Yellowstone Lake Ecosystem Restoration: A Case Study for Invasive Fish Management
Todd M. Koel,
Jeffery L. Arnold,
Patricia E. Bigelow,
Travis O. Brenden,
Jeffery D. Davis,
Colleen R. Detjens,
Philip D. Doepke,
Brian D. Ertel,
Hayley C. Glassic,
Robert E. Gresswell,
Christopher S. Guy,
Drew J. MacDonald,
Michael E. Ruhl,
Todd J. Stuth,
David P. Sweet,
John M. Syslo,
Nathan A. Thomas,
Lusha M. Tronstad,
Patrick J. White,
Alexander V. Zale
Affiliations
Todd M. Koel
U.S. National Park Service, Yellowstone Center for Resources, Native Fish Conservation Program, P.O. Box 168, Yellowstone National Park, WY 82190, USA
Jeffery L. Arnold
U.S. National Park Service, Yellowstone Center for Resources, Native Fish Conservation Program, P.O. Box 168, Yellowstone National Park, WY 82190, USA
Patricia E. Bigelow
U.S. National Park Service, Yellowstone Center for Resources, Native Fish Conservation Program, P.O. Box 168, Yellowstone National Park, WY 82190, USA
Travis O. Brenden
Quantitative Fisheries Center, Michigan State University, 375 Wilson Road, East Lansing, MI 48824, USA
Jeffery D. Davis
Yellowstone Forever, P.O. Box 117, Yellowstone National Park, WY 82190, USA
Colleen R. Detjens
U.S. National Park Service, Yellowstone Center for Resources, Native Fish Conservation Program, P.O. Box 168, Yellowstone National Park, WY 82190, USA
Philip D. Doepke
U.S. National Park Service, Yellowstone Center for Resources, Native Fish Conservation Program, P.O. Box 168, Yellowstone National Park, WY 82190, USA
Brian D. Ertel
U.S. National Park Service, Yellowstone Center for Resources, Native Fish Conservation Program, P.O. Box 168, Yellowstone National Park, WY 82190, USA
Hayley C. Glassic
Montana Cooperative Fishery Research Unit, Department of Ecology, Montana State University, P.O. Box 173460, Bozeman, MT 59717, USA
Robert E. Gresswell
U.S. Geological Survey, Northern Rocky Mountain Science Center, 2327 University Way, Bozeman, MT 59715, USA
Christopher S. Guy
U.S. Geological Survey, Montana Cooperative Fishery Research Unit, Department of Ecology, Montana State University, MSU–P.O. Box 173460, Bozeman, MT 59717-3460, USA
Drew J. MacDonald
Montana Institute on Ecosystems, Montana State University, MSU–P.O. Box 173490, Bozeman, MT 59717-3490, USA
Michael E. Ruhl
Montana Institute on Ecosystems, Montana State University, MSU–P.O. Box 173490, Bozeman, MT 59717-3490, USA
Todd J. Stuth
Hickey Brothers Research, LLC, 4083 Glidden Drive, Sturgeon Bay, WI 54235, USA
David P. Sweet
Wyoming Council of Trout Unlimited, P.O. Box 3008, Cody, WY 82414, USA
John M. Syslo
Montana Cooperative Fishery Research Unit, Department of Ecology, Montana State University, P.O. Box 173460, Bozeman, MT 59717, USA
Nathan A. Thomas
U.S. National Park Service, Yellowstone Center for Resources, Native Fish Conservation Program, P.O. Box 168, Yellowstone National Park, WY 82190, USA
Lusha M. Tronstad
Wyoming Natural Diversity Database, University of Wyoming, 1000 East University Avenue, Department 3381, Laramie, WY 82071, USA
Patrick J. White
U.S. National Park Service, Yellowstone Center for Resources, Native Fish Conservation Program, P.O. Box 168, Yellowstone National Park, WY 82190, USA
Alexander V. Zale
U.S. Geological Survey, Montana Cooperative Fishery Research Unit, Department of Ecology, Montana State University, MSU–P.O. Box 173460, Bozeman, MT 59717-3460, USA
Invasive predatory lake trout Salvelinus namaycush were discovered in Yellowstone Lake in 1994 and caused a precipitous decrease in abundance of native Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri. Suppression efforts (primarily gillnetting) initiated in 1995 did not curtail lake trout population growth or lakewide expansion. An adaptive management strategy was developed in 2010 that specified desired conditions indicative of ecosystem recovery. Population modeling was used to estimate effects of suppression efforts on the lake trout and establish effort benchmarks to achieve negative population growth (λ 46,800 100-m net nights; this effort level was achieved in 2012 and led to a reduction in lake trout biomass. Total lake trout biomass declined from 432,017 kg in 2012 to 196,675 kg in 2019, primarily because of a 79% reduction in adults. Total abundance declined from 925,208 in 2012 to 673,983 in 2019 but was highly variable because of recruitment of age-2 fish. Overall, 3.35 million lake trout were killed by suppression efforts from 1995 to 2019. Cutthroat trout abundance remained below target levels, but relative condition increased, large individuals (> 400 mm) became more abundant, and individual weights doubled, probably because of reduced density. Continued actions to suppress lake trout will facilitate further recovery of the cutthroat trout population and integrity of the Yellowstone Lake ecosystem.
