Is There Such a Thing as Sustainable Salmon?

What are the sustainability issues with farmed fish? 

“Fish farming in open-nets inevitably disrupts local ecosystems, but the extent of the impact depends on factors like the species being farmed, the scale, intensity, and management practices,” says Catalina Cendoya, Director of The Global Salmon Farming Resistance (GFSR), a worldwide community of NGOs, activists and scientists working in collaboration to free the ocean from salmon farming. “In the case of salmon farming – typically done on a large, intensive scale – serious sustainability concerns arise.” 

“Although farmed salmon is often touted as a more sustainable alternative to other forms of animal protein, in reality the industry is facilitating the immense suffering of millions of fish, negatively impacting on the survival of endangered wild Atlantic salmon and wreaking havoc on the environment,” adds Lex Rigby, Farmed Salmon Campaign Manager at Wildfish.  

These issues fall into three main categories: environmental damage, resource demand and animal welfare.

1. ENVIRONMENTAL DAMAGE

With many aquaculture facilities positioned within natural bodies of water, salmon farming does a frankly shocking amount of damage to our oceans and their inhabitants. 

• Farmed salmon escape more often than you might expect. Escaped fish compete with wild fish for food, habitat and spawning partners and can spread disease to wild populations, all of which has a significant impact on ecosystems. There is also the risk of interbreeding, which could potentially affect the long-term genetic resilience of native populations. It is critical that we protect wild stocks and their habitats, and salmon farming is essentially incompatible with this. “Wild salmon populations are 50% less likely to survive when exposed to salmon farms,” shares Amelia Cookson, Industrial Aquaculture Campaigner at Feedback. 
• Many fish farms discharge untreated waste, chemicals, diseases and parasitic sea lice into the surrounding environment, compromising the integrity of marine and freshwater biodiversity, says Rigby. “This has far-reaching impacts on delicate ecosystems and marine life.” Organic and inorganic waste from fish farms accumulates on the seafloor, creating ‘dead zones’ where marine life cannot survive, adds Cendoya. “This degradation of marine ecosystems underscores just how unsustainable the industry is – and it’s only a glimpse of the broader challenges we face.”  
• Antibiotics are routinely used in many fish farms to control disease in crowded facilities. Not only does this have long-term implications for human health, but antibiotics released into the wider aquatic environment can have adverse effects on non-target species. Anti-sea lice drugs and antibiotics used in farming have been found up to 1.5km away from salmon cages. 

2. RESOURCE DEMAND

Industrial salmon farming is incredibly inefficient, posing a steep cost for the planet in terms of the resources it demands.  

• Salmon are naturally carnivorous. Farmed salmon are often fed a diet of wild-caught fish, soy and a pigment called astaxanthin, included to add the distinctive pink colour that customers expect (in wild salmon, this colour develops because of their natural diet).  
• Growing soy to use as animal feed is a major contributor to deforestation worldwide. 
• Feeding wild fish to caged salmon is an incredibly resource-heavy endeavour; Rigby says it takes as many as 440 fish to produce a single farmed salmon. These fish are taken from natural habitats around the globe, reducing biodiversity and damaging local ecosystems. It’s also highly wasteful; as Head Chef at Ozone Coffee Sam Scott points out, around 90% of these wild fish – foods like anchovies, mackerel and sardines – are “perfectly good for human consumption,” and could be eaten directly.  
• Many of the wild fish used as feed are sourced from countries in the Global South, which is highly problematic in terms of food sovereignty and food security: fish that are a vital source of food and income for coastal communities are instead redirected to feed fish consumed in wealthier nations. “Although global aquaculture companies claim that they are relieving the burden on ocean life and improving global food security, the expansion of carnivorous fish farming is driving the depletion of the very fish they say they want to protect and worsening food insecurity,” Cookson says. For example, Norway sources fish feed from West Africa, where this extraction has exacerbated food security issues. “Local populations, already vulnerable, are now struggling even more as the fish they rely on are diverted for salmon feed instead of local markets,” says Cendoya. “This has severe consequences for communities who are now deprived of food from their own regions.” 
• To add further stress to this system, the aquaculture industry is increasingly using so-called ‘cleaner fish’ to treat sea lice infestations. These fish are also carnivorous, so they demand even more feed.  

