Aquaculture has been one of the fastest growing segments of global food production in recent years. It has been hailed as an answer to the problems of declining wild fish stocks due to overfishing and other causes.
There has been (2003) considerable debate on the merits of aquaculture - or "fish farming", as it is often called. In countries like the U.K., Canada and Norway, salmon- and trout-farming are one of the fastest-growing forms of agriculture. As these farms expand, they have been affecting the quality of wild fish, especially salmon. Organic fish farming is seen by some as a way of maintaining environmental and fish quality without losing the opportunities this form of farming offers.
Other problems with aquaculture include the potential for increasing the spread of unwanted invasive species, as farmed species are often not native to the area in which they are farmed. When these species escape, they often prove more resiliant than native species and take over ecosystems. Another possibility is the spread of introduced parasites and pests.
See also fishery