The environmental footprint of salmon aquaculture - sea bed enrichment, escaped fish, feed sustainability - connects to welfare concerns through ecosystem impacts on farmed and wild animals.
Salmon farm environmental impacts connect to welfare in multiple ways: seabed ecosystems degraded by organic enrichment reduce the habitat quality for benthic species; escaped salmon with domesticated genetics reduce wild population fitness; unsustainable fishmeal sourcing removes forage fish that support seabird and marine mammal welfare. The environmental and welfare cases for sustainable salmon aquaculture are aligned - both point toward lower density, better waste management, alternative feed ingredients and farm siting that protects wild fish habitat. Consumers who care about farmed salmon welfare should also consider the wider environmental welfare implications of production system choice, not just the on-farm conditions of the salmon themselves.