Comparison of four types of sampling gears for estimating age-0 yellow perch density

Abstract

To aid biologists in obtaining reliable and efficient estimates of age-0 yellow perch (Perca flavescens) abundance, we compared operational effort and catch characteristics (i.e., density, length frequencies, and precision) of four gear types (beach seines, benthic sleds, drop nets, and push trawls) in littoral habitats in two South Dakota glacial lakes. Gear types were selected on the basis that the volume of water sampled could be determined and, thus, density (number/m3) of age-0 yellow perch could be computed for each. Age-0 yellow perch were collected on three occasions with each gear in both lakes in August 2011. Differences in gear operational effort (i.e., the time required for set-up, deployment, and fish sorting) and age-0 yellow perch density and length frequencies were compared among sampling gears. Mean operational effort ranged from 9 to 65 min, mean density from 0.07 to 4.1 age-0 yellow perch/m3, coefficients of variation of mean age-0 perch density from 33 to 134, and number of samples required to estimate a 25% change in mean age-0 perch abundance from 22 to 305. Beach seines and drop nets may selectively sample larger age-0 yellow perch than benthic sleds and push trawls. We recommend use of beach seines or benthic sleds for sampling age-0 yellow perch in littoral habitats of glacial lakes. However, all sampling gears tested in this study have associated costs and benefits and one may be more suitable than another under different circumstances.