Tilapia are among the world's most farmed fish, and their complex social hierarchies and aggressive behaviour create significant welfare challenges in intensive aquaculture systems.
Tilapia social welfare is a significant concern in intensive aquaculture. Their naturally territorial behaviour creates extreme aggression in high-density tank conditions where individuals cannot establish or maintain territories. Chronic social stress manifests as elevated cortisol, reduced immune function, impaired growth, and physical injury from aggressive encounters. Welfare improvements include optimal stocking density management, provision of structural refuge and visual barriers within tanks, and optimised feeding regimes that reduce competition at feeders. Hormonal sex reversal (feminisation using methyltestosterone) raises ethical questions alongside welfare questions about chemical manipulation of fish physiology. ASC certification for tilapia includes stocking density limits and injury monitoring requirements. Welfare research for tilapia is less developed than for salmon, representing a gap that the growing industry needs to address.