ACIDIFICATION AND FISH OCCURRENCE IN THE UPPER CHEAT RIVER DRAINAGE, WEST-VIRGINIA

The decline of many fish populations within the mid-Appalachian region has been attributed to stream acidification as a result of acid preci pitation. Many previous attempts to examine relationships between fish occurrence and acidification have been hindered by a lack of data on water quality and fish distributions. To assess relationships between water quality and bedrock type in the upper Cheat River drainage, we u sed EPA STORET water quality data (1969-1993) and calculated mean pH a nd mean alkalinity of streams associated with four bedrock types (Hamp shire, Chemung, Mauch Chunk, and Pottsville). We examined the relation ship between fish occurrence and bedrock type for 53 headwater streams . We found that acidity in headwater streams associated with Pottsvill e and Mauch Chunk groups often exceeded biological thresholds for acid -sensitive fish species (pH < 5.5). Streams associated with the Pottsv ille group typically had fewer cyprinid species and fewer total specie s than those associated with Mauch Chunk, Chemung, and Hampshire bedro ck types. The congruent occurrence of streams with low buffering capac ity, streams with pH < 5.5, and streams with low fish species richness indicate that acidification has influenced fish distributions in the upper Cheat River drainage.