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Yellowstone National Park's draft plan for native fisheries does not provide enough details on how it would reduce lake trout populations in Yellowstone Lake, Wyoming Trout Unlimited said in a media release last week.

"It appears the course is the same as what they've been doing," said Dave Sweet, a Cody volunteer who represents the Wyoming Council of Trout Unlimited.

So far, Sweet said, the park's course of action has not resulted in a decline of lake trout, an invasive species that has eliminated an estimated 95 percent of the lake's Yellowstone cutthroat trout population. Instead, an aggressive lake trout gill-netting operation has only kept the population from increasing more quickly.

"They don't know if increased gill netting will drive that population down," Sweet said.

A rigorous monitoring plan is needed to know if progress is being made in removing lake trout, or if the species is holding steady or increasing.

New plan

The park unveiled its 20-year Native Fish Conservation Plan Environmental Assessment last month. Comments are being taken on it through Jan. 31.

As part of the Park Service's efforts to reduce lake trout, commercial netting crews will double their efforts to net fish in shallower water this summer. The park has become increasingly adept at capturing the invasive trout, which were illegally planted in the lake. Yet despite increased netting this past summer that captured about 150,000 lake trout, a census of Yellowstone cutthroat trout showed a decline.

Sweet is urging others to press the Park Service to take a more aggressive stance on lake trout removal and to urge the agency to implement recommendations made by a science review panel in 2008.

Sweet acknowledged that the Park Service's work is limited by funding. But he said that within the park's fisheries budget, more dollars should be concentrated on lake trout removal than on projects such as restoring native westslope cutthroat trout or grayling.

"It's a question of priorities," Sweet said. "If we delay on Yellowstone Lake, we're seriously in jeopardy of losing that entire population of Yellowstone cutts, which at one time was the largest population of Yellowstone cutthroat in the world.

"They do have additional funds available if they prioritize them in different ways," he added.

TU recommendations

Some of the science review panel's recommendations that Trout Unlimited would like to see implemented include a telemetry study to find how lake trout are moving throughout the lake in different seasons; use of netting or mark-and-recapture studies to calculate lake trout numbers; naming an independent science advisory panel to oversee and review operations; and identifying all possible spawning areas to target fish eggs when new technologies become available.

Bob Greswell, a U.S. Geological Survey scientist in Bozeman, Mont., is researching different ways to destroy eggs, including the use of ultrasound and electrical current.

"That's the ultimate solution," Sweet said. "In order to solve the problem you can't just throw nets in the water."

Trout Unlimited has raised money to help Greswell pursue possible egg-killing techniques.

About more than fish

Improving Yellowstone Lake's cutthroat trout population while reducing its lake trout numbers is not just about fishing, Sweet said.

"It's about an ecosystem," he added. "There are more than 40 other species that depend on the Yellowstone cutthroat trout as a part of their diet. So the decline of the Yellowstone cutthroat trout is not just a loss to the fishery, it's a loss to the whole ecosystem up there."

To comment

To comment on the Yellowstone National Park Native Fish Conservation Plan Environmental Assessment, go online to: or write to Native Fish Conservation Plan, Yellowstone National Park, P.O. Box 168, Yellowstone National Park, WY 82190.

The plan can be viewed at 111&projectID=30504&documentID =37967


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