For the latest marine science and other ocean news, subscribe to Ocean Update, Marine Science Review and our other free newsletters.

Commonly Farmed Species

Carp: Carp was one of the first types of fish to be grown in aquaculture systems. In particular, the common carp has been cultured throughout the world. Adult carp tend to be omnivorous, feeding on snails, mollusks, worms, algae, aquatic plants, seeds and detritus and can be reared in inland-based earthen ponds, cage culture, or polyculture systems. They have been incorporated into rice paddies to feed on the insects and other organisms associated with rice culture. Carp are a rapidly growing fish and are able to tolerate less than ideal environmental conditions. They can, however, become a nuisance when cultivated in a non-indigenous area, as has recently been seen in the southern United States following accidental escapes of several kinds of carp from aquaculture facilities in the early 1990s.

Catfish: Channel catfish are a freshwater species native to North America. They are primarily vegetarian, thus not reliant upon fishmeal (their feed is grain-based but may contain small amounts of fishmeal). They are typically cultured in earthen ponds.

Eleanor Partridge / Marine Photobank

Clams: Clams belong to the mollusk family and are filter feeders, feeding mainly on algae. The type of culture for clams differs according to species. Included among clam species are hardshell clams, surf clams, softshell clams, geoducks and ocean quahogs.

Mussels: Mussels are an important part of an aquatic ecosystem. Like clams, they too are filter feeders, and help to maintain good water quality by filtering nutrients, contaminants and sediments from the water. They have been used in polyculture systems to improve the quality of the surrounding environment. Mussels are an important indicator of ecosystem health. They may be cultured using bottom culture techniques, raft culture techniques, or rack culture.

Oysters: Like other mollusks, oysters are filter feeders, with the ability to filter nutrients, contaminants and sediments out of the water. Raft, rack and longline practices are well-developed methods for the cultivation of oysters.

Alexandra Morton / Marine Photobank

Salmon: Wild salmon are naturally aggressive predators and inhabit cold-water streams, estuaries and the ocean areas. Native only to the Northern hemisphere salmon were once plentiful in various countries, though many of these wild populations are currently in serious decline. Varieties such as Pink, Coho, Sockeye and Chinook are salmonids whose wild populations are healthy. Atlantic salmon is the farmed salmonid of choice because of its hardiness and ease of farming. Salmon farming generally occurs in two phases: a freshwater phase and a marine phase. The eggs are hatched in land-based freshwater tanks, and then transferred to net pens in the ocean. It is this second stage of salmon farming that has the most damaging effects on nature. Salmon are a carnivorous species and depend on large amounts of protein in their diet, supplied to them through fishmeal, which is produced from wild-caught fish. Currently, efforts are underway to reduce farmed salmon's dependence on fishmeal as the primary source of protein.

Shrimp: Shrimp are one of the world's most profitable delicacies. However, the farming of shrimp causes a great amount of environmental damage. Cultured primarily in coastal areas that were once mangrove swamps, shrimp farms tend to salinate the land and render it unsuitable for future culturing in just a few short years. The shrimp culture industry is export-oriented. Cultured mainly in Asia, most shrimp exports are transported to countries such as Japan, the United States, Europe and Canada. The wild populations of shrimp are varied around the world. Some species have been depleted while others remain plentiful. The capture fisheries for shrimp also leave a large impact on the environment. Typically caught through the use of trawls, the capture of one pound of shrimp results in the capture of four to ten pounds of unwanted by-catch, which is most often discarded or left to die.

Striped Bass: Also known as the striper or rockfish, the striped bass is one of the most desirable recreational finfish in the country. Striped bass farming methods typically include pond systems and recirculating systems. Oftentimes, the farmed striped bass is actually a hybrid between white bass and striped bass.

Sturgeon: Sturgeon eggs, known commonly as caviar, are one of the world's most well recognized delicacies. Sturgeon live in rivers, coastal marine waters, and lakes in the Northern hemisphere and mature at a relatively late age, usually between 15 and 25 years, though they can live to be over 100 years old. Because of this late maturity, their populations are particularly vulnerable to overfishing. Because of declining natural populations, coupled with the continued popularity and profitability of caviar, sturgeon farming has gained more focus on the global scale.

Tilapia: Tilapia are native to Africa, but have been introduced and cultured in many countries around the world, and are currently one of the most widely cultured fish in the world. The species most commonly cultured are the blue tilapia, the Nile tilapia and the Mozambique tilapia. They are suitable for culture since they can reproduce easily, are disease-resistant, are omnivorous and eat a wide variety of foods (though their preferred diet consists mainly of algae), and can tolerate various environmental conditions. The common culture practices employed for the rearing of tilapia include pond culture and flow-through tank culture.

Trout: Rainbow trout is the most commonly cultivated trout variety in the world because it is a hardy species and easier to cultivate than other varieties. The farming of trout is performed in earthen or concrete raceways with flowing water.