Recirculating aquaculture systems (RAS) for salmon farming promise environmental benefits but introduce distinct welfare challenges. Understanding these trade-offs is essential for responsible production.
RAS salmon farming presents a welfare paradox: it eliminates some of the most severe welfare problems of sea cage farming (sea lice, escapes, interaction with wild fish) while potentially introducing novel stressors. Artificial light regimes, constant mechanical noise, high density, and the risk of sudden water quality failure create a distinctive welfare profile. The welfare implications of life in an entirely artificial environment — without tidal variation, natural light cycles, or environmental complexity — for a species adapted to diverse natural habitats are uncertain. As RAS expands rapidly, welfare assessment frameworks must be developed and validated specifically for this production system rather than borrowed uncritically from sea cage research.