Hatching A Scheme Sockeye Salmon Returned To Old Spawning Grounds

Scientists will try to put the red fish back in Redfish Lake this spring, but it won’t be easy.

Even if they perfect their technique, local officials aren’t thrilled with plans to kill off existing kokanee to make way for sockeye.

The lake, a favorite of campers at the headwaters of the Salmon River near Stanley, is the historic home of the Snake River’s only run of sockeye salmon, now nearly extinct.

Idaho Fish and Game plans to stock it with 100,000 wild sockeye fry raised in captivity. Next spring, when they are about four inches long, most of the sockeye are expected to migrate to the ocean.

The fish are protected by the Endangered Species Act and the National Marine Fisheries Service is the federal agency charged with their recovery.

Before releasing the fish, scientists have to prepare the lake. That means fertilizing the lake so it will grow more plankton to feed young sockeye, and weeding out competition from other fish, Fish and Game fisheries chief Steve Huffaker told Custer County commissioners.

It is risky. If the lake’s food base collapses, it will take years to revegetate the lake, said biologists.

Kokanee will be trapped before the small fry move into the lake.

Custer County commissioners were skeptical of the need for trapping.

“Let’s go back to years ago when the lake was full of sockeye and kokanee and trout and trash fish,” said Chairman Cliff Hansen. “How come there’s not enough food in the lake to support these fish now?”

Biologists said with few sockeye around and little pressure from anglers, kokanee have flourished. Food reserves have dwindled without the decayed carcasses of sockeye adults to provide fertilizer.

Before eight hydroelectric dams on the Columbia and Snake rivers blocked their 900-mile passage to and from the Pacific Ocean, thousands of sockeye spawned in the lake each year, then died.

Their bodies, carrying rich nutrients from the ocean, rotted in the lake, providing fertilizer for the underwater vegetation and other life that would feed the next generation.

After hatching, sockeye live and grow in the lake one or two years before swimming to the ocean. There they stay, feeding in the Pacific one to three years before returning to their birthplace.

Still, no one seemed to want kokanee killed. Stanley businessmen and Fish and Game want anglers to catch the bigger kokanee already living in the lake.