Comparison of Two Mesh Sizes for Collecting Larval Yellow Perch in Surface Trawls

Abstract

Abstract We evaluated the differences in density estimates (larvae/100 m3), mean total lengths (TL; mm), and length frequency distributions of larval yellow perch Perca flavescens collected using 500- and 1,000-μm-mesh surface trawls in a small South Dakota lake. No significant difference in larval yellow perch density between mesh sizes was detected across sampling dates (F = 0.02, df = 1, P = 0.90). Significant differences in the length frequency distributions (Kolmogorov–Smirnov asymptotic test statistic = 1.532; df = 100, 106; P = 0.02) of larval yellow perch were detected on one early sampling date; however, when mean lengths exceeded 9 mm, total lengths and length frequency distributions were similar across mesh sizes. We collected smaller larval yellow perch (mean TL = 4.9 mm) earlier in the 500-μm-mesh net than in the 1,000-μm-mesh net. Peak larval yellow perch density was observed simultaneously and did not differ between mesh sizes. Estimates of precision associated with peak larval densities we...