A Survey of the Fishes and Habitat of the Cheyenne River in South Dakota

Information regarding the fishery of the mainstem Cheyenne river in western South Dakota has not been updated in almost forty years. In addition, the two statewide surveys that were completed during this century sampled only a few locations and did not record any habitat or species abundance data. I sampled fish and habitat at nine reaches between Angostura Dam and Lake Oahe on the mainstem Cheyenne River during the summer months of 1996 and 1997. Thirty species representing ten families were collected. The fish community was dominated by the Cyprinidae, Ictaluridae, and Catostomidae families with 85% of the total catch made up of flathead chub Platygobio gracilis (28%), plains minnow Hybognathus placitus (24%), western silvery minnow H. argyritis (20%), sand shiner Notropis stramineus (7%), and channel catfish Jctaluros punctatus (6%). Among the species captured were five previously considered rare in South Dakota (sturgeon chub Machrybopsis gelida, plains topminnow Fundulus sciadicus, flathead chub, plains minnow, and western silvery minnow). Relative weight (Wr) of channel catfish among three length groups in the Cheyenne River was 73-184 for the 70-279 mm length group, 75-96 for the 280-409 mm length group, and 59-100 for fish over 409 mm long. A pattern of increasing widths, depth, and discharge was observed from upstream to downstream reaches, and many of the habitat variables measured were positively correlated with one another. Differences in channel morphology among study reaches suggest three distinct habitat zones available to aquatic biota. Of several hydrological habitat features measured (i.e. discharge, velocity, surface width, and depth), only depth differed between years, although other qualitative habitat assessment techniques indicate flows may have been higher in 1 997. As the first comprehensive fish and habitat survey of the Cheyenne River, this study provides baseline data for future assessment of the fish community and watershed health