NAT PENNINGTON/AP

Fish counters with the Salmon River Restoration Council measure a fall chinook carcass along the Salmon River, a tributary of the Klamath River in Northern Calif., in October.

GRANTS PASS, Ore. - Fall chinook salmon returns to the Klamath River are running about two-thirds below last year, reflecting the loss of thousands of juveniles to low water in 2000 and 2001 and perhaps signaling a downturn in food available in the ocean.

"There are not a whole lot of live fish swimming around," said Gary Stacey, fisheries program director for the California Department of Fish and Game's North Coast region in Redding, Calif.

Stacey said the reduction was likely due to a combination of factors. Low water during the spring and summer migration down the river to the ocean killed 100,000 to 300,000 juvenile chinook in 2000, and tens of thousands in 2001. The bulk of this year's returning fish are from those year classes.

Stacey said chinook salmon are paying the price for scarce water supplies being managed for coho salmon, which are on the threatened species list. Extra water put down the Klamath River for coho helps some chinook migrate to the Pacific. But the young chinook that wait until summer are left to struggle.

"The combination of low flows when the juveniles are migrating out, warm temperatures, and the interaction with these naturally occurring disease organisms - they are all adding to the problem," said Stacey. "The flows that we are getting are focused entirely on coho, and they are not large enough to provide optimal conditions for fall chinook."

The losses of juvenile fish don't fully explain the declines, indicating that ocean conditions that have produced plentiful runs in recent years may be reversing as a mild to moderate El Nino is forming, Stacey said. The climatic cycle known as El Nino produces warmer waters in the Pacific, leading to less food for salmon. Returns are also down, though not so much, in the Sacramento River to the south and the Rogue River to the north.

Salmon fishermen say this is the first of at least three years in a row of declining Klamath chinook returns that will force reduced ocean harvests up and down the West Coast. The juvenile salmon losses were followed in 2002 by the loss of 36,000 to 70,000 adult chinook to diseases related to low and warm water. Fewer Klamath salmon forces cutbacks in harvests from the central Oregon coast to San Francisco because the fish mix in the ocean.

"It all comes down to too little water at a time fish need it in the river system," said Glen Spain of the Pacific Coast Federation of Fishermen's Associations, which represents California commercial salmon fishermen. "That I lay to the doorstep of the Bureau of Reclamation for cutting off flows in the river and producing what was an artificial drought for several years running."

The U.S. Bureau of Reclamation has been struggling to share scarce water among farms in the Klamath Reclamation Project straddling the Oregon-California border, threatened sucker fish in Upper Klamath Lake, and threatened coho salmon in the Klamath River and its tributaries.

"We are continuing to operate the Klamath project according to a biological opinion from NOAA Fisheries," said Bureau of Reclamation spokesman Jeff McCracken. "They have determined the long-term flows. And these flows have been supported by a water bank that next year is calling for 100,000 acre feet from willing sellers in the basin."

The 3,013 adults that have returned to Bogus Creek and the 950 returned to the Shasta River amount to 23 percent of last year's run at this time, said Stacey. Compared to the good returns of 2001, this year's returns to the Shasta are 9 percent. The 10,500 chinook that have returned to the hatchery at Irongate Dam on the mainstem of the Klamath River are 33 percent of last year's run at this time.

Farms in the Klamath Project got their full deliveries in 2000, though water was scarce enough to delay deliveries to nearby wildlife refuges. In 2001, drought was so bad that the bureau cut off water to most of the Klamath Project to meet Endangered Species Act demands for coho and suckers.

Since then the bureau has been buying water from farmers to give to fish to meet the growing demands set under a biological opinion outlining what the coho need to survive.