Recirculating Aquaculture Systems (RAS) represent a newer technology for salmon farming with different welfare profiles than traditional sea cage farming. Understanding the welfare trade-offs guides informed choices.
The RAS vs. sea cage welfare comparison reveals that technology type does not automatically determine welfare outcome — management choices within each system matter significantly. RAS advantages include elimination of sea lice (avoiding welfare-costly treatment procedures), year-round temperature optimization, and protection from harmful algal blooms. Disadvantages include artificial photoperiods potentially disrupting circadian biology, reduced environmental complexity compared to open water, and the potential for water quality control failures with more immediate consequences than in sea cages. Sea cages provide more natural environmental variation that may support circadian rhythm health, but expose fish to weather events, algal blooms, and sea lice. The most welfare-positive outcome in either system comes from operating at lower density with high management quality.