SGER: Complex Pelagic Interactions in the Southern Ocean: Deciphering the Antarctic Paradox

University Of Florida, Gainesville FL

Investigators

Abstract

The primary goal of the proposed multidisciplinary project is to quantify, examine, model and validate the complex interactions, involving direct, indirect and feedback effects, that regulate the planktonic food web in the coastal waters of the Southern Ocean with the aim of elucidating the causes underlying the low phytoplankton biomass and production despite the high nutrient availability there. In particular, the project will evaluate the feedback mechansisms induced through the role of ammonium, largely released by aggregations of herbivorous zooplankton present in the Southern Ocean, krill specifically, on the resistance to UV stress by the phytoplanktonic community and, in particular, effects on the nitrogen incorporation rates, both ammonium and nitrate, and the subsequent development of phytoplankton blooms. The project will not only address the problem experimentally, but will also consider the complex interactions in the context of the heterogeneous landscape, dominated by small parcels of water, that provides the scenario on which the complex interactions occur. This project will be conducted through a shore-based (Juan Carlos I) operation in 2004 and a subsequent oceanographic cruise (R/V Hesp rides) in 2005.