Federal officials are worried about reports that fishermen have been catching lake trout in Yellowstone Lake because the presence of the non-native species could be devastating to cutthroat trout.
Lynn Kaeding, acting manager of the U.S. Fish and Wildlife Service's fisheries program in Yellowstone National Park, said reports of lake trout in Yellowstone Lake have been trickling in since two fish that anglers believe were lake trout were caught there earlier this month and turned in.He said some of the reports indicated anglers thought they may have caught lake trout in Yellowstone Lake as long as 10 years ago.
"It's hard for me to think of a more potentially damaging act than this one," Kaeding said of the possibility that someone planted lake trout in Yellowstone Lake.
Lake trout are voracious eaters that prey on cutthroat and compete with them for habitat. Most of the other lakes in Yellowstone National Park are dominated by introduced species like brown, rainbow and lake trout.
"There isn't another cutthroat population like this anywhere," Kaeding said of Yellowstone Lake.
The cutthroat also are a major source of food for grizzly bears, eagles, osprey and pelicans in the park.
Officials have not received additional hard evidence that lake trout really exist in Yellowstone Lake, like a dead fish or a picture of a fish, Kaeding said. And he noted that fish can be hard to identify.
However, he said officials suspect that somebody, at some point, illegally dumped lake trout into Yellowstone Lake.
Park managers are asking fishermen to kill any suspected lake trout they catch in Yellowstone Lake.
The best case scenario, Kaeding said, is that only a few small lake trout have been put into Yellowstone Lake and that they have been unable to breed successfully so far.
The worst-case scenario, he said, is that there have been a number of large lake trout in the lake for years, cruising the depths and not being caught by fishermen seeking cutthroats in shallower water.