Fall and Winter Movements and Habitat Selection by Snake River Cutthroat Trout in the Upper Snake River, below Jackson Lake Dam, Wyoming

Authors(s): J. Goldstein

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Publication Date: 0000-00-00

Type: annual report

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Abstract: Objectives Determine movement patterns and habitat selection by cutthroat trout in the upper Snake River. Findings and Status Thirty fish were tracked to examine the effects of winter conditions and flow manipulations on movement and habitat use. A high rate of post-tagging mortality occurred and was attributed to the combined effects of electroshocking and carbonic acid anesthesia during the tagging procedure. Reliable data on movements and habitat selection were collected on only five (17%) of the radiotagged fish. Fish were not displaced following fall flow reductions from Jackson Lake dam (2,200 cfs to 500 cfs, October 1996); however, it appeared that two of the fish were displaced up to 7 km downstream during January 1997 after several frazil ice events had occurred and winter conditions were prevalent. Radiotagged fish were observed using shelf ice as protective cover during this period. Throughout the study period, radiotagged fish selected locations where multiple types of stream habitat were present. Additional study is needed to determine how habitat availability and flow manipulations interact to affect winter distribution and survival of cutthroat trout.

Keywords: Grand Teton National Park, animal, fish, Pisces, Salmonidae, trout, cutthroat trout, Snake River cutthroat trout, Oncorhynchus clarki bouvieri, Jackson Dam, habitat, migration, radio collar, Snake River, mortality