3. WELFARE ISSUES

Salmon farming is undeniably intensive and carries its own host of welfare issues. 

• High volumes of farmed salmon die before harvest, at levels that would never be tolerated in other types of farming. “On average, one in four farmed salmon die before ever reaching the consumer,” Rigby shares. In Scotland, for example, over 25% of Scottish farmed salmon die prematurely – over 16.5 million in 2022 alone. 
• The farms act as breeding grounds for parasitic sea lice, which graze on salmon skin and mucus. Many of the ‘cleaner fish’ used to tackle this issue, such as wrasse and lumpfish, either die in captivity or are culled at the end of the production cycle.  
• In addition, these cleaner fish have been taken from the wild to perform their services within the bounds of the farm. Research suggests that this increases sea lice pressure on wild populations. 

IS THERE SUCH A THING AS SUSTAINABLY FARMED SALMON?

Cendoya is adamant that there is no truly sustainable source of farmed salmon, although some production methods, like Zero Waste Recirculating Aquaculture Systems (Z-RAS) – land-based in enclosed containments – have a lower impact than ocean net-pens. “Only a small number of companies use these methods today, and issues related to feed and animal welfare remain unresolved,” she observes. 

“In my opinion, there is no such thing as a sustainable source of farmed salmon,” says Scott in agreement. “As just one example, Scottish salmon farming produces the same amount of waste as half of Scotland’s population.”  

“I believe that farmed salmon is neither wholesome nor sustainable,” adds Lloyd Morse, Chef-Patron at Edinburgh’s The Palmerston. “We're a very supplier-led restaurant, and we champion our suppliers who grow vegetables and raise animals in a wholesome and sustainable manner. There is nothing sustainable about packing hundreds of thousands of fish into a pen where disease and flesh-eating seal lice are rife.” 

“To make steps towards sustainability, the industry would need to be much smaller and ensure that it is only using FMFO [fish oils] made from by-products that cannot be eaten directly by humans,” says Cookson. “In research published in 2022, which looked at Scottish salmon farming, we found that removing wild-caught fish from salmonid production by using feed made from fish byproducts (rather than whole wild-caught fish) could leave 3.7 million tonnes of fish in the sea while increasing global seafood production by 6.1 million tonnes. This would be a win-win for people and for ocean ecosystems.” 

There are multiple certification bodies whose mission is to drive sustainability in fish farming. As a spokesperson for Global Seafood Alliance (GSA)'s Best Aquaculture Practices certification said, “Aquaculture provides a valuable source of healthy protein to help meet the world’s growing demand for food. With an anticipated 10 billion people expected to inhabit the planet by 2050, the demand for animal protein is expected to increase by 52%. Aquaculture, including salmon farming, is expected to play a crucial role in meeting this challenge. Our mission at GSA is to strive to establish pathways to help ensure aquaculture is done responsibly.” However, the debate continues as to whether truly sustainable aquaculture is even possible. 

WHAT ABOUT CERTIFICATIONS FOR FARMED SALMON? 

“Ultimately, even certification labels are no guarantee of sustainability, whether ‘responsibly sourced’ or ‘organic’, sold fresh or smoked,” says Rigby. Cendoya agrees: “Sustainability certifications are mostly used to deceive consumers, leading to a perception gap between what consumers believe about the ‘responsibly produced’, ‘organic’ or ‘sustainable’ certified products they are buying and the reality,” she says. “In reality, most certified farms cause irreversible environmental degradation, with some falsifying records, operating outside their permitted boundaries and even functioning within marine protected areas. Even the largest and most recognised certifiers, such as BAP and RSPCA, have been reported for greenwashing by independent organisations.” 

