Biodiversity and distribution of fishes of Lake Erie coastal wetlands

Abstract

Coastal wetlands provide essential long-term and periodic habitat for fish species, serving as feeding and spawning grounds, as well as a sheltered nursery for young fish. Between 2011 and 2022, 52 Lake Erie coastal lacustrine, riverine, and protected barrier wetlands were sampled as part of the Great Lakes Coastal Wetland Monitoring Program (26 in the western basin, 16 in the central basin and 10 in the eastern basin) using fyke nets set overnight in or adjacent to the dominant vegetation zones during summer months. Sixty-three fish species were recorded: 56 in the western basin, 46 in the central basin, and 38 in the eastern basin. Catches were comprised largely of catfishes (Ictaluridae; 28% of individuals captured), and non-native Common Carp and Goldfish (Cyprinidae; 25%) but differed among basins. Catches in western basin wetlands were dominated by Ictaluridae species (31%) and Carp and Goldfish (29%). Herrings (Clupeidae) comprised 50% of the individuals captured in the central basin, whereas eastern basin catches were dominated by sunfishes (Centrarchidae; 72%). No clear temporal trends were apparent in absolute or relative abundance of common taxa. Species richness varied widely among wetlands, but maximum richness was lowest in years when Lake Erie summer water levels were highest. Hierarchical agglomerative cluster analysis of fish species relative abundances among wetlands indicated that community composition varied markedly among basins, such that wetlands differed between Lake Erie’s western and central+eastern basins, and secondarily between northern and southern coastlines. Central and eastern basin wetlands had greater relative abundances of Centrarchidae, whereas western basin wetlands were dominated by benthic species (Ictaluridae, invasive Cyprinidae), possibly reflecting differences in geomorphology and productivity.