What factors determine whether divergent hatchery strain lake trout will successfully interbreed with natives in wild populations?
When fish populations are disturbed by human activities they become more vulnerable to decline and eventual disappearance. Since declining populations are often stocked with non-native, cultured fish to boost production, they are exposed to further opportunities for loss of natural genetic variation through interbreeding and introgression. Contrary to some predictions, results from my thesis work indicated that stocking history, which should have been predictive of the abundance of non-native adults in the spawning population, was not a contributing factor to replacement of native genetic diversity in wild lake trout populations. This indicated that other natural and anthropogenic factors were modulating interbreeding and the reproductive success of hatchery strain lake trout. Identification and characterization of these modulating factors will address mechanistically how the genetically divergent, non-native (i.e., primarily of Great Lakes origin) hatchery strains are less suited for