Aerial video footage recently released by the U.S. Geological Survey captures the epic scale of a mass migration of walruses to the coast of Alaska in the face of diminished summer sea ice. Researchers say 10,000 to 20,000 walruses have abandoned the shrinking ice of the Chukchi Sea for land along the U.S. and Russian coasts. The video footage, taken from about 4,000 feet, shows thousands of walruses packed together on the shore of Alaska’s Point Lay. “These walruses are typically out on the sea ice, drifting over shallow continental shelf waters that are really rich in the foods that they eat,” Geoff York of WWF’s Global Arctic Program told Discovery News. In earlier decades, the summer sea ice was like a “conveyor belt” that constantly moved the walruses over food-rich, shallow waters, York said. But with the ice rapidly disappearing in summer, he said, the walruses had to choose whether to remain on sea ice over less fertile, deeper waters or swim to shore. He said this was the third summer in recent memory that the walruses — mainly females and calves — have hauled out en masse on the Alaskan and Russian coasts, and that this summer saw the largest-ever migration of walruses to shore along the Chukchi Sea. A recent USGS report said that hundreds of walruses — mainly juveniles — have been trampled in Alaska and that thousands have been trampled in Russia in the packed conditions.

Photo by U.S. Fish and Wildlife Service

Reprinted with permission from Yale Environment 360