Raised To Be Better

Just like our waters, we like to be clear on the facts about responsible salmon farming.

1. Do pens overcrowd the salmon?

No, farmed salmon occupy 2-4% of a pen’s volume. Farmers keep the stocks low so the fish have space to swim and grow, and densities are regulated and monitored by regional authorities. When looking at a pen it may seem like the fish are close together, but this is because salmon are social animals. They like to ‘school’ and swim together both in the wild and in pens.

2. Does salmon farming cause issues for fish welfare?

Our salmon farmers are out on their farms every day monitoring the fish’s behavior and wellbeing. The smallest change in behavior is always a signal of something, which leads farmers to promptly adjust food or provide veterinary attention. Innovative technology has helped increased the precision and attention farmers can give to care for their fish.

Our salmon farmers take great care and pride in the fish they raise. Our members’ collective expertise, paired with strict regulatory and third-party standards, ensure that we raise healthy, high-quality salmon.

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3. What do farmed salmon eat?

Salmon feed is typically comprised of plant-based ingredients, fish-based ingredients (including fishmeal, oil and protein), as well as vitamins, minerals, amino acids and astaxanthin, an antioxidant that supports fish health and gives salmon its iconic “salmon” hue. This diet replicates salmon’s omnivorous diet in the wild.

One of the biggest evolutions in salmon feed is a decrease in fish-based ingredients and an increase in plant-based ingredients, like algae or canola oil. Soy, wheat, corn, peas and beans are also used as plant-based protein alternatives.1 GSI members are looking to incorporate a variety of options, like insect protein, for future feeds, too. While there appears to be a minimum level of marine ingredients (fish oil/meal) required in salmon feed to meet nutrition requirements, it can be lowered significantly and not negatively affect the health of the fish and final nutritional composition.2 Our associate feed members work with fish nutrition experts to ensure the feed given to our salmon provides the nutrients they need for optimal health and nutritional makeup for consumer consumption.

Skretting Must Give Permission

4. Why are farmed salmon fed wild fish?

To ensure farmed salmon get the same nutrients as their wild counterparts, their feed has traditionally contained wild fish to replicate their natural diets.

In the last 10 years, salmon farmers have drastically reduced the use of forage fish in feeds, replacing them with plant-based and non-marine ingredients such as algae and canola oils. The ratio of fish to non-fish ingredients in feed, known as feed conversion ratio (FCR) has declined from 3:1 to 1:1 or even lower today.

When marine ingredients are used in the feed, our members ensure they are from sustainable wild stocks and increasingly from trimmings or by-products from other fisheries to ensure greater circularity in resources so nothing is wasted.

The combination of innovation and the diversification of resources from utilizing novel plant sources like algae and responsible use of certified marine ingredients helps reduce pressure on wild fish stocks.

5. Why is krill used in salmon feed and how does GSI ensure its use doesn’t harm the Antarctic ecosystem?

Krill is an important ingredient in aquaculture feed because of the nutritional benefits it offers for fish health. As a bottom feeding crustacean, krill is packed with vitamins, proteins, fats and omega-3s EPA and DHA. This nutrient package supports immunity, improves disease resistance and helps salmon grow and thrive. It’s difficult to replicate the benefits that krill provide, and because krill play a pivotal role in marine ecosystems and carbon sequestration, GSI members recognize the importance of sustainable use and ensuring future plentiful stocks of krill. As part of our work, GSI member companies, alongside our feed associates are committed to ensuring sustainable use of krill through several approaches, including:

  • Ensuring all krill are harvested in a responsible manner to preserve stocks, under strict supervision in line with regulated catch limits set by The Commission for the Conservation of Antarctic Marine Living Resources. Any instance of bycatch is unacceptable and should result in immediate changes to processes and best practices by certification bodies to prevent another incident and to ensure responsible practices are not compromised.
  • Sourcing only Marin-Trust or MSC-certified Antarctic krill.
  • Supporting the creation of marine protected areas, including no-fishing areas in the Antarctic.
  • Continuing to evaluate alternative ingredients to replicate the nutritional benefits krill provide, such as algae.
  • Working with the ASC feed standard to ensure all feed ingredients are sourced from only responsible feed companies.

