Tilapia is among the world's most farmed fish, produced primarily in tropical developing countries. Welfare standards in major producing countries lag significantly behind northern European salmon standards.
Tilapia welfare in intensive systems is undermined by overcrowding, poor water quality, aggressive interactions at high density, and hormonal manipulation in fry production. The use of methyltestosterone for sex reversal raises both animal welfare and human food safety concerns. Certification schemes including GlobalG.A.P. are beginning to include welfare indicators for tilapia, but coverage of the global supply chain remains thin.