Impact of a once-through cooling system on the yellow perch stock in the western basin of lake erie

The surplus production model, a conventional fishery stock assessment model, is applied to assess the entrainment and impingement impact of the Monroe Power Plant on the yellow perch standing stock and fishery in the western basni of Lake Erie. Biological parameters of the model are estimated from commercial catch and effort data and entrainment and impingement coefficients are estimated from power plant data. The model is applied to estimate stock biomass, egg production, and larva production; the proportions entrained and impinged are then estimated. The impact of water withdrawal on the equilibrium standing stock and maximum sustainable yield from the fishery is estimated and the impact of increased water withdrawal on the equilibrium standing maximum sustainable yield are larger than the proportion of the standing stock entrained and impinged, but the impact of the Monroe Power Plant is relatively small; it decreases biomass and the maximum sustainable yield of the yellow perch stock by only a few percent. However, there are several power plants impacting the yellow perch stock of the western basin of Lake Erie and the combined impact should be examined.