The role of aquaculture in human nutrition

Aquaculture, the farming and husbandry of freshwater and marine organisms furnishes about 12% of the food man obtains from the waters of the globe. It is most important in Asia and has grown rapidly in the last decade. The development of aquaculture must rely on control over production sites, in most cases, and on the application of various bio-technical inputs. It dates back to antiquity and has relied on fish and molluscs as its mainstays. Freshwater species predominate among the former but increasing competition for the freshwater resources of the globe indicate that the cultivation of marine species (mariculture) will be of increasing importance. Many species are partly or fully cultured with very few having assumed domesticated, i.e., genetically improved status. The world's tropics with their warmer climate present greater development potential for aquaculture than the temperate zone, a fact that promises to make it especially valuable in policies to improve the diets of developing nations. An overview is given here over species and methods of aquaculture with the latter seen as a continuum having at one pole feedlot types of management with strong control over environmental variables and high inputs, also resulting in high yields, and at the other an approach that could be likened to pasturage. Feeding is not excluded in it but recycling and astute steering of ecological processes are equally if not more important management mechanisms here. Biological and engineering research in aquaculture is being pursued widely. However, pollution, site competition, security of tenure to a site and the like have to be addressed in equal measure for aquaculture to hold its promise of furnishing important quantities of high quality protein food.