Summary of Pacific walrus samples.

The region and year of subsistence harvested Pacific walrus liver tissues with annual sample sizes (n) by sex. Annual sea ice persistence (days/year) associated with the year of collection and the sea ice organic carbon content (mean ± SE %) and stable nitrogen isotope composition δ15N (mean ± SD ‰) by sex. Mean sea ice organic carbon values were adjusted to account for a significant interaction between region and sex.