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The finfish communities using the intertidal surfaces of a bay-exposed marsh and a sheltered, channel marsh of the Goodwin Islands, York River, Virginia were studied from May to November 1994. Samples were taken approximately twice monthly using a flume weir at three stations in each marsh. Species composition, abundance and biomass were estimated, and growth patterns and production rates were described for the dominant species. A total of 3001 fish were collected from 11 species and 8 families. Fundulus heteroclitus dominated both marshes and accounted for 83.07% of the total number of fish caught, and 84.83% of the total biomass collected. Menidia menidia was the second most abundant species at 9.00% of the total number of fish, but F. majalis was second in the total biomass at 7.51 % of the total. Abundance first peaked in June, and a second peak occurred in November. Biomass had a small peak in the beginning of August, and a large peak in late September. Analysis of variance showed the number of species captured did not differ significantly between the marshes. However, both the number of individuals and biomass were significantly higher in the protected marsh. Correspondence analysis showed that species composition in the protected marsh was mostly cyprinodontids, but in the open marsh species composition varied more throughout the sampling season. Species densities were highest at 9.8 ± 3.3 fish/m2 for F. heteroclitus in the protected marsh. Production for F. heteroclitus over the summer in the protected marsh was high at 10.1 g dry wt.fm2 due to the large number of rapidly growing larval and juvenile fish. |