6. What is the nutritional difference between farmed and wild salmon?

Both farmed and wild salmon are nutrient-dense, contributing high-quality protein, healthy fats like omega-3 fatty acids, and essential vitamins and minerals like potassium, vitamins D, B-12 and B-5 to the diet. Farmed Atlantic salmon is higher in omega-3 fatty acids than wild salmon, but overall research shows there is no consistent difference in the health benefits of wild or farmed salmon.

The chart below shows a breakdown of the nutrient profiles of various farmed and wild salmon species.3

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Purchased stocksy

7. Do farmed salmon require lots of medication and vaccines?

Like humans and other animals, farmed salmon require vaccination against common illnesses to protect them and keep them healthy, and on occasion they may require treatment with antibiotics if diseases pose a risk that cannot be managed preventively. Antibiotic use in farmed salmon is much lower than in other animal producing sectors.

When treatment is necessary, it is overseen by fish veterinarians under government regulations. In addition, all farmed salmon products have to go through food safety screening programs to enter human consumption markets to ensure they pass all health and safety checks. All farmed salmon are produced and sold in line with global health guidelines and regulations. Even when antibiotics can be found in trace amounts in farmed fish species, these amounts are far below the levels deemed safe by agencies such as the U.S. Food and Drug Administration.

Within GSI we are also working to continually evolve our holistic approach to fish welfare and have achieved a 48% reduction in the average use of antibiotics over the last eight years. We are transparent with our use of medicines/antibiotics and report their use in our annual Sustainability Report and as part of the Aquaculture Stewardship Council (ASC) certification program.

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8. Do all farmed salmon have sea lice?

Sea lice are parasites that are naturally present in marine environments and feed on fish. Sea lice pose a critical challenge for most of the salmon farming industry and preventing sea lice occurrence is a priority area for improvement. GSI members are continually seeking new approaches and effective methods to reduce the number of sea lice, such as:

  • New technologies on the farms like physical barriers around the pens
  • Functional feeds to make the fish more resilient to sea lice
  • Data collection and assessment to model water currents and predict high risk times

Farmers are required under local regulations to limit sea lice numbers so they do not impact the farmed fish or the wider ecosystem. To achieve this, farmers employ a strategic approach to combatting sea lice, combining preventative farming practices like fallowing and low stocking densities with approved treatments when necessary. They are also investing millions into research and development of holistic, non-medicinal sea lice treatment technologies, including freshwater well boats, warm water, brood stock development, and cleaner fish.

While some may argue farmed salmon increase sea lice in wild populations, research from a 2021 report in Canada demonstrated that salmon farms do not influence levels of sea lice on wild fish.

9. Do farmed salmon contain contaminants, like mercury and PCBs?

As with many foods, it is possible for environmental contaminants such as heavy metals, pesticides and dioxins/polychlorinated biphenyls (PCBs) to build up in food, including seafood like wild and farmed salmon. In farmed salmon, the presence of contaminants is closely monitored, and levels are kept well below the safe limits set by global food safety authorities. Recent research from 2020 shows farmed salmon is low in dioxins and has far less exposure to PCBs and dioxins than wild salmon, however this may vary by region.

Experts widely recommend low-mercury seafood options, including salmon, because the health benefits outweigh the risk. It’s recommended as a “best choice” seafood by the US Food & Drug Administration (FDA) because it’s low in mercury, but high in health benefits.4 The Dietary Guidelines for Americans also encourages nutritious seafood choices that have low levels of mercury, like salmon.5

10. Why is salmon sometimes labeled as having “color added”?

“Color added” refers to astaxanthin, an antioxidant added to farmed fish feed which provides the color and nutritional benefits salmon get from krill in the wild. No matter how the salmon get astaxanthin in their diet, whether in feed or in the wild, it’s a necessary and vital part of a salmon’s diet for proper nutrition.

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11. Do farmed salmon escape and mix with wild populations?

For many reasons, farmers take every precaution to avoid fish escapes, which may occur when pens are damaged through severe weather events. Thanks to innovative tools, improved management practices and strict management protocols, we have seen a net reduction in escapes over the years and we work hard to maintain that trend.

On the rare occasion farmed salmon do escape, they are highly unlikely to breed with wild salmon or compete with them for resources. Farmed salmon are domestic animals, so they are poorly suited to wild environments and generally do not survive long enough to breed or seek out food.

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12. Is there high mortality on salmon farms?

