FISH PRODUCTION IN WARM WATERS OF THE SOUTHEASTERN UNITED STATES HAS BEEN INCREASED FROM APPROXIMATELY 100 LBS. PER ACRE IN NATURAL WATERS TO 20,000 LBS. PER ACRE WITH INTENSIVE CULTURE SYSTEMS USING ARTIFICIAL CIRCULATION, FILTRATION, AND SUPPLEMENTAL FEEDING. INTENSIFICATION OF FISH PRODUCTION RESULTS IN ALTERATIONS OF WATER QUALITY. CHANGES IN FACTORS OF IMPORTANCE OF HEALTH AND GROWTH OF AQUATIC ORGANISMS INCLUDE PHOSPHORUS, ORGANIC AND INORGANIC NITROGEN, BOD AND COD. METHODS BY WHICH DETRIMENTED CHANGES IN WATER QUALITY PARAMETERS HAVE BEEN COMBATED INVOLVE MECHANICAL AERATION, POLYCULTURE WITH SECONDARY FISH SPECIES TO CONSUME WASTE FEEDS AND DETRITUS, AQUATIC PLANTS TO ABSORB NUTRIENTS AND PREVENT EXCESSIVE PHYTOPLANKTON BLOOMS, AND RECIRCULATION AND FILTRATION OF WATER TO MINIMIZE BOD AND COD.