Evidence across multiple scales for offshore transport of yellow perch (Perca flavescens) larvae in Lake Michigan

Abstract

Most freshwater fishes have short pelagic early life stages. Lake Michigan presents an interesting scenario for yellow perch (Perca flavescens), a species with a long pelagic larval stage that may not be well adapted to lakes with an expansive pelagic environment and extensive offshore transport. We investigated the possibility that early life stages of yellow perch were transported well offshore from their nearshore spawning grounds and explored whether food resources were more or less favorable offshore. To determine the extent to which pelagic age-0 yellow perch moved offshore, we sampled at multiple scales ranging from local (<2 km) to across the lake (>120 km). Evidence of offshore movement by fish larvae occurred at each scale. Yellow perch larvae were quickly transported offshore from nearshore spawning sites and remained in the offshore pelagia to sizes of at least 30 mm. Zooplankton density was greater offshore than nearshore, suggesting that pelagic age-0 yellow perch find improved food resources offshore compared with their nearshore spawning sites. Currents operating at oceanographic scales likely influenced the offshore movement of pelagic age-0 yellow perch in Lake Michigan. These currents, coupled with prey availability for pelagic age-0 individuals, may influence the recruitment success of this species.