Cutthroat trout live in streams that have a wide range of temperatures, flow conditions, and topography. The goal of this project is to determine how closely adapted cutthroat trout are to the physical environment of the streams that they inhabit. A laboratory experiment will measure how juvenile westslope cutthroat trout survive in water temperatures that are different from their native temperature. A field experiment will introduce several populations of cutthroat trout into a stream currently having no fish and monitor how fish from each population survive. Both experiments will use fish occupying a wide variety of habitats.
This research will help determine how fine of a geographic scale natural selection operates, and ultimately, how the possible benefits of adaptation to a local environment compare to impacts of inbreeding. This will benefit fisheries management because moving fish from large thriving populations to small struggling populations is one of the most promising methods for preserving cutthroat trout. State agencies are currently reluctant to move fish because they lack knowledge regarding how closely adapted cutthroat trout populations are to their native streams. If cutthroats show strong patterns of local adaptation to their native environment, introducing fish into a population struggling to survive could do more harm than good. This project provides research training to graduate, undergraduate, and high school students.
