The federal government was responsible for the deaths of 33,000 salmon and steelhead trout in the Klamath River last fall when it diverted too much water for farmers and didn't leave enough flow for the fish, according to a state report released late Friday.
The California Department of Fish and Game study also warned that unless the U.S. Bureau of Reclamation increases flows in coming years, "there is a substantial risk for future fish kills on the Klamath River." The bureau is the federal agency that oversees agricultural diversions on the Klamath.
The report is the latest development in an intractable dispute over water and wildlife in the region. At issue is how much water should be sold to farmers along the California-Oregon border and how much should escape to the Pacific Ocean to sustain fish life and the tribal and commercial fishermen who depend on it.
In 2001, growers received only 15% of their usual allotment of irrigation water so that more could be made available for endangered sucker fish in Upper Klamath Lake and coho salmon in the lower river.
As a result, many farmers lost their crops. Last spring the Bush administration reversed course and developed a 10-year plan that gave growers their full supply of water in 2002.
That decision was roundly criticized by tribal interests, commercial fishermen and environmentalists after fish began dying in the lower Klamath in late September.
The 63-page study concludes that too many migrating fish crowded into a depleted river, allowing the spread of two naturally occurring parasites that destroy the gills of fish. The salmon and steelhead subsequently died of asphyxiation.
Fish and Game reached its conclusions by eliminating other factors that could have killed the fish, including drought, a late summer heat wave and a possible spill of toxics into the river. Agency scientists found the only difference in the Klamath River in the fall of 2002 compared to other dry years was that the number of salmon returning for their annual spawning run was high and the amount of water in the river was low.
Fishermen and environmentalists hailed the study as a validation of their previous arguments for more water in the river. Farming interests said the report only repeated previous statements made by state wildlife officials with little science to back it up. Officials with the Bureau of Reclamation and the U.S. Fish and Wildlife Service said that further study of the fish die-off was needed.
"The report is very consistent with conclusions reached by Fish and Game when the die-off first happened," said Dan Keppen, executive director of the Klamath Water Users Assn., a group that represents farmers in the Klamath Basin. "I wouldn't be so suspicious if it didn't match the things they've been saying all along. We're going to go after it."
Three more studies on precisely how much water is needed in the Klamath are underway. A report by the U.S. Fish and Wildlife Service will examine reasons for the die-off, said agency spokeswoman Patricia Foulk.
"If we do come up with a different set of reasons, I can assure you we'll have strong scientific evidence to back up those conclusions," Foulk said.
The Bureau of Reclamation is prepared to divvy up water the same as it did in 2002. Critics of the agency are hoping the new studies persuade the Bureau of Reclamation to leave more water for fish in the Klamath and its largest tributary, the Trinity.
Bureau spokesman Jeff McCracken said Saturday that the agency usually makes its decision on water allocations by early April and that all the new studies would be taken into consideration.