Effects of Traveling Screen Operation on Impingement and the Survivability and Latent Health of Impinged Catfish at Barry Steam Generation Plant

Abstract

Two studies were conducted concurrently at cooling water intake structures at a coal fired power plant on the lower Mobile River basin. The first study observed the effects of varying operation times of traveling screen on impingement rates of fish and shellfish. The second study observed the survival rates of blue catfish (Ictalurus furcatus) and channel catfish (Ictalurus punctatus) for seven days post-impingement. Observations were made and recorded of gross lesions, parasite load and presence of known fish pathogens of impinged fish at impingement, of mortalities of the survival study and survivors of the survival study. The travelling screen study results showed no significant difference in freshwater species impinged at the cooling water intake structures but significantly increased impingement of salt-water species when screens were operated intermittently. The survival rates for impinged blue catfish (6.5%) and channel catfish (12.5%) were significantly lower than the channel catfish controls (91.0%). The health study found 87% of the impinged fish had known fish pathogens present. Flavobacterium columnare was the most common pathogen and was found on 66.7% of fish sampled at impingement, on 71.6% of the survival study mortalities, and on 66.7% of the impingement survivors. This was significantly higher than the 4.8% infection rate of the surviving control fish in the study.