Water quality is the most critical determinant of tilapia welfare in aquaculture. Poor dissolved oxygen, high ammonia, and temperature extremes cause chronic stress and suffering in millions of farmed fish.
Tilapia in poor water quality conditions experience the equivalent of slowly suffocating - a physiologically distressing experience. Chronic sub-optimal oxygen and high ammonia suppress immune function, increase disease susceptibility, and cause ongoing behavioral stress. The scale of tilapia production means that even modest welfare improvements in water quality management benefit hundreds of millions of individual fish. Certification schemes that include minimum water quality standards during production and transport provide meaningful welfare improvements when enforced.