The Pacific walrus geographical range and sample harvest locations.

• Main Authors: Chelsea W. Koch (11302104), Lee W. Cooper (8748120), Ryan J. Woodland (11302107), Jacqueline M. Grebmeier (8748126), Karen E. Frey (8748123), Raphaela Stimmelmayr (3164559), Cédric Magen (9769778), Thomas A. Brown (272386)
• Format: Still Image
• Language: unknown
• Published: 2021
• Subjects: Microbiology; Evolutionary Biology; Ecology; Developmental Biology; Inorganic Chemistry; Environmental Sciences not elsewhere classified; Biological Sciences not elsewhere classified; Chemical Sciences not elsewhere classified; Pacific walrus livers; Pacific walrus diet; Odobenus rosmarus divergens; sea ice persistence; iPOC; walrus spring diet; ice algae trophic markers; Female Pacific walruses; contribution; Chukchi Sea; NBS; Pacific walruses; ice algae; Northern Bering Sea; estimate trophic position; Pacific Arctic ecosystem; sea ice; Arctic; Bering Sea; Bering Strait; Pacific; Chukchi; north slope; Odobenus rosmarus; Pacific Arctic; Sea ice; Alaska; walrus*
• Online Access: https://doi.org/10.1371/journal.pone.0255686.g001

Pacific walrus liver tissues were collected by subsistence hunters from several communities in the Bering Strait and from the North Slope of Alaska. The range of the Pacific walrus spans the northern Bering and Chukchi Seas, with sex-segregated distributions throughout the year (green/yellow shading). The Distributed Biological Observatory regions 1 and 4 (boundaries denoted by the black boxes; Grebmeier et al. [ 4 ]) encompass prominent Pacific walrus breeding and foraging grounds, which were used for extracting satellite-derived sea ice measurements and nitrogen stable isotope data for primary consumers from previous studies for the relative trophic position analysis. Pacific walrus range data was modified from Garlich-Miller et al. [ 22 ] and Smith [ 23 ]. Open-source coastline data was retrieved from Natural Earth ( https://www.naturalearthdata.com/ ).