IG01-71 ORAL

ECOSYSTEM DYNAMICS OF THE TROPICAL ATLANTIC OCEAN: MULTISCALE VARIABILITY AND PHYSICAL-BIOLOGICAL COUPLING

S.PIONTKOVSKI (MSRC, State University of New York At Stony Brook and Institute of Biology of the Southern Seas (Ukraine), MSRC, SUNY, STONY BROOK, NY 11794-5000, USA, spiontkovski@notes.cc.sunysb.edu)

Interannual variability and multiscale spatial patterns of zooplankton abundance, biomass and species diversity are discussed and related to the atmospheric pressure systems, water mass dynamics, temperature and salinity fields. The database used has included over 4,000 biological samples collected on 18 major expeditions, the majority of which are enumerated to the species level for phytoplankton, zooplankton and mesopelagic fish. Ancillary information includes measurements from up to 1500 stations of chlorophyll a, nutrients, and basic hydrographic parameters. Samples processed to the species level have enabled us for the first time to analyze interannual changes of zooplankton species diversity on the scale of the tropical zone. Grid surveys were used to estimate variability on a scale of hundreds of km. Continuous records within these grids were used to estimate zooplankton variability on the scale of tens of kilometres and high resolution sampling from drifting vessels was used to investigate variability of kilometer scale. Multiscale sampling has enabled us to estimate the variance of phyto-, zooplankton and mesopelagic fish biomass throughout the 'cascade of spatial-temporal windows' and to reconstruct the multiscale three-dimensional diagrams of the variability.