Food Web Interactions Impacting Kokanee (Oncorhynchus nerka) in an Eastern Washington Lake

Buffalo Lake, located on the Colville Confederated Tribes Reservation in north-central Washington State, is currently managed with the primary goal of maintaining sustainability of a naturally reproducing Kokanee fishery, and a secondary goal of providing quality Largemouth Bass and stocked Rainbow Trout fisheries. In mixed species systems, complex food web interactions can affect fishery quality. For example, Kokanee and hatchery Rainbow Trout competitive interactions, brought on by excess stocking, may reduce food resource availability and viability of both species. Furthermore, competition and predation pressures with warmwater fish species such as Largemouth Bass and Black Crappie can impact Kokanee. In our study, we employed stomach content analysis to quantify seasonal food web relationships for all Buffalo Lake fish species, identifying completive overlap and interspecific predation potentials that may impact Kokanee fishery.