Genetic Comparison of Naturally Spawned and Artificially Propagated Lake Ontario Lake Trout Fry: Evaluation of a Stocking Strategy for Species Rehabilitation

Abstract Two strategies have been used in the effort to restore lake trout Salvelinus namaycush to Lake Ontario. First, lake trout strains from multiple wild and hatchery sources have been stocked to maximize genetic variability in the lake, Second, a unique hatchery “strain” of fish to be stocked was created each year with gametes collected from adult, hatchery-origin fish that had survived to maturity after being stocked into Lake Ontario. Several hatchery strains may be represented among the adults captured and used to propagate this unique strain, termed the “Ontario strain.” The “Ontario strain” may have a genetically based potential for enhanced survival over other strains stocked in Lake Ontario because it is composed of the progeny of fish that have survived from the yearling to the adult life stage, Unlike naturally spawned fish, however, the “Ontario strain” has been shielded from natural selection during the critical period of mortality from spawning through the first year of life, The purpose ...