerical model is presented that incorporates the nonlinear interaction of waves and currents and calculates velocity profiles, boundary shear stress, suspended sediment profiles, and longshore and cross-shore particle flux over 0.5 g intervals throughout the time series. Finally, model calculations of mean suspended load and net longshore and cross-shore flux of sediment are compared to observations. The results show that the model calculates mean suspended load and net longshore and cross-shore flux of sediment within a factor of two of the observations. The model suggests that, for this data set, incident waves and longshore currents contribute equally to the suspended load. For the longshore particle flux, the current contribution is approximately 1.7 times the wave contribution (63% vs 37%), primarily because currents carry suspended sediment higher in the water column where it is advected by stronger longshore currents. Additionally, model results suggest that wave/current interactions enhance suspended sediment load and longshore sand transport by approximately 50-60% over the transport forced by waves alone.
AN: 2883327
62 of 126
TI: The relationship between physical aggregation of phytoplankton and particle flux: A numerical model.
AU: Riebesell,-U.; Wolf-Gladrow,-D.A.
AF: Alfred Wegener Inst. Polar and Mar. Res., D-2850 Bremerhaven, FRG
SO: DEEP-SEA-RES. 1992. vol. 39, no. 7-8A, pp. 1085-1102
LA: English
ER: M (Marine)
AB: Since large, rapidly-sinking particles account for most of the vertical flux in the ocean, mechanisms responsible for particle aggregation largely control the transport of carbon to depth. The particle flux resulting from a variety of different phytoplankton bloom conditions was simulated with a numerical model in which phytoplankton growth dynamics were combined with physical aggregation, particle size-dependent sedimentation and degradation. Model results demonstrate that particle flux to the deep ocean can be generated by solely invoking physical aggregation during phytoplankton blooms. Sensitivity of the model in response to variations of both physico-chemical and biological parameters was tested. The model outcome, described as the fraction of export production leaving the upper ocean carbon pool, proved to be most sensitive to biological variables such as phytoplankton cell size, stickiness, and growth characteristics (i.e. solitary vs chain-forming). Changes in these factors strongly affect the efficiency of the "biological pump" and could explain interannual and geographic variance in deep-ocean flux.
AN: 2874802
63 of 126
TI: Seasonal variability in primary production and particle flux in the northwestern Sargasso Sea: U.S. JGOFS Bermuda Atlantic Time-Series Study.
AU: Lohrenz,-S.E.; Knauer,-G.A.; Asper,-V.L.; Tuel,-M.; Michaels,-A.F.; Knap,-A.H.
AF: Univ. Southern Mississippi, Cent. Mar. Sci., Stennis Space Cent., MS 39529, USA
SO: DEEP-SEA-RES. 1992. vol. 39, no. 7-8A, pp. 1373-1391
LA: English
ER: M (Marine)
AB: The relationship between primary production and sediment trap-derived downward flux of particulate organic matter was characterized over a 2 year period at the U.S. JGOFS Bermuda Atlantic Time-series Study (BATS) site to evaluate the importance of temporal variations in upper ocean biogeochemical processes. Water column-integrated primary production ( integral of PP), determined once each cruise using super(14)C incubations (in situ dawn-to-dusk), peaked in late winter/early spring of both 1989 and 1990. Smaller increases in integral of PP also occurred in July 1989 and October-December 1990. Annual integral of PP was 9.2 mol C m super(-2)/y in 1989 and 12 mol C m super(-2)/y in 1990. This was higher than the 1959-1963 annual average (6.8 mol C m super(-2)/y) determined at Station "S" located approximately 50 km northwest of the BATS site.
AN: 2865866
64 of 126
TI: Particle flux in the ocean: Effects of episodic production.
AU: Wefer,-G.
AF: Geowissensch., Univ. Bremen, 2800 Bremen 33, FRG
CO: Dahlem Workshop on Productivity of the Ocean: Present and Past, Berlin (Germany), 24-29 Apr 1988
SO: PRODUCTIVITY-OF-THE-OCEAN:-PRESENT-AND-PAST.-REPORT-OF-THE-DAHLEM-WORKSHOP-ON-PRODUCTIVITY-OF-THE-OCEAN:-PRESENT-AND-PAST,-BERLIN-1988,-APRIL-24-29. Berger,-W.H.;Smetacek,-V.S.;Wefer,-G.-eds. CHICHESTER-UK WILEY-INTERSCIENCE-PUBL. 1989. no. 44 pp. 139-154
ST: LIFE-SCI.-RES.-PAP. no. 44
LA: English
ER: M (Marine)
AB: Present knowledge on seasonal particle sedimentation in deep-sea environments, based on experiments with trap deployment times of one year and longer, is summarized. All experiments showed seasonal flux variations related to biological processes in the surface waters. At some locations, flux maxima are the results of bloom periods of single plankton species. Grazing by zooplankton is an important process in generating particle flux from primary production. A large variability exists in total flux and composition between the trap experiments. Total annual flux varies over a factor of 300, between about 0.3 g m super(-2)/yr in the Weddell Sea to > 100 g m super(-2)/yr in high production areas such as the Panama Basin, the Bransfield Strait, and the Black Sea.
AN: 2846082
65 of 126
TI: Regional extremes in particulate matter composition and flux: Effects on the chemistry of the ocean interior.
AU: Bishop,-J.K.B.
AF: Lamont-Doherty Geol. Obs., Columbia Univ., Palisades, NY 10964, USA
CO: Dahlem Workshop on Productivity of the Ocean: Present and Past, Berlin (Germany), 24-29 Apr 1988
SO: PRODUCTIVITY-OF-THE-OCEAN:-PRESENT-AND-PAST.-REPORT-OF-THE-DAHLEM-WORKSHOP-ON-PRODUCTIVITY-OF-THE-OCEAN:-PRESENT-AND-PAST,-BERLIN-1988,-APRIL-24-29. Berger,-W.H.;Smetacek,-V.S.;Wefer,-G.-eds. CHICHESTER-UK WILEY-INTERSCIENCE-PUBL. 1989. no. 44 pp. 117-137
ST: LIFE-SCI.-RES.-PAP. no. 44
LA: English
ER: M (Marine)
AB: This paper reviews what is known about productivity patterns and vertical flux of organic carbon, opal, and carbonate in the biologically active upper 100-2000 m of the ocean. The ability to model particulate carbon flux as a function of depth and primary productivity is much worse than the ability to model particulate carbon flux and regeneration rates as a function of depth once the particulate carbon flux at 100 m is known. A major term missing in equations linking primary production and particle flux appears to be one describing the consumption of particles by macrozooplankton and other large animals.
AN: 2846068
66 of 126
TI: Transport and burial rates of super(10)Be and super(231)Pa in the Pacific Ocean during the Holocene period.
AU: Lao,-Y.; Anderson,-R.F.; Broecker,-W.S.; Trumbore,-S.E.; Hofmann,-H.J.; Wolfli,-W.
AF: Lamont-Doherty Geol. Obs., Columbia Univ., Palisades, NY 10964, USA
SO: EARTH-PLANET.-SCI.-LETT. 1992. vol. 113, no. 1-2, pp. 173-189
LA: English
ER: M (Marine)
AB: An ocean-wide study of the rates of removal of super(10)Be and super(231)Pa in the Pacific Ocean has identified intensified scavenging of the super(10)Be and super(231)Pa in several ocean margin area, including the Northeastern and Northwestern Pacific, the Bering Sea, the Eastern Equatorial Pacific and the South Pacific Ocean. Scavenging rates of super(10)Be and super(231)Pa are clearly correlated to particle flux. Principal component analysis further suggest that scavenging of super(10)Be and super(231)Pa may be related to opal productivity in surface waters. A simple box model constructed to partition the deposition of super(230)Th, super(231)Pa and super(10)Be between open ocean and ocean margin sediments. An average Holocene super(10)Be deposition rate for the entire Pacific Ocean is estimated with similar to 70% of the total super(10)Be supplied to the Pacific being deposited in margin sediments underlying only 10% of the ocean. The short residence times of super(10)Be in ocean margin regions (from < 100 to similar to 200 yr) compared to the long super(10)Be residence time in the central open Pacific Ocean ( similar to 1000 yr) reflects the intensified scavenging of super(10)Be in ocean margin waters. The average super(10)Be deposition rate in the Pacific Ocean can be used as an estimate of the global average production rate of super(10)Be in the atmosphere during the Holocene period.
AN: 2830074
67 of 126
TI: Effect of coagulation on nutrient and light limitation of an algal bloom.
AU: Jackson,-G.A.; Lochmann,-S.E.
AF: Dep. Oceanogr., Texas A&M Univ., College Station, TX 77843, USA
SO: LIMNOL.-OCEANOGR. 1992. vol. 37, no. 1, pp. 77-89
LA: English
ER: M (Marine)
AB: Coagulation is the formation of large particles from multiple collisions of smaller ones. We have developed a model of an algal bloom that includes nutrient and light limitation of algal growth rate and coagulation of single algal cells. The results show two effects of coagulation on the growth model. Loss of dividing cells to coagulating particles can occur when algal cells are growing at a fairly constant rate, placing a cap on the concentrations that algae can achieve. The second effect is enhancement of vertical particle flux from the surface mixed layer in aggregates. This enhanced transport moves algal biomass from the surface mixed layer over shorter periods at rates far greater than those associated with settling of single cells. For example, half the material associated with a bloom of 2- mu m-radius algae, which would take 350 d to settle out as isolated cells, took 42 d as aggregates. Aggregation was not limited to the large algae, although the rate was slower for the smaller ones. Coagulation was enhanced by higher initial nutrient concentrations, deeper mixed layers, and higher shear rates. Vertical transport associated with aggregation has the potential to be an important mechanism for removing biological material from eutrophic regions.
AN: 2799330
68 of 126
TI: The distribution and abundance of krill faecal material and oval pellets in the Scotia and Weddell seas (Antarctica) and their role in particle flux.
AU: Gonzalez,-H.E.
AF: Alfred-Wegener-Inst. Polar und Meeresforsch., Columbusstr., D-W-2850 Bremerhaven, FRG
SO: POLAR-BIOL. 1992. vol. 12, no. 1, pp. 81-91
NT: Bibliogr.: 37 ref.
LA: English
ER: M (Marine)
AB: The abundance and depth distribution of zooplankton faeces in spring to early summer were investigated along meridional transects (47 degree W and 49 degree W) that extended from the Scotia Sea (57 degree S) across the Weddell-Scotia Confluence and into the Weddell Gyre (62 degree S). The sea ice edge retreated from 59 degree 30'S to 61 degree S during the study. Faeces were sampled with nets, Niskin bottles and sediment traps and subsequently analysed by light and electron (SEM) microscopy. Krill (Euphausia superba ) faecal strings and oval faecal pellets of unknown origin were by far the most important zooplankton faeces and highest concentrations were always found in the Confluence often close to the ice border. Krill faeces were usually more abundant in the uppermost layer (0-50 m) where they contributed an average of 130 mu g dry weight/m super(3). There was an exponential decrease with depth, with a minimum of 0.6 mu g dry weight/m super(3) in the 500-1000 m stratum. Oval pellets were more evenly distributed in the upper 1000 m of the water column, with an average of 9 mu g dry weight/m super(3).
AN: 2784138
69 of 126
TI: Sources and behavior of anthropogenic radionuclides in the Ottawa River waters.
AU: Joshi,-S.R.; McCrea,-R.C.
AF: Lakes Res. Branch, Natl. Water Res. Inst., Canada Cent. Inland Waters, Environ. Canada, P.O. Box 5050, Burlington, Ont. L7R 4A6, Canada
SO: WATER-AIR-SOIL-POLLUT. 1992. vol. 62, no. 1-2, pp. 167-184
LA: English
ER: F (Freshwater)
AB: Multiphase radionuclide measurements on Ottawa River, Canada, waters are reported for October 1984 to March 1986. Numerous radionuclides are present in detectable amounts in raw, drinking and centrifuged waters as well as in suspended sediment and water filtration plant floc samples. The sediment/water partitioning behavior of these radionuclides is also reported. The prevailing low particle flux allows rapid migration of radionuclides through the system. Most of the super(90)Sr in the river derives from its fallout inventory in the watershed rather than from the Chalk River Nuclear Laboratories (CRNL). On the other hand, fallout and CNRL-derived super(137)Cs appear to contribute equally to the prevailing levels of this radionuclide in the river. The data also suggest that the prevailing levels of the naturally-occurring super(226)Ra impart more dose than super(90)Sr insofar as the radiological quality of the drinking water is concerned. Many of the radionuclides are removed by the floc during filtration of the receiving waters. Though their removal efficiencies cannot be precisely defined from the currently available measurements, the results show that processes other than simple association with suspended sediments may also play significant role in the retention of some radionuclides by the floc.
AN: 2777426
70 of 126
TI: Cylindrical tube traps for larval sampling.
AU: Yund,-P.O.; Gaines,-S.D.; Bertness,-M.D.
AF: Dep. Biol. Sci., Univ. New Orleans, New Orleans, LA 70148, USA
SO: LIMNOL.-OCEANOGR. 1991. vol. 36, no. 6, pp. 1167-1177
LA: English
ER: M (Marine); B (Brackish); F (Freshwater)
AB: Recent interest in the relationship between larval input to an area and settlement and recruitment density has generated a need for a larval sampling device that integrates abundance over time. A simple modification of the cylindrical tube trap commonly used in sedimentation studies can provide unbiased samples of larval dynamics. Our design utilizes a high aspect (height-to-width) ratio and an internal Formalin layer to limit the potential resuspension of collected larvae. Tests both in a laboratory flow tank and under field conditions suggest that capture rate scales linearly with both larval concentration and horizontal advection-two components of larval flux. The important role of horizontal advection has additional implications for the use of such traps to measure sedimentation rates, where only vertical particle flux is of interest. In the field, we found a strong correlation between the capture rate of Semibalanus balanoides larvae and daily settlement rates on adjacent shores. These traps, like sediment traps, may exhibit a particle-size bias in collection efficiency. Consequently, this technique is probably most appropriate for examining intraspecific spatial and temporal variation in the dynamics of a given larval stage.
AN: 2766564
71 of 126
TI: Rapid coupling of sinking particle fluxes between surface and deep ocean waters.
AU: Asper,-V.L.; Deuser,-W.G.; Knauer,-G.A.; Lohrenz,-S.E.
AF: Univ. Southern Mississippi, Cent. Mar. Sci., John C. Stennis Space Cent., SSC, MS 39529, USA
SO: NATURE. 1992. vol. 357, no. 6380, pp. 670-672
LA: English
ER: M (Marine)
AB: Settling particles are thought to be responsible for much of the transport of mass and energy from the upper ocean to the sea floor. Photosynthetic production by phytoplankton is a major source of these particles, either as phytoplankton biomass sinks directly or as it is transformed into rapidly sinking forms such as aggregates and zooplankton faeces. Because a variety of processes may act on sinking matter, however, it is not known to what extent fluxes of organic matter to the deep sea are coupled to processes at the ocean surface. Some studies have provided evidence for direct coupling, but transformation processes and advection exist which have the potential to modify the transmission of surface signals to the deep sea.
AN: 2756337
72 of 126
TI: Scavenging and particle flux: Seasonal and regional variations in the Southern Ocean (Atlantic sector).
AU: Rutgers-van-der-Loeff,-M.M.; Berger,-G.W.
AF: Alfred Wegener Inst. Polar and Mar. Res., Columbusst., D-2850 Bremerhaven, FRG
CO: Int. Symp. on Biochemistry and Circulation of Water Masses in the Southern Ocean, Brest (France), 2-6 Jul 1990
SO: MAR.-CHEM. 1991. vol. 35, no. 1-4, pp. 553-567
LA: English
ER: M (Marine)
AB: Even with large variations in flux rates, the scavenging of Pb and Th remains closely coupled to particle flux. In the Bransfield Strait, > 95% of the scavenging of super(230)Th and super(210)Pb occurs in two productive months, followed by negligible fluxes in winter. In winter, total super(234)Th reaches equilibrium with its parent super(238)U. During the bloom period, it is rapidly adsorbed onto particles and removed from the surface water. Notwithstanding the short production period, the annual fluxes of super(230)Th and super(210)Pb exceed their respective production rates in the water column by 60%. super(210)Pb inventories in the sediment reflect the distribution of average present-day particle flux: high inventories occur in a zone just south of the Polar Front, including the Bransfield Strait and Drake Passage; low inventories are found north of the Polar Front and in the Weddell Sea, with minimum values in the central Weddell Gyre. A general relationship between radionuclide fluxes and particle rain rates as a tool for hindcasting palaeoproductivities cannot be given.
AN: 2735651
73 of 126
TI: Biosiliceous particle flux in the Southern Ocean.
AU: Abelmann,-A.; Gersonde,-R.
