Comparison of Fish and Benthic Faunal Compositions in Polluted and Pristine Forks of a Mountain River

The little Pigeon River in Sevier County, Tennessee presents a near ideal situation for the study of the effects of domestic sewage on species composition in a mountain river. The little Pigeon system has two principal components, the West and Middle Prongs. The West Prong is polluted by municipal effluent from Gatlinburg and Pigeon Forge, while the Middle Prong remains relatively pristine. Physicgraphically, the two prongs are strikingly similar. The great similarity of natural physical and chemical water quality parameters presents an opportunity to use the pristine prong as a control for the study of changes, probably resulting from pollution, in the other.

Fish and aquatic invertebrates were sampled from riffle communities of both streams, and their composition was analyzed to gain insight into possible changes in the West Prong due to pollution. There were drastic differences in benthic invertebrates and observable differences in the fish faunal assemblages. These differences suggest that strong shifts in species composition as well as a sharp decline in population density of many invertebrates and some fish species had resulted in the West Prong due to pollution. It is speculated that these shifts were caused by organic solids.