Rainbow trout are among the most widely farmed fish globally, with established welfare science informing improvements in stocking density, handling, and slaughter.
Rainbow trout welfare science is among the most developed of any farmed fish species, providing a strong evidence base for improvement. The welfare costs of overcrowding — fin injuries, behavioral suppression, chronic stress, and elevated disease risk — are well documented and preventable with appropriate stocking densities. Slaughter welfare has seen significant progress, with percussion stunning replacing CO2 narcosis in higher welfare facilities. Operational stressors including netting, sorting, and live transport all impose measurable physiological costs that careful management can reduce. Consumer and regulatory pressure for improved trout welfare standards is producing results in European production systems.