Snow Crab down 85 % in 6 years.

I think that is a frightening statistic. One solution is that more people could stop eating (as much) wildlife. That's not the answer that the fishermen are looking for - but it may be the best answer for the planet and sea-life in the long term.

Ecological upheaval on the edge of the ice

From the Bering Sea - As the research vessel Thomas G. Thompson steamed toward St. Paul Island, crab fisherman Wayne Baker was holed up in the tiny Alaskan harbor, waiting for a break in the weather.

It hadn't been a great season so far.

"I've never seen so many blanks," said Baker, who set pots for four days without pulling up a single crab.

St. Paul is a speck of land in the Bering Sea, the treacherous expanse of water that separates Siberia and Alaska near the top of the world.

Since Russian fur-traders came seeking otter pelts in the 1700s, this northernmost reach of the Pacific Ocean has created fortunes and claimed the lives of mariners drawn by its astounding bounty of marine life. Whales, walruses, seals - one species after another was slaughtered to the verge of extinction, yet a wealth of living resources remained untapped.

Today the Bering Sea yields half of all seafood harvested in the United States. The annual catch is valued at $1.7 billion. The bulk of that money goes into the pockets of fishermen and processing companies based in Seattle - a 12-day sail from St. Paul.

But the nation's richest ocean ecosystem is in the midst of a major upheaval, and scientists suspect global warming is at least partly to blame. Researchers like those who spent a month this spring on the University of Washington's Thompson are trying to figure out what the future holds for the region called America's "fish basket."

Crabbers like Baker are already feeling the effects.

In the past six years, snow crab catches have dropped 85 percent. Most other crab species are in a similar slump. Overfishing is probably a factor - but not the only one. Biologists also have documented a northward shift of crab populations, away from warming waters in the traditional fishing grounds of the southern Bering Sea.

Fur seal numbers are dwindling, despite a 20-year-old ban on commercial hunting. Stellar sea lions were declared endangered in 1997. Seabirds that once flocked to the region by the millions are in precipitous decline.

The changes coincide with rising water temperatures and shrinking sea ice cover.

"In the Bering Sea ... rapid climate change is apparent, and its impacts significant," scientists concluded in the 2004 Arctic Climate Impact Assessment.

...For creatures adapted to a frozen world, the loss of ice can be catastrophic.

Walruses and so-called ice seals haul out on floes to give birth and rear their pups. As the area that freezes each year shrinks, the animals are forced farther north and into deeper water. More walrus pups are being abandoned - a possible sign that adults can't reach the bottom anymore to fetch clams.

Short-tailed shearwaters migrate more than 9,000 miles from Australia, trusting the normal interplay of ice, sunlight and water temperatures will guarantee a feast of tiny shrimp when they arrive. In 1997, a half-million of the albatrosslike birds starved to death because off-kilter weather triggered a chalky algae bloom that obscured their prey.

Fish also are highly selective about temperature, which varies with the amount of ice.

"It only takes a little bit of warming to change from a place with seasonal ice cover to no ice cover," Hunt said. "That's why these high latitudes are expected to be the places where long-term global warming shows up first and has its most profound impacts."

The Alaskan Arctic is replete with evidence of global warming, from forest fires to melting permafrost and shifting whale migrations. But those changes mainly affect local residents. What happens in the Bering Sea reaches into the Seattle economy and world seafood markets.

..."They're very aware that global warming could have significant impacts, but the scientists aren't able to give them any firm predictions," he said. "The industry is focused on the here and now."

Over the past few years, scientists have discussed what climate change might mean for fishing worldwide. But concrete answers remain elusive because marine ecosystems are still so poorly understood.

Even in Alaska, where the fisheries are considered the best-managed in the world, biologists can't predict how a tug on one part of the ecological web will reverberate through the others....