Seasonal and annual variations in abundance and species composition of two nearshore fish communities in Maine

Twenty-seven species of fishes were caught by fyke net and beach seine during a 5-yr study of an intertidal salt pond and adjacent sandy beach at Kennebec Point on the central coast of Maine. The salt pond catches consisted predominantly of three species,Microgadus tomcod, Fundulus heteroclitus, and one of three pelagic species (Clupea harengus, Menidia menidia, Alosa aestivalis) in all 5 yr. The beach site was dominated by four pelagic species (C. harengus, M. menidia, A. aestivalis, Alosa pseudoharengus). Differences in species composition existed between the fyke and seine catches so neither alone provided a complete description of the fish community. Biweekly sampling showed a clear seasonal cycle in abundance and species composition. At most, one species (M. menidia) occurred in the salt pond or at the beach site in winter, the majority of species were only present from spring through autumn. The pattern, of species composition was similar between years, even though abundance differed. Annual cycles in species richness and abundance paralleled those of temperature. The high diversity and abundance of young-of-year and juvenile fishes in the study area suggest these habitats are important nursery grounds for numerous marine species.