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

We estimated the influence of Smallmouth Bass Micropterus dolomieu predation on recruitment of age-0 Yellow Perch Perca flavescens in two South Dakota glacial lakes.  Using Smallmouth Bass diet information from two time periods representing low (2008) and high (2012 and 2013) consumption of age-0 Yellow Perch and bass population size estimates as inputs in a bioenergetics model, we estimated a likely range in consumption of age-0 Yellow Perch.  Consumption estimates were compared to estimates of age-0 Yellow Perch production to estimate the proportion of the age-0 perch cohort consumed by the Smallmouth Bass populations.  During 2008, age-0 Yellow Perch constituted between 0 and 42% of Smallmouth Bass diets by weight whereas during 2012 and 2013, age-0 perch constituted between 0 and 20% of bass diets by weight.  Across both lakes and time periods, production of age-0 Yellow Perch ranged from 0.32 kg/ha/week to 1.78 kg/ha/week.  Estimates of Smallmouth Bass consumption measured during the same intervals ranged from 0.06 kg/ha/week to 0.33 kg/ha/week, equating to consumption of between 1 and 34% of available Yellow Perch biomass.  Given current conditions, it does not appear that Smallmouth Bass act as a singular factor limiting recruitment of age-0 Yellow Perch in our study lakes.