Real Food Encyclopedia | Salmon

There is perhaps no fish more prized, beloved, revered, fought over — or exploited — than salmon. There are several species of salmon, and all have been important sources of food for people wherever they’re found. But in just the past two hundred years, salmon species have been seriously threatened by human activities, especially overfishing and habitat destruction. More recently, the introduction of farmed salmon — raised in conditions that are akin to land-based factory farms — has disturbed many coastal ecosystems and threatened wild populations with diseases, parasites and more. 

The Atlantic salmon, once abundant in nearly every river north of the Hudson, has been disappearing from North American waters. In 2000, the salmon population in the Gulf of Maine was listed as an endangered species. There is a federal ban on commercial fishing for all wild Atlantic salmon in US waters, so all Atlantic salmon on the market today is farmed. Aquaculture has become the default method of raising “Atlantic salmon” both in this country and abroad; 70 percent of the world’s salmon harvest is now farmed. Wild-caught salmon comes mainly from Pacific species, which are carefully managed to avoid overfishing. However, these populations are still at risk from climate change and other threats, and protecting them is critical for the many Indigenous and coastal communities that depend on them for survival. 

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Sustainability of Salmon

Environmental Impact of Salmon

Salmon populations are sensitive to a number of different pressures. Because they return to a single river to breed, any disturbance to that environment — from pollution, dam construction or development along riversides — can mean extinction for any given group of salmon. Along with the mounting impacts of climate change that make it harder for fish to find food, grow and reproduce, these environmental disturbances make salmon populations more sensitive to overfishing. As a keystone species (one which is central to many intersecting food chains) the disappearance of salmon can adversely affect many other species that rely on them for food, like bears, birds and marine mammals. 

Historically, salmon populations were so rich in areas like the Pacific Northwest that people saw them as an unlimited resource, fueling an explosion of salmon canneries along the Columbia River in the 19th century. The trend continued in Alaska into the first half of the 1900s. But the idea that salmon populations in thePacific could not be overfished quickly proved untrue; salmon runs were so low in Alaska that in 1953, President Eisenhower declared Alaska a federal disaster area.

Atlantic salmon in the United States followed a similar trajectory, leading to the closing of the Atlantic salmon fishery in 1948. Even today, all Atlantic salmon for sale in the US is farmed. Due to the ongoing effects of pollution, daming and other habitat disturbance, wild Atlantic salmon populations are still struggling to rebound.

But some salmon populations have been sustainably managed. The introduction of effective fisheries legislation means that some salmon populations — especially those in Alaska — can be harvested sustainably. Careful monitoring means that fishing communities and Indigenous people in the Pacific Northwest are still able to catch fish for themselves and for sale. 

But this doesn’t mean that fish populations are safe forever. Salmon’s sensitivity to disturbances means that populations can quickly decline. In many areas, salmon runs have become unreliable. In 2008, for example king salmon stocks in the Sacramento River basin mysteriously disappeared, forcing California and Oregon officials to take the unprecedented move of cancelling the season that year and the following. Along the Yukon River delta in western Alaska, king salmon have been steadily declining for the past decade, limiting the ability of indigenous communities to feed themselves. At the same time, populations of other species like sockeye are experiencing population increases. 

Because US fisheries are responsive to these kinds of changes, domestic, wild-caught salmon is still a generally sustainable option. 

Salmon Farming

To accommodate rising demand, salmon farming is increasingly common. 70 percent of the world’s salmon harvest is farmed, primarily in Norway, Chile and Scotland. While other types of salmon are beginning to be farmed, most farmed salmon is Atlantic salmon, and all Atlantic salmon available in the US comes from fish farms regardless of where it originates. While salmon farming may sound like a good way to alleviate pressure on wild fish, the reality is far different: most salmon farms operate much like factory farms on land, spreading waste, excess food and disease into the surrounding ecosystem and providing cramped and unsanitary conditions for the fish. 

Salmon in net pens are generally kept close to shore in open-sided net pens that allow water to flow through. Food and fish waste fall from the pens into the surrounding ecosystems, helping overload delicate coastal environments with nutrients. This can contribute to eutrophication, a process where excess nutrients spawn short-lived algal blooms that deprive water of oxygen, leading to low-oxygen dead zones. 

Those cramped conditions are also a breeding ground for disease and parasites. An epidemic of the Infectious Salmon Anemia (ISA) virus. all but wiped out farmed salmon in Chile in 2007, with earlier incidents in Maine killing millions of fish. While the industry has recovered from these incidents, the disease still circulates. 

To keep bacterial diseases at bay, the industry relies heavily on antibiotics, with Chilean salmon farms used nearly 1 million pounds of antibiotics in 2013. Much like land-based factory farms, antibiotic misuse makes the evolution of antibiotic-resistant bacteria much more likely. It also impacts the environment around salmon pens, changing the microbial community of the seafloor and altering nutrient cycling.

