Abundance and seasonal shifts in vertical and horizontal distribution of lake whitefish (Coregonus clupeaformis) in a western United States reservoir

A series of studies have been implemented on Banks Lake, Washington, in recent years with the overall objective to maximize the fishery by determining the factors that limit the recruitment of various sport fish. When sampling commenced, it became apparent that the lake whitefish (Coregonus clupeaformis) was a major component of the system. The purpose of this study was to estimate the species composition, distribution, and abundance of the limnetic fish community of Banks Lake using hydroacoustics and gill nets. Surveys were conducted in May and July to test for differences in seasonal distribution and efficacy of the survey gear to establish a time period for conducting annual surveys for trend monitoring. Whitefish dominated the limnetic gill-net species composition by weight (95% both months) and number (83% July and 88% May). In May, relatively few fish were distributed deeper than 8 m at the south end of the reservoir, and low densities were common for the deepest strata (16–24 m). In July, most fis...