Nile tilapia aquaculture in East African lakes uses cage systems that raise welfare concerns around water quality, disease, and slaughter methods in a rapidly expanding industry.
Tilapia in East African cage systems face welfare challenges from environmental variability and overcrowding. Seasonal deoxygenation in stratified lakes causes oxygen-depletion events that kill fish rapidly through suffocation, a welfare emergency affecting thousands of animals simultaneously. Disease outbreaks in overcrowded cages cause chronic suffering from streptococcal meningitis, which affects the brain and causes behavioral abnormalities. Harvest by net-lifting causes crowding, physical injury, and oxygen depletion that is acutely stressful. The absence of pre-slaughter stunning in most East African tilapia operations means fish are slaughtered by methods that cause prolonged suffering.