While looking for whales in Alaska’s Chukchi Sea last week, U.S. government officials noticed an unusually high number of polar bears swimming in the open sea. Some were apparently heading for shore and some were heading toward ice. Several of them were 15 to 20 miles from either destination.
Polar bears are good swimmers, of course, and they do cross water to get out to the ice, which they use as a platform to hunt marine life.
Biologists have predicted that polar bears might be in trouble as global warming causes the Arctic ice to retreat.
In northern Alaska the U.S. Minerals Management Service concluded that some polar bears are drowning as they try to swim increasingly long distances between the ice and land. The federal agency documented four drowned bears that had tried to swim a record 160-mile (257-kilometer) gap in September 2004.
Geoff York, the polar bear coordinator for WWF’s Arctic Programme, said yesterday that when polar bears swim so far from land, they could have difficulty making it safely to shore and are at risk of drowning, particularly if a storm arises.
“To find so many polar bears at sea at one time is extremely worrisome because it could be an indication that as the sea ice on which they live and hunt continues to melt, many more bears may be out there facing similar risk,” he said in a WFF statement.
“As climate change continues to dramatically disrupt the Arctic, polar bears and their cubs are being forced to swim longer distances to find food and habitat.”
The New York Times reported today that U.S. Fish and Wildlife Service officials have also seen more polar bears than usual on land this summer. However, one official noted that the bears that have been captured on both land and ice appeared to be in good condition.
Scientists say the Arctic is changing more rapidly and acutely than anywhere on the planet, noting that 2007 witnessed the lowest sea ice coverage in recorded history, according to WWF. Satellite images indicate that ice was absent in most of the region where the bears were found on August 16, 2008, and some experts predict this year’s sea ice loss could meet or exceed the record set last year.
In May, the U.S. Department of Interior listed polar bears as threatened under the Endangered Species Act, citing the strong body of science pointing to the significant loss of Arctic sea ice habitat as the primary reason for protecting the bear with federal legislation.
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