Propagated Fish in Resource Management

A Tale of Two Parks: Management of Nonnative Lake Trout in Yellowstone and Grand Teton National Parks, Wyoming, USA

Scott Bosse


Abstract.—The introduction of nonnative lake trout into lakes across the western United States has had profound effects on adfluvial cutthroat trout Oncorhynchus clarkii and other native ichthyofauna. Such is the case in Yellowstone and Grand Teton national parks, where lake trout from the Great Lakes were first introduced at the end of the 19th century. Today, lake trout Salvelinus namaycush pose a major threat to the world’s largest population of interior cutthroat trout in Yellowstone Lake and have contributed to sharp declines of Snake River finespotted cutthroat trout O. clarkii behnkei in nearby Jackson Lake. The management responses of the two parks to these lake trout invasions have differed markedly. Yellowstone National Park has acted to sharply reduce lake trout numbers in Yellowstone Lake by instituting an aggressive gillnetting program. In contrast, Grand Teton continues to allow the Wyoming Game and Fish Department to stock tens of thousands of lake trout fingerlings in Jackson Lake annually. The discrepancy in lake trout management policies likely stems from the fact that different agencies with conflicting mandates oversee fisheries management in the two parks. While fisheries in Yellowstone are managed by the National Park Service, which has a strict preservation mandate, Grand Teton’s fisheries are managed by the Wyoming Game and Fish Department, whose mission is to maintain an abundant supply of diverse, high quality fishing opportunities.