From sea cages to land tanks: a revolution in salmon farming

Summary: Recirculating Aquaculture Systems — RAS, for short — is a form of farming fish in closed-containment environments. RAS addresses many of the environmental and sustainability challenges associated with traditional sea cages by eliminating fish escapes, reducing or eliminating use of antibiotics and pesticides, minimizing pollution, and enabling efficient water and waste management in controlled environments.²,³

There’s a new wave in salmon farming. It’s found on land, not in oceans, and it’s based on closed systems rather than open pens.¹,²

‍How It Works: Land-based closed containment aquaculture, particularly Recirculating Aquaculture Systems (RAS), involves farming fish in enclosed, controlled environments.²,³ Unlike traditional sea cage farming in open water, these facilities use advanced RAS technology to grow fish in tanks on land.

These systems recirculate water through filtration systems that remove waste, control water quality and maintain a stable environment.*²,³
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Key components of RAS include:²,³
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Water recirculation: Pumps circulate water through biofilters to remove ammonia and maintain oxygen levels.
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Filtration systems: Mechanical filters remove solid waste, and biological filters use beneficial bacteria to process toxins.
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Temperature and salinity control: Sensors and systems ensure optimal growing conditions for salmon, but can also be used for other species, such as trout and shrimp.
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Feed optimization: Automated systems provide precise feeding, which minimizes waste.
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In-water closed containment farming also exists, employing much of the same RAS technology described above, but situating operations in water. It is suited for regions where flat land is scarce, such as fjords.²,³ Fish are raised in fully or semi-enclosed systems submerged in water, addressing many of the same environmental concerns as land-based operations.
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One example is "The Egg," developed by Hauge Aqua Solutions. It is a fully enclosed, egg-shaped salmon farming system designed to address challenges such as sea lice, escapes and environmental impacts associated with traditional open-net pens.5
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Industry Overview and Key Players:
While still small relative to sea cage operations, the closed containment industry has seen rapid growth, and the number of projects existing or under development is steadily increasing due to heightened demand for sustainable seafood production.
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Many industry analysts consider land-based salmon farming an environmentally and economically superior solution to sea cages.⁸
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This is because land-based farming reduces or eliminates the use of antibiotics and pesticides, as well as the threat of escapes and sea lice, and has lower mortality rates compared to sea cage farming. For these reasons, salmon raised in closed containment can earn a premium sale price as a healthier and more sustainable product.²
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Worldwide, there were approximately 90 land-based salmon farms in various stages of development in 2023. Norway is the largest Atlantic salmon farming nation, which is estimated to be home to 30 of these 90 projects.⁴
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It is estimated that 20 of the 90 or so projects are in Europe (excluding Norway), and that 10 projects are in the U.S. Projects also exist elsewhere, including Japan, Saudi Arabia and Brunei.⁴
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Current industry estimates of global production of harvest-size salmon from land-based farms are between 35,000 and 45,000 metric tons in 2025. In five years, analysts expect that number will rise to between 120,000 and 160,000 metric tons.¹
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It’s important to note that identifying the top farmed salmon producers that exclusively utilize closed containment systems (rather than employing them for a single stage of growth before moving fish to sea cages) is challenging due to the industry's rapid evolution and limited publicly available data.
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There is also a key distinction between production capacity and actual production. However, several companies are notable for their commitment to these sustainable farming methods:
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Salmon Evolution: This Norwegian company was the world’s largest land-based salmon producer in 2023 and 2024, with forecasts of harvesting 5,000 gutted metric tons in 2024. The company aims to have 100,000 tons of production capacity by 2032, and was on track for around 25,000 tons of capacity by 2024, as of December of that year.⁹,¹⁰
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Atlantic Sapphire: Operating in Miami, Florida, Atlantic Sapphire is the largest producer of land-based salmon in North America (as of 2024), with a capacity of producing 9,500 metric tons and forecasted production of 220,000 metric tons by 2031.¹¹,¹²
Pure Salmon: A global player specializing in developing and operating vertically integrated land-based salmon farms, with projects in various locations, including Japan and Brunei.¹³,¹⁴
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First Water: One of several land-based salmon operations in “Salmon Row,” located in the Icelandic municipality of Þorlákshöfn, this operation takes advantage of unique geothermal conditions and has harvested 1,500 metric tons of salmon, with plans to produce over 50,000 metric tons by 2029. Its neighbor, GeoSalmo, is building a land-based salmon farm with a planned annual production of 24,000 metric tons.⁶
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Challenges:
Despite the promise of land-based aquaculture and RAS, they still face significant hurdles:²,¹⁵
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High costs: Building and maintaining RAS facilities requires substantial investment, often making it difficult for startups to achieve profitability. For example, Atlantic Sapphire has faced financial challenges, including operational setbacks and higher-than-expected costs.
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Technical complexities: Maintaining water quality, controlling disease outbreaks and optimizing system efficiency are highly technical processes that require constant monitoring and expertise.
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Energy consumption: RAS facilities rely heavily on electricity for pumps, filtration and temperature control, raising concerns about carbon footprints if powered by non-renewable energy sources.
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Biological risks: Fish grown in RAS systems can still suffer from diseases, stress and other health issues if systems are not properly managed. Scaling up production without compromising fish welfare remains a challenge.
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Market acceptance: Consumers are often skeptical of fish grown in RAS systems due to concerns about taste, quality and sustainability. Educating the public and building trust are essential for the industry.
While offshore systems avoid some of these challenges, they must overcome regulatory hurdles, high costs for infrastructure and the need for robust technologies to withstand harsh marine conditions.2 Critics also note that relocating operations miles off land would lead to inadequate site licensing and policing under existing regulatory schemes.¹⁶
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Hopes for the Future:
The future of RAS, land-based aquaculture lies in innovation, scalability and sustainability:
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With demand for seafood expected to double by 2050,(17) land-based aquaculture can provide scalable solutions situated near major distribution hubs, efficiently meeting global protein needs while reducing pressure on overfished oceans.¹,²,³,¹⁵ Improvements in filtration, energy efficiency and automation will reduce costs, making RAS more accessible.¹⁵ And by using fish waste as fertilizer or for biogas production, RAS facilities can contribute to a more sustainable food system.²,¹⁵
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As consumers become more aware of sustainability issues, the demand for responsibly farmed fish is likely to grow, creating new markets for RAS.
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*NOTE: This page addresses closed containment farming option, but other options to sea cage farming exist in the form of semi-enclosed land based and deep sea offshore operations.

Semi-enclosed land based farms rely on naturally occurring environmental features to lessen energy use and cost. For example, First Water in Iceland utilizes a flow-through system, where fresh water is sourced from geothermal springs and continuously flows through the tanks before being discharged.⁶ While these systems are less energy-intensive than full RAS setups, they still require careful management to mitigate environmental impacts, such as nutrient loading in nearby ecosystems.
Deep sea, offshore aquaculture farms are yet another alternative to traditional sea cages. SalMar Aker Ocean is piloting the world’s first sea cage located offshore. It utilizes Norwegian offshore oil and gas technology to situate its farm in a deeper, high-energy environment far from coastal areas.⁷ However, while stronger currents and better water exchange reduce their environmental footprint, critics note that pollution, fish escapes and disease spread are all still of concern.⁷

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