Effects of Lower Troposphere Temperature on Ice Phenology and the Pacific Walrus Population

Résumé

The effects of climate change on biotic communities and their environment have been one of the leading factors of recent population declines. This study investigated how climate change affected sea ice, a key component of the Pacific Walrus’s habitat, and in turn how it can affect walrus populations. Lower troposphere temperatures along with sea ice retreat data were obtained between 1979–2014 for the Arctic Ocean and Chukchi Sea region, respectively. Concurrently, Pacific Walrus population estimates were obtained from the literature. We found a significant, negative relationship between sea ice retreat and temperature such that earlier retreat of sea ice was more common with warmer temperatures. Sea ice retreat and temperature were good predictors and highly correlated with population size. These results provide a possible link between climate change and walrus population decline, and future studies should include life history and sea ice traits to solidify this linkage.