CHINOOK RUN BEING REGULATED : FEAR OF DISEASE TO LIMIT SPAWNING.

Byline: Ralph Jennings Scripps-McClatchy Western Service

Facing the human element of their migration cycle this month, hundreds of salmon are hurling themselves at the federal government dam on Battle Creek.

They're not getting hurt, but they're not getting through.

This week they'll have a place to go. The gates to the U.S. Fish and Wildlife Service's Coleman fish hatchery will be opened. Once the fish are inside, humans will whack them over the head, remove their eggs and give their carcasses to American Indians. Months later, the Fish and Wildlife Service will release 24 million young fish into the creek, which feeds the Sacramento River and Northern California's salmon industry.

Most people don't mind that humans intervene to keep the salmon run alive.

``I don't know if I should say, `Let nature take its course,' but with all the pollution, we've got to have some way for man to do what nature can't do,'' said Breck Breckenridge, one of the 50 or so people watching jumping fish Wednesday from an observation deck at the hatchery.

As early as next year some of the chinook's fall run will make it upstream past the hatchery and spawn in natural habitat. That opportunity will be made available to them by Fish and Wildlife's evolving $27 million plant that will purify creek water with ozone.

When complete, the plant will be able to process 65,000 gallons per minute.

The government doesn't let salmon go upstream now because fish that pass through during winter floods would pass diseases to fish that come back downstream, and those fish would pass the diseases on to hatchery fish. More fish would mean more disease, said Coleman biologist Roger Shudes.

Shudes said the answer is ``ozonation,'' a process that kills fish viruses as well as bacteria and parasites.

``It's going to provide near disease-free water for fish culture,'' said Shudes, who is assistant manager of the nation's largest federal salmon hatchery outside Alaska. ``Ozone is seven times more powerful than chlorine and more water soluble.''

About 40,000 salmon swim up Battle Creek, Shudes said, and the hatchery can take only 15,000. He said ozonation would let thousands more bypass the hatchery. The rest of the run must spawn in the lower reaches of Battle Creek.

A biologist with the state Department of Fish and Game is questioning the ozone plant and calls Coleman's fish production ``ironic.'' Coleman was established to replace fish that quit spawning in the upper Sacramento when the federal government built Keswick and Shasta dams and blocked migration.

``The irony is the hatchery that's compensating for the loss of Keswick and Shasta is blocking 40 miles of (steelhead) migratory territory,'' said the DFG's Harry Rectenwald. ``Myself, personally, I think it's sad (salmon) are blocked.''

Ozone technology, he said, ``is wonderful, but it's expensive and there might be other ways of doing that.''

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Photo

Photo: A fall run Chinook jumps, but finds the fish ladderclosed at the Coleman Fish Hatchery 20 miles south of Redding.

Scripps-McClatchy Western Service