Culture in Flowing Water

Tilapia are usually cultured in static-water ponds at levels of intensity ranging from dependence on natural fertility to utilization of complete dry diets. When fish growth depends upon natural foods produced within the pond, which may be augmented by addition of fertilizers, production is limited by inadequate levels of one or more dietary components. Use of a complete dry diet eliminates these deficiencies and allows for greater fish production. The maximum level of production in fed ponds is determined by the capacities of the ecological mechanisms within the ponds to maintain suitable water quality to ensure a reasonable probability for satisfactory fish growth and health. Low dissolved oxygen (DO) levels, caused primarily by plankton respiration, usually determine the maximum levels of feeding and, hence, fish production. With aeration, maximum production levels are determined by the accumulation of nitrogenous metabolites, the most important of which are ammonia from protein metabolism and nitrite from the nitrification of fish-excreted ammonia.