Salmon escapes from net pen aquaculture cause ecological harm and raise welfare questions for both escaped fish and wild populations they encounter.
Salmon escapes from aquaculture represent both an ecological and a welfare concern. For escaped fish, the transition from a structured farm environment — where food arrives predictably and predators are absent — to wild conditions is deeply challenging. Farm-adapted behaviors are poorly suited to wild survival: escaped salmon often fail to establish feeding behaviors, face predation from species they did not encounter in farms, and experience acute stress. Those that survive long enough to encounter wild salmon disrupt genetic integrity through interbreeding, reducing the fitness of wild populations over generations. The cumulative welfare and ecological harm from escapes across the global salmon farming industry is substantial. Closed containment systems like RAS eliminate escape risk but face their own welfare challenges.