Decline in salmon could restrict catch

Faced with an “unprecedented collapse” of California’s Central Valley salmon population, federal regulators warned Tuesday that the West Coast fishing industry is on course toward steep restrictions this year.

The number of chinook salmon returning to the Sacramento River plummeted to near historic lows last year, and fishery experts are predicting similarly light returns this year.

Donald McIsaac, director of the Pacific Fishery Management Council, said the reason for the decline remains unclear.

But the numbers of chinook or king salmon returning to many other West Coast rivers were also down last year, and scientists suspect the culprit is ocean conditions linked to global warming.

“The implications of a precipitous decline could be substantial for both commercial and recreational fisheries coastwide,” McIsaac said, drawing a comparison to 2006, when plummeting Klamath River salmon stocks prompted major fishing cutbacks.

Some environmentalists blamed the troubles on water exports from the Sacramento-San Joaquin River Delta, headwaters of the giant aqueducts that funnel water to Southern California.

The Sacramento River’s “missing salmon” were juveniles migrating to sea in spring 2005, when state and federal water managers “set records for pumping delta water south,” said Mike Sherwood, an attorney with Earthjustice, a nonprofit environmental legal group that has been jousting with water managers over water exports.

McIsaac sent an e-mail late Monday to members of the Pacific Fishery Management Council outlining the steep salmon decline.

Only about 90,000 returning adult salmon were counted in the Central Valley in 2007, the second-lowest number on record and nearly one-tenth the all-time high of more than 800,000 five years ago.

McIsaac said he wanted to give council members “an early alert to what at this point appears to be an unprecedented collapse.”

Particularly worrisome, he said, is the historic slump in the number of returning 2-year-old salmon, which are used as an indicator of future adult salmon returns.

Just 2,000 of the young fish returned to the Sacramento River last year, an all-time low, compared with more than 76,000 in 2004.

The fishery council, which sets annual federal fishing limits on the West Coast, is slated to meet in Sacramento in March to discuss potential restrictions, with a final decision at the April meeting in Seattle. The salmon season typically begins in May.

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eric.bailey@latimes.com