Spawning Substrate Preferences of Yellow Perch along a Sand–Cobble Shoreline in Southwestern Lake Michigan

Abstract

Yellow perch Perca flavescens in small lakes generally spawn in nearshore areas on rooted macrophytes and submerged brush; however, such materials are absent near many wave-swept shorelines of the Great Lakes. We examined substrate selection by spawning yellow perch in southwestern Lake Michigan. Adult yellow perch were sampled using fyke nets during 1994–1998 at nine sites near Lake Bluff, Illinois. Substrate type at these sites was either cobble, sand, or mixed cobble and sand. Relative densities of yellow perch were higher at sites with cobble substrate than at sites with sand or mixed substrates in all but one year of the study. We conclude that, in areas devoid of vegetation or woody debris, the distribution of spawning yellow perch is nonrandom with respect to substrate type. Information about spawning-site characteristics may permit fishery managers to protect spawning yellow perch by establishing refuges. Substrate type should also be considered when permitting habitat alterations, such as those associated with dredging and dumping. In addition, population-assessment data may be biased by selection of sampling locations without regard to substrate type.