Use of Conventional Fishery Models to Assess Entrainment and Impingement of Three Lake Michigan Fish Species

Two conventional fishery stock assessment models, the surplus‐production model and the dynamic‐pool model, were applied to assess the impacts of water withdrawals by electricity‐generating plants, industries, and municipalities on the standing stocks and yields of alewife Alosa pseudoharengus, rainbow smelt Osmerus mordax, and yellow perch Perca flavescens in Lake Michigan. Impingement and entrainment estimates were based on data collected at 15 power plants. The surplus‐production model was fitted to the three populations with catch and effort data from the commercial fisheries. Dynamic‐pool model parameters were estimated from published data. The numbers entrained and impinged are large, but the proportions of the standing stocks impinged and the proportions of the eggs and larvae entrained are small. The reductions in biomass of the stocks and in maximum sustainable yields are larger than the proportions impinged. The reductions in biomass, based on 1975 data and an assumed full water withdrawal, are 2.86% for alewife, 0.76% for rainbow smelt, and 0.28% for yellow perch. Fishery models are an economical means of impact assessment in situations where catch and effort data are available for estimation of model parameters.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141283/1/tafs0021.pd