AF: Alfred Wegener Inst. Polar and Mar. Res., Columbusstr., D-2850 Bremerhaven, FRG
CO: Int. Symp. on Biochemistry and Circulation of Water Masses in the Southern Ocean, Brest (France), 2-6 Jul 1990
SO: MAR.-CHEM. 1991. vol. 35, no. 1-4, pp. 503-536
LA: English
ER: M (Marine)
AB: The flux of diatom valves and radiolarian shells obtained during short-term and annual sediment trap experiments at seven localities in the Atlantic sector of the Antarctic Ocean (in the Drake Passage, Bransfield Strait, Powell Basin, NW and SE Weddell Sea and the Polar Front north of Bouvet Island) is summarized and discussed. The deployment of time-series sediment traps provided annual flux records between 1983 and 1990. The biosiliceous particle flux is characterized by significant seasonal and interannual variations. The flux pattern of diatoms and radiolarians is similar at most of the sites investigated and shows a close relationship between the production of siliceous phytoplankton and proto-zooplankton. During their transfer through the water column to the ocean floor, the composition of the biosiliceous particles is altered mechanically and by dissolution. Significant lateral transport of suspended biosiliceous particles was observed in the bottom water layer in regions adjacent to shelf areas, and in the vicinity of topographic elevations, indicating considerable redistribution of biogenic silica in these regions.
AN: 2735068
74 of 126
TI: Fluxes of super(226)Ra and barium in the Pacific Ocean: The importance of boundary processes.
AU: Moore,-W.S.; Dymond,-J.
AF: Dep. Geol. Sci., Univ. South Carolina, Columbia, SC 29208, USA
SO: EARTH-PLANET.-SCI.-LETT. 1991. vol. 107, no. 1, pp. 55-68
LA: English
ER: M (Marine)
AB: The super(226)Ra/Ba ratio in particles collected in sediment traps decreases with depth. Fluxes of Ba and Al increase with depth. These observations cannot be explained by simple vertical processes. Instead they require a component to the deep flux which originates at the ocean margins. We suggest that the deep traps are enriched in Ba through the advection of barite originally precipitated in biologically productive regions of the ocean margin. This source is less important for super(226)Ra because some is lost by radioactive decay between the precipitation of barite on the margin and outward transport. The boundary flux is an important source of material to the deep sea. From super(226)Ra fluxes in the upper 1000 m of the water column, we estimate that the residence time of super(226)Ra in the upper ocean is 400 years. The removal of super(226)Ra in the particle flux is approximately balanced by the upwelling of waters enriched in super(226)Ra.
AN: 2729170
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TI: Increased particle flux to the deep ocean related to monsoons.
AU: Nair,-R.R.; Ittekkot,-V.; Manganini,-S.J.; Ramaswamy,-V.; Haake,-B.; Degens,-E.T.; Desai,-B.N.; Honjo,-S.
AF: Natl. Inst. Oceanogr., Dona Paula, Goa-403004, India
SO: NATURE. 1989. vol. 338, no. 6218, pp. 749-751
LA: English
ER: M (Marine)
AB: Monsoons cause seasonal reversals in the surface circulation of the northern Indian Ocean. In the Arabian Sea this results in the upwelling of nutrient-rich water along the coasts, making it one of the highly productive regions of the world's oceans. To assess the impact of monsoon-driven processes on the downward particle flux variations in the open ocean we deployed three moored arrays consisting of six time-series sediment traps at selected locations in the western, central and eastern parts of the deep northern Arabian Sea. Strong seasonality was recorded in particle flux at all three sites with peaks during the southwest and northeast monsoons.
AN: 2708939
76 of 126
TI: Pelagic origin and fate of sedimenting particles in the Norwegian Sea.
AU: Bathmann,-U.V.; Peinert,-R.; Noji,-T.T.; Bodungen,-B.V.
AF: Alfred-Wegener-Inst. Polar- und Meeresforsch., Am Handelshafen 12, D-2850 Bremerhaven, FRG
SO: PROG.-OCEANOGR. 1990. vol. 24, no. 1-4, pp. 117-125
LA: English
ER: M (Marine)
AB: A 17 month record of vertical particle flux of dry weight, carbonate and organic carbon were 25.8, 9.4 and 2.4 g m super(-2)/y, respectively. Parallel to trap deployments, pelagic system structure was recorded with high vertical and temporal resolution. Within a distinct seasonal cycle of vertical particle flux, zooplankton faecal pellets of various size, shapes and contents were collected by the traps in different proportions and quantities throughout the year (range: 0-4,500 10 super(3) m super(-2)/d). The remains of different groups of organisms showed distinct seasonal variations in abundance. In early summer there was a small maximum in the diatom flux and this was followed by pulses of tinntinids, radiolarians, foraminiferans and pteropods between July and November. Food web interactions in the water column were important in controlling the quality and quantity of sinking materials. These data from the Norwegian Sea indicate those mechanisms which either accelerate or counteract loss of material via sedimentation. Connecting investigation of the water column with a high resolution in time parallel with drifting sediment trap deployments and shipboard experiments with the dominant zooplankters is a promising approach for giving a better understanding of both the origin and the fate of material sinking to the sea floor.
AN: 2666096
77 of 126
TI: Seasonal coupling of organic matter production and particle flux in the western Bransfield Strait, Antarctica.
AU: Karl,-D.M.; Tilbrook,-B.D.; Tien,-G.
AF: Sch. Ocean and Earth Sci. and Technol., Univ. Hawaii, Honolulu, HI 96822, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1991. vol. 38, no. 8-9A, pp. 1097-1126
LA: English
ER: M (Marine)
AB: Simultaneous measurements of seasonal depletions in dissolved inorganic carbon ( Sigma CO sub(2)), nitrogen (NO sub(3)@)u- + NO sub(2)@)u-) and phosphate (HPO sub(4)@) super(2)- )and concentrations of C, N and P collected using sediment traps at five representative sites in a 25,000 km super(2) sector of the western Bransfield Strait over a 4-month period have allowed us to evaluate the coupling between primary production and particle flux. During the spring bloom period (December to January), we observed a substantial removal of Sigma CO sub(2), (NO sub(3)@)u- + NO sub(2)@)u-) and HPO sub(4)@) super(2)-c)orresponding to a net upper water column (0-50 m) seasonal production of 8410 mmol C/m super(2), 827 mmol N/m super(2) and 53.1 mmol P/m super(2). This equates to an average C:N:P ratio of 158:15.6:1. These C:N (and C:P) ratios are higher than the expected Redfield ratios and also exceed the C:N and C:P ratios directly measured for suspended and sinking particles. We hypothesize a coupled formation of carbon-rich dissolved organic matter as a sink for approximately 30-50% of the Sigma CO sub(2) removed during net photosynthesis. The rapid production and accumulation of phytoplankton in the northern portion of Gerlache Strait during the spring bloom resulted in a substantial pCO sub(2) undersaturation compared to surface samples collected from lower productivity areas in Drake Passage.
AN: 2620495
78 of 126
TI: Sedimentation of pteropods in the Norwegian Sea in autumn.
AU: Bathmann,-U.V.; Noji,-T.T.; von-Bodungen,-B.
AF: Alfred-Wegener-Inst. Polar- und Meeresforsch., 2850 Bremerhaven, FRG
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1991. vol. 38, no. 10A, pp. 1341-1360
LA: English
ER: M (Marine)
AB: Pteropod vertical distribution on the Voering Plateau (Norwegian Sea) was recorded during a 3 week drifting experiment during August 1988. Parallel to sampling of hydrographical, chemical and biological properties of the water column, sediment traps recorded vertical pelagic flux at five depth strata. Pteropods (Limacina retroversa ) dominated the zooplankton and reached maximum values (> 13,600 individuals/m super(3)) in the upper 25 m of the water column; the size spectrum shifted from small (< 1 mm) towards large (> 3 mm) specimens during the study. Vertical flux at 100 m depth increased from 600 mg dry weight/m super(2)/day to 1000 mg dry weight/m super(2)/day at the end of the experiment. Trap material during the first sampling intervals consisted primarily of phytoplankton and protozoans aggregated within pteropod feeding nets. Through their feeding, reproduction and subsequent mortality pteropods were the main contributors to vertical particle flux in the eastern Norwegian Sea during 1988.
AN: 2612451
79 of 126
TI: Seasonal and depth-related changes in the source of sinking particles in the North Atlantic.
AU: Altabet,-M.A.; Deuser,-W.G.; Honjo,-S.; Stienen,-C.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: NATURE. 1991. vol. 354, no. 6349, pp. 136-139
LA: English
ER: M (Marine)
AB: Large, fast-sinking particles are important in the downward transport and redistribution of biogeochemical species in the deep ocean. Using nitrogen isotope ratio, super(15)N/ super(14)N, as an in situ tracer, we investigate the source and transformation of these particles in the North Atlantic ocean. We observe seasonal variations in delta super(15)N associated with seasonal changes in near-surface nitrate concentration and particle flux; the nitrogen isotope variations are consistent with, but much larger than, previously observed variability. Our results show that the signal from these near-surface changes propagates rapidly into the deep ocean, but is modified depending on the phase of the seasonal production cycle. Surprisingly, we find that delta super(15)N values of sinking particles decrease with depth during low-flux periods--behaviour that may occur generally in the open ocean. The sinking particles must therefore be either gaining light nitrogen or losing heavy nitrogen, an effect that we believe requires there to be another source of sinking particles, apart from recent surface production.
AN: 2611636
80 of 126
TI: Do upper-ocean sediment traps provide an accurate record of particle flux?.
AU: Buesseler,-K.O.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: NATURE. 1991. vol. 353, no. 6343, pp. 420-423
LA: English
ER: M (Marine)
AB: Sediment traps are widely used to measure the vertical flux of particulate matter in the oceans. In the upper ocean, sediment traps have been used to determine the extent to which CO sub(2) fixed by primary producers is exported as particulate organic carbon. In addition, the observed decrease of particle flux with depth has been use to predict regeneration rates of organic matter and associated elements. Over seasonal or annual timescales, the import of limiting nutrients into the upper ocean (new production) should be balanced by particle export. Given the importance of accurately determining the sinking particle flux, it has been suggested that super(234)Th might be used to "calibrate" shallow-trap fluxes. The author presents a re-evaluation of existing super(234)Th data which indicates that trap-derived and model-derived super(234)Th particle fluxes can differ by a factor of plus or minus 3-10, suggesting that shallow traps may not provide an accurate measure of particle fluxes.
AN: 2580752
81 of 126
TI: Settling of particles in a hydrothermal vent field (East Pacific Rise 13 degree N) measured with sediment traps.
AU: Khripounoff,-A.; Alberic,-P.
AF: IFREMER-Cent. Brest, B.P. 70, 29280 Plouzane, France
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1991. vol. 38, no. 6A, pp. 729-744
LA: English
ER: M (Marine)
AB: Samples from nine sediment traps moored in the vicinity of an active hydrothermal vent on a segment of the East Pacific Rise (EPR), near 13 degree N, were collected in 1987 during the Hydronaut cruise. The results show variability in the distribution and composition of the particle flux to the area immediately surrounding the sea-floor vents. The settling of material measured at three distances from the "Totem" vent field demonstrates a sharp decrease in total flux with increasing distance from the source. The amount of particles collected with sediment traps at the vent field is 5.6 times greater than the pelagic flux measured on this site. Comparison of elemental fluxes determined in the near- and far-field experiments reveals the spatial distribution of vent effluent. The sulphur particle flux decreases by a factor of 300 between the near-field station and the seamount station 15 km southeast of the vent. In contrast, the pelagic carbonate flux appears equally distributed throughout the studied area. Few organic particles produced by the vent ecosystem are reaching the seafloor only 80 m away.
AN: 2579689
82 of 126
TI: The biomagnification of polychlorinated biphenyls, toxaphene, and DDT compounds in a Lake Michigan offshore food web.
AU: Evans,-M.S.; Noguchi,-G.E.; Rice,-C.P.
AF: Natl. Hydrol. Res. Inst., 11 Innovation Blvd., Saskatoon, Sask. S7N 3H5, Canada
SO: ARCH.-ENVIRON.-CONTAM.-TOXICOL. 1991. vol. 20, no. 1, pp. 87-93
LA: English
ER: F (Freshwater)
AB: The biomagnification of polychlorinated biphenyls (PCB), toxaphene, and the DDT family of metabolites was investigated in the epibenthic Mysis relicta (mysid), the benthic Pontoporeia hoyi (amphipod), plankton, particulate flux, surficial sediments, and Myoxocephalus thompsoni (deepwater sculpin) in southeastern Lake Michigan. DDE was the most strongly biomagnified compound, increasing 28.7 times in average concentration from plankton to fish. PCB increased 12.9 times in average concentration from plankton to fish while toxaphene increased by an average factor of 4.7. Particle flux was comprised of lower chlorinated PCB homologues (average chlorine number = 3.8) than the biota (4.5-5.0) and sediments (4.6), possibly reflecting strong influences from atmospheric deposition and/or zooplankton egestion. The percent of higher chlorinated PCB homologues (5 and 6 chlorine atoms per PCB molecule) increased from 54-56% of the total PCB in plankton and M. relicta , to 61% in P. hoyi , to 74% in sculpins.
AN: 2531212
83 of 126
TI: Field calibration and performance of sediment traps in a eutrophic holomictic lake.
AU: Flower,-R.J.
AF: Palaeoecol. Res. Unit, Dep. Geogr., University Coll., 26 Bedford Way, London WC1H 0AP, UK
SO: J.-PALEOLIMNOL. 1991. vol. 5, no. 2, pp. 175-188
LA: English
ER: F (Freshwater)
AB: In wind-stressed and unstratified Lough Neagh low aspect ratio sediment traps, which allow for internal resuspension, collected sediment at a rate close to the natural sediment accumulation rate inferred from dated sediment cores. High aspect ratio traps grossly overestimated the natural rate of sediment accumulation as did, but to a lesser extent, burial rate measurements on an artificial stratigraphic marker. The former type of trap deployed over long exposure periods is therefore recommended as providing the best estimate of net downward particle flux in lakes such as Lough Neagh. However, it is emphasized that all sediment trap types, when operated in shallow turbulent lakes, will to a greater or lesser extent be "contaminated" by secondary or redeposited material and so will not provide a direct measure of primary sedimentation. Use of tube traps in lakes such as Lough Neagh should not, however, be discounted since they can provide a record of the quality of sedimenting material through time.
AN: 2522624
84 of 126
TI: Developing model of benthic-water contaminant transport in bioturbated sediment.
AU: Davis,-W.R.; Means,-J.C.
CA: Environmental Protection Agency, Narragansett, RI (USA). Environmental Research Lab.
CO: 21. EMBS, Gdansk (Poland), 14-19 Sep 1986
SO: ECOL.-RES.-SER.-U.S.-ENVIRON.-PROT.-AGENCY. 1989. 14 pp
NT: NTIS Order No.: PB91-109298/GAR. ERLN-803.
RN: EPA/600/J-89/437 (EPA600J89437)
LA: English
AB: Chemicals entering marine waters are incorporated into distinct compartments and these reservoirs are in exchange with one another. The chemo-dynamic storage compartments in marine systems include sediment to the depth of bioturbation (0-50 cm), suspended sediments, dissolved phases (pore, ventilation and overlying water), and tissue residues. The key transport processes are particle flux across the sediment water interface, vertical mixing within the bioturbation zone, and dissolved contaminant exchange between suspended particles or sediment and surrounding seawater or interstitial water. The key transport variables in entrainment are physical shear, bioturbation, and sediment cohesiveness. Vertical mixing may be mostly a function of the rate of conveyor-type feeding. (Pub. in Proceedings of the EMBS (21st), Gdansk, Poland, September 14-19, 1986, p215-226, 1989. Prepared in cooperation with Maryland Univ., Solomons. Chesapeake Biological Lab.)
AN: 2512860
85 of 126
TI: The "particle" flux: Origins and biological components.
AU: Silver,-M.W.; Gowing,-M.M.
AF: Inst. Mar. Sci., Univ. California, Santa Cruz, CA 95064, USA
SO: PROG.-OCEANOGR. 1991. vol. 26, no. 1, pp. 75-113
LA: English
ER: M (Marine)
AB: Sedimentation of organic matter from the ocean's surface layers is intimately tied to biological events within the euphotic zone. Although the sedimentation rate is usually found to be positively correlated with primary production, the biological basis for the correlation is not well understood. Various mechanisms have been invoked to explain the loss of particles with depth. The fundamental causes of differences in export rates and of the rapid loss of particles at depth, however, is reflected in the changing composition of particles across a productivity gradient and down through the water column. We have attempted to investigate the biological processes leading to the productivity-flux relationship and the depth-related losses, using Vertex samples from particle interceptor traps deployed in the Northeastern Pacific between 1980 and 1984.
AN: 2490828
86 of 126
TI: Roles of viral infection in organic particle flux.
AU: Proctor,-L.M.; Fuhrman,-J.A.
AF: Mar. Sci. Res. Cent., State Univ. New York, Stony Brook, NY 11794-5000, USA
SO: MAR.-ECOL.-PROG.-SER. 1991. vol. 69, no. 1-2, pp. 133-142
NT: Bibliogr.: 66 ref.
