Bering Sea Altered by Warm Conditions
Ice seals such as walrus, ringed, bearded, and ribbon seals are common on St. Lawrence Island.
Credit: Lee Cooper

Rising air and water temperatures are altering the environment of the Bering Sea, a new study finds.

Hot Topic

The Controversy

The Effects

The Possibilities

Strange Solutions

The Bering Sea covers more than 700,000 square miles and is demarcated from the North Pacific Ocean by the Alaska Peninsula and Aleutian Islands. The sea is considered one of the world’s most productive fisheries; its northern portions house sea ducks, gray whales, bearded seals and walruses, all of which feed on cold-water critters.

But  warming temperatures of recent years have caused the environment to change from Arctic to sub-Arctic conditions in the region and have created an inviting haven for animals that were previously confined to the warmer waters of the south.

These warmer waters are bad news for animals adapted to cold-water environments, however. These creatures have to move north in search of cooler waters, which in turn is causing problems for people who live off of them.

"We're seeing that a change in the physical conditions is driving a change in the ecosystems," said study team member Jackie Grebmeier of the University of Tennessee.

Observations and satellite images reveal that the sea ice is thinning and shrinking. This affects two important regions of the Bering Sea.

"In the southeast, fish population and bottom-dweller changes are happening in the context of a complete loss of sea ice," said James Overland, an oceanographer at NOAA's Pacific Marine Environmental Laboratory involved in the study. "But in the northern Bering Sea, ecological changes are occurring in the context of shifts in the quality of the sea ice. The ice there is broken and thin compared with ice floes that were more the norm."

Such ecosystem changes could have far-reaching effects, scientists say.

The waters of the Bering Sea are helping to curb global warming by acting as a "carbon sink," absorbing atmospheric carbon dioxide. Any changes to the Bering Sea environment could affect this ability.

The researchers plan to watch the sea and the organisms that live in it closely over the next few years to understand the extent of environmental change.

The study was detailed in the March 10 issue of the journal Science.

The Effects of a Warmer Planet