Global Warming

Lack of Sea Ice Brings Hunger and Orcas

Winter sea ice has re-formed off Siberia so rapidly this year that it has trapped ships and blocked supplies to Russian cities, but Canada’s Hudson Bay now has an extreme lack of ice, threatening the region’s polar bears. The massive Arctic bay typically begins to freeze in November, but temperatures about 11 degrees above normal have left it virtually ice-free into December.

Peter Convey, an ecologist at the British Antarctic Survey, says this is not good for the polar bears, which need the ice to hunt seals. “The longer they don’t have sea ice, they get a gradual loss in (health) condition. Fewer will survive.” Bears are now left standing along the Hudson Bay shores in a season that is second only to 2010 for the lack of ice in early December.

Decreasing sea ice around the North Pole and a rapidly warming Arctic climate appear to be driving orcas, also known as killer whales, deeper into the Arctic Ocean, where they could be a threat to the region’s ecosystem.

While a common sight in many of the world’s oceans, orcas have historically not ventured to waters covered in ice most of the year because of the danger of becoming trapped beneath it. But using underwater microphones to record and date orca vocalizations, Brynn Kimber at the University of Washington and her colleagues found that the marine mammals are now arriving early in summer near the Bering Strait.

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