Illustration by Michelle LaGory. Courtesy of Wyoming Game & Fish

Lake trout (Salvelinus namaycush) are native to northern Canada, Alaska, the Great Lakes and New England. In 1994 their presence was confirmed in Yellowstone Lake, where they were apparently illegally introduced at least 20 years earlier. Despite major efforts to remove them by gillnetting, the lake trout are having a significant ecological impact by consuming and competing for food with the native Yellowstone cutthroat trout, an important food for other native animals, including grizzly bears, osprey, and bald eagles. As potential prey, lake trout differ from cutthroat trout because they can grow larger, occupy deeper areas of the lake, and spawn in the lake instead of shallow tributaries.

Updated 7/23/10