818 Walrus Distributional and Foraging Response to Changing Ice and Benthic Conditions in the Chukchi Sea

We will compare the foraging range and effort of walruses using land haul-outs as a consequence of shelf-free ice conditions to walruses using ice haul-outs in the Chukchi Sea. We predict that foraging effort will be greater, and foraging range will be less, when walruses use land haul-outs than when they are able to use ice haul-outs. The foraging costs due to increased travel time to food patches from land may be significantly higher than the costs from sea ice haul-outs and result in reduced energy stores before wintering in the Bering Sea.

We will also compare nearshore to offshore infaunal and epifaunal walrus prey communities and changes in these communities that may have occurred from retrospective analysis of archived benthic data. We predict that changing ice conditions over the past decade has resulted in a redistribution of productive areas and community structure. In addition, we predict that the community structure of prey that is accessible to walruses from land haul-outs will be different than that in offshore areas where they can be accessed by walruses using sea ice haul-outs.

This project will provide insights into environmental mechanisms responsible for changing distributions and foraging behaviors in walruses from climate change that can ultimately impact benthic communities and walrus vital rates.