How declining sea ice affects whale migration

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How declining sea ice affects whale migration

November 17, 2016 - 21:05
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Native peoples of the Arctic have long appreciated and relied upon the migrations of animals alongside the changing seasons. But how does the declining Arctic sea ice affect the migration of beluga whales?

Adult beluga whales migrating through fractured sea ice in the Alaskan Arctic.

The relationship between Arctic whales and declining sea ice in the Arctic is still a mystery, and there is growing concern over how the species will adapt to climate-related changes in sea ice.

Researchers from Florida Atlantic University's Harbor Branch Oceanographic Institute and a team of scientists working in collaboration with native hunters in Alaska and Canada have published results of a study in the Royal Society Biology Letters journal assessing the relationship between changing sea ice and beluga whale migration as well as summer residency patterns of a number of populations over twenty years of sea ice changes in the Pacific Arctic.

They found that beluga whales exhibited a tremendous ability to deal with varying sea ice conditions from one year to the next over a 20-year time frame upon their return to traditional summering grounds each year.

"It was not clear how sea ice influences beluga whale migration patterns and their summer habitat use, and climate change has added urgency to determining how environmental factors might shape the behaviour and ecology of this species," said lead author Greg O'Corry-Crowe, Ph.D., a research professor at FAU Harbor Branch.

Using genetic profiling, sighting data and satellite microwave imagery of sea ice in the Bering, Chukchi and Beaufort seas, the team found dramatic shifts in migration behaviour in the years with unusually low spring sea ice concentration and in one case with an increase in orca sightings and reported predation on beluga whales.

"Continued reductions in sea ice may result in increased predation at key aggregation areas and shifts in beluga whale behaviour with implications for population viability, ecosystem structure and the subsistence cultures that rely on them," said O'Corry-Crowe.

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