Regional, habitat, and human development influences on coastal wetland and beach fish assemblages in Green Bay, Lake Michigan

High levels of coastal wetland degradation, limited knowledge of fishes that utilize these habitats, and the potentially high ecological importance of coastal wetlands in Great Lakes ecosystems all provided an impetus to characterize fish assemblages associated with coastal wetland and other littoral habitats in Green Bay, Lake Michigan. From May to September 1990 and 1991, I sampled 24 coastal wetland and beach sites spanning Green Bay. Half the sites represented habitats modified by physical alterations, such as dikes and landfills, to allow documentation of the effect of human modifications along the shoreline. A total of 41,867 primarily immature fishes, representing 20 families and 54 species, was captured. Species richness and total fish abundance were highest in undeveloped wetland habitats and in the lower bay, which was typified by warmwater, turbidity-tolerant fishes. The upper bay had a more cool and clearwater assemblage. Undeveloped wetlands were characterized by the presence of several important commercial and sport fishes. Sites adjacent to human development had fewer fish and fish species. They were characterized by a more disturbance-tolerant assemblage. The high biodiversity and large numbers of ecologically and economically important fishes associated with wetlands lend increased significance to maintaining and restoring these habitats in the Great Lakes.