Salmon aquaculture is the major economic contributor to the world production of farmed fin-fish, representing over $1 billion US annually. Other commonly cultured fish species include: tilapia, catfish, sea bass, carp, bream, and trout. Salmon farming is very big in Norway, Sweden, Scotland, Canada, and Chile and is the source for most salmon consumed in America and Europe. Atlantic salmon are also farmed in Russia, Tasmania, Australia and the UK.Salmon are carnivorous and are currently fed a meal produced from catching other wild fish and other marine organisms. Consequently, as the number of farmed salmon increase, so does the demand for other fish to feed the salmon. Work continues on substituting vegetable proteins for animal proteins in the salmon diet. Unfortunately though, this substitution results in lower levels of the highly valued Omega-3 content in the farmed product. Intensive salmon farming now uses open net cages which have low production costs but have the drawback of allowing disease and sea lice to spread to local wild salmon stocks.
Another form of salmon production, which is safer but less controllable, is to raise salmon in hatcheries until they are old enough to become independent.
They are then released into rivers, often in an attempt to increase the salmon population.
