Michigan Department of Natural Resources
Institute for Fisheries Research Report No. 1791, 1972
Dynamics of Yellow Perch in Single-Species Lakes
James C. Schneider
Abstract.-Experimental populations of yellow perch were established in Cassidy and Jewett lakes after the existing fish populations of these lakes were eliminated. Abundance, growth, recruitment and mortality of the perch were followed for several years. Additional observations were made on food habits, fecundity and spawning of perch, and on the plankton and benthos of the lakes. An extremely large year class of perch was produced in each lake. Members of the class stopped growing at a length of 4-5 inches because they had depleted the supply of benthic food organisms. The large year classes dominated the populations, by number and weight, and prevented recruitment of subsequent year classes. As a result, few perch grew to a large size and angling, if it had been permitted, would have been of unsatisfactory quality. A mathematical model was developed which showed that recruitment of both small- and medium-sized perch would have to be controlled by predation (by another species of fish or by man) to optimize the number of large perch in the population and the yield to anglers.