5 years ago, unusual catch led to concern for Idaho lake. Officials just reeled in another

Mike Thomas/IDFG
·2 min read

Nearly five years after the Idaho Department of Fish and Game found an invasive predatory fish in one of the state’s prime perch habitats, officials reeled in another.

In a news release, Fish and Game officials said off-duty fisheries biologist Mike Thomas was fishing the Boulder Creek arm of Lake Cascade on Saturday when an angler he was with caught a 20-inch male walleye weighing nearly 3 pounds. The discovery revived concerns about the popular fishing spot’s ecosystem.

Walleye are native to Canada, the Great Lakes and the Missouri River Basin, though they’ve been introduced in other states — including parts of Idaho — because of their popularity with anglers.

But their appearance in Lake Cascade is alarming to Idaho fisheries experts, who have spent years rehabilitating Lake Cascade into a prime spot for perch fishing. Walleye have never been stocked in Lake Cascade or any of its tributaries out of concern that the predatory fish could disrupt other fish populations. Idaho stocks walleye in select reservoirs, where they aren’t able to travel to other waterways.

Fish and Game officials said they believe this fish was transported to Lake Cascade and illegally stocked, perhaps alongside an unknown number of other walleye. In 2018, another angler discovered a 19-inch walleye near Crown Point, prompting an investigation into its origins.

Thomas said the extent of the walleye infestation still isn’t clear.

“Two reports over a four-year span means walleye could very well be established in the lake, but the fact that we haven’t encountered them during extensive fish population surveys or angler surveys means they are likely not very abundant yet,” Thomas said in the news release. “Our fisheries program will be shifting gears over the coming weeks to try to determine the extent of their occurrence in the lake, and we’ll develop a game-plan for moving forward.”

Anyone with information on the illegal stocking of the walleye in Lake Cascade is urged to report information to Citizens Against Poaching, which is offering a reward. The Citizens Against Poaching hotline is available 24/7 at 1-800-632-5999. Fish and Game also asked any anglers who catch walleye at Lake Cascade to harvest the fish rather than returning them to the water. Anglers should also report any walleye catches to Fish and Game’s McCall office at (208) 634-8137.