Yield of Yellow Perch in Lakes Erie and St. Clair: Community Associations

Abstract

Abstract Commercial catches of yellow perch Perca flavescens in the Canadian gill-net fishery of Lake Erie declined in the 1970s, even though fishing effort increased and mesh size decreased between 1970 and 1975. Multiple stepwise regression of annual catch (kg) on effort (km gill net), recruitment by year-class, total fish community biomass, and weight at age 3 showed that only recruitment explained a significant portion of the variations in catches in the eastern basin, and only weight was important in the western basin. Year-class strength declined in the late 1960s and 1970s; catches from both experimental and commercial gear provided some indication of improvement by the 1980s. Although recruitment was associated with variations in the abundance of some species in four fish communities (Lake St. Clair and the three basins of Lake Erie), there was no evidence that any common groups of species were regulating recruitment. Fish community structures were similar (discriminant function analysis) in the e...