The Fish Community of a Flow-Impacted River Reach in Alabama, USA with Emphasis on Largemouth Bass and Spotted Bass

ABSTRACT

The Weiss bypass reach of the Coosa River, Alabama, USA is a 32-km section of the river bypassed after construction of a power generation facility on Weiss Lake in 1961. This area experiences daily flow reversals that can extend 24 km upstream and increase depth by up to 2 m. During a 15-month period, we used electrofishing to collect 37 fish species from 10 families in this reach. Species richness and diversity increased with distance from the flow reversal, suggesting some influence of the daily flow reversals. However, because nearly all of the species collected were habitat generalists (i.e., none was a fluvial specialist), the flow appeared to influence the overall fish community by eliminating fluvial specialist species that would be expected to inhabit this type of river reach (i.e., a reach with an unmodified flow regime). Relative to largemouth bass (Micropterus salmoides) and spotted bass (M. punctulatus), we found that population characteristics (i.e., age, growth, catch rates, habitat use, diets) generally did not differ from those for fish from lentic areas within the Coosa River nor from other lotic populations.