ANCHORAGE — Two groups of Pacific walrus have been found dead along the Chukchi Sea northwest of Alaska. One incident is the subject of a criminal investigation. The other has been blamed on natural causes.
How many walrus have died and how?
Twenty-five walrus, including 12 calves, were reported dead near Cape Lisburne. The causes of death have not been disclosed but federal prosecutors have taken the case. Some had been beheaded, an indication of poaching for ivory tusks or skulls. A second group of walrus was found dead last week near Point Lay, about 100 miles northeast of Cape Lisburne. Initial reports said 37 animals appeared to have died of natural causes.
How do walrus die of natural causes?
Walrus deaths have been attributed to trampling, exhaustion from prolonged exposure to open sea conditions, and separation of calves from their mothers. In late summer, Chukchi Sea walrus gather in large numbers, nearly shoulder to shoulder, on the Alaska coast. Walrus are powerful swimmers but lumbering and ungainly on land. If panicked by a polar bear, human hunter or airplane, they may stampede to reach the safety of the ocean. In 2009, 131 young walrus died near Icy Cape.
Why do walrus come ashore in September?
Climate warming and a loss of summer sea ice. Sea ice covers the Chukchi Sea and much of the Bering Sea each winter. Male walrus largely stay in the Bering Sea in summer but mothers with calves ride the sea ice edge north as it melts, using the ice as a platform on which calves can rest while adult females dive for clams, sea snails and other food on the ocean floor.
In recent years, sea ice has receded far beyond the shallow outer continental shelf. Walrus mothers have two choices in late summer: ride ice over Arctic Ocean water that’s far too deep to reach the ocean floor, or swim to shore, where calves are vulnerable to predators and stampedes. When sea ice forms again in September, walrus can leave their shoreline hangouts.
What is being done to protect walrus in late summer?
The Fish and Wildlife Service works with coastal villages to minimize contact with walrus that could cause a stampede. When a herd forms, small airplanes must maintain altitude of at least 2,000 feet within a half-mile of walrus. Helicopters and larger airplanes must maintain larger buffers.
The agency has declined a suggestion by an environmental group, Oasis Earth, to test artificial platforms in the Chukchi Sea to give walrus an alternative to coming ashore.
