Posted on March, 13 2006

A new study has found that the Bering Sea ecosystem is responding to changes in arctic climate and the effects could extend from base of food chain to native hunters.

Physical changes--including rising air and seawater temperatures and decreasing seasonal ice cover--appear to be the cause of a series of biological changes in the northern Bering Sea ecosystem that could have long-range and irreversible effects on the animals that live there and on the people who depend on them for their livelihoods.

In a paper published March 10 in the journal Science, a team of US and Canadian researchers use data from long-term observations of physical properties and biological communities to conclude that previously documented physical changes in the Arctic in recent years are profoundly affecting arctic life.

The northern Bering Sea provides critical habitat for large populations of sea ducks, gray whales, bearded seals and walruses, all of which depend on small bottom-dwelling creatures for sustenance. These bottom-dwellers, in turn, are accustomed to colder water temperatures and long periods of extensive sea ice cover.

However, "a change from arctic to sub-arctic conditions is under way in the northern Bering Sea," according to the researchers, and is causing a shift toward conditions favouring both water-column and bottom-feeding fish and other animals that until now have stayed in more southerly, warmer sea waters.

As a result, the ranges of region's typical inhabitants can be expected to move northward and away from the small, isolated Native communities on the Bering Sea coast that subsist on the animals.

Jackie Grebmeier, a researcher at the University of Tennessee and one of the paper's co-authors, said:
"We're seeing that a change in the physical conditions is driving a change in the ecosystems."

Grebmeier said the new report is unusual in that it looks at the potential effects of a changing climate in the Arctic primarily through a life-sciences lens, rather than an analysis of the physics of climate change. "It's a biology driven, integrated look at what's going," Grebmeier said.

Grebmeier is chief scientist for the Western Shelf-Basin Interactions (SBI) research project, which conducted a series of research cruises to observe changes in the carbon balance of the offshore areas of the Alaskan Arctic and their effects on the food chain. The cruises included a number of researchers supported by the US National Science Foundation (NSF), the US National Oceanic and Atmospheric Administration (NOAA), and other US federal agencies.

NSF and the Office of Naval Research (ONR) jointly funded SBI.