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Pacific walrus (Odobenus rosmarus divergens) resource selection in the northern Bering Sea

April 9, 2014

The Pacific walrus is a large benthivore with an annual range extending across the continental shelves of the Bering and Chukchi Seas. We used a discrete choice model to estimate site selection by adult radio-tagged walruses relative to the availability of the caloric biomass of benthic infauna and sea ice concentration in a prominent walrus wintering area in the northern Bering Sea (St. Lawrence Island polynya) in 2006, 2008, and 2009. At least 60% of the total caloric biomass of dominant macroinfauna in the study area was composed of members of the bivalve families Nuculidae, Tellinidae, and Nuculanidae. Model estimates indicated walrus site selection was related most strongly to tellinid bivalve caloric biomass distribution and that walruses selected lower ice concentrations from the mostly high ice concentrations that were available to them (quartiles: 76%, 93%, and 99%). Areas with high average predicted walrus site selection generally coincided with areas of high organic carbon input identified in other studies. Projected decreases in sea ice in the St. Lawrence Island polynya and the potential for a concomitant decline of bivalves in the region could result in a northward shift in the wintering grounds of walruses in the northern Bering Sea.

Publication Year 2014
Title Pacific walrus (Odobenus rosmarus divergens) resource selection in the northern Bering Sea
DOI 10.1371/journal.pone.0093035
Authors Chadwick V. Jay, Jacqueline M. Grebmeier, Anthony S. Fischbach, Trent L. McDonald, Lee W. Cooper, Fawn Hornsby
Publication Type Article
Publication Subtype Journal Article
Series Title PLoS ONE
Index ID 70139238
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center Biology MFEB