Once predominantly a small-scale practice, since the introduction of industrial methods for fishing in the 1970's millions of hectares of coastal land and water have been transformed into farms for shrimp, salmon, sea trout, mussels, clams and oysters. Southern Asia and the fjords and bays of Scandinavia, Ireland and Scotland have seen the greatest development. Certain countries in Africa and South America are also significant producers. There is also a thriving industry for the extraction of flavours, colours and aromas from fish caught in the wild to add zest to the farmed varieties.
One example of the aquaculture boom is shrimp and prawns. Between the early 1970s and 1997, farmed production grew from a negligible quantity in global terms to around 700,000 tonnes; wild-caught netting has also thrived. Prices for large shrimps, especially, have risen sharply.
Carp provide more than a quarter of fish culture production worldwide. It is estimated that more than four million metric tons are produced annually. The brown sea trout as a food stock in aquaculture is now receiving international recognition. In Britain, farmed salmon is now cheaper than cod. It is hoped that the shift to farmed fish will enable such threatened ocean stocks to recover.
Fish farming is fine for supplying salmon or shrimp to the rich. But such fish, at $7-$15 a pound, are far out of reach for poor people making less than $2,000 a year, who once depended on indigenous fisheries for the protein in their diets.