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Secret No More: Plan to Eliminate
Lake Trout from Stanley Lake Underway

by Jerry Painter
Post Register, June 13, 2020

Idaho Fish and Game technicians run a gillnetting operation on Stanley Lake to check fish populations. A full-scale gillnetting operation began this month to remove lake trout from the lake. (Idaho Department of Fish and Game) For many years it was a bit of a secret among a certain group of anglers. Like "No Tell ‘Em Creek," only this was Stanley Lake in central Idaho.

Even the Idaho Department of Fish and Game kept things hush-hush. Some people knew there were more than 500, 5- to 30-pound lake trout in the 180-acre Stanley Lake.

"We've kind of kept that under our hat," said Greg Schoby, fisheries biologist with the Salmon regional office. "It's been a well-kept secret. There's a dedicated group of guys in Challis and Stanley and Ketchum and Idaho Falls and Boise. There's some people in the know."

A former fishing tackle shop owner Jane McCoy of Stanley said occasionally an angler would come in with a giant lake trout they caught at Stanley Lake and ask, "What is this?"

"It was a fantastic fishery," McCoy said. "There were some 30-plus pounders in there."

But the secret was out when biologists identified a danger to other nearby lakes and the endangered fish species in them, specifically trout, salmon and steelhead. Lake trout, also called mackinaw, eat other fish. They feast on young trout, kokanee and sockeye. Although it hasn't happened yet, the danger was that the lake trout would migrate out of Stanley Lake and into some of the key salmon and steelhead nursery lakes such as Redfish Lake where Fish and Game has a massive rescue mission going on to save the state's nearly extinct sockeye salmon.

"What they've seen in other places like up in the Flathead Valley (Montana), lake trout were stocked in Flathead Lake in the 1900s and about 50 to 60 years later they showed up in other lakes about 60 to 70 miles away," Schoby said. "It was a tough lake to access so they assumed that someone didn't put them there, they swam there. That's what we're concerned with, with this population."

All of the stakeholders -- anglers, guides, business owners, the Forest Service and biologists -- gathered to form the Stanley Lake advisory committee in 2017. After several meetings, they settled on a plan that would prevent the lake trout problem and still keep the dedicated lake trout anglers happy.

"The options we were presented with didn't include a do-nothing option," McCoy said, who was a member of the committee. "(The option chosen) seemed to be the least harmful to the fishery that we could see. There were a number of people who were saddened by the action to reduce the population."

The plan is to remove all of the lake trout currently in Stanley Lake and restock the lake with sterile lake trout and capture adult sterile lake trout from a population in Bear Lake to replace the lost adult fish. Gillnetting lake trout began last week.

Schoby said some of the anglers took some time before they came around to the idea of replacing their favorite fishery.

"Most of these anglers were pretty willing to move toward the middle," he said. "They recognized that this could turn into a pretty bad situation if say lake trout did move into Redfish Lake and damage the population there. It would not only impact sockeye recovery efforts but impact multiple trout populations."

Schoby said the final plan is a win-win for everybody.

"What our big concerns are, is what we've seen in other places," Schoby said. "If the lake trout population were to get out of balance, a lot of times fish will move and we had concerns about fish moving from Stanley Lake to Redfish or Alturas or Pettit lakes or one of those we're working on for sockeye recovery."

All of the lakes are connected with outlet streams that flow into the Salmon River.

Fish and Game has hired the same company (the Wisconsin-based Hickey Brothers Research) that is working on gillnetting lake trout in Yellowstone Lake -- a lake where lake trout did get out of control and crashed the native cutthroat population. The project is partially funded by a grant from the Pacific Coast Salmon Recovery Fund.

Gillnetting has also helped Fish and Game get the lake trout population under control in north Idaho's Lake Pend Oreille.

"We started a gillnet project up there (Lake Pend Oreille) going on its 15th year," Schoby said. "It has successfully reduced that population -- not eliminated them just reduced them -- to the point where kokanee would rebound, bull trout would increase and trophy rainbows would come back. … One difference between the Pend Oreille or Yellowstone Lake is that those populations were increasing exponentially. In Stanley we have only a population of 550 fish. It's a pretty different situation. We're in a better situation then they are."

Starting this summer, sterile young lake trout, about 10- to 12-inches long, will be stocked in Stanley Lake and "100 to 200 adult-sized" lake trout -- about 5 to 10 pounds -- will be transported from Bear Lake. Sterile lake trout have been stocked in Bear Lake since the early 2000s.

So why are there lake trout in Stanley Lake in the first place?

"Historically, Stanley Lake has been dominated by suckers and pike minnows," Schoby said. Fish and Game removed the fish and worked to develop the lake into a sport fishery in the 1970s.

"It has been a pretty good balance with lake trout, kokanee, and a decent brook trout population," he said. "We stock about 8,000 to 10,000 rainbows in there for the summer."

Related Pages:
Fisheries Managers Forecast 'Unprecedentedly Low' Summer Steelhead by George Plaven, East Oregonian, 5/22/17

Jerry Painter
Secret No More: Plan to Eliminate Lake Trout from Stanley Lake Underway
Post Register, June 13, 2020

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