Changes in Age-0 Fish Growth and Abundance Following the Introduction of Zebra Mussels Dreissena polymorpha in the Western Basin of Lake Erie

Abstract

We compared fish growth and abundance from the western basin of Lake Erie before (1983–1988) and after (1989–1993) establishment of zebra mussels Dreissena polymorpha to determine if growth and abundance of age-0 fish changed following zebra mussel introduction. We found no significant differences in age-0 growth for yellow perch Perca flavescens, walleye Stizostedion vitreum, freshwater drum Aplodinotus grunniens, gizzard shad Dorosoma cepedianum, alewife Alosa pseudoharengus, white bass Morone chrysops, white perch Morone americana, spottail shiner Notropis hudsonius, emerald shiner Notropis atherinoides, trout-perch Percopis omiscomaycus, and rainbow smelt Osmerus mordax before and after zebra mussel establishment. Zooplankton abundance may still be sufficient following zebra mussel establishment to support the same age-0 fish growth. Fish may be switching earlier or relying more on other prey types, especially the more abundant benthic invertebrates. Some fish may be supplementing their diet with zebra mussel veligers, although this has not been documented. No change in fall abundance was observed, except that the abundance of age-0 yellow perch increased significantly after zebra mussel establishment.