Culture of fish in cages and their use as biological monitors of water quality within heated discharge waters of a power station

Vita.Channel catfish (Ictalurus punctatus), sea catfish (Arius felis), Florida pompano (Trachinotus carolinus), sheepshead (Archosargus probatocephalus), pinfish (Lagodon rhomboides), Atlantic croaker (Micropogon undulatus), black drum (Pogonias cromis), spot (Leiostomus xanthurus), Atlantic spadefish (Chaetodipterus faber), striped mullet (Mugil cephalus) and white mullet (Mugil curema) were cultured in floating cages between 17 July 1972 and 18 August 1975 in the intake are, discharge canal and at five stations in the cooling lake of the Houston Lightning & Power Company Cedar Bayou Generating Station near Baytown, Texas. Mixing of estuarine water drawn up Cedar Bayou by the plant with freshwater flowing down Cedar Bayou created a very unstable environment in the plant intake canal which, after heavy rainfall, changed from brackish to freshwater within a 24 hour period. Fish survival was adversely affected. Mixing of incoming effluent with resident lake water reduced salinity fluctuations at cooling lake stations. After prolonged heavy rainfall, however, cooling lake salinities dropped and survival was adversely affected. None of the species cultured were fully suitable in situ biological monitors of intake waters