Trout are among the most widely farmed fish globally, produced for both meat and sport fishery stocking. Their welfare in intensive aquaculture systems raises important questions about density, water quality, and slaughter methods.
Trout welfare in intensive aquaculture reflects many of the same challenges as salmon welfare but in a less regulated context. Maximum stocking density regulations are less stringent for trout than for salmon in most jurisdictions, and welfare auditing is less developed. At high densities, trout show elevated cortisol, reduced growth efficiency, increased fin erosion from aggression, and immune suppression — all indicators of chronic welfare compromise. Slaughter welfare is particularly variable: on-farm slaughter (without professional slaughter facilities) is common for trout, and practice quality varies enormously. Trout grown for sport fishery stocking often receive even less welfare attention than food-production trout despite facing similar conditions. The scientific evidence for trout nociception and pain experience is strong — trout have been central to fish sentience research and their capacity for pain-like experience is better documented than for most other farmed fish species.