( The warming most global climate models ...)Antarctic warming to reduce animals at base of ecosystem, shift some penguin populations southward

A warming trend during the last few decades in the Antarctic Peninsula has already forced penguin populations to migrate south and perhaps diminished the abundance of krill that are at the base of the massive food chain at the bottom of the world.

"We're already seeing the marine ecosystems respond dramatically to increases in temperatures along the Antarctic Peninsula," explained Berry Lyons, professor in the School of Earth Sciences and director of the Byrd Polar Research Center at Ohio State University.

Lyons was one of many polar researchers reporting this week on the global climate threat during the annual meeting of the American Association for the Advancement of Science in San Francisco .

"Researchers are seeing the movement of penguin populations southward down the peninsula as sea ice lessens along its margins," Lyons said. "Gentoo and chinstrap penguins are shifting south into areas now populated by adelie penguins, and the adelies are being forced further south, all because of the change in sea ice."

A decrease in sea ice along the coast shows a drop in krill in the marine environment. As a major food source for higher animals, the loss of krill will reduce resources for higher mammals and birds.

Data gained through the Long-Term Ecological Research (LTER) site near the American Palmer Station suggests that the ecosystem's response to warming in the region includes changes in both the krill's abundance and availability.

"The data implies that there may be less food there as the temperatures rise," he said.

He manages the LTER site in the Dry Valleys near McMurdo Station, the largest of the three American bases in Antarctica . "It you look at the last
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Source:Ohio State University