Rainbow trout is one of the most important farmed salmonid species globally; understanding and addressing their welfare needs is essential for improving aquaculture standards.
Rainbow trout welfare in aquaculture is substantially influenced by stocking density, water quality, and handling. At high densities, trout compete aggressively for food and space, resulting in fin erosion, increased injury, and chronic stress. Current flow that allows trout to swim against resistance uses energy productively and reduces aggression-related injuries. Feed management that prevents competition for food (multiple feeding stations, automated feeders) improves welfare at the individual level. Pre-slaughter welfare is an area of active improvement: percussive stunning renders trout immediately insensible and is increasingly required by welfare certification schemes. RSPCA Assured has driven significant welfare improvements in UK trout farming through its tiered standards system.