Beluga whales dive deeper, longer to find food in Arctic

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February 20, 2018

A beluga whale pod in the Chukchi Sea.Laura Morse/Alaska Fisheries Science Center, NOAA Fisheries Service

Reductions in sea ice in the Arctic have a clear impact on animals such as polar bears that rely on frozen surfaces for feeding, mating and migrating. But sea ice loss is changing Arctic habitat and affecting other species in more indirect ways, new research finds.
Beluga whales that spend summers feeding in the Arctic are diving deeper and longer to find food than in earlier years, when sea ice covered more of the ocean for longer periods, according to a new analysis led by University of Washington researchers. The study, published this month in the journal Diversity and Distributions, is one of the first to consider the indirect effects of sea ice loss on Arctic species that dwell near the ice, but don’t necessarily depend on it for survival.
“I think this paper is novel in that we’re presenting some of the first indirect effects of sea ice loss for an Arctic whale species,” said lead author Donna Hauser, a postdoctoral researcher at the UW’s Polar Science Center and former doctoral student at the School of Aquatic and Fishery Sciences. “As changes in sea ice affect oceanographic properties, that could be affecting the distribution, abundance or species composition of prey for belugas.”
Two genetically distinct beluga populations spend winters in the Bering Sea, then swim north in the early summer as sea ice melts and open water allows them passage into the Beaufort and Chukchi seas. There they feast all summer on fish and invertebrates before traveling back south in the fall. Both populations are considered healthy.
The researchers analyzed migration data collected intermittently from two different periods — referred to in the paper as “early” and “late” — for two beluga populations, covering the …

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