Yellowstone Lake, Yellowstone National Park, USA. The world’s largest inland cutthroat trout (Oncorhynchus clarkii bouvieri) population is under attack by alien invaders: illegally stocked nonnative lake trout (Salvelinus namaycush). Grizzly bears, river otters, bald eagles, and other iconic wildlife of the Park no longer can dine on the massive spawning runs of cutthroats in Yellowstone Lake’s tributaries and angling success for the stream-run cutts has plummeted.

Federal fisheries biologists have been waging war on the lake trout (cost: $300K per year), setting thousands of miles of gill nets every year. The combat biologists (below) have removed well over 100,000 lake trout so far but still more lake trout are being captured and the cutthroat population continues to dwindle (Koel et al. 2006).

NPS photo

NPS photo

Varley and Schullery (1995)

Learn more:

Bigelow, PE., T.M. Koel, D. Mahoney, B. Ertel, B. Rowdon, and S.T. Olliff. 2003. Protection of native Yellowstone cutthroat trout in Yellowstone Lake – Yellowstone National Park, Wyoming. Technical Report NPS/NRWRD/NRTR-2003/314. National Park Service, Water Resources Division, Fort Collins, Co. [PDF]

Koel, T.M., P.E. Bigelow, P.D. Doepke, B.D. Ertel, and D.L. Mahony. 2005. Nonnative lake trout result in
Yellowstone cutthroat trout decline and impacts to bears and anglers. Fisheries 30(11):10-19. [PDF]

Munro, A.R.,T.E. McMahon, and J.R. Ruzycki.2005. Natural chemical markers identify source and date of introduction of an exotic species: lake trout (Salvelinus namaycush) in Yellowstone Lake. Canadian Journal of Fisheries and Aquatic Sciences 62:79-87. [PDF]

Ruzycki, J.R., D.A. Beauchamp, and D.L. Yule. 2003. Effects of introduced lake trout on native cutthroat trout in yellowstone lake. Ecological Applications 13:23-37. [PDF]

Varley, J.D. and P. Schullery (eds.). 1995. The Yellowstone Lake Crisis: Confronting a Lake Trout Invasion. Yellowstone Center for Resources, National Park Service, Yellowstone National Park, Wyoming. [PDF]