The role of feeds and feeding in aquatic animal production

The goal in aquaculture systems is to maximize the efficiency of the flow of energy and nutrients toward the animal output. This is more complex than in terrestrial animal agriculture since the cultured organism is immersed in its aquatic environment and is often only one member of a food web system. The organic and inorganic inputs into the system are critical not only to the extent that they feed the cultured species directly, but they may also positively or negatively affect the environment supporting the animal, as well as fertilize other aspects of autotrophic and heterotrophic food webs within the system. Aquaculture systems are characterized by the density of animal biomass in a given area of water, which determines the intensity of management inputs required. Extensive systems rely on natural productivity for food; intensive systems require a high degree of management inputs including a complete diet for the species; systems between the two extremes are optimized by balancing applied feed with natural productivity. Balanced nutrient delivery remains an indispensable requirement, regardless of source, for growth of adults as well as larvae, for reproductive success and for generation of a high quality product.