GSA’s BAP standards are designed to establish requirements on environmental responsibility, social accountability, food safety and animal welfare across the entire aquaculture production chain – processing plants, farms, hatcheries and feed mills. BAP standards are created by a third-party Standards Oversight Committee made up of one-third academia, one-third industry, and one-third NGO. GSA highly encourages stakeholder participation in the development process. BAP standards are benchmarked by international third-party organisations such as the Global Sustainable Seafood Initiative (GSSI) and the Global Food Safety Initiative (GFSI). 

In September 2023, WildFish released a report, Responsibly Farmed?, looking at the key certification schemes for Scottish farmed salmon – RSPCA Assured, Aquaculture Stewardship Council (ASC) and Soil Association Organic. “We found two major issues with the schemes – that the requirements were not as stringent as consumers might reasonably expect (sometimes not going beyond national regulation), and that there was little, or no, enforcement of these standards when breached,” Rigby shares. 

“Despite being a welfare certification scheme, there is no maximum mortality level permitted on RSPCA Assured farms,” Rigby continues. “As a result, farms reporting the premature death of hundreds of thousands of farmed fish due to disease, harsh treatment or lethal water conditions can continue to sell the remaining salmon as ‘higher welfare’.” 

An RSPCA Assured spokesperson said, “RSPCA Assured is a not-for-profit charity, and our sole ambition is to drive up farmed animal welfare standards. With over 700 standards designed to improve welfare, the RSPCA welfare standards for salmon are recognised as world leading and go above and beyond both legislation and industry standards. Without RSPCA welfare standards, millions of fish would live worse lives. These standards cover every stage of a salmon’s life from hatchery to slaughter and, since their inception, have continuously driven up standards throughout the entire salmon industry, with most farms now adopting them. 

“Millions of sentient fish are farmed for food in the UK every year and we recognise there are challenges to ensuring their welfare is protected. Whilst we don’t have answers to all of these at present, we are working hard with RSPCA Assured members, the salmon industry, stakeholders and experts to address these challenges and continue to drive up standards further. Sadly, some of these challenges aren't easy to solve but if it wasn't for our hard work and our choice to work with the salmon farming industry, many significant welfare improvements would never have been made.  

“We would also like to give our firm reassurance that we take all reports of poor animal welfare extremely seriously and immediately investigate and take appropriate action as soon as any concerns are raised. We have a strict procedure for reporting any incidence of increased fish mortalities so that we can investigate swiftly and work with the producer to look at ways to try and prevent such an incident occurring in future.” 

IS ORGANICALLY CERTIFIED SALMON SUSTAINABLE?

Certified ‘organic’ salmon is reared using the same open-cage production method as uncertified farms, where fish waste still discharges directly into the surrounding environment. “I find it hard to say that it’s an organic product,” Scott says. “The regulations around what is allowed in the fish feed and the pesticides used to try and kill sea lice are far too soft.” In contrast to other organic food products, the organic standard for salmon also does not prohibit the use of pesticides; it does, however, limit their use. A restricted list of pesticides may be used only when there is an identified risk (like sea lice) that would affect the health and welfare of the salmon. This must be done under the control of a veterinary surgeon and cannot be done preventatively.  

There are some important differences in organic certification compared to other certification schemes. For example, organic producers must prioritise feeding salmon with trimmings of sustainable fish already caught for human consumption, removing the issue around resource inefficiencies we mentioned above. They can also use organic plant or animal-derived feed materials. If they cannot meet the nutritional needs of the fish through these means, they can use whole fish, but this must be the last option and these fish must be sourced from a fishery certified as sustainable, for example by MSC. Furthermore, mortality at any level is not accepted; producers must report all mortalities, and action must be taken for every preventable death. 

A spokesperson for the Soil Association – responsible for organic certification within the UK – said, “Organic farms are legally required to follow strict rules to minimise impacts on the environment and animal welfare, and when problems occur, they must prove they are taking action in order to use the organic logo. Our robust standards and inspection processes require producers to take a proactive approach, giving more space to fish with restrictions on vet treatments and sustainable feed requirements.  

