Correlations of Regulated Lake Levels and Climatic Factors with Abundance of Young-of-the-Year Walleye and Yellow Perch in Four Lakes in Voyageurs National Park

The relationships between year-class strengths of walleye Stizostedion vitreum and yellow perch Perca flavescens, as determined from seine catches of young of the year, and regulated lake levels, air and water temperatures, and wind velocities during the spawning period of both species were studied in four lakes in Voyageurs National Park, Minnesota, from 1981 through 1985. Significant positive correlations were found between lake level and walleye year-class strength in three of the four lakes sampled. The correlation between lake level and yellow perch year-class strength, while generally positive, was significant in only one lake. Significant positive correlations were also found between thermal conditions during the 30-d period following ice-out and year-class strengths of walleye and yellow perch; the strongest year classes of both species were produced in years with higher, more stable temperatures. An alternative water management scheme is proposed that may enhance walleye and yellow perch reproductive success by providing higher lake levels earlier in the spring.