Parasites, particularly salmon lice, are another big issue on salmon farms. Unfortunately, these can spread to wild populations, endangering them when they are already vulnerable to other environmental stressors. 

Even farmed salmon’s central claim – that it helps relieve pressure on wild fish – isn’t entirely true. Traditionally, farmed salmon feed has included a high proportion of fish oil and fish meal – products rendered from small fish that are caught in huge numbers. While salmon feed has become more efficient over the years, it still takes nearly two kilograms of wild fish to farm one kilogram of salmon. Many of these small fish could be eaten by other marine animals or more efficiently consumed by people directly, so rendering them into fish meal and fish oil for farmed salmon is inefficient. 

Recent developments have allowed fish farmers to feed farmed salmon more plant-based feed, but that comes with its own issues. Industrially raised corn and soy are destructive to land-based ecosystems because of high chemical use and poor soil health practices, adding a new dimension to the farmed salmon’s foodprint. The shift to plant-based diets also changes the salmon’s nutritional profile, reducing the amount of heart-healthy omega-3 fatty acids and making the meat a pale color unless a colorant is added to the feed. 

Escaped salmon from aquaculture facilities pose yet another risk to wild fish and the surrounding ecosystem. In areas where they are not native, escapees could outcompete other fish and deplete resources, and in places where Atlantic salmon are common, there’s risk of genetic contamination that could make the wild population less suited to its environment. 

There are some promising developments that might allow farmed salmon to become sustainable: the development of indoor recirculating systems, where water is filtered through tanks with fish and often plants, have allowed for lower-impact farming of species like salmon. While it’s challenging to scale these closed-loop systems, they have a far lower impact on water quality than open net pens and other aquaculture systems where fish are in close contact with the environment.

GMOs and Salmon

Until recently, genetic modification in agriculture was limited to crops. A variety of Atlantic salmon, called the AquAdvantage salmon, was recently approved that would change that. For the past two decades, AquaBounty Technologies has been developing its AquaAdvantage salmon, genetically modified with a Chinook salmon growth gene that would accelerate growth in a fraction of the time. In 2010, the company applied for approval from the FDA. In 2012, the agency announced its preliminary findings of “no significant impact” of introducing a GMO salmon to the marketplace. Public comment (which amassed more than 1.8 million signatures in opposition) ended in April 2013, and after a long drawn out process with passionate feelings expressed on both sides, it was approved in 2015. Although the salmon is now ready for market, a large group of retailers have agreed not to sell the product. 

Although the AquAdvantage salmon is raised entirely indoors, making the risk of escape low, advocates say that the approval for the product sets a dangerous precedent for future fish and livestock that could enter the market with less oversight, heightening the potential risks associated with fish escape. 

Salmon Seasonality

The wild Pacific salmon harvest spans from mid-May to early November, depending on the species. For king and sockeye, the season is May to September; for coho, it’s June until October, and for chum and pink, June until November. July and August are boon months for wild salmon lovers, particularly in the Northwest.

Food Sovereignty and Salmon

The nineteenth century was like a salmon rush on both coasts; by 1805, Lewis and Clark had made note of the Pacific Northwest bounty. White settler’s lust for salmon in Washington’s pre-state era prompted concerns for the subsistence diet of neighboring Indian tribes, resulting in government-mandated protections. In 1855, territorial governor Isaac Stevens signed the The Treaty of Point No Point, a declaration of native rights to fish and process salmon.

In its first year of statehood in 1889, Washington closed six rivers to salmon fishing, all of which fed native Americans. News of the salmon frenzy reached the other Washington; in his 1908 state of the union address, President Theodore Roosevelt mentioned the decline of salmon fisheries along the Columbia River.

One hundred years later, the tensions between white settlers and native tribes in Washington resurfaced. In 1959, Washington state authorities evicted tribal fisherman from fishing sites protected in the 1855 treaty. The next decade would become known as the Fish Wars, a tense time of “Fish-ins,” resulting arrests and ultimately, the federal government taking the state of Washington to court. In 1974, US District Court judge George Boldt upheld the native treaty-protected fishing rights, entitling Washington tribes to 50 percent of annual catch in state waters. Famously known as the Boldt Decision, US v. Washington was upheld by the Supreme Court in 1979.

In recent years, native fishing communities in western Alaska have joined the commercial marketplace. In 2002, a cooperative of six Yup’ik villages along the Yukon River Delta a sustainable fishery that would directly benefit its community. In 2005, it became the first Fair Trade fishery in the world.

As climate change and other environmental threats impact salmon populations more and more, food security for many communities that rely on the fish becomes tenuous. Indigenous communities in Alaska are also in close communication to help each other weather ups and downs in individual salmon catches, helping to move fish caught in one area to communities who are experiencing low landings in others. Ultimately, protecting salmon from these environmental threats — like the proposed Pebble Mine in Alaska — is critical for maintaining Indigenous food sovereignty.