“We recognise there are still many challenges to be tackled, which is why we are currently reviewing our aquaculture standards. We are listening hard to concerns and we have convened an independent group of experts to look at what good welfare looks like for farmed salmon from a fish viewpoint, as well as considering environmental impacts. Updates on this process will be shared at key moments as it reaches its conclusion, which is expected in Winter 2024/25.” 

All organic farmers are required to adhere to strict standards with robust inspection requirements that do not permit poor standards of animal welfare. When health issues arise, fish must be treated immediately to prevent suffering and measures put in place to minimise the risk of those health issues occurring in future whenever possible. All organic farmers are subject to physical inspections at least once a year, and if concerns arise. Soil Association Certification takes swift action to investigate and, where necessary, may require action to be taken by the licensee or may remove certification. 

What about sourcing wild salmon? Is that sustainable? 

With overfishing compounding the effects of climate change, pollution and biodiversity loss, global salmon populations are in serious decline; the population of wild North Atlantic salmon today is just one-quarter of what it was in 1970.  

“Since wild salmon populations are declining worldwide, due to multiple factors including the effects of salmon farms on wild stocks, responsibly sourcing wild salmon is a challenge,” says Cendoya. “In many countries with native stocks, wild salmon fishing is strictly regulated to protect endangered salmon populations, prevent overfishing and preserve ecosystems.” 

This means that the sustainability of wild salmon depends largely on its source. For example, Seafood Watch covers 127 varieties of salmon in its guide, with 39 certified as sustainable, eight of which are classed as the ‘best choice’, while 30 varieties should be avoided. Similarly, in the UK and EU, the MCS Good Fish Guide lists 17 varieties with three to avoid. These figures illustrate the clear need for visibility over what type of salmon you buy, where it comes from and how it was caught. It’s crucial to have suppliers who share your concerns and priorities.  

If you’re buying wild salmon, choose only certified sources. In general, certifications for wild-caught fish tend to cover issues across these four main pillars:

1. Does the fish come from sustainable stocks? Fishing this species should allow the population to remain productive and healthy.  
2. Is the environmental impact of the fishing kept to a minimum, and are other species and ecosystems being considered/monitored?  
3. Is the fishery being managed effectively and responsibly? This can include keeping up with local laws and regulation around labour rights, working conditions and protected areas.  
4. Is the supply chain fully traceable?  

WHO CAN HELP ME DETERMINE THE SUITABILITY OF MY SALMON?

• The most recognisable certification for wild-caught fish is probably the Marine Stewardship Council’s blue tick/chain of custody certification.  
• In the UK, the Marine Conservation Society has a ‘Good Fish Guide’ that also covers international waters. In addition to an extensive database of fish varieties, it’ll give you an instant overview of how your sources stack up and suggest more sustainable alternatives. There’s also an app available, making it very user-friendly. 
• In the US, Monterey Seafood Watch is a fantastic resource. 
• WWF has a range of country-specific guides, covering Portugal, Italy, South Africa, Indonesia and more, although these aren’t available for every country.  
• In Mexico and expanding throughout Latin America, an organisation called Pesca Con Futuro has created a detailed map of sustainable local species.  
• In South Africa, there's the Southern Africa Sustainable Seafood Initiative (SASSI). 
• If you’re in Australia, you can check goodfish.org.au. 

How can restaurants support salmon populations? 

SAY NO TO SALMON

Multiple global organisations and campaigns are now calling for consumers and hospitality businesses to ditch farmed salmon for good, and many have already done so. Farmed salmon has been permanently removed from food outlets at all Tate sites, following ‘Salmon: A Red Herring’ (2020-2021), a thought-provoking installation by London-based Cooking Sections that reflected on the impact of salmon farms on the environment. They’ve since replaced salmon with alternative marine ingredients that promote regenerative aquacultures, including bivalves and seaweeds. 

Similarly, at The Palmerston, Morse is clear that it’s not about finding a replacement. “We've never served salmon, and we never will. Wild salmon numbers are under threat for a variety of reasons, including wild populations being damaged due to sea lice and pollutants in the water from salmon farms. We're proud to have close relationships with our fish suppliers and buy line-caught wild fish where possible.” 

