Sustainable salmon is salmon that has been caught or farmed in ways that protect wild fish populations, minimize damage to surrounding ecosystems, and can continue producing food long into the future. That applies to both wild-caught and farmed salmon, but the specific criteria look very different for each.
What Makes Wild Salmon Sustainable
For wild salmon, sustainability comes down to two things: the health of the population being fished and how well the fishery is managed. A sustainable wild fishery catches fish at a rate that allows the population to fully reproduce and replenish itself each season. It also avoids significant harm to other marine life and ocean habitats, meaning minimal bycatch (unintended species caught alongside salmon) and no destruction of seafloor ecosystems.
Alaska is widely considered the gold standard. NOAA Fisheries calls Alaska’s fisheries “among the best-managed, most sustainable in the world.” Federal managers work with scientists and a regional council to set fishing levels using current population data, with the explicit goal of allowing fishermen to harvest an optimal amount while leaving enough fish in the ocean to reproduce. This science-based approach, authorized under federal law, adjusts limits season by season rather than relying on fixed quotas that might not reflect changing conditions.
Not all wild salmon fisheries meet this bar. Overfishing, habitat loss from dams and development, and climate-driven changes to river temperatures have pushed some wild salmon populations into decline. A species being “wild-caught” does not automatically make it sustainable.
What Makes Farmed Salmon Sustainable
Farmed salmon introduces a completely different set of concerns. The biggest environmental risks from conventional salmon farms, which typically use open-net pens in coastal waters, are fish escapes and chemical use. When farmed salmon escape into the ocean, they can spread disease to wild populations and interbreed with native fish, weakening genetic fitness. Farms also use chemicals to control parasites and disease, and heavy or poorly regulated chemical use is a major red flag.
Sea lice are perhaps the most publicized concern. These parasites thrive on densely packed farm fish and can transfer to wild juveniles migrating past coastal pens. In British Columbia’s Broughton Archipelago, high sea lice levels on juvenile wild pink salmon were initially blamed for a dramatic population crash in the early 2000s. Subsequent research found that the number of lice on wild juveniles closely tracked lice levels on nearby farm fish, with farm lice abundance explaining 98% of the annual variation in wild lice prevalence. However, the same long-term data showed that wild salmon productivity was not significantly associated with farm lice numbers or farm production levels, suggesting other factors drove the population decline. The interaction is real, but its ultimate impact on wild populations remains debated.
Sustainable farmed salmon operations aim to eliminate or sharply reduce these risks. Land-based recirculating aquaculture systems (RAS) represent the most environmentally contained approach. These facilities recirculate more than 90% of their water, virtually eliminate the chance of fish escaping into the wild, and allow precise control over water quality, temperature, and disease management. When integrated with plant-growing systems, some RAS facilities can approach zero waste discharge by converting fish waste into plant nutrients.
RAS technology has its own challenges. The artificial environment can stress fish, and system failures have caused mass die-offs. High stocking densities and the closed nature of these systems mean that if a disease outbreak does occur, it can spread rapidly. Capital costs are also significantly higher than traditional net-pen farming. Still, certification programs generally rate RAS operations favorably compared to open-net pens.
The Feed Problem
One of the less visible sustainability questions is what farmed salmon eat. Salmon are carnivorous, and their feed has historically relied heavily on wild-caught fish ground into fishmeal and fish oil, effectively requiring several pounds of wild fish to produce one pound of farmed salmon. This created a troubling cycle where fish farming increased pressure on wild fisheries rather than relieving it.
That picture has changed substantially. Fish-based ingredients in Atlantic salmon feed have dropped from roughly 90% in the 1990s to about 25% today. Modern feeds incorporate proteins from soybeans, corn, peas, and wheat, and supplement fish oils with canola, flaxseed, and soybean oil. Researchers are pushing further: NOAA-funded trials have successfully raised fish on completely fish-free diets using algae-based oils in place of fish oil, and studies show that fish raised on mealworm-based protein grow just as large as those fed traditional fishmeal. Algae cells that convert sugar into omega-3 fatty acids through fermentation are already being developed commercially. As one NOAA researcher put it, “fish meal and fish oil are not nutritionally required to raise healthy farmed fish that are good for consumers.”
How Certification Labels Work
Two main certification programs help consumers identify sustainable salmon at the store. The Marine Stewardship Council (MSC) certifies wild-caught seafood. Its blue label means the fishery has been independently assessed on three criteria: the health of the target fish stocks, the fishery’s impact on the broader marine environment (including habitats and other species), and the effectiveness of its management system. Every company in the supply chain that processes, packages, or sells MSC-labeled fish must also be certified to a chain-of-custody standard, ensuring the fish on your plate actually came from the certified fishery.
The Aquaculture Stewardship Council (ASC) plays a parallel role for farmed seafood, evaluating responsible farming practices. Monterey Bay Aquarium’s Seafood Watch program takes a different approach, rating individual salmon products as green (best choice), yellow (good alternative), or red (avoid) based on detailed assessments of each fishery or farm. Green-rated wild salmon comes from a healthy population with well-managed fishing practices, while red-rated farmed salmon signals serious concerns about escapes, disease transmission to wild fish, or excessive chemical use.
Nutrition: Wild vs. Farmed
Sustainably farmed and wild salmon are nutritionally comparable. Norwegian data on Atlantic salmon shows that farmed fish contain slightly more EPA and DHA, the two omega-3 fatty acids linked to heart and brain health. Farmed salmon provides about 0.5 grams of EPA and 0.9 grams of DHA per 100-gram serving, compared to 0.4 grams of EPA and 0.8 grams of DHA in wild salmon. The difference is modest and largely reflects the higher overall fat content of farmed fish, which get consistent feed rather than foraging in the wild.
Both types deliver well above the omega-3 levels found in most other protein sources. From a pure nutrition standpoint, choosing between sustainable wild and sustainable farmed salmon is less important than simply eating either one regularly.
How to Choose Sustainable Salmon
At the grocery store or fish counter, look for MSC certification on wild salmon and ASC certification on farmed salmon. If neither label is present, the origin matters. Wild salmon from Alaska is a reliable choice given the strength of its federal management system. For farmed salmon, look for products from land-based RAS facilities or from countries with strong regulatory oversight like Norway, where contaminant and chemical use monitoring is rigorous.
Avoid farmed salmon with no country of origin or production method listed. Vague labeling like “Atlantic salmon” without further detail often signals open-net pen farming from regions with weaker oversight. Frozen and canned wild salmon, particularly sockeye and pink salmon from Alaska, tend to be both affordable and consistently sustainable. Sustainability does not require paying a premium for the most expensive fillet on display.