Rainbow trout is one of the most farmed fish species in Europe and North America, with well-established welfare research informing best practice.
Rainbow trout welfare benefits from a relatively strong evidence base compared to many farmed fish species. Research has established clear relationships between stocking density, water quality, and welfare indicators including cortisol levels, fin erosion, and aggressive interaction rates. Best practice guidance is available and increasingly incorporated into certification schemes. Key welfare challenges include crowding stress during grading and harvest, disease management including use of chemical treatments, and slaughter welfare where electrical stunning followed by rapid killing is the most humane current method for most production systems.