GENETIC DIVERSITY OF LOGPERCH AND GREENSIDE DARTERS ABOVE AND BELOW THE MUNROE FALLS DAM ON THE CUYAHOGA RIVER, OH

Dams have been built for centuries on waterways and have been found to act as barriers to fish migration and thus impede gene flow. The Munroe Falls dam on the Middle Cuyahoga River in northeast Ohio was built in 1817 and may act as such a barrier. This study characterizes the populations of two species of darters, Etheostoma blennioides (greenside darter) and Percina caprodes (logperch darter) upstream and downstream from the dam using samples collected in 2003, in comparison to outgroup populations from the Grand River, Ohio. Genomic DNA was isolated and the mtDNA control region was amplified and sequenced. The greenside darters had a predominate haplotype that was shared between the sites upstream and downstream from the dam, with three unique haplotypes found upstream and two unique haplotypes downstream. None of the haplotypes were found in the Grand River outgroup population. The logperch had shared haplotypes in the upstream and downstream sites, with five unique haplotypes upstream and one unique haplotype downstream. Results suggest that the Munroe Falls Dam may form a greater barrier to gene flow for logperch than for greenside darters, indicating a potential for species-specific differential effects. Removal of lowhead dams may restore historic levels of gene flow, increasing genetic diversity of local populations.