Angela Szesciorka, PhD

As the Arctic warms four times faster than the rest of the planet, visual, acoustic, and satellite tagging evidence suggests bowhead whales might be changing their migration patterns. We analyzed 11 years of recordings of bowhead whale calls and songs to explore relationship between migration timing and sea ice in the Chukchi and Bering Seas. Fall migration into the Bering Strait and spring migration into the southern Chukchi Sea was strongly tied to sea ice in the Chukchi Sea, while sea ice in the Bering Sea was responsible for how long whales were absent between the southward and northward migration. Since 2013, some whales are remaining in southern Chukchi Sea rather than moving into the northwestern Bering Sea for the winter. Changes to bowhead whale migration could increase the overlap with ships and impact Indigenous communities that rely on bowhead whales for nutritional, cultural, and spiritual subsistence. Read our recent publications in Movement Ecology and Geophysical Research Letters.

Reductions in sea ice and a longer “open water” season have increased vessel traffic through the Bering Strait and expanded transit opportunities in the Northwest Passage and Northern and Transpolar Sea Routes. While only two percent of harvested bowhead whales have been documented with vessel strike scars, increased vessel traffic has the potential to increase vessel strikes, especially in the Bering Strait and southern Chukchi Sea, areas that overlap with bowhead whale core use areas. These are also areas where satellite tag and passive acoustic data suggest that some whales are spending winter instead of the northwestern Bering Sea. Additional questions remain about disturbance due to vessel noise and the general trends in vessel traffic in the Bering Strait and Chukchi Sea. Knowledge of the trends in vessel traffic and potential overlap between with bowhead whale core use areas will be useful for understanding future risk to this population.