Coho salmon are farmed across North America and Chile with distinct welfare challenges related to their anadromous life cycle, territorial behavior, and slaughter practices.
Coho salmon welfare challenges begin in freshwater hatcheries where territorial behavior causes aggression and fin damage at high densities. The smoltification process — a physiological transformation enabling saltwater tolerance — requires precise temperature and photoperiod management; mistakes cause failed smolts that suffer osmoregulatory failure in seawater. In marine net-pens, coho are less tolerant of crowding than Atlantic salmon — maintaining appropriate stocking densities is important for welfare and growth. Lice infestations, while less severe than in Atlantic salmon, still cause welfare compromise. Chilean coho production has been criticized for antibiotic use — high-density farming plus warmer-than-optimal water temperatures drive disease requiring pharmaceutical intervention. Harvest by crowding and ice slurry without prior stunning is the dominant practice in Chile — far behind the welfare standards of European salmon harvest.