Salmon escapes from fish farms cause ecological harm to wild populations and represent a welfare event for escaped fish. Understanding and preventing escapes is an important aquaculture welfare issue.
Salmon escapes represent both a conservation and welfare concern. For the escaped fish, the transition from a highly controlled, food-abundant farm environment to the wild is stressful and often fatal. Farmed salmon domesticated over many generations may have reduced anti-predator responses and foraging skills compared to wild conspecifics, making survival in the wild difficult. The welfare of escaped fish includes exposure to unfamiliar predation pressure, competition for food, and physiological stress from environmental changes including temperature and salinity variation. Prevention through robust net integrity, predator exclusion, and early escape detection is the most welfare-appropriate approach, as escaped fish generally face poor survival prospects and cause ecological harm to wild salmon populations.