European perch is a growing aquaculture species in Central and Eastern Europe, farmed in RAS systems for its premium white flesh. Its predatory nature, cannibalism risk, and cold-water requirements shape welfare management approaches.
European perch welfare in RAS systems is shaped by the species' predatory ecology and schooling behaviour. Early life cannibalism requires aggressive size grading that creates repeated handling stress but prevents the greater welfare harm of predation. The long grow-out period in cold-water RAS means that any ongoing welfare deficit compounds over nearly two years per individual. Thermal management is critical: perch outside their optimal temperature range show metabolic stress and increased disease susceptibility. Schooling behaviour means that group housing at appropriate densities is beneficial — unlike some other aquaculture species, perch may show lower stress in social settings. Slaughter welfare for perch is typically poor — ice slurry or CO2 narcosis without prior electrical stunning leaves fish conscious during the stressful initial phase. Electrical stunning adapted for perch physiology would substantially improve welfare at the most acute intervention point.