UT Research Shows Ecological Impact of Global Warming

KNOXVILLE – Research by University of Tennessee scientists has shown potentially irreversible changes in the ecology of the Bering Sea that they argue are likely to be a consequence of global warming.

Cooper & Grebmeier

The research by UT professors Jackie Grebmeier and Lee Cooper will appear in the March 10 issue of the journal Science.

Long-term observations including rising air and seawater temperatures and a reduction in the amount of ice cover leads them to conclude that these changes are having a major impact on the ecosystem.

“Our research shows that these physical changes resulting from climate change are altering the face of these ecosystems,” said Grebmeier, who, along with Cooper, is a research professor in UT’s ecology and evolutionary biology department. “The influence is being felt throughout the food web, including the native human populations of the area.”

A number of large animals in the northern Bering Sea, including walruses, bearded seals, gray whales and some sea-ducks are specialized feeders who dive to the bottom to feed on creatures dwelling in the sediments that thrive in cold water and a thick ice cover for long periods of the year. As those bottom-dwelling creatures’ habitat moves farther north, the larger animals must move with them. This is leaving small isolated Native Inuit and Yupik Eskimo communities that rely on animals, especially walrus, without one of their primary sources of food.

The results of the research paint a difficult picture for the future of the region, due to the sea’s role as a “carbon sink.” Biological activity in the water serves to absorb carbon dioxide that would normally be present in the atmosphere, contributing to climate change. As the ecological changes they describe take place, less of that carbon dioxide will be stored, potentially creating a cyclical pattern.

Grebmeier and Cooper, along with other authors of the study from several institutions in the U.S. and Canada, took an unusual approach to their research by examining the effects of global warming through biological research, as opposed to examining only physical evidence.

“It-s a biology-driven, integrated look at what-s going on,” she said.

Other signs of a changing ecology in the area include a northerly movement of fish that have not been previously common or important parts of the foodweb, probably in response to warmer ocean temperatures.

“Taken together, this study indicates that the Bering Sea is shifting from arctic to sub-arctic conditions in a way that is fundamentally changing the ecosystem,” said Cooper.

The research was funded by the National Science Foundation and the Office of Naval Research as part of the Western Shelf Basin Initiative (SBI), which is one of the largest U.S. global change research efforts currently underway in the Arctic. Grebmeier serves as the chief scientist for the program, which includes a University of Tennessee project office managing the research efforts of scientists across the country. The NSF and the National Oceanic and Atmospheric Administration also funded this work as part of the Bering Strait Environmental Observatory.

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Contact:

Jay Mayfield, media relations (865-974-9409, jay.mayfield@tennessee.edu)

Jackie Grebmeier, professor of ecology and evolutionary biology (865-974-2592, jgrebmei@utk.edu)

Lee Cooper, professor of ecology and evolutionary biology (865-974-2990, lcooper1@utk.edu)

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