Land-Based RAS Aquaculture: Welfare Potential

Recirculating aquaculture systems on land offer new possibilities for controlling fish environment and welfare, but also introduce novel challenges.

Key Facts

RAS recycles 95-99% of water, dramatically reducing environmental discharge
Parameters like dissolved oxygen, ammonia, temperature, and pH can be precisely controlled
Higher stocking densities are possible but require careful management to avoid stress
Land-based salmon RAS facilities are operating in Norway, Denmark, Canada, and the USA
Capital costs are high, making welfare investment economically challenging for some operators

Welfare Considerations

Land-based RAS offers significant potential to improve fish welfare by giving operators precise control over water quality, photoperiod, temperature, and feeding. Unlike sea cage aquaculture, RAS farms are not subject to external environmental variability like algal blooms or sea lice from wild fish. However, the intensive nature of RAS means that equipment failures — loss of oxygen or filtration — can be catastrophic within hours. Good welfare in RAS requires robust monitoring systems with alarms, emergency backup protocols, species-appropriate stocking densities, and environmental complexity where possible. The technology is promising but implementation quality varies significantly between facilities.

What You Can Do

Support aquaculture certification schemes that include water quality and welfare standards
Advocate for mandatory emergency backup systems in RAS operations
Ask seafood retailers which supply chains use welfare-audited RAS facilities
Support research into optimal environmental parameters for fish wellbeing in RAS
Encourage government standards that set minimum welfare requirements for land-based farms