Ecology of young-of-the-year fishes in Severn Sound, Lake Huron

Abstract

Seasonal occurrence, distribution, density, and size were estimated for young-of-the-year fishes collected in altered and unaltered littoral areas of eastern Severn Sound, Lake Huron, a Great Lakes "Area of Concern." Fishes were sampled with nets and seines (0.3-mm mesh) in open water and at the shore from May to October, 1989, 1990, and 1991. The highly diverse young-of-the-year fish community reflects unfragmented heterogeneous habitats that range from exposed rock and sand shores to densely vegetated embayments and marshes. Fishes (89 000 specimens) were represented by 9 reproductive guilds, 16 families, and 38 taxa. Cyprinids, centrarchids, and percids dominated collections; common and abundant species included Perca flavescens (56% of total catch), Lepomis gibbosus (18%), and Alosa pseudoharengus (8%). Generally, fewer species at lower mean densities occurred in unaltered habitats than in altered areas. Large spatial and temporal differences were observed in peak density and mean total lengths of most species collected on the same date at several sites. Fish species diversity and abundance were consistently highest in mixed submersed plants and lowest in open water and on exposed shores.