Eating Salmon

Storing Salmon

Salmon is extremely perishable. Use fresh salmon within two days of purchase, and keep it as cold as possible without freezing. Since most home refrigerators run somewhere between 36 and 40 degrees, that means a layer of ice is key.

Pack whole fish under flaked or crushed ice (less damaging to the flesh than cubes) just like it’s done at the fish counter. If space is an issue, surround or sandwich the fish with a layer of reusable soft ice packs. Wrap fillets or steaks in a zip-style plastic bag. Place in a colander. Find a bowl or dish that the colander neatly fits into, and place the colander on top. Surround the wrapped fish with ice; as it melts, the bottom vessel will catch residual water. Add more ice as needed for up to 48 hours.

Thaw frozen fish in the refrigerator.

Cooking with Salmon

No matter how you prepare salmon, food safety is the first order of business. Wash your hands before handling raw salmon (or any kind of raw seafood) and use a nonporous cutting board (plastic, rubber, acrylic) which is easier to clean and sanitize than one made from wood. It’s also a good idea to have a separate cutting board for handling seafood. Wash all work surfaces, knives, other utensils — and your hands! — immediately after handling raw salmon to minimize cross-contamination. Maybe it’s obvious, but worth repeating: Never serve cooked salmon on the same plate that just moments ago held the raw stuff.

Unless the fish has been previously frozen, eating raw salmon carries the risk of contracting Diphyllobothrium latum, an invasive tapeworm that can grow up to more than 30 feet long. The resulting infection is known as diphyllobothriasis. Freezing the fish for 15 hours or more, which is standard practice at sushi and sashimi restaurants, effectively kills the tapeworm larvae.

So how can you tell when the salmon is cooked, anyway? Setting your timer is a good starting point, but not a fool-proof guarantee of doneness. You’ll need a ruler or tape measure for a more accurate read: For salmon fillets and steaks, estimate about 8 minutes of cooking per inch of thickness; for whole fish, estimate at least 10 minutes per inch. Make sure you’ve measured the thickest part.

A few rules of thumb:

• As a member of the fatty fish club, salmon, by and large, takes longer to cook than lean fish like flounder. Salmon steaks take longer than fillets due to the bones.
• In its raw state, salmon is translucent. As it cooks, it becomes opaque. Ideally, we’re looking for mostly opaque, with just a hint of translucence.
• Don’t be afraid to poke at the middle (or thickest part) of the fish with a paring knife. Does it resist a little bit and easily flake? These are good indicators of doneness.
• Whole fish will spring back and will be firm to the touch on the outside when done.
• You may also see white curd-like stuff coagulating on top; that’s a protein called albumin. It’s totally harmless, but if there’s a lot on top, it may be a sign of overcooked fish.

Salmon is fatty and rich, even when it’s pink and lean. As such, it can handle assertive flavors like curry, smoked paprika, even barbecue sauce. It likes astringent and acidic partners, too — ginger, mustard, capers and tomatoes all are great contenders. There’s a lot of room to get creative and expand beyond salmon with a little herb butter on top (not that there’s anything wrong with that).

Grilling salmon on an alder or cedar plank is an easy method for beginners that confers delicious smoky flavor from the wood. Soak the plank in water for an hour. Meanwhile, you can do a spice rub or simply olive oil, salt and pepper and fresh herbs. Char the soaked plank on the hot grill for at least 5 minutes, then turn the plank so that the charred side is facing up, and place the prepared fish, skin-side down, on top. Cover and cook until the fish is opaque, about 130 degrees on an instant-read thermometer.

Whole, on the grill: As veteran fishmonger Paul Johnson writes in his book, Fish Forever, “Serving whole fish at the table slows down the pace of the meal…the skin becomes crisp, like that of a well-roasted chicken,” and the “fins, crisped from the heat, break apart into crunchy bits that taste like a cross between dried nori and bacon scraped from the bottom of a cast-iron pan.”

Preserving Salmon

Cured, as in gravlax, for Sunday morning bagels and snack plates at all times of the day: Making your own gravlax is easier than you think. This is for the kitchen project person, as the fish needs to cure for about five days. Check out this step-by-step tutorial from the Kitchn. P.S.: As mentioned earlier, cured salmon is a raw preparation and as such, we recommend that using frozen (and thawed) fillets to minimize risk of tapeworm.

Salmon Nutrition

The nutritional heft of wild salmon as a lean protein is tough to beat. A three-ounce serving of cooked wild coho contains 23 grams of protein for 156 calories. But where the salmon really shines is in the omega-3 department, those heart-healthy fatty acids with anti-inflammatory and cardiovascular supportive powers. Omega-3 fatty acids may also play a role in lowering the risk of macular degeneration as well as dry eye syndrome. The carotenoid-rich flesh of all wild salmon is loaded with disease-fighting antioxidants. Salmon is also rich in vitamins B12 and D (both exceed daily recommended values), which target several issues, from bone density to heart health and depression.