Tilapia are the second most farmed fish globally, raised in intensive pond and tank systems across tropical and subtropical regions. Their welfare in aquaculture depends on stocking density, water quality, handling practices, and slaughter methods.
Tilapia in overcrowded ponds experience chronic hypoxia, elevated cortisol, impaired immune function, and increased disease susceptibility — welfare states that are invisible to consumers but cause continuous suffering at the population scale. Their capacity for pain is supported by neurological evidence comparable to other fish species. Welfare-conscious aquaculture operations maintain dissolved oxygen above 5 mg per litre, stock below 20 kg per cubic metre in intensive systems, implement disease management plans, and use rapid chilling or CO2 narcosis followed by spiking for slaughter. Certification schemes for responsibly farmed tilapia are available through Aquaculture Stewardship Council.