The North Pacific Fishery Management Council, meeting in Seattle, voted unanimously to prohibit industrial fishing in nearly 200,000 square miles of U.S. waters in the Chukchi and Beaufort seas. The U.S. Commerce Department is expected to approve the recommendation.

"This will close the Arctic to all commercial fishing," says Jim Ayers, vice president for Pacific and Arctic affairs at ocean conservation organization Oceana, based in Juneau, who testified before the vote. "This is the beginning of a concept of large protected marine areas."

The move comes as warming temperatures continue to melt sea ice above the Arctic Circle. No commercial fishing currently occurs in the region but the concern is that it will begin as navigable waters replace the ice.

Summer 2007 set a record for the minimum extent of arctic sea ice at 4.3 million square kilometers, with 2008 close behind. The summer ice cover has fallen by more than 40% from the 1980s, opening around 1.3 million square kilometers of the Arctic to fishing, oil exploration and shipping.

The North Pacific Fishery Management Council voted to prohibit fishing in nearly 200,000 square nautical miles of Arctic waters in the so-called U.S. Exclusive Economic Zone, which stretches from 3 miles offshore to 200 miles offshore, starting at the Bering Strait and extending north and east to the U.S.-Canada border.

Current fishing spots in the Arctic Sea will remain unaffected, and indigenous tribes will still be allowed to subsistence fish in new regions, but nobody else gets to cast line or net.

The decision, which follows years of work by conservation groups including Oceana, Audubon Alaska, Ocean Conservancy, and the Pew Environment Group, is precedent-setting: It's one of the largest precautionary measures in fisheries history.