Is Farmed Salmon a Toxic Food?

Norwegian Salmon farmers care as much about the welfare of their fish as they do about the pristine environment in which they raise them. Get the facts on the great lengths they go to to maintain the highest levels of safety, security and sustainability in regard to feed, contaminants, antibiotics and sea lice.

There is an overwhelming amount of information available to us, especially on the Internet. So how do you decipher the true, credible content from the rumors and unsubstantiated information out there?

You may have come across articles claiming that farmed salmon is bad for you, that it contains contaminants or that it should be avoided. When it comes to farmed fish, it is important to remember that not all fish are raised the same way or adhere to the same standards. It’s also important to recognize where the information is being sourced and if it has credible content to support its claims. 

There is an alarming number of clickbait websites that continue to publish negative, over exaggerated stories, such as “farmed salmon is toxic.” Clickbaiting is aimed at generating page views and online advertising revenue. Publishers use sensational headlines (such as the title of this article) and eye-catching photos to get readers to click on them—with each click, the publisher can bill the advertiser for that page view. Clickbait often uses misrepresented, unsupported content and unverifiable assertions to attract readers and cause the story to go viral. 

Farmed salmon recently became the topic of a clickbait article that went viral. True to its defining characteristics, the article contained a sensationalized headline and unproven content. This can make it incredibly difficult for consumers to know what to believe, and in this case, what to eat.

The Truth about Norwegian Farmed Salmon

Natural Feed

As the aquaculture industry has undergone substantial growth the last decade, it has been forced to look for sustainable resources other than wild fish for its fish feed and has therefore started to integrate sustainably sourced plant based protein into the feed. Salmon are fed an all-natural diet comprised of 70 percent plant based ingredients and 30 percent marine raw materials like fishmeal and fish oil.

Plant based ingredients come from a range of sources such as sunflowers, rapeseed, corn, broad beans and wheat—they are a source of protein, carbohydrates and fat. Fishmeal and fish oil are produced from the fish heads and other parts that are not used for human consumption. Salmon have a unique biology and produce their own omega-3. Thus, there is more omega-3 in salmon than in the feed they eat. As long as the feed has been blended correctly, the salmon are able to convert plant omega-3 to marine omega-3. Omega-3 fatty acids like EPA and DHA, have been proven to reduce heart disease risk and enhance brain function. Norwegian farm-raised salmon contains 3.2 grams of omega-3 (1.9 grams EPA and DHA and 1.3 grams ALA) per 150 g portion fish.Due to the higher fat content, farm-raised salmon has as much or more EPA and DHA per serving than wild-caught, according to the 2015 Dietary Guidelines Advisory Committee.

The pink color of Norwegian Salmon comes from an oxycarotenoid called astaxanthin. In nature, salmon receive astaxanthin by eating crustaceans. Norwegian Salmon receive these same beneficial nutrients as supplements in their feed. Studies have shown that astaxanthin acts as an antioxidant and can actually boost fish and human immune response.


Antibiotics in Norwegian farmed salmon today are a non-issue. Since the late eighties, there has been a 99 per cent reduction in the usage of antibiotics. Today, less than 1 percent of all Norwegian farmed salmon are treated with antibiotics due to effective vaccines in the early stage of the salmon’s life cycle. In numbers, 0.36 grams are used per metric ton of salmon ( Fish Health Report 2015). Antibiotics are only used when there is a medical reason to do so. In these cases, the medicine is prescribed and administered by fish health biologists or veterinarians. In the last decade no residues of antibiotics have been detected in Norwegian farmed salmon (National Institute of Nutrition and Seafood Research/NIFES 2015).


PCBs, dioxin-like PCBs and dioxins are usually mentioned when referring to contaminants in farmed salmon. All fish, both wild and farmed, contain traces of PCBs and dioxins, which they obtain from their diet and the natural surroundings. However, as the ingredients in fish feed have been shifting from marine based to plant based ingredients, farmed salmon today contain less of these contaminants than many wild species. In fact, since 2006, the content of dioxins and dioxin - like PCBs has decreased by 67 percent (Norwegian Scientific Committee for Food Safety 2014).

Persistent organic pollutant (POP) levels—including dioxins and PCBs—in Norwegian Salmon are six times lower than the international accepted European limit values. The Norwegian authorities control the entire supply chain to ensure compliance with the EU limits. The results of various tests are public and accessible on the National Institute of Nutrition and Seafood Research (NIFES) website. NIFES carries out over eleven thousand tests a year on Norwegian Salmon, and POP levels in Norwegian farmed salmon have never exceeded the international accepted European limit values.

Sea Lice

It’s important to know that sea lice pose no threat to humans or food safety. Sea lice are common parasites that live naturally in our oceans and often attach themselves to wild and farmed fish. Factors such as water temperature and density can fluctuate the presence of sea lice. The fish farmers are constantly monitoring their fish farms and must report the sea lice count on a weekly basis. Lice counts are reported to the authorities (digitally), and all statistics are available to the public. The authorities and the industry itself use this data for deciding and coordinating the best strategies to keep the lice count as low as possible. 

The aquaculture industry and research organizations work intensively to find holistic alternatives to traditional veterinary medications such as delousing methods. The industry is constantly developing and testing new methods to address sea lice. For example, lumpfish and other “cleaner fish” are used to naturally eliminate i.e. eat the sea lice. Tepid and fresh water cause the sea lice to fall off the fish. Additional methods include using a special feed that strengthens the mucus layer on the upper 5-10 metres of the cage's shielding skirt, to prevent lice from attaching themselves to the fish. Tube nets are also used to keep the fish below the level where lice are usually found. There is even a laser that targets and removes the lice without affecting the salmon.

The above information is based on fundamental principles within Norwegian aquaculture: a transparent, regulated and controlled activity by an industry whose full attention is on producing safe and healthy seafood products.


1National Institute of Nutrition and Seafood Research (Norway), 2015