Habitat use by fishes of the New River, West Virginia

Abstract

Density estimates of the species and life stages in different habitat types were made from electrofishing collections and underwater fish counts. During midday, fish densities in edge pool and riffle habitats were comparable, but densities in edge pool habitat were significantly higher than densities in middle pool and run habitats. Snag and edge riffie habitats supported the highest densities of fish. Habitat use and activity shifts between daytime and nighttime were found for many species. Fish species and lifestage composition and densities differed among the habitat types, and five habitat-use guilds (edge-pool, middle-pool, edge-channel, riffie, and generalists) were described. Larger centrarchids preferred deep habitats with slow velocities (deep edge and middle pool, and snags), while young centrarchids preferred shallower habitat. However, all sizes of smallmouth bass were nearly ubiquitous in the habitats of the study area. The cyprinids and percis preferred shallow areas, but preferences for velocity differed among the species and lifestages.

Spawning and habitat preferences of the endemic bigmouth chub, Nocomis platyrhynchus, were described. Bigmouth chubs used areas with plenty of small to large gravel (3-64 mm diameter), shallow depths, and moderate velocities for constructing spawning mounds. Bigmouth chubs were seen only using riffie and adjacent run habitat during late summer. Within these areas, depth, velocity, substrate, and cover were used in accordance with their availability, except for an avoidance of the shallowest available depths. Bigmouth chubs occupied positions near the substrate, where velocities were slower than the mean water column velocity.