Phase 2 Studies: Impacts of Commercial Navigation Traffic on Freshwater Mussels at the W.H. Zimmer Station, 1989-90 Baseline Studies
1991
Miller, Andrew C. | Payne, Barry S.
Qualitative and quantitative baseline data were obtained at nine and six sites, respectively, at a mussel bed located on the Ohio River near the W. H. Zimmer Station, in July 1989 and September 1990. This information, in conjunction with data to be collected after the power plant has operated for at least 1 year, will be used to assess the effects of coal deliveries by barge on freshwater mussels. Total species richness (24) was similar to that at other large-river mussel beds. Average unionid density (+ or - SD) at RM 444.4 and RM 444.6 (36.7 + or - 45.9 + 14.8 individuals sq m, respectively) was slightly less than typical value at similar habitats. The unionid fauna consisted almost entirely of thick-shelled species and was dominated by Pleurobema cordatum, Quadrula metanevra, and Quadrula pustulosa. The assemblage was characterized by an equitable distribution of species with no clear dominants. Corbicula fluminea (1,227.7 + or - 274.2 and 915.2 + or - 155.5 individuals/ sq m at RM 444.4 and 444.6, respectively) outnumbered unionids, although there was no evidence of competition (either in terms of density or biomass) between native and nonnative bivalves. Population of dominant unionids consisted of large numbers of intermediate-sized individuals and moderate to low numbers of juveniles and adults. All had multiple age classes and showed evidence of moderately strong recruitment by several recent year classes.
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