Atlantic salmon aquaculture faces persistent welfare challenges including sea lice infestations, crowding, and disease that cause significant suffering to billions of fish.
Farmed Atlantic salmon face welfare challenges that operate at enormous scale. Sea lice infestations cause painful open wounds, particularly around the head and gill area, reducing fish welfare and causing significant mortality. The parasites are difficult to control and many treatments cause additional stress and some mortality. High stocking densities in net pens prevent normal swimming patterns and create environments where stress, disease transmission, and injury are elevated. Salmon are migratory fish with strong behavioral drives that cannot be expressed in net pen aquaculture. The use of wrasse and lumpsucker cleaner fish to control sea lice creates additional welfare concerns - these fish experience high mortality and are afforded little welfare consideration. The scale of salmon aquaculture - billions of fish - makes welfare improvement in this sector critically important.