Genetic History of Maumee River Spawning Walleye (Sander vitreus): Comparisons of Adult and Larval Gene Pools

Walleye is an ecologically and economically valuable North American fish, supporting large fisheries, especially in Lake Erie. Our objective is to analyze the temporal genetic patterns of Walleye from its largest and most highly exploited spawning run, Lake Erie’s Maumee River. Maumee River Walleye have experienced a century of exploitation, habitat changes, and pollution that may have affected its genetic composition and possibly, its future sustainability. A recent published study by our laboratory showed relative genetic consistency across 14 years. We here expand this temporal sampling to 20 years, compare adult and larval gene pools, and increase the number of nuclear microsatellite loci from 9 to 14. We test 746 Maumee River Walleye for differences in genetic composition (1) among annual spawning runs (1995-2013), (2) age cohorts, (3) between the sexes, and (4) adult vs. larval gene pools. Results show that genetic composition does not significantly vary among annual spawning runs, age cohorts, or between the sexes. Comparisons of adult and larval gene pools indicate that larvae are most similar to adults spawning ~20 days prior to their sampling. Overall, our results indicate Maumee River Walleye exhibit temporal genetic stability and have maintained high diversity, despite intensive anthropogenic pressures.