Summer distribution of fish species in the vicinity of a thermal discharge, New River, Virginia

Studies were conducted to determine the effect of several variables on the summer distribution of important species in the vicinity of a heated discharge located on the New River in southwestern Virginia. For some species (Hypentelium nigricans, Ictalurus punctatus) there was a marked effect of temperature on the spatial and temporal distributional patterns. For other species multivariate techniques were used to screen for the effects of temperature, photoperiod, time since last chlorination period, river flow, and gradient on abundance. Three major responses to temperature were found: 1) an avoidance to high temperatures (Hypentelium nigricans; Campostoma anomalum; Notropis rubellus; 2) an attraction to high temperatures (Ictalurus punctatus); 3) an indifference to temperature changes within the range observed (Notropis spilopterus).