Fish farms produce supermarket protein with high concentrations of antibiotics, pesticides and lower levels of healthy nutrients. Research has found that farmed fish has less usable omega-3 fatty acids than wild-caught fish and a 20% lower protein content. A USDA review confirmed the findings. Farmed fish are fattier and have a high concentration of omega-6 fatty acids. Imbalances in the levels of omega-3 and omega-6 fatty acids create inflammation in the body.
Farm-raised fish are given antibiotics to stave off disease that results from crowded conditions and are also treated with pesticides to combat sea lice. Sea lice from fish farms kill up to 95% of migrating juvenile wild salmon.
The pesticides used to treat sea lice in fish farms circulate throughout the ocean. Pesticides that have been banned for decades have concentrated in the fat of much marine life.
This fat is used in the feed that fish farms use, and studies by the Environmental Working Group, along with those done in Canada, Ireland and the UK, have found that cancer-causing polychlorinated biphenyls (PCBs) exist in farm-raised salmon at 16 times the rate of wild salmon.
Dibutyltin is a chemical used in PVC plastics. Dibutyltin can interfere with normal immune responses and inflammation control in both animals and humans. A 2008 study found that dibutyltin may be contributing to the rise of allergies, asthma, obesity and other metabolic and immune disorders in humans. Scientists have found that dibutyltin in farm-raised mussels is more than 6 times higher than that of wild mussels.
Researchers have also found levels of polybrominated diphenyl ether (PBDE), a chemical used as a flame retardant, in high levels in farm-raised fish. PBDEs are endocrine disruptors that are thought to contribute to cancer. Scientists believe that both fish feed and increasing concentrations in the open oceans are contributing to high PBDE levels in fish and humans.
Another study, conducted at the University of New York at Albany found that dioxin levels in farm-raised salmon are 11 times higher than those in wild salmon.
Dioxins are one of the “dirty dozen,” says the World Health Organization (WHO) because they are highly toxic and are stored for a long time in the body: their half life in fat cells is 7 to 11 years.
Dioxins impair the endocrine, immune, nervous and reproductive systems and are carcinogens.
Canthaxanthin is a synthetic pigment that is used to add a pink color to farm-raised salmon. Wild salmon get their color naturally by feeding on krill. Canthaxanthin is a compound found in sunless tanning pills. Studies have found that canthaxanthin can affect pigments in the retina of the eye, leading to a ban of its use in the UK—but not the US.
University of British Colombia professor Daniel Pauly calls aquafarms “floating pig farms” because tremendous amounts of fish feed and fish waste accumulate on the sea floor because of them, creating a perfect breeding ground for bacteria that threaten other marine life.
Researchers from the George Mateljan Foundation say that “a good sized salmon farm produces an amount of excrement equivalent to the sewage of a city of 10,000 people.”
Fish farms threaten other sea life in other ways too. Fish farms don’t really combat overfishing: they contribute to it. Salmon, for instance, are carnivores. It takes about 2 ½ to 4 pounds of other fish to create the salmon chow needed to produce 1 pound of farm-raised salmon. The overfishing of wild sardines, anchovies, mackerel, herring and other fish upset natural ecosystems. “We are not taking strain off wild fisheries,” says agricultural economist Rosamond L. Naylor. “We are adding to it. This cannot be sustained forever.”
Another fear many scientists have is about dwindling biodiversity of fish. What makes the food supply more sustainable is the wide variety of fish and other species and their genetic make-ups. Diversity=survival.
About 1 million farm-raised salmon have escaped from holes in nets from farms in the Puget Sound alone. Biologists fear that farm-fish escapees may out-compete wild fish for food and territory, contributing to the demise of many fish species.
Interbreeding between escaped fish and wild may also dilute the wild salmon gene pool.
Drugs that could reduce farmed-fish growing times have also begun to arise. These drugs alter genes in fish so that they produce growth hormones and grow six times faster than normal fish, increasing the danger that wild species will be overcome.
Benefits of Wild Caught Fish
This information is certainly sobering and should be enough to convince you to stay away from conventional farmed fish. These practices are even affecting the population of fish in the wild.
That’s why I don’t recommend eating fish–even wild caught fish–on a daily basis. But the health benefits of certain wild caught fish like salmon just can’t be ignored.
Wild caught salmon is very high in Omega 3 fatty acids. These fats are known as essential fatty acids. Our bodies don’t produce them, so must obtain them through our food. Wild caught salmon also has a healthy balance of Omega 3 to Omega 6 fatty acids. When you have too many Omega 6 fatty acids in your body, inflammation occurs.
Cold water fish such as salmon are a good source of Vitamin D-an extremely important nutrient that is essential to wide variety of bodily functions. The sun is your best source of Vitamin D, but since most people don’t get enough sun in the winter months, wild caught salmon is a great way to add more of it into your diet.
Also found in wild caught salmon are healthy protein, selenium, niacin, vitamin B12, phosphorus, magnesium and vitamin B6.