Estimating the Influence of Smallmouth Bass Predation on Recruitment of Age-0 Yellow Perch in South Dakota Glacial Lakes

Introduced populations of Smallmouth Bass Micropterus dolomieu have become important components of fish assemblages in South Dakota glacial lakes.  Recent evidence on the extent of Smallmouth Bass predation on age-0 Yellow Perch Perca flavescens suggests the potential for bass to adversely influence perch recruitment.  Thus, the objective of this study was to estimate the influence of Smallmouth Bass predation on recruitment of age-0 Yellow Perch.  Estimates of Smallmouth Bass population size and consumption were used as inputs in a bioenergetics model to estimate the extent of bass consumption of age-0 Yellow Perch.  Consumption estimates were compared to estimates of age-0 Yellow Perch production to determine the proportion of the age-0 perch cohort consumed by bass during the first growing season.  Most age-0 Yellow Perch were found in diets of Smallmouth Bass < 180 mm total length (TL), whereas bass > 180 mm TL primarily consumed crayfish.  Results suggest that primary predation pressure on age-0 Yellow Perch is exerted by a relatively small proportion of the Smallmouth Bass population and is driven by spatial overlap between juvenile bass and age-0 perch.  Furthermore, it appears that Smallmouth Bass predation is not a substantial factor limiting Yellow Perch recruitment in our study lakes.