Aquaculture is the proper term used to describe the commercial farming of fish, shellfish, and other aquatic plants or animals, whether in natural or artificial bodies of water.
Farmed fish and shellfish account for over 30% of all seafood consumed worldwide.
The Chinese, who have been farming fish for 2,000 years, pioneered an ecologically safe and sustainable method in which nothing is wasted. Farmers dig ponds around rice paddies and feed carp in the ponds with weeds from the rice field. The silt from the ponds is used as fertilizer for the fields, and crabs are grown to eat pests. This method, however, is not always readily adapted in the Western world. And as one of the world’s fastest growing food industries, aquaculture also has its critics.
Bivalves, such as mussels and oysters, are easiest, ecologically speaking, to maintain. As filter feeders, they generally make their surrounding environment cleaner. Farmed vegetarian freshwater fish, such as carp, catfish and tilapia, are also relatively harmless to the ecosystem, as they do not require large quantities of fishmeal to survive, and thus produce little waste. Salmon and shrimp, on the other hand, pose the greatest environmental hazards. Both species eat several pounds of fishmeal to gain a pound of weight, and both create lots of waste. Furthermore, shrimp farms can raise the salinity of surrounding soil and water, poisoning agricultural land.
Raising large numbers of fish in close quarters also brings the risk of easily spreading disease. Administering antibiotics to minimize this risk, in turn poses its own danger, as many of these pass easily into the surrounding environment, and some are highly toxic. Parasite infestations, as well as the relatively common occurrence of captive fish escaping and competing with - or even consuming - native fish are other chronic problems of high-density fish farms. Wild fish stocks then face crossbreeding issues, which lead to diluting the genes that have helped them survive.
Ethical aquaculture can easily feed the world without polluting it, but it takes a conscious and regulated worldwide effort.
