Population genetics of walleye and yellow perch in the St. Marys River

We assessed the genetic diversity of walleye (Sander vitreus) and yellow perch (Perca flavescens) in the St. Marys River system. Walleye samples were collected from four current spawning populations, one historic population, and the two sources used for stocking the St. Marys River. Non-spawning perch were collected from ten sites along the St. Marys River. Five microsatellite loci were used for screening each species to create a genetic baseline to which future populations can be compared and to assess the impacts of past stocking on the walleye populations. Resulting allele and genotype frequencies were characterized to quantify genetic variation and differentiation of the respective populations. Both the walleye and yellow perch populations in the SMR exhibited some degree of population structure. Although stocking has modified the genetic diversity of walleye, there is still at least one unique population (Bar River, Ontario) remaining in the St. Marys River system. Both species had unique populations in Lake George, suggesting that this area may have been isolated in the recent past and should be protected from future stocking events to preserve this uniqueness. Further work is encouraged to understand the nature of this possible genetic isolation.