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Kokanee comeback

David Cole | Hagadone News Network | UPDATED 11 years, 11 months AGO
by David Cole
| December 3, 2012 8:00 PM

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<p>Doug Burton, a fishery pathologist for the Idaho Department of Fish and Game, collects samples from 60 kokanee at the Granite Creek fish trap to study the health of the population.</p>

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<p>A male kokanee.</p>

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<p>A female kokanee.</p>

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<p>Volunteers process kokanee at the Granite Creek fish trap last week. Eggs and semen are taken from the kokanee, then the fish are piped downstream where they will decompose and provide important nutrients to the creek.</p>

HOPE - About 200,000 Lake Pend Oreille kokanee have returned to Granite Creek to spawn this winter, making it one of the largest returns in a dozen years.

The lake's population of kokanee - a land-locked sockeye salmon - has rebounded enough that for the first time since 1999, fishermen next year will be able to keep some of the kokanee they catch.

Right now, the Idaho Department of Fish and Game is collecting kokanee eggs at Granite Creek, the mouth of which is about a dozen miles south of Hope on the east shore of the lake. Harvesting of kokanee eggs has been going on annually since the 1970s.

Through Wednesday of last week, Fish and Game employees and volunteers had collected 10.5 million eggs through 11 days of collection. They will continue until late this month, depending on the weather.

The department is likely to collect about 14 million eggs total this year at the Granite Creek fish trap.

In both 2007 and 2008, the smaller number of kokanee returning to Granite Creek only gave up 500,000 eggs. That was for 20 days of collection in both years.

"Our ultimate goal is to bring the fishery back for the sportsman," said John Rankin, manager of the Cabinet Gorge Hatchery in Clark Fork, where the eggs are taken. The hatchery was built to mitigate fish losses from Albeni Falls Dam.

The fertilized eggs are placed in incubators for about three months at the hatchery, and then are fed until June when they are released as 2-inch fry into Sullivan Springs. That stream flows for about a half mile, then merges with Granite Creek, not far from where they empty into the lake.

Sometimes a few excess fry are released at different locations around the lake shore. Kokanee can and do spawn in suitable shoreline gravels.

From start to finish, it costs about $18.50 to produce 1,000 2-inch fry for stocking in the lake.

Fish and Game has been finding that returns of kokanee to Granite Creek have reached 4 percent.

"Four percent - we haven't seen those numbers in a long time," Rankin said. The fish showing up now are part of the 3.8 million fry released in 2009 at Sullivan Springs and Granite Creek.

Kokanee provide food for endangered bull trout, and for the trophy rainbow trout in the lake.

"It's also a very highly sought after game fish," Rankin said.

A major reason why the kokanee population dropped off was because of the lake trout, or mackinaw as they're sometimes known. The lake trout are voracious predators.

The reduction of lake trout in recent years has made for better kokanee returns. Lake trout have been netted, and anglers have been offered incentives to kill them.

Calvin Fuller, sporting goods manager at Big R of Ponderay and a regular fisherman on Pend Oreille, said the 10-plus million kokanee eggs already harvested this year is great news for fishermen.

"That's a huge year," Fuller said.

Good news for kokanee is likely to turn into good news for another vital sport fish.

He said fishermen on the lake hope improvements in kokanee populations mean the state will soon add some pure-strain rainbow trout from Canada to Pend Oreille, to help re-establish the trophy rainbow trout fishery. He said rainbow trout populations, which depend on a healthy kokanee population, are now depressed.

If some rainbow trout are added, those fish could bulk up to 10 pounds in only three to four years. In five or six years, the rainbows would explode to 20-plus pounds.

"Those are 'patch fish,'" he said, referring to the patch given by the Lake Pend Oreille Idaho Club to fishermen who land a 25-pound rainbow.

Pure-strain rainbows haven't been added to the lake since the 1990s, he said. That could change now, he said.

"We can see the light at the end of the tunnel," he said. "We're eager to see that next step."

Ed Dickson, owner of Diamond Charters in Hope, hopes to see some rainbow trout from Canada added to the lake soon.

"We've done a really good job of knocking the predator population out," he said. "I think we're well on to a return of kokanee now."

He's been taking people fishing on the lake since 1990. Dickson has seen recently more large masses of kokanee in his fish finders.

He's said he's seen the lake "lighting up at night with kokanee jumping," which is great, but, "The rainbows are what made the lake famous."

Unlike westslope cutthroat and bull trout, kokanee aren't native to the lake. But they've been in the lake a long time.

The state's kokanee spawning efforts will likely continue for the foreseeable future, too.

"I think it will always be necessary to some extent," Rankin said.

The 14 million eggs collected this winter will turn into about 12.5 million to 13 million fry stocked next summer.

The kokanee grow to about a foot in length before returning to spawn three years later.

They're good to eat and easy to catch, he said.

Last week, Doug Burton, a fishery pathologist for Fish and Game, collected wedges from 60 kokanee heads, and a similar number of kidney and spleen samples.

The wedges from the skulls would reveal the presence of Whirling disease, and the kidney and spleen samples would reveal any viruses. He took a second kidney sample from each fish to test for bacteria kidney disease.

He said past annual samples have shown the kokanee population in the lake to be healthy.

"If anything is keeping the population down, it's not a disease agent," he said.

While healthy, it's also good to see them returning to the stream bigger, he said.

"I've seen when they were averaging an inch or so less than this" in size, Burton said.

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