Alaska In what some scientists see as another alarming consequence of global warming, thousands of Pacific walruses above the Arctic Circle were killed in stampedes earlier this year after the disappearance of sea ice caused them to crowd onto the shoreline in extraordinary numbers.
The deaths took place during the late summer and fall on the Russian side of the Bering Strait, which separates Alaska from Russia.
"It was a pretty sobering year - tough on walruses," said Joel Garlach-Miller, a walrus expert for the U.S. Fish and Wildlife Service.
Unlike seals, walruses cannot swim indefinitely. The giant, tusked mammals typically clamber onto the sea ice to rest, or haul themselves onto land for just a few weeks at a time.
But ice disappeared in the Chukchi Sea this year because of warm summer weather, ocean currents and persistent eastern winds, Garlach-Miller said.
As a result, walruses came ashore earlier and stayed longer, congregating in extremely high numbers, with herds as big as 40,000 at Point Shmidt, a spot that had not been used by walruses as a "haulout" for a century, scientists said.