MAKE A SWAP

Looking at your menus, could you swap salmon for something else? At Ozone Coffee in the UK, they have only used Chalk Stream Trout since late 2018, feeling a responsibility to be a driving force that encourages the industry to talk openly about why they serve trout instead of salmon. “I have put together full sourcing policies for my Head Chefs to follow when buying all seafood,” says Scott. “Chalk Stream Trout has a much better sustainability impact due to the old mill races they use that are offshoots of the Test and Itchin rivers.” 

DEMAND TRANSPARENCY

For all seafood you buy, ask all the questions you can of your supplier. Where, when and how was the fish sourced? You want to be confident that you know every part of the journey from the water to your kitchen, and that your supplier has the right practices in place to ensure transparent sourcing throughout the value chain.  

This due diligence process should be repeated with every new menu and with any new suppliers, as fish stock levels are always changing. If you do source farmed fish, the four pillars we mentioned earlier when talking about certified wild fish still apply – but there are further details about which you should be crystal clear. 

• Where was the fish farmed? 
• What type of farming methods were used: was it a closed container system or farmed in the ocean? These both have different but important environmental consequences. 
• What type of feed is used and where does it come from?  
• How is water quality maintained?  
• How is biodiversity impacted?  
• How does the facility control for, prevent and manage disease? 
• What are the animal welfare implications? 

If you are buying farmed fish, it is essential that you choose only sources with rigorous third-party certification. The most well-known globally are ASC, Best Aquaculture Practices (BAP) and GlobalG.A.P.   

A spokesperson from ASC said, “We drive the world’s leading certification programme for responsibly farmed seafood by setting the most robust standards and providing the highest assurance, integrity and transparency throughout the supply chain. In line with ISEAL best practice, ASC farms are audited by fully independent third-party assessment bodies with audit reports published on our website to ensure full transparency. The ASC Farm Standard, which includes salmon and 11 other species, lays out requirements that help farmers contribute towards responsible social and labour practices, fish health and welfare, disease management, and ecosystem conservation. 

“By transforming salmon farming towards environmental and social responsibility, we can help meet the growing global demand for food while minimising negative impacts. When consumers purchase ASC-certified salmon, they can feel confident they are selecting seafood certified to the highest social and environmental and animal welfare standards.” 

SPREAD THE WORD

Whether you decide to swap salmon for something more sustainable or simply take it off the menu for good, it’s important to use this as an opportunity for education. From your website and social media to your menus, in-house communications and providing training for front-of-house staff, making sure your customers are well informed means you’re bringing them along with you. 

“Educating consumers about the true costs of farmed salmon is fundamental to reduce the demand,” says Cendoya. “By highlighting sustainability and responsible sourcing, restaurants can both take farmed salmon off their tables and add value to their menus, aligning with the growing number of people who care about where their food comes from and how it’s sourced.” 

JOIN OFF THE TABLE.

If you do decide to remove farmed salmon from your offering, join the ‘Off the table.’ movement, initiated by Wildfish in the UK and now also in Australia, Iceland and Canada. Launched in 2022, Off the table. is a coalition campaign to raise awareness about the negative impacts of intensive salmon farming and urges chefs, restaurants, food writers and catering businesses to remove farmed salmon from their menus. The campaign is supported by more than 250 pioneers in the hospitality sector across the UK, Iceland, Australia, Canada and more. 

“Salmon has been misrepresented as a sustainable food source for far too long, due to clever marketing and claims of ‘responsible sourcing’,” says Rigby. “By harnessing the food industry’s power and influence over consumer awareness, we’re seeing people starting to recognise what a high environmental price we pay for farmed salmon, and it’s one that many are increasingly unwilling to pay.” 

We’ll be talking about Sourcing Seafood Sustainably throughout October. For more global stories, insights and practical advice for your restaurant, follow us on Instagram and LinkedIn and sign up to our newsletter! You can read more about why this is an important focus area of our Food Made Good Framework here. 

Lead image: Photo by Corin Smith and courtesy of The GSFR.