Farmed Salmon RAS Welfare: Land-Based Recirculating Systems

Land-based recirculating aquaculture systems offer transformative welfare improvements for farmed salmon by eliminating open-ocean risks.

Key Facts

RAS salmon farms filter and recirculate 95-99% of water, enabling precise environmental control
Sea lice — the most significant welfare problem in open-net salmon farming — cannot establish in closed RAS systems
Water temperature, oxygen, CO2, and ammonia are continuously monitored and adjusted in RAS
Land-based RAS eliminates the risk of salmon escape and interaction with wild populations
Energy costs are significantly higher than open-net pen systems, affecting production economics
Several large-scale commercial RAS salmon projects are operational in Norway, USA, and Denmark

Welfare Considerations

RAS technology offers a genuine welfare step-change for farmed salmon. By eliminating sea lice entirely, removing exposure to pathogens from wild fish, enabling optimal water quality year-round, and avoiding the stress of weather-driven environmental variation, RAS provides conditions qualitatively superior to open-net pen farming from a welfare perspective. Stocking density remains a welfare variable that RAS does not automatically resolve — responsible RAS operators must manage density with welfare in mind alongside production targets. The higher energy footprint of RAS is a sustainability concern that must be weighed against substantial environmental and welfare improvements. As costs reduce through technological improvement, RAS is likely to become increasingly central to welfare-positive aquaculture.

What You Can Do

Look for salmon labelled as from land-based or RAS farms when making purchasing decisions
Ask retailers about their salmon supply chain and whether RAS options are available
Support policy incentives for RAS development as a welfare-positive aquaculture approach
Advocate for welfare standards to be applied to RAS farms, not assumed by default
Support research into energy efficiency improvements that make RAS more sustainable