Spatial Genetic Structure of Muskellunge in the Great Lakes Region and the Effects of Supplementation on Genetic Integrity of Remnant Stocks

摘要

The Muskellunge Esox masquinongy is an ecologically important apex predator that supports numerous recreational fisheries throughout their range. Several strains of Muskellunge exist in the Great Lakes region, including Great Lakes Muskellunge nativeto the five Great Lakes and the St. Lawrence River and northern Muskellunge native to tributaries of the Mississippi River and other inland waters (Becker 1983). Unfortunately, declines in Muskellunge abundance from overharvest and environmental degradation have threatened the viability of many populations and prompted restoration efforts that often include stocking. However, Muskellunge were commonly stocked without an understanding of existing spatial genetic structure, potentially subjecting native populations to admixture and the negative effects of outbreeding depression. The goal of our study was to investigate spatial population structure and genetic diversity in 42 populations of Muskellunge sampled across Great Lakes spawning aggregates, GreatLakes tributaries, and adjacent inland populations to inform future management and supplementation practices.