Land-Based Salmon Farming: RAS Technology and the Welfare Promise

Recirculating aquaculture systems (RAS) for salmon offer significant welfare advantages over open net pen farming by eliminating sea lice, controlling water quality, and removing fish from adverse ocean conditions.

Key Facts

RAS salmon farms recycle 99% of their water, maintaining precise control over temperature, oxygen, pH, and ammonia levels.
Sea lice cannot survive in RAS systems, eliminating the welfare and environmental costs of chemical and biological lice treatment.
RAS enables year-round consistent water temperature, eliminating thermal stress from seasonal ocean temperature fluctuations.
The capital cost of RAS facilities is significantly higher than open net pen systems — a major barrier to industry transition.
Norway has introduced the "traffic light" development permit system partly to incentivise the shift toward enclosed farming systems.
Several large commercial RAS salmon farms have commenced production in the US, Canada, and Europe, demonstrating commercial viability.
RAS enables salmon production anywhere — eliminating the coastal and fjord habitat limitations of net pen farming.

Welfare Considerations

From a welfare perspective, RAS represents a substantial advancement over open net pen salmon farming. The elimination of sea lice infestation removes one of the most prevalent and painful welfare problems affecting farmed salmon. Consistent, controllable water quality prevents the oxygen depletion events, temperature excursions, and algal bloom impacts that cause acute welfare emergencies in coastal net pens. The closed environment also enables rapid detection of disease through continuous monitoring rather than relying on visual inspection of large ocean cages. The welfare case for RAS is strong; the challenge is economic transition — RAS salmon costs more to produce, requires consumer willingness to pay for higher-welfare products, or regulatory incentives to accelerate industry uptake.

What You Can Do

Choose RAS-farmed salmon where available, recognising the premium reflects genuine welfare and environmental improvement.
Ask retailers and restaurants whether their farmed salmon comes from RAS or open net pen systems.
Support policy incentives for transition from open net pen to RAS salmon farming.
Advocate for transparent country-of-origin and farming method labelling on all salmon products.
Reduce conventional farmed salmon consumption while higher-welfare alternatives become more widely available.