LA: English
ER: M (Marine)
AB: Sediment trap material from 30 to 400 m collected from the north Pacific Ocean during the "VERTEX" cruises in 1980 to 1982 was examined by transmission electron microscopy. Viruses were present in all of the sinking particles examined except for those from one sample, of highly degraded algal cells or small fecal pellets, from 400 m. Viruses in the sinking particles often appeared aggregated. From 0.7 to 3.7% of the bacteria in sinking particles contained mature phage; from these data and limited information from pure cultures, we estimate that 2 to 37% of the particulate-associated bacteria may be killed by viral lysis. Many eukaryotic cells were also apparently infected with viruses, but none ( less than or equal to 50 cells observed) of the cyanobacteria or "Chlorella -like" cells appeared infected. Viral lysis of bacteria associated with sinking particles and free-living bacteria may be causally linked and may play a role in dissolved organic carbon production and the dynamics of sinking particles.
AN: 2458645
87 of 126
TI: Effects of ice coverage and ice-rafted material on sedimentation in the Fram Strait.
AU: Hebbeln,-D.; Wefer,-G.
AF: Univ. Bremen, Geowiss., Postfach 330440, 2800 Bremen 33, FRG
SO: NATURE. 1991. vol. 350, no. 6317, pp. 409-411
LA: English
ER: M (Marine)
AB: As little is known about pelagic sedimentation processes in Arctic environments, the interpretation of biological and chemical processes, as well as the reconstruction of ancient conditions, including those in the glacial North Atlantic, is difficult. Here we provide sediment-trap results, which show that the position of the sea-ice boundary significantly influences the particle flux. The seasonal variability of the particle flux differed markedly in the various sediment-trap sites in Fram Strait, depending on the behaviour of the sea ice. Under complete ice cover, sedimentation is very low, whereas maximum sedimentation is found at the ice margin. The highest particle flux observed, showing a large lithogenic component, was observed at the ice edge where the water was warmer (> 2 degree C). We find that high biogenic opal fluxes are characteristic of the summer ice margin, indicating that the sedimentary record of opal fluxes may allow the position of ice margins in the past to be reconstructed.
AN: 2449050
88 of 126
TI: France-JGOFS, ECOMARGE. Particle fluxes and ecosystem response on a continental margin: The Mediterranean experiment.
AU: Monaco,-A.; Biscaye,-P.E.; Pocklington,-R.-(eds.)
AF: Lab. Sedimentol. et Geochim. Mar., Univ. Perpignan, Ave. Villeneuve, 66025 Perpignan, France
SO: CONT.-SHELF-RES. 1990. vol. 10, no. 9-11, pp. 807-1155
LA: English
ER: M (Marine)
AB: This special issue summarizes several years of effort within the ECOMARGE programme (France-JGOFS, PFO) and is the first French multidisciplinary result within the field of particle flux studies.
AN: 2438343
89 of 126
TI: Passive suspension feeding by an octocoral in plankton patches: Empirical test of a mathematical model.
AU: Patterson,-M.R.
AF: Div. Environ. Stud., Univ. California, Davis, CA 95616, USA
SO: BIOL.-BULL.-MAR.-BIOL.-LAB.-WOODS-HOLE. 1991. vol. 180, no. 1, pp. 81-92
LA: English
ER: M (Marine)
AB: Feeding rate in the octocoral, Alcyonium siderium , was investigated as a function of colony size, flow speed, and prey concentration. The feeding rate decreases with time in high prey concentrations. A model of passive suspension feeding is formulated that successfully predicts feeding behavior. At low prey concentrations, the model predicts a linear feeding response as particle flux or colony size increases. The dominant constraint on feeding is the "handling time" required to transfer prey from tentacle to pharynx and to re-extend the tentacle. The time constant of prey capture shows no relation to particle flux, in agreement with the model. Another constraint, the "filtration time," is inversely related to colony size and flow speed. Filtration time becomes important only during feeding in sparse prey concentrations, when feeding rate is proportional to flow speed, colony size, and prey concentration. In the field, Alcyonium colonies reduce filtration time by orienting at right angles to the dominant flow direction.
AN: 2437537
90 of 126
TI: Seasonal occurrence of silicoflagellate morphologies in different environments of the eastern Pacific Ocean.
AU: Sancetta,-C.
AF: Lamont-Doherty Geol. Obs., Columbia Univ., Palisades, NY 10964, USA
SO: MAR.-MICROPALEONTOL. 1990. vol. 16, no. 3-4, pp. 285-291
LA: English
ER: M (Marine)
AB: Data on weekly to bimonthly particle flux collected by sediment traps in three environments show that forms of silico-flagellates do not have a simple and consistent relationship to either temperature or productivity of the overlying water column. Sites were located in the fjords of British Columbia, along a transect off the coast of southern Oregon, and in San Pedro Basin of the southern California Bight. Either the "cool" Distephanus speculum or the "warm" Dictyocha messanensis may dominate at temperatures over a range from 10-19 degree C. D. speculum dominated high-productivity periods off Oregon, while D. messanensis dominated during coastal upwelling events in the San Pedro Basin, regardless of surface temperature. Octactis pulchra showed no distinctive trend in the San Pedro Basin, the only locality where it was observed. The isolated presence of D. speculum in the fjords, where mixed-zone salinity may be as low as 11 ppt, indicates a tolerance for hyposaline waters, but no other trends could be defined with respect to surface salinity.
AN: 2432763
91 of 126
TI: The nature of reactions on particle surfaces in seawater.
AU: Fisher,-N.S.
AF: Oceanogr. Sci. Div., Brookhaven Natl. Lab., Upton, NY 11973, USA
CO: CHEMRAWN IV. Modern Chem. and Chem. Technol. Appl. to the Ocean and Its Resources, Keystone, CO (USA), 4-9 Oct 1987
SO: CHEMRAWN-IV.-MODERN-CHEMISTRY-AND-CHEMICAL-TECHNOLOGY-APPLIED-TO-THE-OCEAN-AND-ITS-RESOURCES.-PROCEEDINGS-OF-AN-INTERNATIONAL-CONFERENCE-AND-WORKSHOP-SPONSORED-BY-THE-INTERNATIONAL-UNION-OF-PURE-AND-APPLIED-CHEMISTRY,-HELD-AT-KEYSTONE,-COLORADO,-U.S.A.,-4-9-OCTOBER-1987. Goldberg,-E.D.-ed. 1988. vol. 3, no. 1 pp. P. 76
ST: APPL.-GEOCHEM. vol. 3, no. 1
NT: Summary only.
LA: English
ER: M (Marine)
AB: One area regarding metal-particle interactions which has received comparatively little study is the degree to which metals, once associated with biogenic particulates, are retained by these particles as they sink through the water column. To what extent can we consider the association of different metals with biogenic debris irreversible? What are the rates of release of different metals from particulate matter, and how are these rates influenced by environmental factors? It is really self-evident that this information would have direct bearing on our understanding of the particle-mediated flux of metals in marine systems.
AN: 2419924
92 of 126
TI: Surface-ocean color and deep-ocean carbon flux: How close a connection?.
AU: Deuser,-W.G.; Muller-Karger,-F.E.; Evans,-R.H.; Brown,-O.B.; Esaias,-W.E.; Feldman,-G.C.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1990. vol. 37, no. 8A, pp. 1331-1343
LA: English
ER: M (Marine)
AB: Seven years of simultaneous, quasi-continuous data collected by the Nimbus-7 Coastal Zone Color Scanner and by a deep-ocean sediment trap in the Sargasso Sea allow the derivation of empirical relationships between remotely sensed ocean color and the sinking of particulate carbon into the deep sea. In agreement with earlier observations, the results indicate a 1.5-month lag between surface-ocean events observed by the satellite and arrival of a record of those events, carried by sinking particles, at a depth of 3200 m. In addition, the results suggest that the sea-surface area most influential on particle-flux characteristics recorded by the sediment trap in the Sargasso Sea lies to the northeast of the trap's mooring site. The results point towards possible ways of quantifying the role of marine biota in the regulation of atmospheric carbon dioxide through use of satellite observations.
AN: 2408864
93 of 126
TI: Cryptic zooplankton "swimmers" in upper ocean sediment traps.
AU: Michaels,-A.F.; Silver,-M.W.; Gowing,-M.M.; Knauer,-G.A.
AF: Bermuda Biol. Stn. Res., 17 Biological Lane, Ferry Reach, GE01, Bermuda
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1990. vol. 37, no. 8A, pp. 1285-1296
LA: English
ER: M (Marine)
AB: Sediment traps are the major oceanographic tool for collecting passively sinking particulate material (the "particle flux") in the ocean. Sediment traps in the upper ocean also collect actively sinking zooplankton that are usually manually removed prior to analysis. Microscopic analysis of sediment trap samples collected over a 19-month period in the eastern North Pacific reveals that zooplankton "swimmers" are a larger problem than previously recognized. Zooplankton that are cryptic (i.e. difficult to see or distinguish from the detrital material) and difficult to remove (principally gelatinous zooplankton) may have contributed up to 20 mg C/m super(2)/day to the "particulate flux," with the highest values in the upper 150 m. This swimmer problem is in addition to the previously recognized presence of crustaceans and other large metazoans in traps. Additionally, the detritus-laden, mucous-feeding structures (houses) of larvaceans probably enter the traps with the larvaceans and would be impossible to remove. We estimate that the contribution of the cryptic swimmers and larvacean houses could be as much as 96% of the measured carbon flux.
AN: 2407577
94 of 126
TI: Modelling of organic particle flux through the metalimnion in lakes.
AU: Szeligiewicz,-W.
CO: Int. Conf. on Reservoir Limnology and Water Quality, Ceske Budejovice (Czechoslovakia), 15 Jun 1987
SO: PROCEEDINGS-OF-THE-INTERNATIONAL-CONFERENCE-ON-RESERVOIR-LIMNOLOGY-AND-WATER-QUALITY.-1.-PHYSICAL-LIMNOLOGY,-MATHEMATICAL-MODELS-AND-MICROBIAL-DECOMPOSITION. Henderson-Sellers,-B.;Straskrabova,-V.-eds. 1989. no. 33 pp. 169-177
ST: ERGEB.-LIMNOL.-ADV.-LIMNOL. no. 33
LA: English
ER: F (Freshwater)
AB: It was considered whether the changes of flux of organic particles in the metalimnion due to changes of slope of the thermocline calculated according to a one-dimensional model based on the model AQUAMOD could agree in quality with Gliwicz's hypothesis about the influence of metalimnetic temperature gradient on the vertical flux of organic particles.
AN: 2378092
95 of 126
TI: Effects of flow velocity, food concentration and particle flux on growth rates of juvenile bay scallops Argopecten irradians .
AU: Cahalan,-J.A.; Siddall,-S.E.; Luckenbach,-M.W.
AF: Univ. North Carolina at Chapel Hill, Inst. Mar. Sci., 3407 Arendell St., Morehead City, NC 28557, USA
SO: J.-EXP.-MAR.-BIOL.-ECOL. 1989. vol. 129, no. 1, pp. 45-60
LA: English
ER: M (Marine)
AB: Studies in a recirculating seawater flume were conducted to examine the growth rates of juvenile bay scallops Argopecten irradians irradians (L.) (3-10 mm in shell height) in four flow velocities (0, 1, 6, and 15 cm/s) over a range of food concentrations (0-75,000 cells/ml) in a four-by-four factorial design. Particle flux (algal cells/cm super(2)/s) encountered by the scallops is the product of food concentration (cells/ml) and flow velocity (cm/s). The experimental levels of food concentration and flow velocity were chosen to produce a wide range of fluxes. Several treatments with equal flux derived from different flows and food concentrations were used to decouple the effects of each factor. Within a given flux of particles, growth rates were not significantly different between flows or particle concentrations. Growth was only weakly correlated to flux of particles over the range of fluxes tested. The effects of algal concentration were more pronounced than the effects of flow velocity suggesting that differences in growth were a result of differences in algal concentrations.
AN: 2370269
96 of 126
TI: Particulate matter dynamics and phytoplankton seasonality in a reservoir embayment ecosystem.
AU: Ford,-C.J.; Kimmel,-B.L.; Olsen,-C.R.
CA: Oak Ridge Natl. Lab., TN (USA)
SO: TECH.-MEMO.-OAK-RIDGE-NATL.-LAB. 1989. 160 pp
NT: NTIS Order No.: DE90008079/GAR.
RN: ORNL/TM-11010 (ORNLTM11010)
LA: English
AB: Phytoplankton losses from the water column and the relationships among seasonal change, algal community structure, and the fate of particle-associated materials were investigated in the Walker Branch embayment of Melton Hill Reservoir, Anderson County, Tennessee. Sinking and ascent rates of phytoplankton were measured using settling columns, and in situ particle removal by sinking was estimated using the naturally-occurring radionuclides Beryllium-7 and Lead-210. Changes in autochthonous phytoplankton assemblage composition, concentration and production reflected the seasonal aspects of suspended particle flux. (Contract AC05-84OR21400. Sponsored by Department of Energy, Washington, DC, USA. Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted.)
AN: 2362516
97 of 126
TI: A generalized model for the scavenging of trace metals in the open ocean. 1. Particle cycling.
AU: Clegg,-S.L.; Whitfield,-M.
AF: Plymouth Mar. Lab., Citadel Hill, Plymouth PL1 2PB, UK
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1990. vol. 37, no. 5A, pp. 809-832
LA: English
ER: M (Marine)
AB: A self-consistent one-dimensional particle cycling model has been constructed using two particle size classes, and particle flux, size and sinking rate data. The estimation of particle properties from model size spectra applied to real ocean data is discussed, as are remineralization, the relationship between primary production and flux, and other important aspects of model parameterization. Realistic standing concentrations of particulate material were generated by the model for a steady-state mesotrophic system using flux, sinking rate and particle size data. High rates of remineralization in surface waters make this likely to be the principal pathway for the return of adsorbed or incorporated elements to the dissolved state.
AN: 2329830
98 of 126
TI: Interannual variability in particle flux in the southwestern Black Sea.
AU: Hay,-B.J.; Honjo,-S.; Kempe,-S.; Ittekkot,-V.A.; Degens,-E.T.; Konuk,-T.; Izdar,-E.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1990. vol. 37, no. 6A, pp. 911-928
LA: English
ER: M (Marine)
AB: Vertical particle flux was measured at two sites in the southwestern Black Sea using automated time-series sediment traps over a period of 4.5 years. The particle flux between but sites varied considerably. (1) At site BSC (80 km from shore) the dominant fraction of the annual flux was deposited during short blooms; at site BS (40 km from shore, but still beyond the shelf break), the particle flux was less dominated by short-term blooms. (2) At site BSC, plankton blooms were the dominant cause for removal of suspended lithogenic matter; at site BS, vertical transport of lithogenic matter was linked also to the occurrence of storms and to high discharge periods of local rivers. Upwelling in the southwestern Black Sea may play an important role in triggering plankton blooms.
AN: 2329753
99 of 126
TI: Heterotrophic activity on appendicularian (Tunicata: Appendicularia) houses in mesopelagic regions and their potential contribution to particle flux.
AU: Davoll,-P.; Youngbluth,-M.J.
AF: Harbor Branch Oceanogr. Inst., 5600 Old Dixie Highw., Fort Pierce, FL 34946, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1990. vol. 37, no. 2A, pp. 285-294
LA: English
ER: M (Marine)
AB: Repeated observations and collections of appendicularian houses (ca 1-10 cm dia.) from Johnson-Sea-Link submersibles indicate these conspicuous mucoid aggregates (0.08-0.49 houses/m super(3)) were a common component of the biodetritus at midwater depths (490-760 m) in Bermuda and the Bahamas during May and November 1984, respectively. Microorganisms and olive-green bodies found on these houses were 1-3 orders of magnitude more numerous than in an equal volume of surrounding seawater. The production rates of bacteria on aggregates varied from 0.01 to 10.83 ng C/house/h and accounted for 0.01-4.0% of total bacterial production in the water column. The potential carbon flux from these large particles amounted to 0.83 mg C/m super(2)/day (= 8% of total carbon flux).
AN: 2326188
100 of 126
TI: (Process and quantitative estimation of particulate flux on progressive margins.).
OT: Processus et quantification des flux de matieres sur les marges progressives
AU: Courp,-T.; Monaco,-A.
AF: Lab. Sedimentol. Geochim. Mar., Univ. Perpignan, Ave. Villeneuve, 66025 Perpignan, France
CO: 1. Congr. Francais de Sedimentologie, Paris (France), 19 Nov 1987
SO: RECL.-TRAV.-LAB.-SEDIMENTOL.-GEOCHIM.-MAR.-UNIV.-PERPIGNAN. 1987. vol. 4, 1 p
NT: Summary only.
LA: French
ER: M (Marine)
AB: These studies were conducted as a part of the Ecomarge programme to study energy and particle transfer on continental margins and their relation to the benthic ecosystem. The characteristics of particle flux are studied in relation to the geochemical properties of the sediment-water interface.
AN: 2308962
101 of 126
TI: (The dirty area of the lower Mazafran wadi and the suspended particulate matter dynamics: First results.).
OT: Le coin sale dans le cours inferieur de l'oued Mazafran et la dynamique du materiel en suspension: Premiers resultats
AU: Pauc,-H.
AF: Inst. Sci. Terre, USTHB, BP 32 El Alia, Alger, Algeria
SO: RECL.-TRAV.-LAB.-SEDIMENTOL.-GEOCHIM.-MAR.-UNIV.-PERPIGNAN. 1987. vol. 4
NT: Summary only.
