Aquaculture Recirculating Systems and Welfare Advantages

Recirculating aquaculture systems offer significant welfare advantages over open-net farming through precise water quality control, disease elimination and reduced environmental impact.

Key Facts

RAS systems filter and recirculate water, maintaining precise control of temperature, oxygen and ammonia
Closed systems eliminate sea lice entirely — a major welfare and chemical treatment benefit for salmonids
Water quality parameters can be optimised for each species' specific physiological requirements
RAS eliminates escapes and prevents disease transmission to wild populations
Energy costs of RAS are higher than open-net systems but technology improvements are reducing this gap
Several large commercial RAS salmon facilities are now operating in Europe and North America

Welfare Considerations

Recirculating aquaculture systems represent a significant welfare advance over open-net farming by eliminating the sea lice problem that currently requires welfare-compromising treatments in most salmon farming. Precise water quality control enables optimisation for fish physiology rather than compromise between fish needs and environmental variability. The elimination of disease transmission to wild fish addresses ecosystem welfare concerns alongside on-farm welfare. The higher cost of RAS production — reflected in higher retail prices — is a welfare investment that consumers and retailers can choose to support.

What You Can Do

Choose seafood produced in RAS facilities when available as a higher-welfare option
Ask retailers whether their salmon comes from RAS or open-net facilities
Support investment in RAS technology development that reduces costs and enables wider adoption
Advocate for regulatory incentives supporting transition to closed containment systems
Follow advances in RAS technology that are making welfare-superior production increasingly viable