New Bering Sea Research Reveals Impact on American Fisheries

Recent research conducted in the Bering Sea has shown a change in the patterns of birds, mammals and fish based on ice extent and duration. These changes in behavior include the shifting of habitat location, and where they eat and bear their young. Researchers from NOAA and the University of Washington’s Joint Institute for the Study of the Atmosphere and Ocean (JISAO) published their findings in the journal Deep Sea Research II. The research, which took place over a six year time period, focused on ice and ecosystem conditions in an effort to understand the processes that influence the eastern Bering Sea marine ecosystem. The NOAA led findings included measurements that show a potential impact of climate change on species from zooplankton to whales living on the Bering Sea shelf, a relatively shallow portion of the sea directly off the Alaskan coast. The study, led by PMEL’s Phyllis Stabeno, Ph.D., projects warming of southern shelf waters will limit the distribution of Arctic species such as snow crab, while the distribution and abundance of whales will change as their food source moves. The presence or absence of sea ice was previously thought to have a large impact on the production of microscopic plant life, or phytoplankton. PMEL’s Calvin Mordy, Ph.D., and others found that the wind accounts for a larger piece of the phytoplankton production puzzle. They can now use this finding for future models of the Bering Sea ecosystem. Using an electronic fish finder on an icebreaker, Alex De Robertis, Ph.D., AFSC, and Edward Cokelet, Ph.D., of PMEL, provide the first comprehensive observation of fish in the ice-covered portion of the Bering Sea. They conclude that each winter, sea ice and the cold water that comes with it force fish southeastward, out of their summer habitat. Using similar electronic fish finders mounted on NOAA Fisheries survey vessels, Patrick Ressler, Ph.D., of the AFSC and coauthors documented a recent increase in krill, which pollock eat, that coincided with the end of a warm period and the beginnings of a cold period in the eastern Bering Sea. The distribution of forage fish, which are used as food by other fish, seabirds, and marine mammals, is affected by the warm and cold cycles in the eastern Bering Sea. Anne Hollowed, Ph.D., of the AFSC and co-authors examined historical record data collected by the AFSC in warm and cold years and described how they differ and the consequences of these shifts. Mike Sigler, Ph.D., of the AFSC and co-authors studied the differences in how seabirds and ballen whales hunt for food (krill and young pollock) and how their predatory patterns change when they are bearing and rearing their young.