Cooperative Fish and Wildlife Research Units Program: South Dakota
Education, Research and Technical Assistance for Managing Our Natural Resources

Rainbow trout are an important sport fish species in the Black Hills of South Dakota. While primarily stocked into lakes and streams to provide put-and-take fisheries, natural reproduction and subsequent recruitment into the adult population has been observed in two locations in the Black Hills. In one of those locations, Deerfield Reservoir, naturally reproduced rainbow trout were estimated to make up around 25% of the total population. Given natural reproduction, biologists propose to manage the fishery for wild rainbow trout, and reduce stocking efforts. In order to better understand this unique fishery, this goals of this study are to quantify growth, survival, and distribution of naturally produced rainbow trout, as well as the diet composition of piscivorous fishes and potential predation on rainbow trout in Deerfield Reservoir.