Tilapia are among the most widely farmed fish globally, but their welfare in intensive systems is compromised by crowding stress and social aggression. Better management can significantly improve their wellbeing.
Tilapia in intensive cage or tank culture experience significant social stress from hierarchical dominance interactions. Subordinate fish that receive less feed and bear the cost of social defeat stress show stunted growth and reduced immune function. The production incentive to pack maximum biomass into available space directly conflicts with tilapia welfare requirements for social stability and feeding access. Crowding also exacerbates water quality deterioration, with ammonia and dissolved oxygen changes imposing additional physiological stress. All-male monosex culture reduces but does not eliminate social aggression, as dominant males still compete vigorously even without reproductive motivation.