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Plankton communities of the South Atlantic anticyclonic gyre
Sergey A. Piontkovski a, b,*, M. R. Landry c,
Zosim Z. Finenko a, Alexander V. Kovalev a,
Robert Williams d, Christopher P. Gallienne d, Alexey V.
Mishonov e,
Valery A. Skryabin a, Yuri N. Tokarev a, Viktor N.
Nikolsky a
a Institute of Biology of the Southern Seas, Sevastopol 99011, Ukraine
b Marine Sciences Research Center, Stony Brook University, Stony Brook, NY
11794-5000, USA
c Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI
96822, USA
d Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
e Department of Oceanography, Texas A&M University, College Station, TX
77843-3146, USA
Abstract
Data collected during cruises of the Former Soviet Union (in 1963–1989) and
the British Atlantic meridional transect program (in
1995–1999) were used to analyse macroscale patterns in phyto- and zooplankton
biomass, size structure, species diversity, chlorophyll a, and
plankton bioluminescence in the macroscale anticyclonic gyre of the South
Atlantic Ocean.
The spatial pattern of bioluminescence intensity
was in good agreement with that of remotely sensed (CZCS) chlorophyll a,
phosphate, salinity, and copepod species diversity index
distributions especially in terms of geographic inclinations of the isolines,
both associated with the north-westward pattern off the South
equatorial current.
Among the 416 copepod species recorded in samples, 51 species
were noted throughout the whole gyre. On the other hand,
there were a number of species found only in one of the currents.
The mesozooplankton biomass size spectra (calculated in carbon units),
exhibited a fairly stable slope of the curve from the eastern periphery of the
gyre to its centre. The British Atlantic meridional transect program
meridional transect through the western part of the gyre showed mesozooplankton
size spectra in greater detail between the equator and 50°
S.
Although the spectra change slowly along the transect as far as 36° S, there
is a general trend toward increasing slopes from the equatorial
region to the oligotrophic central gyre. The calculated phyto-to-zooplankton
ratio indicated that for the tropical anticyclonic gyres, the
mesozooplankton carbon biomass could be represented as the exponential function
of the phytoplankton carbon.
Oceanologica Acta , 2003, Iss.26, pp. 255–268
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