Exploratory Analysis of Population Genetic Assessment as a Water Quality Indicator: I. Pimephales notatus

Biological sampling has been implemented to assess water quality in many states. The purpose of this study was to examine whether genetic diversity and structure of Pimephales notatus could serve as effective biomarkers of exposure to anthropogenic stressors by comparing genetic measures with other biological indicators of water quality. Fish were collected from 15 sites on eight streams by the Ohio Environmental Protection Agency as part of their stream water quality evaluation program. Values for the Index of Biotic Integrity (IBI) and the Invertebrate Community Index (ICI) were determined for these 15 sites. Starch gel electrophoresis was used to collect genetic data for seven variable enzyme loci. Genetic diversity measures were not associated with site IBI or ICI values. However, the range of site IBI and ICI values was limited. The proportion of individuals not expressing esterase locus 3 could be used to predict IBI; IBI decreased as the proportion of nonexpression increased. Allele and genotype frequency differences were observed between sites on the Little Scioto River, the one stream with a large difference in IBI and ICI values between sites. This study suggested that allele and genotype frequencies may have been impacted without affecting overall species diversity.