Also, farmed salmon that is certified by the Aquaculture Stewardship Council (ASC), has advanced in their sustainable seafood ranking to a ‘Good Alternative’. About a quarter of all farmed salmon produced globally is ASC certified.
Seafood Watch measures impacts on marine and freshwater ecosystems of fisheries (wild-caught) and aquaculture (farming) operations. Their assessments and calculations result in a biannual Sustainable Seafood Guide. Check out their current recommendations on Salmon.