Dynamics and species interactions in the commercial fishery of the Red Lakes, Minnesota

The Red Lakes have supported a commercial fishery for walleye Stizostedion vitreum vitreum and yellow perch Perca flavescens since 1917. Since 1972, harvests indicate increased variance in recruitment of percids and an increase in biomass of freshwater drum Aplodinotus grunniens. Commercial catch-per-unit-effort (CPUE) records of walleye, yellow perch, and animal feed (composed primarily of drum) were subjected to spectral analysis. Estimated power spectra displayed peaks at 8.5, 10, and 17 yr for walleye, yellow perch, and animal feed, respectively. Walleye and yellow perch CPUE time series were significantly coherent at periods ranging from 5-10 yr, confirming the predator-prey relationship and common recruitment patterns of these two species. -from Authors