LA: French
ER: B (Brackish)
AB: An unstable equilibrium between marine hydrostatic pressure and the fluvial flow is observed in the lower area of river, and affects the particle flux, flocculation and sedimentation. In this paper, the author studies the seasonal variations of this process.
AN: 2292734
102 of 126
TI: (Research vessel Meteor . Cruise no. 6. Atlantic 87/88. Legs no. 1-3. October-December 1987.).
OT: Forschungsschiff Meteor . Reise nr. 6. Atlantik 87/88. Fahrtabschnitte nr. 1-3. Oktober-Dezember 1987
AU: Mueller,-T.J.; Siedler,-G.; Zenk,-W.
AF: Inst. Meereskd., Univ. Kiel, Duesternbrooker Weg 20, 2300 Kiel 1, FRG
SO: BER.-INST.-MEERESKD.-CHRISTIAN-ALBRECHTS-UNIV.-KIEL. 1988. no. 184, 77 pp
LA: German
ER: M (Marine)
AB: The first three legs of Meteor cruise no. 6 were carried out between Hamburg, Las Palmas, Dakar and Abidjan. The core programme was part of the special research program "Warm Water Sphere of the Atlantic" at Kiel Univ. It included investigations of the North Atlantic subtropical gyre circulation and of mixing processes in the Cape Verde Frontal Zone. Tracer sampling was added to this programme. Furthermore, measurements were carried out to study heavy metals and petroleum hydrocarbons, and samples were collected for investigations of the oceanic particle flux, of the taxonomy and regional distribution of ichthyoplankton and of benthic communities. Air chemistry measurements were aimed at determining mixing ratios of various trace gases in the tropospheric boundary layer. The present report summarizes the goals of the investigations, the work at sea and first results.
AN: 2274912
103 of 126
TI: Particulate new nitrogen fluxes in the Sargasso Sea.
AU: Altabet,-M.A.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS. 1989. vol. 94, no. C9, pp. 12771-779
LA: English
ER: M (Marine)
AB: Seasonal variations of up to sevenfold in the flux of new nitrogen as sinking particles are observed at a site near Bermuda between January 1986 and May 1988. Maxima occur in the late winter with minima in the late fall. While this particle flux from the euphotic zone depends on levels of suspended particulate nitrogen (PN), NO sub(3) super(-) flux modulated by seasonal variations in the magnitude of vertical transport appears to be the ultimate forcing. The downward mixing of suspended PN may make a significant contribution to the downward flux, particularly in the winter. Its inclusion raises the annual new nitrogen flux to 0.33 mol m super(-2)/yr.
AN: 2261420
104 of 126
TI: (Vertical distribution and sedimentation of phytoplankton in the central Baltic Sea during spring 1986.).
OT: Vertikalverteilung und Sedimentation von Phytoplanktonarten in der mittleren Ostsee waehrend des Fruehjahres 1986
AU: Psssow,-U.
CA: Christian-Albrechts-Univ., Kiel (FRG). Mathematisch-Naturwissenschaftliche Fak.
SO: BER.-INST.-MEERESKD.-CHRISTIAN-ALBRECHTS-UNIV.-KIEL. 1990. no. 192, 203 pp
NT: Bibliogr.: 219 ref. Diss. (Dr. rer. nat.)
LA: German
ER: M (Marine)
AB: Vertical phytoplankton distribution, temporal fluctuations and sedimentation rates were studied in the central Baltic Sea during the "Baltic Sea Patchiness Experiment 1986" (PEX'86). Vertical particle flux was measured with free drifting sediment traps. Water samples were collected in 10-12 depths down to 70 m and vertical profiles of temperature, salinity, beam attenuation and light intensity were measured at three hour intervals. Water samples were analyzed for Chl.a, POC and PON content, dry weight and nutrients. Particulate parameters including the activity of super(137)Cs were measured in trap samples. Precision and accuracy of the microscopical counts are discussed and confidence limits are calculated for different species and applied counting schemes. Errors in all cases were smaller than the observed in situ variability.
AN: 2260440
105 of 126
TI: Flume evaluation of the relationship between suspended sediment concentration and excess boundary shear stress.
AU: Hill,-P.S.; Nowell,-A.R.M.; Jumars,-P.A.
AF: Sch. Oceanogr., Univ. Washington, Seattle, WA 98195, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS. 1988. vol. 93, no. C10, pp. 12499-509
LA: English
ER: M (Marine)
AB: A flume study was undertaken to determine the source of the large variability in field estimates of gamma , the coefficient of proportionality between excess shear stress and concentration of suspended sediment at a reference height above the bed. Accuracy in predicting suspended sediment concentration and particle flux demands accurate knowledge of this coefficient. To avoid error due to incorrect assumptions concerning the eddy diffusion coefficient for mass, reference concentration was estimated from concentration profiles. A linear relationship was found adequate to describe the dependence of reference concentration on excess boundary shear stress. We show that the variability in previous field-derived estimates of gamma over 4 orders of magnitude is most likely due to improper treatment of the eddy diffusion coefficient for mass and to measurement error.
AN: 2239536
106 of 126
TI: Role of plankton in the carbon and nitrogen budgets of Santa Monica Basin, California.
AU: Small,-L.F.; Landry,-M.R.; Eppley,-R.W.; Azam,-F.; Carlucci,-A.F.
AF: Coll. Oceanogr., Oregon State Univ., Corvallis, OR 97331, USA
SO: MAR.-ECOL.-PROG.-SER.. 1989. vol. 56, no. 1-2, pp. 57-74
NT: Bibliogr.: 44 ref.
LA: English
ER: M (Marine)
AB: The photic zone portions of a particle budget, resolved as carbon and, through appropriate C:N ratios, as nitrogen, are reported for the Santa Monica Basin, a 900 m deep basin in Santa Monica Bay, within the Southern California Bight west of Los Angeles, California. Included are standing stocks of phytoplankton, bacteria and zooplankton, primary production, new production, and particle flux leaving the photic zone. These are compared with rates of fecal pellet production by macrozooplankton and consumption by bacteria and zooplankton within the photic zone using data from 3 October cruises and 2 spring cruises, 1985 to 1987. Most of the primary production (either as C or N) was recycled within the photic zone. Zooplankton food intake rate was always greater than the new production rate in the photic zone, and was usually > 20% of the primary production rate.
AN: 2182426
107 of 126
TI: Surface water particles: Coagulation and sorption.
AU: Culkin,-G.W.; Lawler,-D.F.
AF: Dep. Civ. Eng., Univ. Texas, Austin, TX 78712, USA
CO: Specialty Conference on Environmental Engineering, Austin, TX (USA), 10-12 Jul 1989
SO: ENVIRONMENTAL-ENGINEERING.-PROCEEDINGS-OF-THE-1989-SPECIALTY-CONFERENCE. Malina,-J.F.,Jr.-ed. 1989. pp. 766-772
LA: English
AB: A size-dependent particle and particle-associated contaminant transport and fate model is presented. The unsteady, two-dimensional model couples the water column and bed and enables analysis of size-dependent processes such as sedimentation, reaction (coagulation), erosion, and sorption. The particle-contaminant linkage is also size-dependent, provided by a surface area based partition coefficient. Expected results outline the conditions where coagulation becomes significant in particle flux.
AN: 2178452
108 of 126
TI: Transport and settling of organic material in a deep-sea hydrothermal plume: Evidence from particle flux measurements.
AU: Roth,-S.E.; Dymond,-J.
AF: Coll. Oceanogr., Oregon State Univ., Corvallis, OR 97331, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1989. vol. 36, no. 8, pp. 1237-1254
LA: English
ER: M (Marine)
AB: Results of time-series experiments using moored sediment traps to quantify the settling hydrothermal particle flux above Endeavour Ridge suggest that the oceanic effects of carbon production associated with mid-ocean ridge hydrothermal systems are not limited to the area immediately surrounding seafloor vents. We hypothesize that particulate organic material is entrained, possibly generated in, and removed from the hydrothermal plume at least 2 km from a site of active venting. More than 95% of the organic carbon collected 21 m directly above a site of hydrothermal fluid discharge has a near-bottom, chemosynthetic source. Despite injection of organic carbon at plume depths, perplexing minima in the fluxes of biogenic and inorganic detrital particles are observed at plume-depth 1900 m traps.
AN: 2174268
109 of 126
TI: Transport and settling of organic material in a deep-sea hydrothermal plume: Evidence from particle flux measurements.
AU: Roth,-S.E.; Dymond,-J.
AF: Coll. Oceanogr., Oregon State Univ., Corvallis, OR 97331, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP.. 1989. vol. 36, no. 8A, pp. 1237-1254
LA: English
ER: M (Marine)
AB: Results of time-series experiments using moored sediment traps to quantify the settling hydrothermal particle flux above Endeavour Ridge suggest that the oceanic effects of carbon production associated with mid-ocean ridge hydrothermal systems are not limited to the area immediately surrounding seafloor vents. We hypothesize that particulate organic material is entrained, possibly generated in, and removed from the hydrothermal plume at least 2 km from a site of active venting. More than 95% of the organic carbon collected 21 m directly above a site of hydrothermal fluid discharge has a near-bottom, chemosynthetic source. Up to 62% of the total organic carbon flux measured 100-200 m above bottom and approximately equals 2 km northeast of the vent field (47 degree 57.05'N, 129 degree 06.30'W, depth approximately equals 2200 m) is chemosynthetic. Despite injection of organic carbon at plume depths, perplexing minima in the fluxes of biogenic and inorganic detrital particles are observed at plume-depth 1900 m traps.
AN: 2154292
110 of 126
TI: The dynamics of near-bed seston flux and suspension-feeding benthos.
AU: Muschenheim,-D.K.
AF: Mar. Ecol. Lab., Bedford Inst. Oceanogr., Dartmouth, N.S. B2Y 4A2, Canada
SO: J.-MAR.-RES. 1987. vol. 45, no. 2, pp. 473-496
LA: English
ER: M (Marine)
AB: Benthic suspension feeders depend on the fluid medium for their supply of edible particles. The horizontal flux of organic seston is a function of the interaction of particles of varying densities with the near-bed velocity field. Analytical and numerical models of this process predict that the shape of the flux profile varies with flow rate, bottom roughness and particle setting velocity. Bulk horizontal particle flux may either decrease or increase with height above the bed. The feeding ecology and diet of a passive suspension feeder, the polychaete, Spio setosa , were examined in light of the modelled seston dynamics.
AN: 2133220
111 of 126
TI: Effects of flow velocity, food concentration, and particle flux on growth of juvenile bay scallops, Argopecten irradians .
AU: Cahalan,-J.A.; Siddall,-S.E.; Luckenbach,-M.
AF: Mar. Sci. Res. Cent., SUNY, Stony Brook, NY 11794, USA
CO: 1987 Annu. Meet. of the Natl. Shellfisheries Assoc., Halifax, N.S. (Canada), 9 Aug 1987
SO: J.-SHELLFISH-RES. 1988. vol. 7, no. 1, pp. 151-152
NT: Summary only.
LA: English
ER: M (Marine)
AB: Growth rates of suspension feeding organisms are determined by many interacting factors, efficiency of particle capture and food particle concentration being 2 of the more influential. Flume studies were conducted to examine the growth rates of juvenile bay scallops Argopecten irradians in 3 flow velocities (1,6, & 15 cm/sec) over a range of food concentrations (6000-80000 cells/ml). The 3 channels of the experimental flume, each running at a different flow rate, were gravity fed from a single reservoir. Juvenile scallops were positioned on rigid eelgrass mimics, and placed in the flume channels. Particle flux passing by the scallops is the product of food concentration and flow velocity. Initial results show differences in growth, within a given flux of food particles. These differences were due to interactions between flow velocity and food concentration, not due to differential food fluxes, indicating measurement of flux alone to be a poor predictor of growth. Food concentration is more important than flow velocity.
AN: 2098853
112 of 126
TI: The vertical particle flux in the northern North Sea, its seasonality and composition.
AU: Kempe,-S.; Jennerjahn,-T.C.
CA: Scientific Comm. on Problems of the Environment
United Nations Environment Programme, Hamburg (FRG). Int. Carbon Unit
SO: BIOGEOCHEMISTRY-AND-DISTRIBUTION-OF-SUSPENDED-MATTER-IN-THE-NORTH-SEA-AND-IMPLICATIONS-TO-FISHERIES-BIOLOGY. Kempe,-S.;Liebezeit,-G.;Dethlefsen,-V.;Harms,-U.-eds. 1988. no. 65 pp. 229-268
ST: MITT.-GEOL.-PALAEONTOL.-INST.-UNIV.-HAMBURG. no. 65
NT: 38 ref. SCOPE/UNEP Sonderband. Final rep., BMFT-Project MFU 05438.
LA: English
ER: M (Marine)
AB: Two-time-series MARK VI Honjo traps were moored in the Northern North Sea in 1985 and 1986. One trap was stationed in the western Skagerrak the other in the Norwegian Channel. Total flux measured was highly variable ranging from 2.7 to 232.4 mg/m super(2)/d in the Norwegian Channel and from 114.2 to 1039.3 mg/m super(2)/d in the Skagerrak. This variation is governed by the seasonality of the biological activity in the surface waters. In short, four "seasons" occur in flux rates and composition of settling material. In spring the diatom bloom causes peak sediment fluxes, also of terrigenous matter while in summer and in autumn large amounts of calcite are deposited as a consequence of a coccolithophorid bloom.
AN: 2092668
113 of 126
TI: A pelagic ecosystem model simulating production and sedimentation of biogenic particles: Role of salps and copepods.
AU: Andersen,-V.; Nival,-P.
AF: Stn. Zool., CEROV, BP 28, F-06230 Villefranche-sur-Mer, France
SO: MAR.-ECOL.-PROG.-SER.. 1988. vol. 44, no. 1, pp. 37-50
NT: Incl. 64 ref.
LA: English
ER: M (Marine)
AB: Production and sedimentation of biogenic particles are investigated by a depth-dependent model of a Mediterranean coastal pelagic ecosystem. The model considers living and dead phytoplankton and its sedimentation, 2 herbivores, salps and copepods, and sedimentation of their fecal pellets and carcases. Results underline the major role played by fecal pellets and by both living and dead salps in vertical matter flux. Although salp and copepod biomasses are similar, the magnitude and composition of the particle flux are much more influenced by salps than by copepods: salp fecal pellets and carcases account for 72% of the maximum overall flux.
AN: 1974910
114 of 126
TI: Seasonal variability of particle flux in the Weddell Sea and its relation to ice cover.
AU: Fischer,-G.; Fuetterer,-D.; Gersonde,-R.; Honjo,-S.; Ostermann,-D.; Wefer,-G.
AF: Univ. Bremen, Geowiss., 2800 Bremen, FRG
SO: NATURE. 1988. vol. 335, no. 6189, pp. 426-428
LA: English
ER: M (Marine)
AB: In the Weddell Sea, primary production varies seasonally as a result of the solar cycle and the large-scale oscillation of the ice edge across much of its area. The annual ice transgression is the largest of any region on Earth and has a profound influence on the production and transportation of particulate matter. In order to clarify the flux, origin and mode of vertical transport of oceanic particles in the pelagic Weddell Sea, the authors deployed a multi-year sediment trap. The annual particle flux measured was the smallest yet observed in the world ocean, and showed extreme variability. Phytoplankton production is at least partly seeded by diatoms released from the melting of sea ice which had formed in the coastal area of the Antarctic continent.
AN: 1967949
115 of 126
TI: Suspension feeding in oscillating flow: The effect of colony morphology and flow regime on plankton capture by the hydroid Obelia longissima .
AU: Hunter,-T.
AF: Zool. Dep., 4079 Life Sci. Build., Univ. California, Berkeley, CA 94720, USA
SO: BIOL.-BULL.-MAR.-BIOL.-LAB.-WOODS-HOLE. 1989. vol. 176, no. 1, pp. 41-49
LA: English
ER: M (Marine)
AB: The effect of flow regime on the ability of the hydroid Obelia longissima to capture plankton was examined in a laboratory flume and a wave tank. Feeding effectiveness--the proportion of the gastrozooids with tentacles successfully capturing food in a fixed amount of time--is significantly greater in oscillating flow than in unidirectional flow at the same average velocity and particle flux. Thus quantitative feeding studies in unidirectional flow may seriously underestimate feeding in the field if flow in the natural habitat is unsteady. Increasing colony bushiness (weight/colony length) decreases feeding effectiveness in unidirectional and low frequency oscillating flow, but not in high frequency oscillating flow.
AN: 1951523
116 of 126
TI: Particle flux in the western Black Sea in the present and over the last 5,000 years: Temporal variability, sources, transport mechanisms.
AU: Hay,-B.J.
CA: Woods Hole Oceanographic Inst., MA (USA)
SO: TECH.-REP.-WOODS-HOLE-OCEANOGR.-INST. 1987. 212 pp
NT: NTIS Order No.: AD-A188 487/3/GAR. Doctoral thesis. Contract N00014-85-C-0001.
