Module 6 - Aquaculture Production Systems

Aquaculture is the farming and husbandry of aquatic organisms such as fish, crustaceans, mollusks, seaweed, and the production of freshwater and marine pearls. Aquaculture has grown at an annual average rate of 10 percent since the mid-1980s, reaching almost 55 million tons (or about 37 percent of global fish supply) in 2003. During the same period, capture fisheries averaged an annual growth rate of less than 2 percent, and its contribution to direct human nutrition actually declined by about 10 percent because of an increase in the proportion of lower-value species, typically used to produce fishmeal for feed and fertilizer. As almost one-third of capture fish production is reduced to fish meal, in the near future aquaculture is likely to provide half the fish used for direct human consumption. Based on this trend, it is likely that production from aquaculture as of 2005 equals that from capture fisheries in terms of products directly consumed by people.

With a growing fish supply gap and declining yields of capture fisheries, the potential for aquaculture production in developing countries continues to rise. Worldwide production from aquaculture is growing rapidly (table 6.3), far outstripping the growth rate in capture fisheries.

Table 6.3 Animal and plant aquaculture

Benefits

Aquaculture can be integrated with other farming systems. Inland fish culture is often carried out in farm ponds with direct links to animal husbandry and agriculture, where by-products of each subcomponent are recycled as resources for the others (for example, fish waste that enters irrigation canals becomes a supplementary fertilizer for crops). Pond culture on farms of this kind often includes the culture of many fish species that feed on grasses, legumes, benthic invertebrates, detritus, zooplankton, and phytoplankton. Fish culture has been gaining application in rice fields where a second benefit is control of insect pests and reduced the need to apply pesticides.

Areas that are not suitable for agriculture and are not critical habitats for wildlife can often be effectively used for aquaculture pond development. Publicly owned lands and waters suitable for conversion to aquaculture can be developed or leased to poor households that otherwise lack productive assets. Furthermore, aquaculture can often offer direct management roles for women.