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Fish Facts: Atlantic Salmon

Salmonids Health

By the National Fisheries Institute - This article looks at the facts surrounding the farmed Atlantic Salmon.

Fish Facts: Atlantic Salmon - By the National Fisheries Institute - This article looks at the facts surrounding the farmed Atlantic Salmon.

Atlantic salmon are native to rivers in North America and Europe. They spawn in fresh water but spend much of their lives in the ocean. Atlantic salmon are similar to King salmon in oil content, but its meat is more orange in color.

Wild Atlantic salmon stocks are at depressed levels and those spawning in U.S. waters cannot be sold. Fortunately, Atlantic salmon is relatively easy to farm and is grown in large quantities by farmers in the United States, Chile, Canada and Norway and are available year-round. These fish are reared to smolt size in shorebased fresh water hatcheries and then transferred to floating sea cages. They remain in the cages for about 18 months, until they are ready for market.

Salmon farmers operate under very stringent regulations regarding the siting of their farms, farm practices, fish health and treatment, site management, environmental monitoring, research, and food product safety and inspection. The end result is a system that ensures environmental protection and a sustainable product.

Because salmon need a healthy environment to survive, farmers must protect the environment or their salmon will die. Advancements in technology and science have significantly reduced the amount of salmon excrement and unconsumed feed released into the ocean. In Maine, for example, divers regularly sample the ocean floor beneath the salmon pens to monitor the health of the ecosystem, and farms must shut down if they dont meet strict pollution standards.

Because salmon are susceptible to bacterial, viral and fungal diseases as well as parasites, salmon farmers also rigorously maintain prevention and control systems to prevent the loss of their fish and the potential spread of diseases into wild populations. Concerns have been raised regarding antibiotics, vaccines, and other therapeutants used in farming. Use of medicated feeds, however, is low (less than 2%) and must be conducted through veterinarian prescription.

Sometimes sea cages fail and release salmon into adjacent waters. Although escaped salmon tend to remain near their farms, some can enter nearby rivers to spawn and possibly interbreed with wild salmon. Conservation groups and Maines salmon farmers have signed a precedent-setting agreement to monitor and improve measures to reduce the accidental release of salmon through mandatory, verifiable containment systems.

Genetic experiments are being conducted to accelerate growth rates, improve flesh color and increase disease resistance of Atlantic salmon. One firm has engineered an Atlantic salmon to grow four to six times faster than a wild salmon using a promoter gene from either a flounder or an ocean pout and has applied to U.S. and Canadian officials for approval to market the product. Plans are to sterilize these fish before putting them in net pens so that they cannot establish breeding populations if they escape. Critics argue that the risk of interbreeding cannot be eliminated and are opposed to this proposal. Another issue surrounding genetically modified organisms is the use of genetically engineered ingredients in some of the salmon feed (e.g. soy protein).

Salmon farming is a very efficient way of producing protein because it takes less than two pounds of feed to produce one pound of salmon. In the wild, salmon must eat about 5 pounds of fish to produce one pound of salmon. Production of fishmeal used for fish and animal feed has remained relatively stable for the past 15 years, and stocks of food fish, such as menhaden, are healthy.

Farm salmon help conserve wild salmon populations by providing an alternative source for consumers and by ensuring that the species continues to have a broad genetic pool.

For more information, visit the National Marine Fisheries Service website at, the FDAs Fish Encyclopedia at or the National Fisheries Institute website at

Source: National Fisheries Institute - August 2004