Retrospective Study of Walrus Foraging and Movement Patterns During a Major Ecosystem Shift in the Bering and Chukchi Seas, Alaska, 1950-2010

This study developed a historic ~50-year time series of carbon (δ13C) and nitrogen (δ15N) isotope values with annual resolution to test the hypothesis about whether northward shift of benthic ecosystems is influencing walrus movement and diet, as well as the ecology of other benthic predators. Collected and archived Pacific walrus (Odobenus rosmarus divergens) teeth (lower canines) during subsistence harvests on Saint Lawrence Island. All teeth were originally collected from Native subsistence harvested animals except for one set of teeth collected in the Bering Sea during a research cruise conducted in 1981. Age via cementum annuli counts were estimated and targeted teeth from younger animals (<15 years old). Teeth were recovered from collections made between 1960-2012. This dataset contains the estimated age and tooth dentin carbon (δ13C) and nitrogen (δ15N) isotope values of male and female walrus collected over the past ~50 years from subsistence harvests.