Stream Restoration

To reverse the decline in genetically pure Yellowstone cutthroat trout and westslope cutthroat trout, and to help ensure the subspecies’ long-term preservation, Yellowstone National Park will work with other government agencies and non-governmental organizations to return headwater streams in the park’s Yellowstone and Gallatin/Madison river drainages to native species-only status. This work will initially focus on identifying those watersheds providing a high probability for restoration success. Characteristics to be considered will include watershed size, habitat availability, water temperature, gradient, fish species present, accessibility, and location of any existing natural barriers to upstream invasion by non-native fish. Watersheds being considered for restoration must be small enough to ensure successful removal of all exotic salmonids, but large enough to support a robust, genetically diverse assemblage of cutthroat trout following treatment. The watersheds need to be isolated from the mainstem river by a barrier, which usually is similar to that constructed naturally by beavers. Approved piscicides will then be used to remove non-native fish species, prior to restocking with genetically pure cutthroat trout. By stocking cutthroat trout from different sources, such as wild, genetically pure trout from nearby streams or strains reared in a hatchery, we will be able to compare the survival and reproductive success among these sources to determine if there is any advantage to using one of the individual stocks as opposed to another.