Factors Affecting Native Cutthroat Trout Population
Phaedra Budy - Department of Aquatic, Watershed, and Earth Resources, Utah State University
The Logan and Bear rivers in northern Utah and southern Idaho support a population of endemic Bonneville cutthroat trout, a species that is threatened to varying degrees by habitat degradation, hybridization, disease, and competition with non-native fishes. While the Logan River experiences some anthropogenic impacts, this system is considered relatively pristine and provides a refuge and popular fishery for cutthroat trout. In contrast, much of the Bear River is highly degraded, and fish are exposed to highly variable and frequently low flows, poor water quality, and even complete de-watering due to river management for water development; farming and grazing practices have also resulted in substantial erosion and sedimentation. The contrast between these two systems provides an ideal situation for evaluating and understanding the complex and synergistic effects of biotic and abiotic factors, anthropogenic impact, and species interactions on the distribution, abundance, and health of Bonneville cutthroat trout in the Great Basin. The overall objective of this project is to monitor and evaluate the distribution, abundance, and health of native and exotic fishes in the Bear and Logan rivers and to understand the effect that varying degrees of anthropogenic impacts on stream ecosystems has in determining fish health and population dynamics. This research will benefit from 4 years of previous monitoring and research on the Logan River, continued collaboration with the state and federal agencies as well as local fishery groups, and partial, supportive funding for the Logan River component from UDWR, a University CURI grant, and a PhD student funded, in part, by a Quinney fellowship. In addition, this research directly supports the establishment of the Bear River Laboratory Watershed, a fundamental goal of the University Water Initiative, and will provide the preliminary investigations and baseline data necessary for establishing multidisciplinary research and teaching opportunities in this new Laboratory Watershed. The goals of this research are complimentary to the hypotheses outlined by the Laboratory Watershed Committee and to EPA water quality monitoring and research proposed for the watershed.