Tilapia are among the most farmed fish globally, often reared in intensively crowded systems in tropical countries with limited welfare oversight.
Tilapia in high-density intensive systems experience chronic social stress from inability to establish territories. Aggressive hierarchies at high density cause injury from bite wounds to fins and body. Poor water quality, often tolerated in intensive tilapia systems, causes chronic physiological stress even without acute mortality. Handling during grading and harvest causes acute stress responses. Slaughter by asphyxiation in air or on ice causes prolonged suffering in fish with demonstrated nociceptive capacity. The global scale of tilapia production means welfare improvements could benefit an enormous number of individual animals.