Salmon is a very popular fish, eaten by millions of people around the world. Due to its popularity, a lot of salmon now comes from fish farms rather than the wild.
This article compares wild salmon with farmed salmon and discusses the differences between them, including their environment and their diet.
Differences between wild and farmed salmon
Eating fatty fish, such as salmon every week has health benefits. The 2015–2020 American Dietary Guidelines recommend eating 8 ounces (oz) of seafood per week
Salmon is an excellent source of:
- omega-3 fats
- protein
- vitamin A
- vitamin D
- calcium
We explore the differences between farmed and wild salmon below.
1. Wild and farmed salmon living conditions
Farmed salmon are fish stocks kept in netted pens. The farmers control breeding, feed them, and provide medicine if needed. Sometimes, the pens are very crowded and the salmon cannot swim very far.
Overfishing of the world’s fish stocks has led to an increase in fish farming. Fish farming also keeps the price of fish lower.
Wild salmon live and breed in their native bodies of water. Humans have no control over their breeding, feeding, or health. Wild salmon swim long distances with no restriction.
Environmental and chemical contaminants affect wild salmon as well as farmed salmon.
2. Nutritional differences
Typically, wild salmon have fewer calories, saturated fat and vitamins A and D than farmed salmon, but contain more protein.
In both wild and farmed salmon, the omega 3 content will vary depending on what the salmon eats.
According to a 2017 review, wild salmon have higher levels of omega-6 fatty acids than wild salmon. Both farmed and wild salmon had comparable levels of an omega-3 acid called EPA, but farmed salmon had lower levels of the omega-3 acid DHA than wild salmon.
Wild and farmed salmon may differ in color due to their diet.
Wild salmon eat a lot of krill, crabs, and shrimp. These shellfish are high in a carotenoid called astaxanthin, which gives the salmon their pale pink-red color.
Sometimes wild salmon are white because of the way they process astaxanthin.
Astaxanthin is a potent antioxidant and anti-inflammatory that is essential for the general health of the fish. Fish farmers feed the salmon with pellet foods containing an artificial version of astaxanthin . The synthetic version of astaxanthin is not as strong as the natural version but is still beneficial.
Neither the natural and synthetic versions of astaxanthin are toxic to humans.
4. Persistent organic pollutants (POP)
According to an article in Diabetology & Metabolic Syndrome, POPs are human-made organic chemicals that take a long time to break down. POPs can build up in animal tissue. Fatty fish can contain high amounts of POPs.
POPs are also known as:
- persistent, bio-accumulative and toxic (PBT)
- toxic organic micropollutants (TOMP)
POPs include:
- pesticides
- pharmaceuticals
- industrial chemicals
The same article states that POPs can increase the risk of type 2 diabetes in humans. POPs do this by affecting insulin. Insulin controls the body’s blood sugars.
Another study looking at POPs in indigenous communities where the people eat a lot of wild fish found an increase in type 2 diabetes.
POPs may also cause neurotoxicity. Neurotoxicity may increase the risk of Parkinson’s and Alzheimer’s disease.
Farmed salmon contains more fat than wild salmon. The fat may be visible, and farmed salmon may look rounder in shape than wild salmon.
Wild salmon are seasonal and only available in the summer. They may have a wider variety of color as they have a different diet to farmed salmon.
Unfortunately, it is not always possible to tell the difference between wild and farmed salmon by reading the labels on the packages. The organization Oceana, found that 43 percent of the restaurants and shops they surveyed mislabelled salmon.
Takeaway
Judging whether farmed salmon is safe to eat is difficult. The level of contaminants in farmed salmon varies from location to location and depends on their diet.
Exposure to pollutants is still a risk for wild salmon, but studies may not always capture the level of risk.
Typically, wild salmon are nutritionally better, and sustainably-fished salmon have a lower impact on the environment.
Both wild and farmed salmon are safe to eat and are excellent sources of nutrients.
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