“Think of an earthworm that weighs two tons,” says G. Carleton Ray. “That’s a walrus.” A research professor of environmental sciences, Ray and his wife and department colleague, Jerry McCormick-Ray, study the arctic environment. Recently, they returned to the Bering Sea to gather data on walrus distribution, feeding patterns and the effect of the receding sea ice that provides essential habitat for walruses and seals. Their work, they hope, will “add to the growing and irrefutable store of information that climate change is a serious matter and people are part of the cause,” Ray says.

Like earthworms, hungry walruses improve marine soil. They turn over as much as a billion cubic meters of sediment each year in their quest to extract clams and other invertebrates from the bottom of the shallow Bering and Chukchi seas, where they live.

“People have this idea that the Arctic is very cold and not very productive,” says Ray. But as walruses turn over the seabed, they release nutrients that support other marine creatures and help make the Bering Sea among the most productive in the world. Walruses depend on drifting ice floes to transport them to areas where they feed, breed and raise their pups. But as global temperatures rise, the ice in the Bering Sea is diminishing. Climate models predict that most of the walrus’ ice habitat could disappear by the end of this century.

“The reduction of ice threatens ice-dependent animals, but it also could change the basic ecology and productivity of the sea itself,” says Ray. “The ramifications of this sea-ice change are quite impressive.”

Ray believes international treaties are needed to protect walruses and seals and to reduce the rate of climate change. He fears that the disappearing sea ice will lead to overfishing the Bering Sea. “If the ice recedes, the fisheries are going to move in,” he says. That could threaten the walrus’s food supply, which in turn could disrupt the entire ecosystem.