Coyle, K. O., Institute of Marine Science, U, Fairbanks, USA, coyle@ims.uaf.edu
Pinchuk, A. I., Institute of Marine Science, University of Alaska, Fairbanks, USA, ftaip1@uaf.edu
Eisner, L. B., Auke Bay Laboratories/Alaska Fisheries Science Center/NOAA, Juneau, USA, lisa.eisner@noaa.gov
Napp, J. M., NOAA, Fisheries Service, Alaska Fisheries Science Center, Seattle, USA, jeff.napp@noaa.gov

ZOOPLANKTON SPECIES COMPOSITION AND ABUNDANCE IN THE EASTERN BERING SEA IN SUMMER: THE ROLE OF WATER COLUMN STABILITY ON ZOOPLANKTON COMMUNITY STRUCTURE

Recent shifts in climate toward warmer conditions may threaten commercial fisheries by altering lower-trophic level productivity and trophic relationships on the southeastern Bering Sea shelf. We examined zooplankton community structure near the Pribilof Islands and on the middle shelf of the southeastern Bering Sea in summer of 1999 and 2004. Between 1999 and 2004, the summer zooplankton community of the middle shelf shifted from large to small species with significant declines in the biomass of large scyphozoans, large copepods, arrow worms and euphausiids, and significant increases in small copepods and small hydromedusae. Stomach analysis of age-0 pollock from the middle shelf indicated a dietary shift from large to small copepods from 1999 to 2004. This shift in zooplankton community was accompanied by a three fold increase in water column stability in 2004 relative to 1999, primarily due to warmer water above the thermocline. These results suggests that if climate on the Bering Sea shelf continues to warm, the zooplankton community may shift from large to small taxa which could strongly impact apex predators and the economies they support.

Oral presentation

Presentation is given by student: No
Session #:034
Date: 03-04-2008
Time: 09:45