RN: WHOI-87-44 (WHOI8744)
LA: English
ER: M (Marine)
AB: The particle flux in the present and over the last 5,000 years was investigated in the western Black Sea in a comparative study with samples from time-series sediment traps and laminated core sediments. The particle flux varies considerably seasonally and regionally. Dominant particle sources are biogenic and terrigenous matter. The relative importance in the particle supply varies seasonally and can be grouped into three phases. (Prepared in coop. with Massachusetts Inst. of Technology, Cambridge, MA. Grant NSF-OCE84-17106.)
AN: 1925436
117 of 126
TI: Particle flux beneath fast ice in the shallow southwestern Beaufort Sea, Arctic Ocean.
AU: Carey,-A.G.,Jr.
AF: Coll. Oceanogr., Oregoan State Univ., Corvallis, OR 97331, USA
SO: MAR.-ECOL.-PROG.-SER.. 1987. vol. 40, no. 3, pp. 247-257
NT: Incl. 54 ref.
LA: English
ER: M (Marine)
AB: Flux of organic particulate materials under sea ice to the benthic environment was measured in the nearshore Arctic Ocean during spring 1980. Downward flux of organic carbon started early in the spring and continued at fairly uniform but low levels similar to 1% of daily carbon production of ice algae) from Apr until early Jun. Particulate organic nitrogen flux tended to be low and erratic. Fecal pellets from 2 crustacean species were among the few recognizable large particles. The sinking particles were derived from both the pelagic and ice environments, although most of the material appeared to be from the ice biota.
AN: 1854358
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TI: Annual particle flux and a winter outburst of sedimentation in the northern Norwegian Sea.
AU: Honjo,-S.; Manganini,-S.J.; Wefer,-G.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES. 1988. vol. 35, no. 8A, pp. 1223-1234
LA: English
ER: M (Marine)
AB: Monthly samples were collected by a sediment trap deployed for one year at 473 m above the sea floor in water 2123 m deep at a station located at 75 degree N, 11 degree E, southwest of Spitsbergen. This station was positioned at the northernmost extension of the Norwegian Current and was not covered by sea ice throughout the year of the experiment. The annual particle flux was 28.3 g m super(-2), of which 49% was biogenic and 51% was lithogenic particles. The annual fluxes of organic carbon, calcium carbonate, and biogenic opal were 2.9, 6.6 and 2.0 g m super(-2), respectively. There were three distinct seasonality phases in sedimentation. During December to May was a period of outburst of lithogenic particle sedimentation which peaked during mid-January to mid-February. This outburst may be related to cold deep water generated on the Barents Sea shelf and flowing southwestward through the Storfjord Trough into the Norwegian Sea.
AN: 1843913
119 of 126
TI: Seasonal particle flux in the Bransfield Strait, Antarctica.
AU: Wefer,-G.; Fischer,-G.; Fueetterer,-D.; Gersonde,-R.
AF: Fachber. Geowissenschaften, Univ. Bremen, Bibliothekstr., 2800 Bremen 33, FRG
SO: DEEP-SEA-RES. 1988. vol. 35, no. 6A, pp. 891-898
LA: English
ER: M (Marine)
AB: Time-series sediment traps were deployed at 494 and 1588 m water depth in Bransfield Strait from 1 December, 1983 to 25 November, 1984. During austral summer (December and January) total flux was more than 1.5 g m super(-2)/day to both water depths, while during all other months 1984 flux was between 10 and 1,000 times lower. The annual total flux to the deeper trap (1,588 m) was 110 g/m super(-2). The flux of the two most productive months was 97% of the total. Biogenic components (carbonate, POM and opaline silica) accounted for about 67% in the upper trap and 50% in the lower one. The remaining portion of the material collected were lithogenic particles. The transfer of the particles is mainly through the fecal pellets of krill.
AN: 1838621
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TI: Vertical flux of particulate matter by sedimentation and zooplankton movements in St. Georges Bay, the southern Gulf of St. Lawrence.
AU: Harding,-G.C.; Hargrave,-B.T.; Vass,-W.P.; Sheldon,-R.W.; Pearre,-S.,Jr.
AF: Dep. Fish. Oceans, Mar. Ecol. Lab., Bedford Inst. Oceanogr., P.O. Box 1006, Dartmouth, N.S. B2Y 4A2, Canada
CO: Fluxes of Particulate Matter Across Benthic Boundaries, St. Andrews, N.B. (Canada), 29 Oct 1985
SO: FLUXES-OF-PARTICULATE-MATTER-ACROSS-BENTHIC-BOUNDARIES. Grant,-J.G.;Mills,-E.S.-eds. 1987. vol. 4, no. 3 pp. 323-357
ST: BIOL.-OCEANOGR. vol. 4, no. 3
LA: English
ER: M (Marine)
AB: Particulate sedimentation and upward movement by zooplankton were measured simultaneously as dry matter, organic carbon, and nitrogen in two field experiments in St. Georges Bay, N.S. The size of the metazooplankton populations and the seasonal stability of the water column determined the relative magnitude of vertical particle flux. The interaction of zooplankton with their food supply appear to be of critical importance in influencing their vertical movements. Food produced and consumed in the euphotic zone is redistributed throughout the water column by both mortality and defecation of daily migrating zooplankters. In summer, when production and consumption of phytoplankton was high and in approximate balance, the rate of organic carbon and nitrogen transferred vertically as swimming zooplankters exceeded that by gravitational sedimentation. Near isothermal conditions in spring allowed storms to resuspend bottom materials, which gradually settle out of the water column.
AN: 1819574
121 of 126
TI: (Kapverden-Expedition October-December 1986 (RV "Meteor " cruise no. 4).).
OT: Forschungsschiff Meteor , Reise Nr. 4 - Kapverden-Expedition Oktober - Dezember 1986
AU: Siedler,-G.; Schmickler,-H.; Mueller,-T.J.; Schenke,-H.-W.; Zenk,-W.
AF: Inst. Meereskd., Univ. Kiel, Duesternbrooker Weg 20, 2300 Kiel, FRG
SO: BER.-INST.-MEERESKD.-CHRISTIAN-ALBRECHTS-UNIV.-KIEL. 1987. no. 173, 123 pp
NT: Mainly numerical data.
LA: German
ER: M (Marine)
AB: The first part of Meteor cruise no. 4 between Kiel and Lisbon included a technical and scientific testing program. The aim was to test the new side-looking echosounder system HYDROSWEEP and the integrated navigation system INS. This report summarizes the activities and presents results of this project. The second part of the cruise from Lisbon via Sta. Cruz and Dakar to Kiel included a multidisciplinary research program in the Canary and Cape Verde Basins. The principal aim was to study the circulation and mixing in the eastern part of the North Atlantic subtropical gyre. The following program was carried out: Sampling with sediment traps for the determination of the oceanic particle flux; Air chemistry measurements for the observation of Sahara aerosol; Aerological measurements in the atmospheric boundary layer. The report summarizes the observational program, and tentative results are presented.
AN: 1801742
122 of 126
TI: The oceanic chemistry of the rare-earth elements.
AU: Elderfield,-H.
AF: Dep. Earth Sci., Univ. Cambridge, Madingley Rd., Cambridge CB3 0EZ, UK
CO: Tracers in the Ocean, London (UK), 21-22 May 1987
SO: TRACERS-IN-THE-OCEAN. Charnock,-H.;Lovelock,-J.E.;Liss,-P.S.;Whitfield,-M.-eds. 1988. vol. 325, no. 15831 pp. 105-126
ST: PHILOS.-TRANS.-R.-SOC.-LOND.-SER.-A. vol. 325, no. 15831
LA: English
ER: M (Marine)
AB: Because of the unique chemical characteristics of the rare-earth elements (REEs), they provide information as oceanic tracers of element source and reactivity. Within the REE group, Ce anomalies occur in response to oceanic redox conditions; Eu anomalies in response to aeolian and hydrothermal input; and Nd isotopic variations reflect element sources. Both REE concentration patterns and Nd isotopic variations allow the effects of the vertical particle flux and of lateral advection to be separated.
AN: 1761551
123 of 126
TI: (On board the Polarstern .).
OT: A bordo del Polarstern
SO: BOL.-ANTART.-CHIL. 1985. vol. 5, no. 2, pp. 37-39
LA: Spanish
ER: M (Marine)
AB: The projects developed during the second stage of the Fourth Antarctic Expedition on board the R/V Polarstern are described. These projects comprise studies on: oceanography and applied physics; phytoplankton research; holocenic sedimentation in the Bransfield Strait and in the South Shetland Islands channel; petrographic survey of Bransfield Strait superficial sediments; thermal interaction of the expansion transarch vulcanism and the Bransfield Strait sedimentary basin; flux particle in antarctic waters; Bransfield Strait siliceous planktonic organisms and foraminifera distribution; nanoplankton distribution and analytic surveys of Atlantic Ocean atmospheric inorganic components. Vessel installations and facilities are given.
AN: 1733224
124 of 126
TI: A particle flux study in the Santa Monica-San Pedro Basin off Los Angeles: Particle flux, primary production, and transmissometer survey.
AU: Nelson,-J.R.; Beers,-J.R.; Eppley,-R.W.; Jackson,-G.A.; McCarthy,-J.J.; Soutar,-A.
AF: Inst. Mar. Resour., A-018, Scripps Inst. Oceanogr., Univ. California at San Diego, La Jolla, CA 92093, USA
SO: CONT.-SHELF-RES. 1987. vol. 7, no. 3, pp. 307-328
LA: English
ER: M (Marine)
AB: In May 1983, two short-term deployments of sediments traps at 100, 300, and 500 m measured the sinking flux of mass (as dry weight), particulate organic carbon and carbonate carbon in the nearshore basins off Los Angeles. The flux of organic carbon at 100 m depth was about 15% of the mass flux and about 5% of the rate of primary production measured in the surface waters. At 500 m the efflux of organic carbon had decreased to about half that at 100 m. Characteristics of the trap collections indicated a large biogenic contribution. The biomass carbon of microorganism determined by microscopy (exclusive of heterotrophic bacteria) in the surface waters was dominated by nano- and picoplankton size categories. In the sediment trap collections, total microorganism carbon comprised < 3% of the carbon flux. A six-month (May-November) sediment trap deployment was also made. The higher mass flux to the deeper of these traps indicates near-bottom transport of suspended sediments.
AN: 1729777
125 of 126
TI: Environmental time series measurement in the central Gulf of California -- small vessel instrument adaptation.
AU: Soutar,-A.; Singleton,-J.; Rau,-S.; Butler,-M.; Zaneveld,-R.; Baungartner,-T.; Duffrin,-E.; Folson,-T.
AF: Scripps Inst. Oceanogr., Univ. California at San Diego, La Jolla, CA 92093, USA
CO: Oceans '85 "Engineering and the Environment", San Diego, CA (USA), 12-14 Nov 1985
SO: OCEANS-'-85-PROCEEDINGS:-OCEAN-ENGINEERING-AND-THE-ENVIRONMENT. Marine-Technology-Soc.,-Washington,-DC-USA;-IEEE-Ocean-Eng.-Soc.,-NY-USA 1985. vol. 1, pp. 635-643
ST: OCEANS-'-85.
LA: English
ER: M (Marine)
AB: A number of instruments are being adapted for use off small vessels. These devices will help to implement time series study of coastal biology and sedimentation response to seasonal and interannual climatic change in an area off Guaymas, Mexico. The capabilities include: 1/ digitally recorded vertical profiles of conductivity, temperature, oxygen and light transmission; 2/ collection of a contamination free water sample at depth for calibration and water chemistry; 3/ collection of a fully integrated water sample from 50 meters to the surface for phytoplankton and nutrients; 4/ vertical net sampling from 150 meters to the surface for zooplankton estimation; 5/ moored collection of particle flux at depth; 6/ measurement of current velocity and direction; 7/ collection of an undisturbed surface sediment sample.
AN: 1700477
126 of 126
TI: Flux of particle matter and biogeochemical processes at the sediment-water interface.
OT: Flux de matiere et processus biogeochimiques a l'interface sedimentaire
AU: Buscail,-R.; Monaco,-A.
AF: Lab. Sedimentol. Geochim. Mar. Perpignan, Univ. Perpignan, Ave. de Villeneuve, 66025 Perpignan, France
CO: Oceans (Suite), Bordeaux (France), 2 Dec 1985
SO: OCEANS-THE-LAST-PART:-SPECIAL-MEETING-OF-THE-SOCIETE-GEOLOGIQUE-DE-FRANCE,-BORDEAUX,-DECEMBER-2nd-AND-3rd-1985.. OCEANS-SUITE:-SEANCE-SPECIALISEE-DE-LA-SOCIETE-GEOLOGIQUE-DE-FRANCE,-BORDEAUX,-2-3-DECEMBRE-1985.- Peypouquet,-J.P.-ed. Societe-Geologique-de-France,-Paris-France1987. vol. 3, no. 4 pp. 715-722
ST: BULL.-SOC.-GEOL.-FR.-8-SER.. vol. 3, no. 4
LA: French
ER: M (Marine)
AB: Qualitative and quantitative characteristics of particle fluxes at the head of a submarine canyon (Lacaze-Duthiers canyon, gulf of Lion, western Mediterranean margin) are compared with biogeochemical properties of the bottom layer at 345 m depth (Ecomarge program). Preliminary data shows: 1) an important fine particle flux (90% < 40 mu m) which indicates a linear increase from 4 g multiplied by m super(-2) multiplied by d super(-1) at 100 m to 13 at 315 m depth; 2) a biogenic fraction (combustible matter, biogenic silica, carbonates) which comprises 39 to 45% of the total mass flux; 3) a lithogenic fraction which accounts for 50 to 60 percent of the total mass flux (quartz, feldspar particles and phyllosilicates (illite)); 4) a fecal pellet flux increasing with depth: 2.3 to 7.4 10 super(6) multiplied by m super(-2) multiplied by d super(-1). Elemental analyses of suspended matter show minor variations with depth. Moreover, different selective chemical attacks reveal that Cu appears to be related to biogenic flux which decreases in the deeper nepheloid (200 and 315 m).
AN: 1668558
No. Records Request
1: 71 JGOFS
Searches and records above from: ASFA 1997-1998/09
3: 200 #1
4: 14252 INDIA
5: 1 #3 and INDIA
6: 200 #3
Searches and records above from: ASFA 1988-1996
8: 0 #6
9: 1797 PARTICLE
10: 2284 FLUX
11: 20 PARTICLE FLUX
Searches and records above from: ASFA 1978-1987
13: 126 #11
Searches and records above from: ASFA 1988-1996
15: 35 #13
1 of 35
TI: Particle tracking simulation of pollutant discharges
AU: Scott,-C.F.
AF: Dep. Civ. and Build. Eng., Loughborough Univ., Loughborough LE11 3TU, UK
SO: J.-ENVIRON.-ENG. 1997 vol. 123, no. 9, pp. 919-927
LA: English
ER: M (Marine)
AB: A two-dimensional particle tracking simulation of pollutant discharges in a vertically well-mixed tidal current is performed for an idealized straight coast with parametrically defined parallel bathymetry and realistic spatially and temporally varying longshore velocity and diffusivity fields. Two methods of random-walk simulation in varying diffusivity media are compared: one where the random walk is performed in a transformed (spatially) uniform diffusivity space and the other where the random walk takes place in the untransformed space. For the special case of a steady coastal current - and subject to a suitable choice of a random-number generator, time step, and particle flux - the stochastic solutions in either case are found to be in reasonable agreement with the analytic solution of a previous researcher. Further simulations of steady and of "optimal" discharges in tidal flows with and without a mean longshore current are presented. The major conclusion is that in the absence of shorelines, discharging optimally - in the sense of maintaining a constant global maximum concentration in the presence of a varying current - allows a much greater mass of pollutant to be discharged over the tidal cycle. However, in the presence of shorelines discharging optimally leads to much higher shoreline concentrations and thus has little effect in reducing global maximum concentrations. This suggests that there is little advantage to be gained by varying the discharge in such cases.
AN: 4320984
2 of 35
TI: Vertical particle flux on the shelf off northern Spitsbergen, Norway
AU: Andreassen,-I.; Noethig,-E.-M.; Wassmann,-P.
AF: Norwegian College of Fishery Science, University of Tromsoe, N-9037 Tromsoe, Norway
SO: Mar.-Ecol.-Prog.-Ser. 1996 vol. 137, no. 1-3, pp. 215-228
NT: Incl. bibliogr.: 54 refs.
LA: English
ER: M (Marine)
AB: Suspended and sedimented particulate matter was examined along transects on the continental shelf off northern Spitsbergen, Norway, during summer 1991. The transects were situated in non-ice-covered areas dominated by Atlantic water, areas with multi-year ice and the marginal ice zone. The variability of the sedimented matter with regard to composition, quantity and quality between the 7 investigated stations was considerable. The open Atlantic water showed the highest suspended biomass [100 to 280 mg particulate organic carbon (POC)/m super(3)] and the vertical flux was moderate (24 to 30 mg POC/m super(2)/d) and dominated by faecal matter. While the suspended biomass in areas covered by multi-year ice was low (<65 mg POC/m super(3)), the vertical flux was relatively high (18 to 76 mg POC/m super(2)/d) and dominated by terrestrial organic and faecal matter. The contribution of phytoplankton cells to the vertical flux of POC was small in areas covered by multi-year ice, on average about 1%. The contribution of phytoplankton cells to the vertical flux in the marginal ice zone was higher (5.6% of POC), consisting mainly of Chaetoceros socialis and Fragilariopsis, but a considerable amount of faecal matter also settled. At all stations zooplankton strongly influenced the vertical flux, not only by faecal pellet production but probably also by direct mediation of fluxes (e.g. coprophagy).
