Chinese carp in pond
Aquaculture comprises diverse systems of farming plants and animals in inland, coastal and marine areas, using and producing a wide variety of animal and plant species. While it is usually advisable to use local species, introduced (or alien) species have significant social and economic impact. Genetic resources are the foundation on which species, stocks and genetically-improved strains are based. The culture of several important species still relies on the collection of brood stock or seed from natural populations.
Aquaculture can be a very productive use of resources, with the amount of food produced per hectare considerably higher than with arable farming or livestock rearing. Aquafeed resources production is one of the fastest expanding agricultural industries in the world, with growth rates in excess of 30 percent per year. Resource availability and use have allowed a more than three times faster sector growth compared with terrestrial farm animal meat production.
Freshwater finfish, particularly Chinese and Indian carp species, account for the greatest share of total aquaculture production, followed by molluscs. Although low in production quantity, some of the minor product groups, such as shrimp and marine fish, have a disproportionate economic importance because of their high unit value.
The most harvested species in recent years have been the Pacific cupped oyster and the silver carp. By 2006 aquaculture was provided nearly 50 percent -- or 51.7 million tonnes -- of all world fisheries production.