Stabeno, P. J., NOAA -- Pacific Marine Environ, Seattle, USA, Phyllis.Stabeno@NOAA.gov
Napp, J. M., NOAA -- Alaska Fisheries Science Center, Seattle, USA, Jeff.Napp@NOAA.gov
Mordy, C. W., Univ. Washington -- Joint Institute for the Study of Atmosphere and Oceans, Seattle, USA, Calvin.W.Mordy@NOAA.gov
THE INFLUENCE OF SEASONAL SEA ICE ON THE EASTERN BERING SEA SHELF ECOSYSTEM: 2005
Seasonal sea ice is a major structuring element of the eastern Bering Sea shelf ecosystem and responds directly to changes in climate. Sea ice determines the timing and fate of the spring phytoplankton bloom, rates of secondary production, and leaves behind a pool of cold water that influences migratory movements of fishes and the foraging of apex predators. In spring and fall of 2005 we conducted cruises using cross- and along-shelf transects to evaluate the influence of sea ice on the ecosystem. The hydrography, nutrients, chlorophyll, and zooplankton biomass and species composition were all affected by the presence or absence of sea ice along a north-south transect. The position of the transition between ice-affected and ice-free areas differed according to the variable, but the transition migrated to the north as the season progressed. Mooring data demonstrated that the changes were due to advection of water into the region. Thus the influence of sea ice on a particular area during an annual cycle is long lasting, but can be modified by processes such as advection, which are also mediated by climate.
Presentation is given by student: No