Aquaculture operations affect wild fish and invertebrate populations beyond farm boundaries through disease, escape, and environmental impacts that have welfare dimensions.
Aquaculture welfare extends beyond farm boundaries to encompass the wild populations affected by farm operations. Sea lice transmission from farms to wild salmon causes significant welfare harm across wild populations unable to escape the elevated parasite loads created by farm proximity. Escape events introduce domesticated fish with altered behavior and genetics that may reduce wild fish fitness. Site selection, farm management, and technology choices determine the extent of these external welfare impacts. Certification standards that include external ecosystem welfare as well as on-farm welfare — and consumer demand for such standards — are the most effective tools for comprehensive welfare improvement.