Wildlife

Mass gathering of walruses - latest sign of global warming

Pacific walrus that can't find sea ice for resting in Arctic waters are coming ashore in record numbers on a beach in northwest Alaska.

An estimated 35,000 walruses were photographed on Saturday about 5 miles (8 kilometers) north of Point Lay, according to the National Oceanic and Atmospheric Administration.

Point Lay is an Inupiat Eskimo village 300 miles (482 kilometers) southwest of Barrow and 700 miles (1,126 kilometers) northwest of Anchorage.

The gathering of walruses on shore is a phenomenon that has accompanied the loss of summer sea ice as the climate has warmed.

Pacific walruses spend winters in the Bering Sea. Females give birth on sea ice and use ice as a diving platform to reach snails, clams and worms on the shallow continental shelf.

Unlike seals, walruses cannot swim indefinitely and must rest. They use their tusks to "haul out," or pull themselves onto ice or rocks.

As temperatures warm in summer, the edge of the sea ice recedes north. Females and their young ride the edge of the sea ice into the Chukchi Sea, the body of water north of the Bering Strait.

In recent years, sea ice has receded north beyond shallow continental shelf waters and into Arctic Ocean water, where depths exceed 2 miles (3 kilometers) and walruses cannot dive to the bottom.