Tilapia is the second most farmed fish globally, with production exceeding 6 million tonnes annually. Their welfare in intensive systems raises important questions about stocking density, water quality, and humane slaughter.
Tilapia welfare challenges in intensive aquaculture center on stocking density, water quality management, and slaughter practices. High densities cause chronic stress, immune suppression, fin damage from aggression, and reduced growth. Ammonia accumulation in poorly managed systems causes gill damage and osmoregulatory failure. The practice of androgen-induced sex reversal — feeding fry methyltestosterone to produce all-male populations — is widespread despite concerns about fish welfare and environmental hormone contamination. Slaughter practices vary widely: CO2 stunning followed by bleeding is more humane than common alternatives like ice slurry or asphyxiation. Research on tilapia cognition shows they have learning abilities, social preferences, and stress responses consistent with sentience, supporting stronger welfare standards.