Wild vs. Farmed Salmon

by | Mar 23, 2016 | Global Food, Sustainable Agriculture

The Dirt:

Is eating farmed salmon or wild salmon better for the environment and healthier for you? Up until now, we believed wild salmon to be the healthier, cleaner, and a more environmentally conscious salmon option. But after visiting salmon farms in Norway, you may be surprised to learn what we found out…

I traveled along the coast of Norway to visit salmon farms and see if there truly was a difference to our health and the environment between wild and farmed salmon   Before this trip, I would always purchase wild salmon over farmed. When I think of “wild caught salmon” I thought of untouched salmon leaping and splashing upstream to spawn in a clean river nestled below forested and snowcapped mountains. And while it is true that wild salmon do jump upstream—you can watch the grizzlies enjoying that—not all wild salmon are better for you and it is not necessarily better for the envrionment to eat wild salmon.

The general understanding of farm-raised salmon is vague because the process of farming these typically wild fish is not discussed very often. It is safe to say that the majority of salmon-eaters are not quite sure how farmed salmon are grown, bred, and harvested for food. This uncertainty often leads to fear of the unknown. You might envision a large metal holding tank filled with dirty water, chemicals, fish food residue, and packed with fish unhappily swimming in circles. Well, thankfully, this perception is not reality.

The Global Salmon Initiative

The Global Salmon Initiative (GSI) is a leadership initiative established by leading farmed salmon CEOs from around the world who share a vision of providing a healthy and sustainable source of protein to feed a growing population, while minimizing their environmental footprint, and continuing to improve their social contribution. source: Global Salmon Initiative

Why is salmon such a popular food?

These fish are a healthy source of protein and fatty acids. A four ounce serving of salmon contains 23 grams of protein! That is roughly 50% of your suggested daily intake of protein. Salmon are also loaded with Vitamins B-6, B-12, C, potassium, and more. Not to mention they are extremely high in omega-3 fatty acids, which can help your body protect itself against heart disease, lower the levels of unhealthy blood fats (also known as triglycerides), and may reduce joint inflammation.
A 4 oz serving of salmon contains 23 grams of protein!

Where does our salmon come from?

Today, wild salmon primarily come from the rivers off the northern Pacific Ocean surrounding Alaska, Russia, and Japan. Wild Atlantic salmon also border the northern shores of the United States, Canada, and Scandinavia. These fish are born in fresh water and migrate to the ocean but return to the fresh water when they reproduce. The average wild salmon lives for about six years. This is assuming life goes well and there are no diseases, predators, extreme temperature fluctuations, or too much competition for food.
In the wild, salmon are born in fresh water and migrate to the ocean but return to the fresh water when they reproduce. Image source
After hatching, wild salmon remain in the fresh water river for roughly two to three years before they make their way to the ocean. Once in the ocean, they grow to their full size and navigate back to their stream of birth to spawn. These fish miraculously find their way home using the earth’s magnetic field and their early fish-hood smells. Some even swim over 1,000 miles to their birthplace. After they spawn, many of them die or are eaten.

Wild Caught or Farmed

The salmon on your plate is either from a wild-capture fishery or a fish farm, otherwise known as aquaculture. Capturing salmon from the wild is much more sophisticated than a few men wielding several large fishing poles.
Commercial salmon fishermen use electronic fish finders, hydraulic equipment, and large nets in order to capture the most salmon possible in a given expedition. In fact, they have been so effective that many of the wild salmon fisheries are fished out. While many salmon are coming back throughout the East Coast river system, they are still protected and are only fished as catch and release. The largest population of Atlantic Salmon can be found off the coast of Maine. As a result, salmon in the Pacific Northwest are under the watchful eye of government regulators in the United States.

