Cold Temperature Effects on Cutthroat Trout Recruitment
Part of Ph.D. Research at Colorado State University
(January, 2002-Dec, 2005)
Client: Colorado Division of Wildlife, USDA Forest Service, Central Utah Project Completion Act, National Park Service
Summary: Colorado River cutthroat trout (CRCT, Onchorhynchus clarki pleuriticus) have declined and now occupy only a small fraction of their original native range. They are currently granted special status by the states of Colorado, Utah, and Wyoming, as well as the U.S. Forest Service and Bureau of Land Management. In order to preserve sufficient fish and habitat to avoid the listing of the species under the Endangered Species Act, these states and agencies have joined forces in conservation efforts aimed at preserving the purity and abundance of existing remaining populations. One primary conservation strategy has been to translocate CRCT to high elevation streams uninhabited by trout due to migration barriers downstream, or to streams where existing nonnative trout have been removed. The success rate of this strategy in establishing persistent populations of cutthroat trout was below 50% up to 1995. The low success rate and high cost of each translocation makes conservation efforts costly and may lead to public dissatisfaction with science-based management efforts. Previous research suggested that summer stream temperatures are correlated with translocation success in high elevation streams in the Southern Rocky Mountains. I conducted an integrated laboratory and field study, including the largest, most longterm laboratory study on mortality during early life history stages in cutthroat trout, and collecting over three years of data in the field on abundance of young of year fry and adults, and the habitat critical for spawning and recruitment. My field sites included six headwater streams in the Arapaho and Roosesvelt National Forests and Rocky Mountan National Park, which contained populations of Colorado River or greenback cutthroat trout. Through this research, I was able to define the coldest summer thermal regimes likely to support recruitment, and thus self-sustaining populations, of cutthroat trout in Southern Rocky Mountain Headwater streams.
Related Publications/Reports
Coleman, M. A. and K. D. Fuasch. IN PRESS. Cold summer temperature limits recruitment of age-0 cutthroat trout in high-elevation Colorado streams. Transactions of the American Fisheries Society.
Coleman, M. A. and K. D. Fausch. 2007. Cold summer temperature regimes cause a recruitment bottleneck in age-0 Colorado River cutthroat trout reared in laboratory streams. Transactions of the American Fisheries Society 136:639–654.
Coleman, M. A., Fausch, K. D. 2006. The role of cold summer temperatures in translocation success in native cutthroat trout in high elevation Colorado streams. Project Final Report to the Central Utah Project Completion Act Office, Department of Interior, Provo, Utah, Colorado Division of Wildlife, Denver, Colorado, and the USDA Forest Service, Rocky Mountain Region, Denver, Colorado.
Coleman, M. A., Fausch, K. D. 2005. Causes of recruitment bottlenecks in translocated cutthroat trout populations: investigations of low temperature effects. Annual Report to the Central Utah Project Completion Act Office, Department of Interior, Provo, Utah, Colorado Division of Wildlife, Denver, Colorado, and the USDA Forest Service, Rocky Mountain Region, Denver, Colorado.
Coleman, M. A., Fausch, K. D. 2004. Causes of recruitment bottlenecks in translocated cutthroat trout populations: investigations of low temperature effects. Annual Report to the Central Utah Project Completion Act Office, Department of Interior, Provo, Utah, Colorado Division of Wildlife, Denver, Colorado, and the USDA Forest Service, Rocky Mountain Region, Denver, Colorado.
Coleman, M. A., Fausch, K. D. 2003. Causes of recruitment bottlenecks in translocated cutthroat trout populations: investigations of low temperature and brook trout effects. Annual Report to the Central Utah Project Completion Act Office, Department of Interior, Provo, Utah, and the Colorado Division of Wildlife, Denver, Colorado.
Related Presentations
Coleman, M. A., Fausch, K. D. 2005. Oral Presentation: can cold summer temperatures reduce recruitment of cutthroat trout and explain differences in translocation success? National Meeting of the American Fisheries Society, Anchorage, Alaska.
Coleman, M. A., Fausch, K. D. 2005. Oral Presentation: can cold summer stream temperature reduce recruitment of cutthroat trout populations in Colorado and explain differences in translocation success? Colorado-Wyoming Chapter American Fisheries Society, Fort Collins, Colorado.
Coleman, M. A., Fausch, K. D. 2004. Oral Presentation: can cold summer water temperature cause recruitment bottlenecks in translocated cutthroat trout populations? Western Division American Fisheries Society, Salt Lake City, Utah.