AN: 4213490
3 of 35
TI: Qualitative evolution of particle flux since 12600 yrs in the Lake Chambon watershed, Massif Central, France
OT: Evolution qualitative des flux particulaires depuis 12600 ans dans le bassin du lac Chambon, Massif Central, France
AU: Gay,-I.; Macaire,-J.J.; Cocirta,-C.
AF: Lab. Geologie des Systemes Sedimentaires, Faculte des Sciences et Techniques, Parc de Grandmont, 37200 Tours, France
SO: Bull.-Soc.-Geol.-Fr. 1998 vol. 169, no. 2, pp. 301-314
LA: French
ER: M (Marine); F (Freshwater)
AB: Analysis of grain size, composition of sand-size and < 2(m size fractions of sediments stored in the Lac Chambon watershed during the Postglacial period, using the earlier quantification of sediments, made it possible to precise the effect of watershed parameters on detrital sediment yield. The whole yield of 1/5 pebbles and gravels, 2/5 sands, 2/5 silts and some % clays, taken front volcanic and granitic areas about in proportion to their respective outcrop surfaces, shows effect of non-varying watershed parameters: lithology, relief and tectonics. Fluctuations of climate and vegetation induced variations in grain size of sediment yield. Sediment yield (from 49 ( 15 to 166 ( 50 m super(3)/km super(2)/yr) dominated either on volcanic areas (B lling-Aller d, Younger Dryas, Pre-Boreal periods), either on granitic areas (Boreal period), or was in proportion to the outcrop surfaces of these rocks (first half of the Subatlantic period). During the second half of the Subatlantic period, man made vegetation clearance increased sediment yield from granitic areas.
AN: 4318786
4 of 35
TI: Mechanical design of hydroids: Flexibility, flow forces, and feeding in Obelia longissima.
AU: Hunter,-T.
CA: California Univ., Berkeley (USA)
SO: DISS.-ABST.-PT.-B-SCI.-ENG. 1989 vol. 49, no. 12, 228 pp
NT: Diss. Ph.D.: Order No.: DA8902128.
LA: English
ER: M (Marine)
AB: In this dissertation I examine the relationship between the morphology of the hydroid Obelia longissima, the flexibility of the colony, the hydrodynamic forces it experiences, and its ability to capture food in uni-directional and oscillating flow regimes. The water flow encountered by Obelia in the field was measured. For laboratory experiments, oscillating flow was produced by a wave tank, while uni-directional flow was produced in a recirculating flume. Feeding effectiveness, defined as the proportion of tentacle-bearing gastrozooids successfully capturing food in a fixed amount of time, is significantly greater in oscillating flow than in uni-directional flow at the same average (root mean square) velocity and particle flux. Increasing colony bushiness (weight /colony length) decreases feeding effectiveness in uni-directional and low-frequency oscillating flow, but not in high-frequency oscillating flow. The effect of flow regime on colony morphology was investigated in the field by growing Obelia in habitats subjected to oscillating flow of differing peak velocity, and by growing Obelia on a spinning turntable that provided uni-directional flow of different velocities. At comparable ambient flow velocity, colony length, weight, and business were higher for animals grown in uni-directional flow on the turntable than for animals grown in oscillating flow in the field. Colony weight was significantly higher in the "medium velocity" treatments than the "high-" or "low velocity" treatments in both experiments. Number of annuli per annulated region, annulated region length, and perisarc diameter were significantly higher in the "medium velocity" treatment than in the "low velocity" or "high velocity" treatments of transplant experiment, but the differences would not effect the flexural stiffness or critical buckling stress of non-annulated regions. Increased diameter would be expected to increase stiffness and decrease damage in bending of annulated regions. The observed differences in these morphological parameters with "flow velocity" in the transplant experiment reflected a correlation of these parameters with colony size rather than a response to flow velocity per se. Thus adaptive explanations of hydroid morphological changes in response to ambient flow probably do not obtain (DBO).
AN: 4302702
5 of 35
TI: Protactinium-231 and thorium-230 abundances and high scavenging rates in the western Arctic Ocean
AU: Edmonds,-H.N.; Bradley-Moran,-S.; Hoff,-J.A.; Smith,-J.N.; Lawrence-Edwards,-R.
AF: Grad. Sch. Oceanogr., Univ. Rhode Island, Narragansett, RI 02882, USA
SO: Science-Wash. 1998 vol. 280, no. 5362, pp. 405-407
LA: English
ER: M (Marine)
AB: The Canadian Basin of the Arctic Ocean, largely ice covered and isolated from deep contact with the more dynamic Eurasian Basin by the Lomonosov Ridge, has historically been considered an area of low productivity and particle flux and sluggish circulation. High-sensitivity mass-spectrometric measurements of the naturally occurring radionuclides proctatinium-231 and thorium-230 in the deep Canada Basin and on the adjacent shelf indicate high particle fluxes and scavenging rates in this region. The thorium-232 data suggests that offshore advection of particulate material from the shelves contributes to scavenging of reactive materials in areas of permanent ice cover.
AN: 4299123
6 of 35
TI: Biological components of the particle flux in the Ross Sea polynya: November and December 1994
AU: Gowing,-M.M.; Garrison,-D.L.; Kunze,-H.; Mathot,-S.
AF: Institute of Marine Sciences, University of California, Santa Cruz, CA 95064, USA
SO: Antarct.-J.-U.S. 1995 vol. 30, no. 5, pp. 206-207
LA: English
AB: Food web structure determines the nature and magnitude of material sinking from the euphotic zone (e.g., Michaels and Silver 1988; Peinert, von Bodungen, and Smetacek 1989, pp. 35-48). The Ross Sea, with its Phaeocystis and diatom blooms and their associated food webs, provides a unique location to compare the fate of carbon under two very different primary productivity regimes. As part of the Ross Sea Polynya Project (Smith, Antarctic Journal, in this issue), we are investigating the differences in algal sedimentation, protozoan assemblages accompanying sinking detritus, and products of grazing (minipellets of microzooplankton and fecal pellets of larger zooplankton) during the progression of both types of bloom.
AN: 4261102
7 of 35
TI: Particle flux in the Ross Sea polynya: November and December 1994
AU: Asper,-V.L.; Diercks,-A.-R.; Tuel,-M.D.
AF: University of Southern Mississippi, Center for Marine Science, Stennis Space Center, MS 39529, USA
SO: Antarct.-J.-U.S. 1995 vol. 30, no. 5, pp. 204-205
LA: English
AB: As part of a multidisciplinary program to investigate the dynamics of a large phytoplankton bloom in the Ross Sea, we sampled the export of material from the upper water column. The particles exported derive from both the direct settling of algal cells and from the products of grazing, including fecal pellets. To intercept the settling particles, we deployed an array of sediment traps attached to a surface drifting array which was tracked using a surface buoy constructed of Kevlar registered and fiberglass. Inside this buoy were dual Argos registered transmitters which were tracked by satellite and the positions relayed to the ship (R/V Nathaniel B. Palmer) with a minimum 2-hour delay. Below this buoy were a bungee cord to absorb wave energy, 10 thermographs to record temperature and depth pairs during the deployment, five sediment traps, an electromagnetic current meter to monitor the flow of water relative to the array, and a special sediment trap, the marine aggregate flux investigation apparatus (MAFIA), that also incorporates cameras (Asper in preparation). At each of the five sediment trap depths (50, 75, 100, 150, and 200 meters), 12 of the vertex multitrap (Knauer, Martin, and Bruland 1979) design particle interceptor traps (PITs) were deployed on a single supporting structure.
AN: 4261101
9806
8 of 35
TI: Sea surface temperature and productivity records for the past 240 kyr in the Arabian Sea
AU: Rostek,-F.; Bard,-E.; Beaufort,-L.; Sonzogni,-C.; Ganssen,-G.
AF: CEREGE, University d'Aix-Marseille III et CNRS-FR 6094 et UMR 6536, Europole de l'Arbois, BP80, 13545 Aix-en-Provence Cedex 4, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 6-7, pp. 1461-1480
NT: Special issue: Netherlands Indian Ocean Program 1992-1993: First results.
LA: English
ER: M (Marine)
AB: Deep-sea sediments of two cores from the western (TY93-929/P) and the southeastern (MD900963) Arabian Sea were used to study the variations of the Indian monsoon during previous climatic cycles. Core TY93-929/P was located between the SW monsoon driven upwelling centres off Somalia and Oman, which are characterized by large seasonal sea surface temperature (SST) and particle flux changes. By contrast, core MD900963, was situated near the Maldives platform, an equatorial ocean site with a rather small SST seasonality (less than 2 degree C).
AN: 4292422
9 of 35
TI: Simulating large scale transport of suspended matter
AU: Segschneider,-J.; Suendermann,-J.
AF: European Cent. for Medium Range Weather Forecast, Shinfield Park, Reading, Berks, RG2 9AX, UK
SO: J.-MAR.-SYST. 1998 vol. 14, no. 1-2, pp. 81-97
LA: English
ER: M (Marine)
AB: In this paper a Lagrangian numerical transport model is presented that simulates suspended matter concentrations on large scales. The model is based on the velocity fields of a 22-layer version of the 3.5 degree x 3.5 degree Hamburg Large Scale Geostrophic OGCM. Here, the model is applied to the transport of resuspended sediment from the hypothetical source of deep sea mining in the eastern equatorial Pacific. The advection and dispersion of an initially concentrated cloud are simulated for a time range of five decades. Three-dimensional time dependent concentration fields, sedimentation rates at the ocean bottom, the residence time of the particles in the water column and the length of their transport paths are presented. The computed sedimentation rates are compared to the natural background values and estimates of possible consequences for the benthic ecosystem are made. Three experiments are described in this paper. The first one simulates the drift of a particle in the conveyor belt over 1850 years. This experiment is performed to test the advection scheme of the transport model and the currents that are simulated with the underlying circulation model. The second and the third experiment simulate the dispersion of resuspended sediment close to the ocean's bottom and the release of tailings from ocean mining close to the ocean's surface, respectively. In the last two experiments the suspended matter cloud is represented by Lagrangian tracers which possess a mass and diameter distribution according to observations. A main result of experiment two and three is that for the near-bottom source of suspended matter, the drift of resuspended sediment is confined to less than 1000 km, whereas the release of tailings into the surface layer may result in basin wide transport of the fine-grained fraction of the material. The residence time (which here is the time between the release of a Lagrangian tracer and its touch-down at the ocean bottom) of the medium-sized particles is 2 to 3 years for the near-bottom source and up to 20 years for the surface release. The computed sedimentation rates are up to five orders larger than the natural background. Thus, the additional particle flux caused by deep sea mining might easily bury the thin layer of food on which the benthic ecosystem feeds. We also compare the computed residence times of the particles within the water column with residence times derived from super(238)U to super(230)Th observations. We estimate, that the settling velocity of the particles doubles by scavenging through biogenic particle fluxes and physical particle interactions (which are not included in the model yet).
AN: 4265700
10 of 35
TI: Particle flux through sediment fingers
AU: Chen,-C.F.
AF: Dep. Aerospace and Mech. Eng., Univ. Arizona, Tucson, AZ 85721, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 9-10, pp. 1645-1654
LA: English
ER: M (Marine)
AB: Experiments were carried out to examine the fingering convection process occurring at the interface between a layer of warm, particle-laden water overlying a layer of cold, fresh water. In the formation stage, the rapidly descending fingers were irregular, with large caps or vortex rings at their tips. However, when fully developed, the sediment fingers were of approximately the same size, appearing in a regular array all along the interface. Contrary to the case of salt-finger convection, in which the downward diffusing component is thoroughly mixed in the upper layer at all times, the particle-laden fluid descends as an integral unit as convection proceeds, leaving behind a growing fluid region with a much-reduced particle concentration in the top part of the upper layer. The measured flux of SiC particles as a result of finger convection for a range of initial density ratios is much increased from that caused by sedimentation based on settling velocity when the relative density difference because of particle concentration is high. At low relative density differences, the particle flux is essentially due to settling.
AN: 4256857
11 of 35
TI: Scavenging processes and export fluxes close to a retreating seasonal ice margin (Ross Sea, Antarctica)
AU: Langone,-L.; Frignani,-M.; Cochran,-J.K.; Ravaioli,-M.
AF: Istituto di Geologia Marina CNR, Via Gobetti 101, 40127 Bologna, Italy
CO: 7. Int. Symp.: The Interactions Between Sediments and Water, Baveno (Italy), 22-25 Sep 1996
SO: Water,-Air,-and-Soil-Pollution 1997 vol. 99, no. 1-4, pp. 705-715
LA: English
ER: M (Marine)
AB: The distribution of dissolved and particulate super(234)Th in the upper 200 m of the water column was obtained for three stations in the Ross Sea off Victoria Land and Terra Nova Bay. At site 24a, close to the retreating ice margin, all the sampled depths showed deficiencies in super(234)Th relative to the equilibrium with super(238)U. These are related to uptake of super(234)Th onto sinking particles. Residence times of super(234)Th in solution and of particulate super(234)Th were 130-247 days and 8.1-6.6 days, respectively. A high particle flux (1.23-5.03 g m super(-2) d super(-1)) was calculated at this station. At the other two sites (11c and 15c), super(234)Th depth profiles are irregular, probably due to the release of dissolved super(234)Th by decomposing particles at certain depths, or to the contribution from lateral advection. Bulk mass fluxes measured by floating traps at stations 11 c and 15c are very low (66-138 mg m super(-2) d super(-1)). Also fluxes of organic carbon and nitrogen, and biogenic silica are reported for these two sites. The calculated fluxes are discussed with respect to methodologies and to the dynamics of the ice margin retreat.
AN: 4229764
12 of 35
TI: Pelagic-benthic coupling in the Nordic seas: The role of episodic events
AU: Wassmann,-P.; Andreassen,-I.; Reigstad,-M.; Slagstad,-D.
AF: Norwegian College of Fishery Science, University of Tromsoe, N-9037 Tromsoe, Norway
CO: 29. European Marine Biology Symposium., Vienna (Austria), 29 Aug-2 Sep 1994
SO: Influences-of-organisms-on-their-environment.-The-role-of-episodic-events. Dworschak,-P.C.;Stachowitsch,-M.;Ott,-J.A.-eds. Berlin-FRG Blackwell-Wissenschafts-Verl. 1996 vol. 17, no. 1-3 pp. 447-471
ST: Mar.-Ecol. vol. 17, no. 1-3
NT: Incl. bibliogr.: 68 refs.
LA: English
ER: M (Marine)
AB: The consequences of the following episodic phenomena for the pelagic-benthic coupling in the Nordic Seas are illustrated: (1) Advection of water masses between fjords and shelf environments, (2) freshwater run-off and vertical stability, (3) dynamics of the marginal ice zone in the central and northern Barents Sea and the Polar Ocean, (4) drift patterns of sinking particles along the North Norwegian coast, (5) advection of zooplankton into subarctic fjords and the southern Barents Sea, zooplankton overwintering and composition, and (6) transport of organic particulate matter from the Barents Sea shelf. It is shown that physical processes in the north-eastern North Atlantic and Polar Ocean can be strongly variable on time scales of days to decades. They have a significant influence on the dynamics of pelagic-benthic coupling. The physical oceanography influences the vertical and horizontal particle flux not only directly (mixing advection, up- and down-welling), but also indirectly through its impact on the biota (for example radiation wind, ice cover freshwater run-off and overwintering, advection and retention of zooplankton). Understanding pelagic-benthic coupling at high latitudes depends even more on a best possible understanding of the physical oceanography and the time scales involved than elsewhere.
AN: 4213112
13 of 35
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
14 of 35
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
15 of 35
TI: [New view on the pelagic system of the Ligurian Sea]
OT: Nouvelles vues sur le systeme pelagique de mer Ligure
AU: Jacques,-G.
AF: Observatoire Oceanologique, 66650, Banyuls-sur-Mer, France
CO: 24. Congr. della Societa Italiana di Biologia Marina, San Remo (Italy), 1-5 Jun 1993
SO: Biol.-Mar.-Mediterr. 1994 vol. 1, no. 1, pp. 65-82
NT: Includes 82 refs.
LA: French
ER: M (Marine)
AB: Current knowledge of the pelagic system in the Ligurian Sea, in particular the Liguria-Provence basin, has progressed considerably during the last decade due to the following main 3 elements: 1) the development of complementary study strategies (realization of continuous horizontal and vertical profiles for a series of physical, chemical and biological factors, teledetection of circulation and primary production, anchoring instruments for the study of particle fluxes and hydrology, coupling of sampling studies using surface vessels and submersibles for zooplankton and abyssal fauna, repetitive studies on circulation and water masses, and circulation models); 2) the utilization of new tools and materials; and, 3) the setting up of interdisciplinary programmes. General and frontal circulation are discussed, considering consequences on the pelagic ecosystem. Particle flux in the superficial layer and new production, and the role of zooplankton in the transport towards deeper layers are also examined.
