Seafood: Land-Based Salmon Farming - Today's Dietitian Magazine

Seafood: Land-Based Salmon Farming
By Barbara Ruhs, MS, RDN
Today’s Dietitian
Vol. 24 No. 7 P. 14

The future of sustainable seafood is here.

Did you know that salmon is the number one consumed fish in the United States? In fact, the salmon aquaculture industry is the fastest growing food production system in the world, and farmed salmon accounts for 70% or greater of salmon produced worldwide.1 Aquaculture is the farming of fish, shellfish, and marine organisms in the ocean and on land and was initially introduced as a solution to replenishing wild stocks and restoring ocean habitats. However, as the demand for salmon continues to rise in the United States, industrialized marine-based salmon aquaculture is increasing ocean pollution, threatening wild species and coastal ecosystems, and contributing to climate change, driving more salmon farming innovation out of the ocean and onto land.

Land-based salmon farming offers a sustainable path forward to meet the growing appetite for salmon in the United States. Many of the largest global salmon farming operations are in the world’s most pristine ocean environments, including the fjords of Norway and Patagonia (Chile), the sea lochs of Scotland, and Pacific coastlines of British Columbia. Land-based farms can help protect these places while offering consumers a more planet-friendly and more local choice for farmed salmon. Water recirculation technologies used in land-based farms provide the conditions necessary for salmon to thrive while capturing wastes, eliminating water pollution, and excluding fish diseases and parasites that can pass between farmed and wild salmon in ocean net pens.

This article discusses the origins of land-based salmon, the advantages of creating domestic supplies, their nutrition profile, and more detail about how water recirculation technology boosts sustainability.

The History
Using land-based systems to raise salmon is nothing new. In fact, for nearly 50 years, salmon farmers have been using land-based freshwater systems to hatch salmon eggs and raise juveniles past the point in the salmon lifecycle, called smoltification, when they’re ready to move to seawater. Thus, after starting on land, farmed salmon are transferred to net pens in the ocean, where they spend the next year and a half to two years until they’ve reached an optimal harvest weight. As salmon farmers began to experiment with extending the life of smolts raised on land in tanks to reduce exposure to sea lice, a parasite plaguing the health of salmon in ocean aquaculture operations, the evolution of land-based farming gained momentum as an even bigger solution to many other sustainability issues facing industrialized salmon production.

Creating a Domestic Salmon Supply
One of the greatest sustainability advantages of land-based salmon farming for US consumers is the ability to create a domestic supply. As the largest global market for salmon, 70% to 85% of the farmed salmon Americans consume is flown in from other countries located thousands of miles away in Chile, Norway, Scotland, Faroes, and New Zealand. According to the Intergovernmental Panel on Climate Change, emissions from fossil fuels are the dominant cause of global warming. Reducing air transportation and food miles by providing a locally farmed salmon option is just one of the many ways land-based salmon farming can improve the future sustainability of salmon in the coming years.

The Food and Agriculture Organization of the United Nations’ 2022 State of World Fisheries and Aquaculture Report illustrates the vital importance of aquatic food consumption as a sustainable food source to feed a growing population.2 As the per capita consumption of aquatic foods has almost doubled the population growth rate, farmed salmon offers an eco-efficient protein that also can relieve pressure on wild salmon species.

Optimizing Omega-3 Fats Without Sacrificing Sustainability
One factor that has the greatest influence on the sustainability of farmed salmon is their diet. As carnivores, their optimal diet includes other smaller fish, such as anchovies, sardines, mackerel, and herring. As the salmon farming industry grew and the supply of small, wild fish species dwindled to meet this demand, many large-scale salmon industry leaders increased the percentage of vegetable oil ingredients in feed to improve sustainability and relieve pressure on wild stocks. However, as feed ingredients of farmed salmon veered further away from the natural diet of wild salmon, research showed that the concentration of omega-3 fats (EPA + DHA) in farmed salmon had decreased up to 50% over the past 15 years.3 Emerging land-based salmon producers also are focused on improving the quality of salmon feed to optimize omega-3 fat levels for health-minded consumers. In fact, a report from Accenture shows that 74% of consumers buy seafood for its abundance in omega-3 fats.4

Reducing Ocean Pollution and Exposure to Contaminants
Unlike other salmon raised in the ocean, land-based farms use water recirculation technology that creates a clean environment free from ocean pollutants without contributing tons of waste that damage the surrounding ocean ecosystem. For example, some estimate that 80% of the phosphorus and 60% of the nitrogen fed to salmon is wasted and then pollutes surrounding waters. Land-based salmon farms capture and remove wastes from water while providing controlled environments with ideal conditions for salmon to grow and flourish without impacting natural marine habitats. With reduced exposure to PCBs (polychlorinated biphenyls), dioxins, microplastics, and hard metals such as mercury, land-based farmed salmon offer consumers added confidence that increasing salmon consumption won’t pose the same exposure risks as eating wild or other farmed salmon. Wild salmon was found to have three times the levels of dioxins, PCBs, and mercury when tested against farmed salmon due to the added quality control of feed ingredients used in salmon aquaculture operations.4

Consumer Confidence
Because of the technology and quality controls associated with land-based salmon farming, seafood ranking and certifying organizations, such as the Monterey Bay Aquarium Seafood Watch, rate these operations with the highest sustainability ratings, such as “Best Choice” by Seafood Watch. With the average American consuming 25 times more beef than seafood, choosing to buy more land-based farmed options is one of the most climate-friendly and nutritious ways to put protein on the plate. And RDs can continue educating consumers to meet their daily nutrition requirements.

— Barbara Ruhs, MS, RDN, is a retail supermarket industry expert and the owner of MarketRD.com, a consultancy that provides health and wellness marketing solutions for food brands.

*Ruhs reports the following relevant disclosure: In May 2022, she started consulting with Superior Fresh, an aquaponics company raising organic-fed Atlantic farmed salmon in harmony with USDA organic leafy greens, based in the United States.

References
1. Global Salmon Initiative. Sustainable Salmon Farming: The Future of Food. 2021 Sustainability Report. https://globalsalmoninitiative.org/en/about-salmon-farming/ https://globalsalmoninitiative.org/files/documents/GSI_Handbook_2020.pdf. Published 2020. Accessed July 20, 2022.

2. Food and Agriculture Organization. The State of World Fisheries and Aquaculture 2022: Towards Blue Transformation. https://doi.org/10.4060/cc0461en. Published 2022.

3. Colombo SM, Mazal X. Investigation of the nutritional composition of different types of salmon available to Canadian consumers. J Agr Food Res. 2020;2:100056.

4. The big catch. Accenture website. https://www.accenture.com/no-en/insights/consumer-goods-services/the-big-catch. Published June 23, 2021.

5. Jensen IJ, Eilertsen KE, Otnæs CHA, Mæhre HK, Elvevoll EO. An update on the content of fatty acids, dioxins, PCBs and heavy metals in farmed, escaped and wild Atlantic salmon (Salmo salar L.) in Norway. Foods. 2020;9(12):1901.

6. International Salmon Farmers Association. The Evolution of Land-Based Atlantic Salmon Farms. https://bit.ly/3oGiibf. Published November 2016.

7. Kearns M. Top 10 list of most-consumed seafood species in US revealed. SeafoodSource website. https://www.seafoodsource.com/news/supply-trade/shrimp-scallops-among-americans-top-10-most-consumed-seafood-species-in-2020. Published May 17, 2022.