An excellent article quoted from the Cody Enterprise on YellowstoneInsider.com tells about the remarkable turnaround in the fishing scene in our oldest national park. Since the mid 1990s, when large lake trout were introduced into Yellowstone Lake from an unknown source, the carnivorous fish have been devouring native cutthroats, a so-called keystone species. Combating them has been a struggle, since lake trout swim and spawn in the deepest water, while cutthroat trout swim near the surface and spawn in inlet streams.
The National Park Service and the Yellowstone Park Foundation have cooperated in fighting lake trout since soon after they were discovered, but at first with limited success. In the last six years, however, things have been turning around. Gillnetting and electrofishing removed about 300,000 lake trout last year. And the latest technique is particularly effective. Quoting the Yellowstone Insider article: “over the past few years, crews have started catching and attaching telemetry gadgets to the fish; telemetry allows crews to trace lake trout to their spawning beds and remove both fish and fry from them.”