AN: 4235228
16 of 35
TI: Vertical particle flux on the shelf off northern Spitsbergen, Norway
AU: Andreassen,-I.; Noethig,-E.-M.; Wassmann,-P.
AF: Norwegian College of Fishery Science, University of Tromsoe, N-9037 Tromsoe, Norway
SO: Mar.-Ecol.-Prog.-Ser. 1996 vol. 137, no. 1-3, pp. 215-228
NT: Incl. bibliogr.: 54 refs.
LA: English
ER: M (Marine)
AB: Suspended and sedimented particulate matter was examined along transects on the continental shelf off northern Spitsbergen, Norway, during summer 1991. The transects were situated in non-ice-covered areas dominated by Atlantic water, areas with multi-year ice and the marginal ice zone. The variability of the sedimented matter with regard to composition, quantity and quality between the 7 investigated stations was considerable. The open Atlantic water showed the highest suspended biomass [100 to 280 mg particulate organic carbon (POC)/m super(3)] and the vertical flux was moderate (24 to 30 mg POC/m super(2)/d) and dominated by faecal matter. While the suspended biomass in areas covered by multi-year ice was low (<65 mg POC/m super(3)), the vertical flux was relatively high (18 to 76 mg POC/m super(2)/d) and dominated by terrestrial organic and faecal matter. The contribution of phytoplankton cells to the vertical flux of POC was small in areas covered by multi-year ice, on average about 1%. The contribution of phytoplankton cells to the vertical flux in the marginal ice zone was higher (5.6% of POC), consisting mainly of Chaetoceros socialis and Fragilariopsis, but a considerable amount of faecal matter also settled. At all stations zooplankton strongly influenced the vertical flux, not only by faecal pellet production but probably also by direct mediation of fluxes (e.g. coprophagy).
AN: 4213521
17 of 35
TI: Enhanced scavenging of super(231)Pa relative to super(230)Th in the South Atlantic south of the Polar Front: Implications for the use of the super(231)Pa/ super(230)Th ratio as a paleoproductivity proxy
AU: Walter,-H.J.; Rutgers-van-der-Loeff,-M.M.; Hoeltzen,-H.
AF: Alfred Wegener Inst. for Polar and Mar. Res., Bremerhaven, Germany
SO: EARTH-PLANET.-SCI.-LETT. 1997 vol. 149, no. 1-4, pp. 85-100
LA: English
ER: M (Marine)
AB: The fractionation of super(230)Th and super(231)Pa was investigated throughout the Atlantic sector of the Southern Ocean. Published scavenging models generally assume that the super(231)Pa/ super(230)Th ratio of surface sediments is primarily determined by the mass flux of particles. This relationship holds north of the Polar Front, where low primary productivity coincides with ratios of unsupported super(231)Pa/ super(230)Th - sub(xs)( super(231)Pa/ super(230)Th) - in surface sediments below the production ratio of both radionuclides in the water column. However, we observed high super(2) sub(x) super(3) sub(s) super(1)Pa / super(230)Th ratios, conventionally interpreted as a high-productivity signal, in surface sediments south of the Polar Front, especially throughout the Weddell Sea, in contradiction with the low particle flux of this region. Measurements of both dissolved and particulate fractions of super(231)Pa and super(230)Th in the water column revealed a strong N-S decrease in the Th/Pa fractionation factor, from typical open ocean values around 10 north of the Polar Front to values between 1 and 2 south of 60 degree S. This observation clearly indicates that the high super(2) sub(x) super(3) sub(s) super(1)Pa/ super(230)Th ratios in surface sediments south of the Antarctic Circumpolar Current are produced by a N-S increase in the relative scavenging efficiency of super(231)Pa relative to super(230)Th, most probably due to a change in the chemical composition of particulate matter, and not by a high mass flux. It is speculated that biogenic opal, suggested not to significantly fractionate super(231)Pa and super(230)Th, may explain the enhanced scavenging of super(231)Pa to the south. This assumption is further supported by extremely high super(231)Pa/ super(230)Th ratios up to 0.34 in material collected with sediment traps south of the Polar Front, where fluxes are primarily determined by biogenic opal. Based on these results we conclude that, in regions where the sedimenting flux is dominated by biogenic opal, the super(231)Pa / super(230)Th ratio is not a reliable indicator for the mass flux of particles, thus limiting its use as a paleoproductivity proxy in the Southern Ocean.
AN: 4224413
18 of 35
TI: Biology and ecology of cryopelagic amphipods from Arctic Sea ice
OT: Biologische und oekologische Untersuchungen zur kryopelagischen Amphipodenfauna des arktischen Meereises
AU: Poltermann,-M.
CA: Bremen Univ., Bremen(FRG), Fachber. (Biologie/Chemie)
SO: Ber.-Polarforsch.-Rep.-Polar-Res. 1997 no. 225, 170 pp
NT: Incl. bibliogr.: 186 refs. Year of thesis 1996.
LA: German
ER: M (Marine)
AB: The present study aims at the investigation of ecology and biology of four species of Arctic sea ice amphipods Gammarus wilkitzkii, Onisimus nanseni, Onisimus glacialis ndApherusa glacialis.Topics are sea ice biota structure, amphipod adaptations (behaviour, morphology), amphipod position in the community, population dynamics and feeding ecology. This study investigates (i) the role of ice amphipods within the Arctic food web and (u) the features enabling the amphipods to colonize the Arctic sea ice permanently. Samples were taken during two expeditions with RVPolarstern n the Fram Straight (March 1993) and the Barents and Laptev Sea (August/September 1993) and on one expedition with RVGolitzyn o Franz Josef Land (August 1994). Animals were collected from first and multi year pack ice and first year fast ice. Investigation of the under ice biota by video techniques and diving observations provided a first morphological classification scheme for lower sea ice surfaces. Four main types of ice edges and three main types of lower surfaces were distinguished. This scheme and videoprints will enable further studies to classify ice floes. In total 3028 animals were caught under the sea ice. At Franz Josef Land ice amphipods had a mean abundance of 420 ind./m2 nd a mean biomass of 10.93 g WW /m2.Gammarus wilkitzkii as the most abundant species (88 %) with the highest biomass (86 %). Distribution of ice amphipods at the lower sea ice surface was extremely patchy. The small scale morphology of sea ice and detritus algal lumps were important criteria for amphipod occurence. Abundance and biomass were generally higher at the ice edge than under the ice.G. wilkitzkii, O. nanseni ndO. glacialis refered rough surfaces, whileA. glacialis as more abundant at flat, smooth surfaces. Behavioural studies onG. wilkitzkii ndO. nanseni howed that both species spend most time resting, probably to save energy. Both species have a positive phototaxis, which may enable them to find bright spots at the lower ice surface or the ice edge and hence places with intense algae growth. OnlyG. wilkitzkii howed a body cleaning behaviour. This species regularly uses about 20 % of its time to collect small particles from its body, using them probably as additional food. Movements and limb morphology of the ice amphipods show no peculiarities and are very similar to gammaridean amphipod species from other biota, especially from the benthal. Most of the characteristics of ice amphiods investigated in this study are advantageous for a life under the sea ice, but can also be found in amphipod species from other biota. Hence these features are no special adaptations to the sea ice, but reflect the general high flexibility and adaptability of amphipods The positve phototaxis, the camouflage during the passive escape from predators and the high fecundity are probably the only special adaptations to the life under the sea ice. Cryopelagic amphipods play a central role in the Arctic food web. On the one hand they use all available food sources under the sea ice and on the other hand they provide food for top predators as fish and birds. Ice amphipods are important links in the ctyopelagobenthic coupling, since their carcasses, exuvies and fecal pellets contribute significantly to the vertical particle flux of the Arctic Ocean.
AN: 4212993
19 of 35
TI: Seasonal occurrence of planktic Crustacea in sediment trap samples at three depth horizons in the Greenland Sea
AU: Seiler,-S.; Brandt,-A.
AF: Institut for Polar Ecology, Wischhofstrasse 1-3, D-24148 Kiel, FRG
SO: Polar-Biol. 1997 vol. 17, no. 4, pp. 337-349
LA: English
ER: M (Marine)
AB: Zooplankton were quantitatively investigated in sediment trap samples deployed in the Greenland Sea at three locations (72 degree 00.7'N, 7 degree 02.5'W, 72 degree 23.0'N, 7 degree 42.7'W and 72 degree 22.9'N, 7 degree 42.7'W). Overall samples covered a period of three annual cycles (July 1989 to July 1992). The investigation of zooplankton, consisting almost exclusively of Crustacea ( > 99 %), shows that the majority of the species must be regarded as "swimmers", which actively invaded the traps. Crustacea were composed of 45 species, mainly Copepoda, Amphipoda and Ostracoda. Each depth level showed a characteristic species composition. Diversity decreased with depth. The samples were dominated by Copepoda in terms of abundance and by Amphipoda with respect to biomass. The seasonal occurrence of Crustacea showed a maximum during winter and a minimum during summer. Carnivores were regularly found in the collected material, indicating that they had been actively attracted by the organic matter emanating from the traps. Omnivores showed a distinct seasonal occurrence. During winter, when primary production is low, omnivores change to a predatory way of life and they were consequently also found in increasing numbers. Herbivores were always rare. Due to the high number of "swimmers" found in winter, when particle flux is at its minimum, particle flux measurements may be severely biased at this time of the year.
AN: 4212906
20 of 35
TI: super(234)Th and super(210)Pb evidence for rapid ingestion of settling particles by mobile epibenthic megafauna in the abyssal NE Pacific
AU: Lauerman,-L.M.L.; Smoak,-J.M.; Shaw,-T.J.; Moore,-W.S.; Smith,-K.L.,Jr.
AF: Mar. Biol. Res. Div. - 0202, Scripps Inst. Oceanogr., La Jolla, CA 92093-0202, USA
SO: LIMNOL.-OCEANOGR. 1997 vol. 42, no. 3, pp. 589-595
LA: English
ER: M (Marine)
AB: Particle-scavenged super(234)Th and super(210)Pb can be used to trace the fate of particulate matter reaching the deep-sea floor. We used this technique to demonstrate rapid ingestion of particles arriving at the sea floor (at a depth of 4,100 m) by mobile epibenthic holothuroids (Abyssocucumis abyssorum and Oneirophanta mutabilis). Excess super(234)Th and super(210)Pb activities of sediment trap material, detrital aggregates from the sea floor, and animal gut contents all were similar while activities of surface sediments (top 0-5 mm) were considerably lower. A simple calculation using the excess super(210)Pb concentration of two potential food sources, sediment trap material and surface sediments, shows that similar to 91% of gut content material of A. abyssorum must have come from material similar to that found in the sediment trap cups. By setting the sediment trap material as age 0, apparent ages of <0-20 d, >100 d, and 12-13 d were estimated for the aggregates, surface sediments, and A. abyssorum guts, respectively. The population of A. abyssorum at this site could potentially process 0.2-4% of the vertical mass flux (m super(-2) d super(-1)) during the high particle flux period between June and October 1994. The percentage of vertical flux processed could be substantially greater when all of the mobile epibenthic megafauna species are considered.
AN: 4206803
21 of 35
TI: Particle flux and its conversion to the sediment record: Open ocean upwelling systems
AU: Shimmield,-G.B.; Jahnke,-R.A.
AF: Mar. Geosci. Unit, Dep. Geol. and Geophys., Univ. Edinburgh, West Mains Rd., Edinburgh, EH9 3JW, Scotland, UK
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. 171-192
ST: ENVIRON.-SCI.-RES.-REP. 1995 no. 18
LA: English
ER: M (Marine)
AB: Open ocean upwelling systems (the equatorial Pacific and Atlantic, the Southern Ocean, and major divergent fronts) have a major impact on the cycling of carbon because of their large areal extent. The concept of new production allows quantification of the vertical flux of organic matter in a variety of oceanographic settings. To determine vertical flux in the upper water column (subeuphotic zone) accurately, particle-reactive radionuclide tracers have much to offer. In mid- and deep waters, time-series sediment traps are beginning to provide details on the rates and types of particulate flux transformation that occur under open ocean upwelling conditions. In particular, the link between seasonal plankton bloom, rapid sedimentation, and benthic faunal response is beginning to be documented. However, interpretation of particulate proxies of productivity in the historical record is still difficult. The more dissolution-resistant tracers (barium, aluminium) offer advantages over more easily remineralized proxies (organic carbon, opal, calcite) as long as the scavenging and depositional processes are well understood. (DBO)
AN: 4205460
22 of 35
TI: Particle flux and its conversion to the sediment record: Coastal ocean upwelling systems
AU: Jahnke,-R.A.; Shimmield,-G.B.
AF: Skidaway Inst. Oceanogr., 10 Ocean Sci. Circle, Savannah, GA 31411, 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. 83-102
ST: ENVIRON.-SCI.-RES.-REP. 1995 no. 18
LA: English
ER: M (Marine)
AB: Despite previous research efforts, fundamental questions remain concerning the processes that determine the deposition and preservation of the major biogenic phases (organic carbon, CaCO sub(3), and opal) in sediments underlying coastal upwelling systems. Our ability to interpret the accumulation of these phases in sediments is currently hindered by uncertainties in (a) estimating the contributions of different sources of organic matter to a particular coastal location; (b) the processes and seafloor conditions controlling the remineralization and preservation of organic matter in seafloor sediments; (c) the linkages between sedimentary remineralization of organic matter and the dissolution of CaCO sub(3); and (d) the reactivity and solubility of biogenic opal at the seafloor. These fundamental limitations obviate accurate interpretation of variations in the sedimentary distributions of the major biogenic phases, and paleoceanographic reconstructions will continue to depend on the interpretation of surrogate and tracer distributions until such uncertainties are resolved. (DBO)
AN: 4205458
23 of 35
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
24 of 35
TI: Seasonal variability of sediment trap collections in the Northeast Water Polynya. Part 1: Sea-ice parameters and particle flux
AU: Ramseier,-R.O.; Bauerfeind,-E.; Garrity,-C.; Walsh,-I.D.
AF: Microwave Group - Ottawa River, Inc., 3954 Armitage Ave., RR#1, Dunrobin, Ont. K0A 1T0, Canada
CO: Northeast Water Polynya Symp., Helsingor (Denmark), 1-5 May 1995
SO: J.-MAR.-SYST. 1997 vol. 10, no. 1-4, pp. 359-369
LA: English
ER: M (Marine)
AB: Vertical particle flux was recorded in the Northeast Water polynya (NEW) by means of moored time series sediment traps from August 1992 to July 1993. Traps were deployed with USCGC Polar Sea at four positions in a trough of the polynya. The recorded annual flux varied between 4.2-9.8 g/m super(2) at 130 m and 26-33 g/m super(2) at 50 m above the sea bottom. The amount of settling particles in the NEW is controlled to a high degree by the ice regime (e.g., total ice concentration, variability, ice type fraction, snow and the melt period) due to its impact on the production of primary formed particles. By using passive microwave satellite data from the Special Sensor Microwave/Imager, it was possible to relate particle flux with total ice concentration and its changes on short (several days) and long term scales for individual sampling periods. In combination with the dry weight of the collected particles, it is possible to examine the relation of ice parameters and its impact on the sedimenting processes in the NEW. Of particular interest is the correlation of three sedimenting periods associated with ice formation in the fall, the effect of the winter polynya based on new ice formation, and the melt period.
AN: 4066111
25 of 35
TI: Seasonal variability of sediment trap collections in the Northeast Water Polynya. Part 2. Biochemical and microscopic composition sedimenting matter
AU: Bauerfeind,-E.; Garrity,-C.; Krumbholz,-M.; Ramseier,-R.O.; Voss,-M.
AF: Sonderforschungsbereich 313, Univ. Kiel, Heinr, Hecht Platz 10, D-24118 Kiel, Germany
CO: Northeast Water Polynya Symp., Helsingor (Denmark), 1-5 May 1995
SO: J.-MAR.-SYST. 1997 vol. 10, no. 1-4, pp. 371-389
LA: English
ER: M (Marine)
AB: The annual pattern of vertical particle flux in the Northeast Water (NEW) Polynya was recorded from August 1992 to July 1993 by means of moored time-series sediment traps. A distinct seasonal pattern in sedimentation was observed, with highest flux rates during August-October 1992. During this time 40-70% of the annual total sedimented matter (dry weight, DW) and the components, carbonate, particulate organic carbon and nitrogen (POC and PON), particulate biogenic silica (bPSi) and biogenic matter were recorded: 9.83, 2.04, 1.03, 0.69, 0.14 and 5.55 g/m super(2), respectively. Microscopic analysis of the particles revealed that diatoms contributed about 10% of the POC flux, but up to 40% of the POC flux originated from the houses and faeces of appendicularians during the period of highest flux rates. In contrast, faecal pellets were only a minor component of sedimenting POC after the opening of the polynya in June 1993. During this period a sedimentation event of Melosira arctica dominated the microscopically recognizable fraction of the POC. Following the low winter values a significant deviation in POC flux in March documented an early onset of plankton growth and a rapid response to the formation of a winter polynya paralleled by a local change in ice conditions. This was supported by the stable nitrogen isotope signature of the sedimented matter, also indicating an early onset of plankton production in the NEW Polynya. However, the overall amplitude of the delta super(15)N signal in the sinking particles showed only small variations (<4ppt) and was significantly below the amplitude observed in sedimented material from the Northern North Atlantic ( approximately equal to 8ppt). The composition of the sedimented matter, comprising mainly fast sinking particles (appendicularian houses, faecal pellets and Melosira aggregates) lead us to conclude that sedimentation in the NEW Polynya was spatially heterogeneous.
