Walleyes invading Lake Pend Oreille

Once walleye showed up in the Clark Fork River in Montana, biologists knew the non-native fish would eventually find their way to Lake Pend Oreille, on their own or with a little illicit help.

“We got 33 walleye altogether,” said Mark Liter, Idaho Fish and Game Department biologist, describing what he found in the gillnets researchers were using earlier this month to sample the lake’s mackinaw and whitefish populations.

The fish were caught near the mouth of the Pack River, indicating the walleye were staging to spawn.

“Since big bass boats came on the scene with all their live wells, fish are turning up all over,” Liter said. “One of our guys even caught a walleye in Hayden Lake.”

Walleyes already had been collected during electrofishing in the Idaho section of the Clark Fork River in recent years.

A few were also caught last year near the Long Bridge in Sandpoint.

Some walleye have been in the system up to 10 years.

“I think they are naturally reproducing, now,” Liter said.

Some walleye have also been spotted in shallow gravel areas at the base of the Monarchs.

Although there has been some interest from local anglers for a new game fish to replace the dwindling kokanee in Lake Pend Oreille, Fish and Game has been reluctant to stock walleye for fear of unintended consequences of planting yet another nonnative species in the lake.

Intentionally introduced species like lake trout, kokanee and Kamloops rainbows have taken a toll on native species, including cutthroat trout and bull trout.

Walleye may be the next angling darling on the lake.

It’s already happened with illegally introduced smallmouth bass.

“Ten years ago who ever heard of smallmouth in Pend Oreille?” Liter said. “Now we have tournaments.”

But walleye won’t appeal to novices, because the fish won’t be easy to find in scattered habitat in the 43-mile-long lake, Liter predicted.

In the clear waters of Lake Pend Oreille, walleye may tend to feed at night, when people are least likely to fish for them.

Tournament angler Ted Beach of Hayden said Idaho is missing out on hundreds of thousands of dollars anglers spend on walleye tournaments in Eastern Washington.

He said he also enjoys the competitiveness of the professional circuit and the added bonus that walleye make fine table fare.

“At Lake Roosevelt, kokanee, rainbows and smallmouth bass coexist with walleye,” he said.

While it is a new predator species, walleye won’t have an immediate effect on kokanee, which managers are trying to save from collapse.

“For now, they are eating peamouth, pikeminnow and yellow perch,” he said, noting he hasn’t found kokanee in a walleye’s gut.

“They are spatially separated,” he said. “Kokanee are in 100 to 300 feet of water at midlake.”

Walleye are more apt to hang around structures closer to shore.

But walleye and kokanee habitats overlap seasonally.

Walleye eventually will learn to key where kokanee fry emerge from spawning gravels and where stream-born kokanee enter the lake, Liter said.

Chip Corsi, regional supervisor for Fish and Game, agreed that walleye could pose a new risk for kokanee, which are being decimated by rainbows and lake trout.

“I feel like we’re playing Space Invaders,” he said of the new threat.

The Idaho Fish and Game Commission has removed the bag limit for walleye in most of Idaho.

“The message is, don’t introduce walleye, because we’re not going to manage for them,” Corsi said. “If folks want to go fish for them, I hope they do and I hope they whack ‘em.”

Brad Lierman, Montana Fish Wildlife and Parks biologist, said researchers haven’t studied the feeding habits of walleye in the Noxon Reservoir upstream from Lake Pend Oreille.

“In other western reservoirs they do eat a lot of salmonids,” he said. “We expect to see effects on trout.”

Lierman hasn’t noticed much angler pressure on walleye in Noxon Reservoir, where walleyes have reproduced for at least four years.

“But I’m getting more phone calls from people who want to fish for them,” he said.