The Purse Seiner is one type of commercial salmon fishing vessel. Image: Alaska Dept. of Fish and Game

As the concern over depleting our natural wild resources has increased, there has also been a substantial focus on producing farmed salmon over the last few years. Today, roughly 95% of the salmon is farmed in Norway, Chile, Scotland, and Canada. Additionally, 70% of this farmed fish are grown by only fifteen producers. Aside from carp and tilapia, salmon is the third largest aquaculture species. In 2013, global aquaculture production of fish, crustaceans, and other species totaled 97 million tons. And to put that in perspective, global cattle weighed in at 64 million tons. According to the World Wildlife Fund, “Salmon Aquaculture is the fastest growing food production system in the world – accounting for 70 percent of the market. This is three times higher than it was in 1980”. Over the past 13 years, salmon production has increased by 133% to two million tons, while wild-caught salmon has decreased by 53%.

 What are the benefits of farmed salmon?

Raised and harvested responsibly, farmed salmon meet all the benefits of sustainable agriculture farming: good for the environment, and good for our health. Because of the high standards most farms uphold, these farmers ensure that the entire value chain from the fish feed to the ecosystem are taken into consideration.

What are farmed salmon fed?


According to the World Wildlife Fund, “Salmon Aquaculture is the fastest growing food production system in the world – accounting for 70 percent of the market. This is three times higher than it was in 1980”.


In aquacultures, the purpose of the nutrient rich diet is to enable fish to maintain their health and reach maturity in three years. A key component in sustainable salmon farming is ensuring the amount of salmon harvested outweighs the amount of food the salmon in the farm consume. The feed to fish ration is 1:1 in farmed salmon versus 6:1 for wild salmon. One and a half pounds of food generally produces roughly a pound of salmon, as opposed to wild fish which need to eat six pounds of fish to gain one pound of weight. This is because the wild fish expend a lot of calories swimming many miles against strong currents.
Carnivorous fish, like salmon, are happy to eat – other fish. The ingredients used in fish feed have changed in recent years. Historically, salmon feed was made up of fish meal, fish oil, and micronutrients. However, to maintain the right balance between catching fish and feeding fish today, some of the fish oil and fish meal is replaced with terrestrial raw materials such as canola, soybean oil, and vegetable protein sources. This substitution of fish oil is discussed because some people are concerned that the nutritional benefits of salmon will change.
However, even with substitution of the marine ingredients, farmed salmon still provide more than enough omega-3 per portion. The health benefits of omega-3 capsules is yet another reason for the demand of fish oil – in fact, salmon are a much more efficient converter of omega–3 than the capsules. Luckily for all the omega-3 junkies, because of the nutrients fed to farmed fish, their omega-3 content is generally a little higher than those in the wild. So don’t be afraid of your farmed salmon dinner. It will provide you with the same health benefits as wild caught salmon.
You might be curious about the genetically engineered Aqua Advantage Salmon from AquaBounty. This is a case of taking the Atlantic salmon and inserting a growth promoting gene from the Pacific Chinook salmon along with an ocean pout. The modified salmon will now grow year-round instead of only during the spring and summer. Market size can be reached in 16 to 18 months rather than the more typical three years. However, this fish is not yet on the market and is only grown in Panama. At the moment, the overall salmon industry is not leaping over the falls to embrace this fast growing fish as they feel that selective breeding will ultimately produce the same result. (image: www.aquabounty.com)

 Do farmed salmon have more risk of disease?


Image credit: Patrick Pleul

Unlike the large fish tanks you may have first pictured, farmed salmon are raised in big open water netted pens about the size of a football field.


There are certainly challenges that present themselves in aquacultures, but unfortunately, there is an over-publicized fear of diseases and sea lice. It is believed that because of the threat of disease, farmed fish are given antibiotics to prevent the spread. However, antibiotics are not used in salmon farming practices! Instead of antibiotics, farmed fish are vaccinated early in their life. They are also bred to be hardy and resistant to disease. The one exception is for the bacterial disease, found only in Chile, called SRS. In response to this threat, many companies are working on launching a vaccine.
As for sea lice, while it is an issue, salmon farming has been accused of allowing sea lice infested salmon to escape and infect the wild salmon swimming nearby. The truth is that the wild cousins swimming nearby infect the farms. However, it is still an issue to manage for the farmer as well as a major consideration by consumers and NGOs alike. There are two main methods of treating sea lice. One is adding ‘pilot fish’ to the pens; they eat the sea lice off the salmon. The next is a treatment called SLICE, which is put into fish feed to kill the lice if it is contracted. Of course the use of SLICE is regulated and not used before the fish is harvested, thus it is not finding its way onto your dinner plate. While it is true that both sea lice and disease are enemies of farmed salmon, wild salmon are certainly not exempt either.

