Lake trout in Yellowstone Lake now less menacing to native wildlife

Back in 1994 someone must have purposely and illegally stocked Yellowstone Lake with lake trout. Before it could be proven that these non-native fish had spread throughout the lake, they began adversely affecting the much smaller native cutthroat trout.

Many Yellowstone animals depend on the native fish as an important part of their diet but cannot catch the big lake trout. For example, grizzly bears and pelicans eat cutthroat from the lake, particularly in early summer.

Now, with major help from sources such as the Yellowstone Foundation and the Wyoming Wildlife and Natural Resource Trust Board, more and more lake trout are being removed every year— up to 300,000 in 2013 alone. At the same time many more juvenile cutthroat trout are surviving than in the early years of this century.

Three commercial boats and one National Park Service boat regularly net the lake trout with gill and trap nets and also use electroshocking. In addition they use telemetry by tagging some fish to locate lake trout spawning sites, and the movement of those fish toward spawning beds in the fall can now be tracked. A volunteer from Trout Unlimited said recently, “These patterns indicated at least three areas of suspected spawning activity: just off West Thumb Geyser Basin; off Solution Creek; and in the Plover Point, Frank Island triangle. Because these were suspected spawning grounds, arrays of receivers along with reference signals were placed in these three areas in early September in an effort to pinpoint any spawning beds in these areas.”

Meanwhile, anglers again this summer must kill all lake trout and either eat them or puncture the air bladder and dispose of the carcass in deep water. And cutthroat trout must be returned to the water immediately.

See the book excerpt about fish and fishing if you’d like to know more about the subject.