Limitations on Native Species Recovery Potential in Bear Lake
Scientific Poster Presentation for WATS 4600 course at Utah State University, Fall 2022
Non-native species invasions threaten the future of native fish diversity worldwide (Wilcove et al., 1998). Bear Lake is an oligotrophic natural freshwater alkaline lake on the Idaho–Utah border in the Western United States which is home to 5 endemic species, Bonneville Cisco, Bonneville Whitefish, Bear Lake Whitefish, Bear Lake sculpin and an apex predator, the Bear Lake strain of the Bonneville Cutthroat trout, commonly called the Bear Lake Cutthroat (Palacios et al., 2007). Nonnative Lake Trout were introduced to Bear Lake for sportfishing
opportunity impacting the native species through competition and predation (McHugh and Budy, 2006, Witte et al., 1992). Bear lake is limited in productivity with low densities of phytoplankton, zooplankton, and benthic invertebrate known to result in a natural bottom-up regulation of the fish communities found in lakes (Dean et al., 2009; Hayden et al., 2017). The addition of a nonnative apex predator, such at the Lake Trout, creates a top-down control on an already naturally impaired system (Albrecht et al., 2004; Koel et al., 2005; Palacios et al., 2007). While recovery efforts have brought wild Bear Lake Cutthroat back from eight percent to over 50 percent of the total population of hatchery and wild cutthroat in the Bear Lake (Tolentino, 2022), this interaction between top-down and bottom-up controls may be the limiting factor in increasing population recovery potential as well as the cause of a decrease in maximum size of the Bear Lake Cutthroat trout (Behnke, 2002). Halting programs to stock nonnative Lake Trout or pairing this action with the removal of the present fish, may result in greater success in protecting the native fish species of Bear Lake.
References: Albrecht, B., J. Robinson, C. Luecke, and B. Kennedy. (2004). Bioenergetics simulations assessing the consumption demand of different
stocking regimes of sterile Lake Trout in Bear Lake Utah-Idaho. Final report to Idaho Department of Fish and Game. Department of
Aquatic, Watershed, and Earth Resources, Utah State University, Logan. Behnke, R. J., and Tomelleri J. R. (2002). Trout and Salmon of North America. Free Press.Dean, W. E., Wurtsbaugh, W. A., & Lamarra, V. A.
(2009). Climatic and limnologic setting of Bear Lake, Utah, and Idaho. Special Paper of the Geological Society of America, 450 (450), 1–14. https://doi.org/10.1130/2009.2450(01). Hayden, B., Myllykangas, J. P., Rolls, R. J., & Kahilainen, K. K. (2017). Climate and productivity shape fish and invertebrate community
structure in subarctic lakes. Freshwater Biology, 62(6), 990–1003. https://doi.org/10.1111/FWB.12919. 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, DOI: 10.1577/1548-8446(2005)30[10:NLTRIY]2.0.CO;2. McHugh, P., & Budy, P. (2006). Experimental Effects of Nonnative Brown Trout on the Individual and Population-Level Performance of Native
Bonneville Cutthroat Trout. Transactions of the American Fisheries Society, 135(6), 1441–1455. https://doi.org/10.1577/T05-309.1. Palacios, P.; Luecke, C.; and Robinson, J. (2007). "Fish of Bear Lake, Utah," Natural Resources and Environmental Issues: Vol.14, Article 15.
Available at: digitalcommons.usu.edu/nrei/vol14/iss1/15 Tolentino, S. (2020). Bear Lake Status Report. [Unpublished manuscript] Utah Division of Wildlife Resources. Wilcove, D. S., D. Rothstein, J. Dubow, A. Phillips, and E. Losos. (1998). Quantifying threats to imperiled species in the United States.
Bioscience 48:607–615. Witte, F., T. Goldschmidt, P. C. Goudswaard, W. Ligtvoet, M. J. P. van Oijen, and J. H. Wanink. (1992). Species extinction and concomitant
ecological changes in Lake Victoria.Netherlands Journal of Zoology 42:214–232.