Aquatic Sciences Meeting, Albuquerque 2001

SS30 Climate Change Impacts in the Arctic: Ecosystems and Societies (Science and Society Connections)

Date: Wednesday, February 14, 2001, Time: 2:45:00 PM

Location: Ruidoso/Pecos

Gradinger, R, R, University of Alaska, Fairbanks, USA, gradinger@ims.uaf.edu

THE IMPACT OF GLOBAL CHANGE ON ARCTIC ICE ALGAL PRODUCTION

The sea ice conditions in the Arctic have considerably changed in recent years. Major reductions in its extent and thickness were interpreted as signs of Global Change. To identify the potential impact of future changes on the Arctic marine food web, we investigated its present state during three expeditions to the East Greenland Current. Abiotic and biotic parameters were determined in multi-year ice floes over the entire ice thickness in spring, summer and autumn. The analysis of the biomass and composition of the photo-and heterotrophic communities revealed that regenerated production and microbial processes are dominant in summer, probably caused by the shut off of nitrate supply from the water column due to under-ice water stratification. In spring and autumn, in contrast, light and brine salinity are the major controlling parameters. A further freshening of Arctic surface waters might reduce net ice algal production and enhance activity along the microbial network, causing reduction of the carbon export by ice melt and activity of under-ice fauna.

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Aquatic Sciences Meeting, Albuquerque 2001

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