Tilapia is the third most farmed fish globally, but intensive production practices raise welfare concerns that are rarely addressed in sustainability discussions.
Tilapia welfare has historically been neglected because of assumptions that a hardy, tolerant species does not suffer significantly under intensive conditions. Research increasingly challenges this view. Tilapia show stress responses to crowding, aggression-related injury at high densities, and behavioural evidence of pain. The existence of a validated Tilapia Grimace Scale allows welfare assessment in research and production settings. Lower stocking densities, stable social groups, pre-slaughter stunning and enriched environments with structural complexity are welfare improvements that are technically achievable within tilapia farming systems.