Relations between Climatological Variables and Larval Yellow Perch Abundance in Eastern South Dakota Glacial Lakes

We evaluated relationships between climatological variables and abundance of larval yellow perch (Perca flavescens) in eastern South Dakota glacial lakes. Age-0 yellow perch were collected using a 0.75 m diameter ichthyoplankton net from May through mid-June at 7 to 10 d intervals. Highest correlation coefficients with larval yellow perch abundance were for April total precipitation (r-0.95–0.99; P=0.09–0.01; three lakes), mean March wind speed (r=-0.98 to −0.99; P=0.02–0.006; two lakes), mean of May average daily temperatures (1-0.78; P=0.12; one lake) and mean May wind speed (r=-0.82; P=0.02; one lake). Given the low number of years in some samples, individual years at times had undue influence on the relationship, resulting in high correlation coefficients. Multiple regression modeling resulted in improved models for only two of the seven lakes (R2=0.90–0.98; P=0.05–0.02). However, March through May weather patterns in some combination were related to larval yellow perch abundance in all seven study lakes. Larval abundance tended to be higher in years with less wind, more precipitation, and warmer air temperatures. Whether wind, temperature, or precipitation were most influential seemed to vary by lake.