Rainbow trout are among the most widely farmed fish in Europe and North America. Welfare standards are more developed for trout than most other farmed fish species.
Rainbow trout welfare has benefited from relatively strong regulatory attention compared to most aquaculture species. Fin erosion scoring, water quality monitoring, and stunning requirements before slaughter provide a framework for welfare improvement. Key ongoing challenges include crowding stress during grading and harvest operations, handling trauma, and disease-related morbidity from furunculosis and other bacterial infections. High-welfare trout farms maintain low stocking densities, rapid disease detection and treatment protocols, and humane slaughter by percussion stunning.