How wild salmon welfare and population health are affected by farmed salmon operations.
The welfare of wild salmon must be considered alongside farmed salmon welfare when evaluating aquaculture practices. Wild salmon populations whose migration routes pass salmon farms face sea lice loads that can exceed the immune capacity of juvenile smolts, causing welfare harm and mortality. The genetic integrity of wild populations — their locally adapted characteristics built over millennia — is compromised by hybridization with escaped farm fish. These harms are measurable and serious, affecting wild fish welfare and population viability simultaneously. The technical solution — closed containment systems that prevent both escape and disease transmission — exists and is increasingly economically viable. Consumer demand for responsibly produced salmon creates the market incentive for transition.