Do you buy farmed salmon in the belief that it’s the environmentally responsible thing to do? Think again. Fish farms are the water-based equivalents of land-based concentrated animal feeding operations (CAFOs), and as such they create the same, if not worse, environmental concerns. Since the salmon pens are placed along wild salmon runs, they pose a severe threat to wild salmon stocks that pass by, exposing wild fish to diseases such as sea lice, pancreas disease,¹ infectious salmon anemia virus and piscine reovirus.

For a quick review, see “Racing a Virus”² above — a video created by Alexandra Morton, a Canadian marine biologist who has spent decades studying the impact of salmon farming on wild salmon. Piscine reovirus is a highly contagious blood virus that causes heart disease in the affected fish. The virus was first discovered in Norwegian salmon farms and has proven to be nearly impossible to eradicate. And, with the spread of this disease into wild populations, wild salmon may soon go extinct.

Toxins Abound in Farmed Salmon

Importantly, farmed salmon also poses health risks to those who eat them. In fact, toxicology testing reveals farmed salmon is one of the most toxic foods in the world — more than five times more toxic than any other food tested.³ A global assessment of farmed salmon published in the January 2004 issue of Science⁴ found no less than 13 persistent organic pollutants in the fish, including PCBs and dioxins.

Other investigations⁵ reveal PCB concentrations in farmed salmon are, on average, eight times higher than in wild salmon. According to the authors, “Risk analysis indicates that consumption of farmed Atlantic salmon may pose health risks that detract from the beneficial effects of fish consumption.” Another group of scientists concluded that⁶ “Consumption of farmed salmon at relatively low frequencies results in elevated exposure to dioxins and dioxin-like compounds with commensurate elevation in estimates of health risk.”

Farmed Salmon Contain Harmful Fats

One of the reasons why farmed salmon contains much higher levels of toxins than wild is because the feed they’re given is highly contaminated. Another reason is because farmed salmon contains far higher levels of fat, which binds and accumulates these toxins. Wild salmon contains about 5 to 7 percent fat, whereas the farmed variety can contain anywhere from 14.5 to 34 percent.

The exaggerated fat content in farmed salmon is a direct result of the processed high-fat feed that farmed salmon are given. Their diet also results in radically skewed ratios of omega-3 to omega-6 fats.⁷ Rather than being a wonderful source of healthy omega-3s, farmed salmon contains far more omega-6 than omega-3.

Half a fillet of wild Atlantic salmon contains about 3,996 milligrams (mg) of omega-3 and 341 mg of omega-6.⁸ Half a fillet of farmed salmon from the Atlantic contains just a bit more omega-3 — 4,961 mg — but an astounding 1,944 mg of omega-6;⁹ more than 5.5 times more than wild salmon.

This lopsided ratio can have negative health ramifications since most people are deficient in omega-3 while already getting far more omega-6 than they need thanks to processed foods, which tend to be high in damaged omega-6 fats.

The elevated omega-6 level in farmed salmon is also a result of the feed they’re given, which includes such species-inappropriate ingredients as poultry meal, fish meal, poultry fat, fish oil, whole wheat, soybean meal, corn gluten meal, feather meal and rapeseed oil.¹⁰ In essence, the salmon are being fed a processed junk food diet high in toxic contaminants and drugs, and their nutritional composition reflects this.