warmer climate 'profoundly altering' arctic food chain

Warmer climate alters Arctic food chain
Researchers assess long-term impact
Robert Lee Hotz, Los Angeles Times
Friday, March 10, 2006

Whales, walruses, seabirds and fish are struggling to survive the changing climate of the Bering Sea, their northern feeding grounds perhaps permanently disrupted by higher temperatures and melting ice, scientists reported Thursday in the journal Science.

By pulling together a broad range of observations and surveys, an international research team concluded that they are witnessing the transformation of an entire ecosystem in a region home to almost half of all U.S. commercial fish production.

All in all, the researchers said, the Arctic climate of the northern Bering Sea is in full retreat, yielding to the sub-Arctic system of the south.

The changes are "profound" and perhaps irreversible, even if cold weather eventually returns, the researchers said.
...

... the local sea ice now melts three weeks earlier than in 1997, records of recent years show. Last year, Arctic ice retreated further than in 25 years of satellite monitoring.

"Here we put all the pieces of the puzzle together," Grebmeier said.

The researchers found that by 2002, Pacific gray whales were fleeing northward to feed in cooler currents, while pink salmon by the millions swarmed into warmer waters the whales had abandoned. Bottom-dwelling species, unable to adapt, were decimated.

As sea ice diminished, breeding grounds for seals were disrupted and populations plummeted. Polar bears started to drown. Walruses, accustomed to diving in the shallows to feed along the sea bottom, found themselves adrift on broken ice floes in waters 6,500 feet deep. The animals starved.