Wild-Caught vs. Farm-Raised Salmon—Which Is Better for You?

Salmon is one of the top seafood choices among Americans. In fact, according to data presented at the Global Seafood Market Conference last year, this bright pink fish is the third most popular option in the U.S. But with this popularity comes discussions about which salmon variety is the healthiest and most sustainable—for both us and the planet. 

These discussions have teased out the hotly debated topic of whether wild-caught or farm-raised salmon is the best purchase. Here, we’ll explore how these two varieties of salmon differ in terms of how they’re raised, the nutrition they impart, and their environmental impacts.

Wild-Caught vs Farm-Raised Salmon: What’s the Difference?

While these two salmon-rearing methods may seem self-explanatory, each can look very different depending on location, catch or farming method, and producer philosophy. “Farm-raised salmon is most often farmed in marine net pens, which are structures that hold the salmon in open (ocean) water as they develop,” says Sharon Palmer, MSFS, RDN, sustainable nutrition expert.

Farmed salmon can also be raised in recirculating aquaculture systems (RAS), a land-based method of production where the fish are kept in highly-controlled environments out of the ocean and water and waste are recycled. “But we don’t get much of RAS-produced salmon in the U.S.,” Palmer explains.

Meanwhile, wild-caught salmon is procured from the ocean through a variety of catch methods, depending on the fisherman. “Wild caught salmon are caught using long nets that drift in the current, lift nets, purse seines (nets that close like a drawstring purse), and trolling lines (moving fishing lines with hooks),” Palmer says.

Nutritional Differences

Though both wild-caught and farm-raised salmon have pretty similar nutrition, there are some differences worth noting. Both options are rich in protein, selenium, phosphorus, and B vitamins like niacin, thiamin, pantothenic acid, B6, and B12. These nutrients support immune, bone, gut, and metabolic health while also encouraging tissue growth, maintenance, and repair.

But where these salmon varieties really differ is their fat profiles. “Wild salmon has lower calories and fat content compared to farmed [salmon], which is higher in omega-3s, but also higher in saturated fat, according to the United States Department of Agriculture (USDA),” Palmer says. The diets of farmed salmon are often intentionally aimed at producing a higher omega-3 final product, as this fatty acid is what many folks are after when purchasing this fish.

Omega-3 vs. Omega-6

Omega-3 fatty acids are well-known for offering anti-inflammatory benefits compared to omega-6 fatty acids, which support pro-inflammatory pathways in the body. And while both fats are needed, omega-3s are harder to come by in the diet compared to omega-6s and are famously linked to impressive health benefits like lowering cholesterol levels and supporting brain, eye, immune, and hormonal health.

However, the higher saturated fat content of farmed salmon can work in opposition to some of these health perks, given that it can increase blood cholesterol levels—though conflicting evidence has found the controversial fat to not have as significant of an impact on heart disease risk as once thought. But the differences in saturated fat content between the two varieties can be pretty minimal (depending on where they’re from), sometimes with only a gram of difference.

Additionally, both varieties can contain contaminants like heavy metals, polychlorinated biphenyls (PCBs), and dioxins, as illustrated in a 2020 article on Norwegian salmon published in Foods. All of these substances negatively impact several body systems including the immune, cardiovascular, hormonal, and cellular systems. While both varieties in the study were below European Union (EU)-informed maximum levels, the tested wild salmon actually contained more of these contaminants than farmed. Though, again, this varies greatly depending on where and how the salmon was raised.

Sustainability Impacts

When it comes to sustainability, the impacts of farmed versus wild-caught salmon are highly dependent on their producers. “According to Seafood Watch (a global leader in the sustainable seafood movement), wild-caught salmon from the U.S. is a good choice from a sustainability standpoint,” Palmer offers. “Most of it is sourced from populations that are healthy.” However, when wild salmon is caught using large netting systems, bycatch can occur, resulting in the loss of several species and negatively impacting the greater marine environment.

Palmer also goes on to explain that certain farmed salmon types can be rated well, too, if they have minimal impact on their surrounding marine environments. “For example, farmed Atlantic Salmon from Maine and the Faroe Islands are rated as good choices by Seafood Watch,” she says. “But Atlantic Salmon farmed in Canada, Chili, Norway, or Scotland that is not Aquaculture Stewardship Council (ASC)-certified is not considered to be a good choice.”

While farming can be done with minimal environmental impact, there’s a litany of potential issues that can arise with these operations. These include escapes to ocean environments, pollution from waste, medications, and fertilizers, and even nutrient overload or algae blooms related to uneaten feed. 

However, while wild salmon may rank higher in sustainability compared to farmed salmon, it’s important to note that global fish populations are on the sharp decline. “It’s important to consider that there are not enough wild salmon available to meet consumers’ desire for salmon,” Palmer adds.

Which Is the Better Choice?

So, between farm-raised and wild-caught salmon, which is the better all-around choice?

While farmed salmon often has higher omega-3 fatty acid content, it also can contain more saturated fat. Otherwise, the nutrition profiles of these two salmon varieties are generally quite similar, offering much of the same health benefits.

On the sustainability front, while wild salmon can have lower environmental impacts compared to many farmed options, overfishing is a serious global issue, with the World Bank citing nearly 90% of global fish stocks being overfished in 2017. Interestingly, certain fish farming operations can be quite sustainable, especially those employing circular practices where waste and water are repurposed and reused. Though this isn’t always the case, with other operations taking a serious toll on their surrounding environments.

Thankfully, organizations like Seafood Watch, ASC, and the Marine Stewardship Council (MSC) can help you make smarter purchasing decisions. “Seafood Watch has recommendations for a variety of types of salmon on their website and many supermarkets, such as Whole Foods, follow Seafood Watch recommendations, making it easier for consumers to make better choices in their purchases,” Palmer shares.

Price is also a factor here. Some wild-caught options simply aren’t in the budget of many Americans—an obvious leg up for farmed salmon.

Given that farmed salmon can offer slightly better nutrition, can be raised in a sustainable fashion, and is more affordable, it is ultimately a better choice for many in the U.S.—as long as it is certified by ASC or a similar organization. That said, ethically-caught wild salmon (look for terms like pole-and-line-caught, pole caught, troll-caught, and free school when shopping) can also be a healthy choice for us and the planet, particularly if enjoyed occasionally.

“You can also look beyond salmon to other types of seafood options that may be more sustainable and local in your region,” Palmer says. “For example, Seafood Watch launched their Super Green List which highlights 10 different seafoods that consumers should consider as more sustainable options, which include bivalves and seaweed.”