As with all animal rearing sectors, there is mortality in the stocks. This can happen due to unusual weather caused by climate change, poor health, escapes, or other reasons. As farmers, we are working harder than ever to understand the root causes of fish mortality and how to prevent them. We are continually implementing evolving best practices to better protect our fish. For example, to better predict harmful algae blooms, we introduced additional water monitoring technology to closely analyze changes in water temperature and oxygen levels to predict when these may occur and prevent harmful impacts on the fish.

13. What is farmed salmon’s environmental footprint?

Farmed salmon is one of the most efficient and sustainable forms of protein available when compared to other animal sources. It has a lower carbon footprint, uses less land and is more resource efficient. Despite these facts, GSI members are committed to making continual improvements that ensure salmon farming supports healthy, sustainable and resilient food systems in the most environmentally conscious way. This includes assessing and developing the use of land-based systems and alternative feed ingredients.

  • While land-based farming operations show promise, currently they are not the most carbon-efficient systems and carry a high risk of failure and fish mortality. We are exploring alternatives, including post-smolt facilities that keep salmon on land for longer periods and reduce time at sea and risk of sea lice or disease.
  • Innovation in salmon farming’s FCR is not just about looking at the feed ingredients. It also requires consideration of genetics, the environment and fish husbandry. Together with improvements in the feed ingredients profile, the salmon farming industry has reduced its FCR from 1.9:1 in the 1980s to 1.15:1 on average today, making it one of the most efficient sources of protein available.
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14. What impact does salmon farming have on the local marine ecosystem?

Clean marine conditions are an essential component of raising the highest quality farmed salmon, so we take a number of measures to keep them this way:

  • Operating at optimal locations with deep, fast-moving waters with good currents
  • Measuring water quality daily
  • Using technology like underwater cameras to check feed dispersion and monitor seabed conditions
  • Fallowing sites to allow seabed to natural reverse any temporary footprint from pens

Farmed salmon, like all fish, do produce waste in the form of feces. This can affect the environment, however, the waste is formed of organic matter (i.e., it does not release new toxins into the environment). In salmon farms, vs. wild populations, the waste is contained to one area instead of being dispersed throughout larger bodies of water. For this reason, all farmers are required by law to monitor the seabed, so any environmental impact is within acceptable limits. GSI members do this in alignment with third-party certification bodies like ASC and Best Aquaculture Practice (BAP), which require regular checks of benthic impacts. To stay within limits, GSI members regularly fallow farming sites to allow the seabed to rest and rejuvenate.

15. How does salmon farming impact local communities?

Our salmon farms are often located in rural communities, and through the jobs we create we often help these small communities thrive and retain the younger generations who not only work with us but also in other local businesses.

Collectively, GSI members employ over 24,000 full-time employees across their operations, not including the wider value chain and network of supporting businesses we work with.

We also offer mentorship programs and work experience to cultivate the next generation of responsible salmon farmers.

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Norway Youths

16. How do we ensure we are operating with full transparency?

We are committed to providing greater transparency across our business operations, collaborating with multi-sector stakeholders, complying with government regulations and innovating new technologies to ensure farmed salmon is a healthy, sustainable choice.

Transparency is hugely important to us. Not only to be accountable to our stakeholders but also as a way for us to see where we must focus improvement efforts. For this reason, all GSI members annually report on 15 environmental and social indicators in our Sustainability Report, which is independently audited and updated each year.

hatchery technician walks through facility of tanks with juvenile salmon on each side

17. How does a consumer know if farmed salmon at their local market is responsibly raised?

First, look for the ASC logo, which provides the highest level of assurance that the seafood is independently verified to be sustainable and responsible. If you don’t see the label, ask your grocer if they source sustainably certified farmed seafood varieties, like ASC or BAP.


1 All About Feed. Salmon industry turns to plant based proteins. 2016.

2 Beheshti Foroutani et al. Minimizing marine ingredients in diets of farmed Atlantic salmon (Salmo salar): effects on growth performance and muscle lipid and fatty acid composition. 2018.

3 Global Aquaculture Advocate. Farmed Or Wild? Both Types Of Salmon Taste Good And Are Good For You. 2010.

4 United States Food and Drug Administration. Advice about eating fish. 2021.

5 USDA and HHS. Dietary Guidelines for Americans 2020-2025. 2020.

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