Great Lakes Fishery Commission

Prey Species

A self-sustaining assemblage of prey dominated by indigenous species at population levels capable of supporting desired populations of predators and a managed commercial fishery

While prey fish abundance in Lake Superior during the reporting period has been relatively low, the nearshore prey fish community did meet the target level of 80% native species for three of the five reporting years and the proportion of native species in nearshore waters was trending up during the reporting period. The bulk of non-native prey fish in nearshore waters is rainbow smelt. The offshore prey fish community continues to be largely comprised of indigenous species. Cisco recruitment was below the targeted annual level during the reporting period, causing some concern but cisco continue to provide for a stable commercial fishery in several jurisdictions in the western end of Lake Superior. Despite prey biomass being relatively low and variable, lake trout exhibit a broadly diverse diet that minimizes impacts of lower prey fish biomass during the reporting period.