There are certainly challenges that present themselves in aquacultures, but unfortunately, there is an over-publicized fear of diseases.


Another fallacy of farmed salmon is that they are full of toxins, specifically polychlorinated biphenyl (PCB). However, what we need to do is put wild salmon under the microscope. In fact, because wild salmon live longer and humans cannot control what these salmon eat, they often may have a higher level of unwanted substances in their system than that of a farm raised salmon. Farmed fish have a controlled diet and life cycle and their lifespan is shorter.
If you’ve ever had a goldfish you know that the bowl can get pretty dirty and has to be cleaned regularly. Those opposed to fish farming apply the same logic to aquacultures. They argue the dirty water of the aquaculture somehow pollutes the surrounding water and transmits bacteria to humans. However it behooves the farmer to maintain a farm with clean flowing water. Generally the ratio is around 2.5% fish to 97.5% fresh water. If the water isn’t clean and fresh in the sea cages, the fish will become diseased, die and have to be discarded. Not the optimum result for the farmer. Additionally, general practice is to leave the harvested pen empty for a period of three to six months to eliminate any possibility of cross contamination.
The sophisticated technology is such that fish farmers can feed the fish exactly what they need to grow efficiently without excreting large amounts of waste into the ecosystem. This limits the possibility of excess feed spreading throughout the ecosystem as well. This also means that only a minimal amount of waste is flowing through the fish pens and spreading out to the bottom of the sea. This small amount of fish waste is actually a positive nutrient for kelp, prawns, crabs, and other sea creatures! AND in order to verify that the salmon are healthy and safe, the water inside and around the pens is frequently measured, tested, and regulated.

 Sustainable Salmon = Wild and Farmed

It is important to know that not all salmon farms are created equal. So, how do you know the farmed salmon you are eating is safe and was raised sustainably? Is the salmon you eat certified to any standards?

In order to ensure that all farmed fish, and future fish, are raised in a healthy, clean manner, fifteen of the largest salmon companies from Norway, Chile, and Scotland recognized the need for a global certification process and created the Global Salmon Initiative (GSI). According to their mission statement, “the GSI is a leadership initiative by global farmed salmon producers, focused on making significant progress toward fully realizing a shared goal of providing a highly sustainable source of healthy protein to feed a growing population, while minimizing our environmental footprint, and continuing to improve our social contribution.”

GSI has selected the Aquaculture Stewardship Council (ASC) to monitor best practices and provide a certification label. The ASC assures you that farmed fish are raised in farms that abide by national and local laws; and that fish farmers conserve the ecosystem, protect the health of wild populations, use resources in an environmentally responsible manner, manage disease in an environmentally responsible manner, operate in a socially responsible manner, and are a good neighbor and conscientious citizen. These standards help to ensure we are getting healthy fish while promoting sustainable aquaculture.
For those of you who shop at Whole Foods, you know that they are also a proponent of farmed salmon and have their own “responsibly farmed 3rd party certification” where they partner with salmon farmers in Norway, Iceland, and Scotland.
On the other hand, how do you know that your wild salmon was caught responsibly? Have the fishermen followed the regulations on caught fish? Have they fished in areas where the fish are diminished? Is the eco-system healthy? Luckily, there are standards here too. The Marine Stewardship Council (MSC) “offers the world’s only wild-capture seafood certification and eco-labeling program that is consistent with international organizations.”

The Bottom Line:

You will be making a healthy choice whether you choose wild salmon or farmed salmon. Just look for the ASC or MSC labeling to make sure you are eating fish that has been raised, or caught, with the safest and healthiest sustainable practices.



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