AN: 4066110
26 of 35
TI: Coupling between SW monsoon-related surface and deep ocean processes as discerned from continuous particle flux measurements and correlated satellite data
AU: Rixen,-T.; Haake,-B.; Ittekkot,-V.; Guptha,-M.V.S.; Nair,-R.R.; Schluessel,-P.
AF: Inst. fuer Biogeochemie und Meereschemie, Univ. Hamburg, Hamburg, Germany
SO: J.-GEOPHYS.-RES.-C-OCEANS 1996 vol. 101, no. C12, pp. 28569-28582
LA: English
AB: Particle flux data obtained by time series sediment traps deployed at water depths of approximately 3000 m in the western, central, and eastern Arabian Sea since 1986 were compared with wind speeds derived from measurements made by microwave radiometer flying on polar orbiting satellites and sea surface temperatures (SSTs) provided by the Physical Oceanography Distributed Active Archive Center at Jet Propulsion Laboratory. This comparison has allowed us to trace the link between the oceanographic and biological processes related to the development of the SW monsoon with the pattern and interannual variability of particle fluxes to the interior of the Arabian Sea. We could recognize the well-known upwelling systems along the coasts of Somalia and Oman as well as open ocean upwelling at the beginning of the SW monsoon. Both open ocean upwelling and coastal upwelling off Oman cause a cooling of surface waters at our western and central Arabian Sea stations. When SSTs fall below their long-term average, an increase in fluxes which are dominated by coccolithophorid-derived carbonates occurs. The timing of this increase is determined by the rate of surface water cooling. Further intensification of upwelling as the SW monsoon progresses causes, additional increases in biogenic opal fluxes denoting diatom blooms in the overlying waters. The total fluxes during this period are the highest measured in the open Arabian Sea. At the central Arabian Sea location the fluxes are only randomly affected by these blooms. The particle flux in the eastern Arabian Sea is as high as in the central Arabian Sea but is influenced by a weaker upwelling system along the Indian coast. The observed interannual variability in the pattern of particle fluxes during the SW monsoons is most pronounced in the western Arabian Sea. This is controlled by the intensity of the upwelling systems on the one hand and the transport of cold, nutrient-poor, South equatorial water into the Oman region on the other. The latter effect, which is strongest during the SW monsoon with highest recorded wind speeds, reduces the influence of upwelling and the related particle fluxes at the western Arabian Sea station, where highest fluxes occur during SW monsoons with moderate wind speeds. Thus coastal and open ocean upwelling are most effective in transferring biogenic matter to the deep sea during the SW monsoons of intermediate strength.
AN: 4059340
27 of 35
TI: [Amino acids in the North Atlantic: Particle composition and remineralisation]
OT: Aminosaeuren im Nordatlantik: Partikelzusammensetzung und Remineralisierung
AU: Lundgreen,-U.
SO: BER.-INST.-MEERESKD.-CHRISTIAN-ALBRECHTS-UNIV.-KIEL 1996 no. 283, 128 pp
NT: Incl. bibliogr.: 197 refs.
LA: German
ER: M (Marine)
AB: The present investigation was conducted in the framework of the internationally coordinated Joint Global Ocean Flux Study (JGOFS). The major aim is to get information about the processes of production, remineralisation and export of marine particles. Amino acids may be appropriate tracers. For that purpose, particles were sampled at three JGOFS sites in the North Atlantic between 33 degree N and 54 degree N and analyzed for their amino acid content and composition. The total amino acid flux varies seasonally resulting from variations in particle flux and particle amino acid content. The changes in amino acid content are related to the changes in particle composition (CaCO sub(3), opal, total chlorophyll and the CaCO sub(3)/opal ratio). This reflects the seasonal changes in plankton community structure at the euphotic zone, which is the area of origin of the particles collected. The major change from more phytoplankton derived particles to more zooplankton derived particles is also reflected in the amino acid composition of the sediment trap material. This was observed from cluster analysis of the appropriate data.
AN: 4053935
28 of 35
TI: Model studies on the pelagic nitrogen flux and vertical particle flux in the Norwegian Sea
OT: Modellstudien zum pelagischen Stickstoffumsatz und vertikalen Partikelfluss in der Norwegensee
AU: Haupt,-O.J.
SO: BER.-SFB-313-MEERESFORSCH. 1995 no. 60, 140 pp
NT: Incl. bibliogr.: 172 refs.
LA: German
ER: M (Marine)
AB: This paper deals with the mostly non-linear interactions between physico-chemical and biological processes in the Norwegian Sea. A three-dimensional ecosystem model was developed simulating the seasonal nitrogen cycle in the Norwegian Sea by means of the Eulerian continuum method. The model is vertically structured and enables individual parameter values to be modified in the course of a run. Parameters thus can be better adjusted to the seasonal cycles of different processes. Owing to the vertical resolution of the model, the biogenic particle flux in the Norwegian Sea can be simulated for various depths. The results of a standard run were compared to field data collected mainly within the framework of special research programme 313 at Kiel University. Validation of the model results showed good correlation in the seasonal cycles of nitrate and phytoplankton. Also particular organic nitrogen during the growth period could be simulated relatively well. The calculated total annual new production was confirmed for the Norwegian Sea, whereas regenerated production was underestimated considerably.
AN: 4053918
29 of 35
TI: Scavenging of super(234)Th and super(7)Be in Lake Constance
AU: Vogler,-S.; Jung,-M.; Mangini,-A.
AF: Heidelberger Akademie der Wissenschaften, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 7, pp. 1384-1393
LA: English
ER: F (Freshwater)
AB: Particulate and dissolved concentrations of super(234)Th and super(7)Be, along with fluxes of total mass and particulate super(234)Th and super(7)Be into sediment traps, were measured in Lake Constance (Bodensee) from March to December 1993. During the same period, atmospheric deposition rates of super(7)Be and super(210)Pb were determined. Variations in atmospheric fluxes of super(7)Be and super(210)Pb were found to reflect variability in rainfall. The mean atmospheric flux for super(7)Be was 13.5 dpm cm super(-2) yr super(-1) and for super(210)Pb it was 0.65 dpm cm super(-2) yr super(-1). Total super(234)Th activities in surface water were generally high in winter and low in summer, primarily in response to the seasonality of biological activity. About 50-70% of super(234)Th was found in particulate form, depending on particle concentration and particle residence time. Scavenging rates for dissolved super(234)Th ranged from 0.14 to 0.88 d super(-1), having increased slightly with total particle concentration. super(7)Be activities in surface water exhibited large variations because of variable atmospheric input and particle flux. During periods of high biological productivity, particulate super(7)Be in surface water increased from similar to 20 to similar to 60% of the total super(7)Be concentration. The scavenging rates for dissolved super(7)Be (0.01-0.12 d super(-1)) were generally lower than those for dissolved super(234)Th because of the lower particle reactivity of super(7)Be. Although the super(7)Be flux into sediment traps at 50 m did not differ significantly from the flux at 120 m, the super(234)Th flux increased with depth because of the further adsorption of water column-produced super(234)Th onto sinking particles. The range of residence times for the total radionuclide inventories estimated from an irreversible scavenging model was 33-83 d for super(234)Th and 40-340 d for super(7)Be (box depth, 50 m). The residence times of both nuclides were controlled by the particle flux, which, in turn, was determined by biological productivity in the surface water.
AN: 4048415
30 of 35
TI: Towards a new generation of sediment traps and a better measurement/understanding of settling particle flux in lakes and oceans: A hydrodynamical protocol
AU: Juerg,-B.
AF: Swiss Federal Inst. for Environ. Sci. and Technol. (EAWAG) CH-8600 Duebendorf, Switzerland
SO: AQUAT.-SCI. 1996 vol. 58, no. 4, pp. 283-296
LA: English
ER: M (Marine)
AB: This article is aimed at established sediment trap specialists as well as young learning scientists. The development of sediment trap techniques and hydrodynamics are briefly reviewed, with special emphasis on the experimental and in-situ trap calibration. The ongoing controversy within the trap community on the validity of flux data obtained by sediment traps can only be overcome by understanding the effects of hydrodynamics on the entrapping of settling particles in turbulent waters. A proper trap protocol is still missing. Also, the problems of entering swimmers and preservatives are not yet fully solved. Innovative ideas and robust data are needed to improve our knowledge on trapping efficiency, particle settling flux data, and the interpretation of lake and oceanic nutrient cycles. It is emphasized that controversial papers should be published when based on documented experiments and/or theory applied.
AN: 4036590
31 of 35
TI: Particle accumulation in a cylindrical sediment trap under laminar and turbulent steady flow: An experimental approach
AU: Gust,-G.; Bowles,-W.; Giordano,-S.; Huettel,-M.
AF: Arbeitsbereich Meerestechnik 1, Technische Univ. Hamburg-Harburg, 21079, Hamburg, Germany
SO: AQUAT.-SCI. 1996 vol. 58, no. 4, pp. 297-326
LA: English
ER: M (Marine)
AB: The hydrodynamical, fluid and particle parameters which control flushing rates, flow cells, and accumulation rates of particulate matter in cylindrical (MultiPIT) sediment traps were quantified in a flume simulation using a seeding technique for 25-45 mu m particles. Particle collection was found to be a trap- and particle-specific filtering process encompassing advective and gravitational entry of particles over a reduced trap aperture area, and gravitational-turbulent removal of particles at the bottom of the internal flow cell. Trapping efficiency increased up to 10-fold with increasing horizontal flow velocity (1-30 cm/s). For given flow velocity, the trap over- and undercollected particles relative to their weight, i.e. (theoretical) Stokes settling velocity. The trapping efficiency increased with increasing trap Reynolds number Re sub(T), changed by the approaching velocity in our experiments. Opposite findings from earlier experiments using the flume seeding technique and changing Re sub(T) by altering the trap diameter (Butman, 1986) are discussed. Semi-empirical equations are derived for the accumulation process of light, heavy and intermediate particles. From these, measured trap fluxes can be converted into in-situ verticle particle flux except for light particles.
AN: 4036589
32 of 35
TI: Pulsed delivery of subthermocline water to Conch Reef (Florida Keys) by internal tidal bores
AU: Leichter,-J.J.; Wing,-S.R.; Miller,-S.L.; Denny,-M.W.
AF: Stanford Univ., Hopkins Mar. Stn., Pacific Grove, CA 93950, USA
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 7, pp. 1490-1501
LA: English
ER: M (Marine)
AB: Internal tidal bores generated by breaking internal waves cause dramatic, high-frequency variation in temperature, salinity, water velocities, and concentration of chlorophyll a on Conch Reef, Florida Keys. The arrival of bores on the reef slope is linked to a semidiurnal internal tide and is marked by temperature drops of up to 5.4 degree C and salinity increases of up to 0.6ppt in 1-20 min. These changes are accompanied by the sudden onset of upslope flow 1-15 m above the bottom with speeds of 10-30 cm s super(-1). Cool, high-salinity water is transported from below the thermocline seaward of the reef and is resident on the reef slope for up to 4 h before it mixes with surface waters and recedes downslope. Compared with ambient surface water, this deep water can contain significantly elevated concentrations of dissolved nitrate. Physical variability produced by this mechanism increases significantly with depth on the reef slope. Analysis of 3-yr temperature records indicates the arrival of internal bores is a consistent feature at this site from May through November, with peak activity in July-September. Pulsed delivery of subthermocline water appears to significantly affect the temperature, nutrient, and particle flux regimes on this coral reef.
AN: 4036555
33 of 35
TI: Temporal variability in dissolved phosphorus concentrations in the subtropical North Pacific Ocean
AU: Karl,-D.M.; Tien,-G.
AF: SOEST, Department of Oceanography, University of Hawaii, Honolulu, HI 96822, USA
SO: MAR.-CHEM. 1997 vol. 56, no. 1-2, pp. 77-96
LA: English
ER: M (Marine)
AB: Dissolved phosphorus pool measurements were made on approximately monthly intervals during the period October 1988-November 1994 at an oligotrophic, deep-ocean station near Hawaii (Station ALOHA; 22 degree 45'N, 158 degree W). Data include depth profiles (0-200 m) of soluble reactive phosphorus (SRP), measured by two independent techniques (a high-sensitivity, magnesium-induced coprecipitation (MAGIC) method, and standard autoanalysis procedure), and total dissolved phosphorus (TDP) based on UV photo-oxidation treatment followed by automated SRP analysis. Considerable variability in SRP was observed both with depth and with time over the 6-yr period. Upper water column (0-100 m) SRP concentrations varied in time from >150 to <10 nM, and generally conformed to one of two distinct concentration vs. depth patterns: ``Type I'' profiles were characterized by uniform SRP concentrations with depth (concentration gradients less than or equal to 0.05 mu mol m-4 SRP) and ``Type II'' profiles were characterized by distinct near-surface (0-30 m) SRP concentration maxima. The Type I profiles were further divided into low (Type I-L) or high (Type I-H) categories based on whether the average SRP concentration was <60 or >60 nM, respectively. Throughout the entire 6-yr observation period, the upper water column (0-100 m) inventory of SRP displayed a systematic decrease from similar to 10 to similar to 5 mmol m-2 P, a result that is consistent with the hypothesized role of N2 fixation and P control of new and export production at Station ALOHA. Three independent, but not mutually exclusive, models are presented to explain these time-varying SRP concentrations: (1) convective mixing; (2) atmospheric deposition; and (3) upward P flux. The upward P flux model including both passive (upward particle flux) and active (biological transport) processes, is the most consistent model for the available data set.
AN: 4017186
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TI: Unbalanced particle flux budgets in Crater Lake, Oregon: Implications for edge effects and sediment focusing in lakes
AU: Dymond,-J.; Collier,-R.; McManus,-J.; Larson,-G.L.
AF: Coll. Oceanic and Atmos. Sci., Oregon State Univ., Corvallis, OR 97331, USA
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 4, pp. 732-743
LA: English
ER: F (Freshwater)
AB: Flux estimates show that upward mixing of the deep-water nitrate pool accounts for more than 85% of the total new nitrogen input to the euphotic zone of Crater Lake. Because measured primary productivity (360 mg C m super(-2) d super(-1)) is 10-30 times higher than a level supported solely by the input of new nitrogen into the euphotic zone, nitrogen must be recycled in the euphotic zone many times before it is transferred by particles to the deep lake. Nitrogen recycling in the deep lake is also very efficient. Sediment trap measurements of particulate nitrogen fluxes reveal a major imbalance in our estimates of the lake's internal nitrogen budget. We propose the imbalance reflects an "edge effect," whereby enhanced biological production occurs near the lake margin and the shallower portions of the lake. Our measurements also reveal that Al, an element carried by refractory phases, is accumulating in basin sediments at a rate 15-30 times higher than the flux we measure with sediment traps. This difference is maintained by the near-bottom transport of lithogenic particles from the lake margins to the deep basins of the lake. These comparisons of nutrient and refractory element fluxes reflect two important lake processes - enhanced productivity at the lake margin that may be due to greater availability of macro- and micronutrients at the lake edges and focusing of particulate material into the deep lake basins.
AN: 4005983
35 of 35
TI: Fluid flow and suspended particulates as determinants of polychaete feeding behavior
AU: Bock,-M.J.; Miller,-D.C.
AF: Darling Mar. Cent., Univ. Maine, Walpole, ME 04573, USA
SO: J.-MAR.-RES. 1996 vol. 54, no. 3, pp. 565-588
LA: English
ER: M (Marine)
AB: We examined the interactive effects of fluid flow, bed characteristics and suspended load on the feeding behavior of four species of marine polychaetes. Two species of obligate deposit feeders (Marenzelleria viridis and Ampharete parvidentata) and two species of palp-coiling facultative suspension feeders (Spiochaetopterus oculatus and Spio setosa) were exposed to flow and sediment-bed treatments that served to decouple fluid flow and particle flux. We employed low (no particle transport), medium (transport of flocs only) and high (transport of sand) flow speeds in factorial treatments of natural sediment, winnowed bed (flocs removed), armored bed (no sand transport at high flows), and armored bed plus fines (flocs added). For each species, worms were exposed to an increasing (low, medium and high) and then decreasing (high, medium and low) flow leg for each bed treatment. We recorded visual observations of animal behavior of the four polychaete species. We found little systematic response to flow and bed differences in the two obligate deposit feeders. When fine material was present, one of the two species exhibited higher variability in time spent deposit feeding, possibly responding to small-scale depositional pockets enriched with fine particles and organic matter. For both facultative suspension feeders, there was an increase in time spent suspension feeding with increasing flow and suspended particle concentrations. Percent suspension feeding was also greater on the decreasing flow legs in treatments with fine material available for suspension. Exploratory analyses of the data reveal a direct relationship between time spent suspension feeding and the flux of suspended high quality organic matter. For both species, compositional parameters of particulate nitrogen and enzymatically available amino acid concentrations were the best correlates of suspension feeding behavior.
AN: 3975059