Farmed salmon escaping into wild environments threaten wild salmon welfare through competition and genetic introgression, requiring prevention as a welfare concern.
The welfare implications of farmed salmon escapes extend beyond the individual escaped fish to the wild populations they affect. Hybridization between domesticated and wild strains produces offspring with reduced survival rates — a form of intergenerational welfare harm. Disease transmission can cause mass mortality events in wild populations. The structural solution — transitioning to closed containment aquaculture systems — eliminates the welfare and conservation problem simultaneously, though at higher capital and operating cost.