Early Mortality Syndrome (EMS/AHPND) devastates farmed shrimp populations in Asia, causing billions of shrimp to die in acute suffering with massive economic and welfare consequences.
The welfare implications of EMS involve both the acute suffering of affected shrimp and the systemic conditions that enable disease spread. EMS causes rapid organ dissolution — shrimp with advanced EMS exhibit lethargy, pale coloration, and failure to feed before dying. Whether shrimp experience subjective suffering remains scientifically debated, but the precautionary principle supports treating mass mortality events as welfare concerns. The intensification practices that drive EMS — extreme stocking densities, poor water quality, prophylactic antibiotic use that creates resistant Vibrio strains — are themselves welfare risk factors. Disease management through high-welfare practices (lower density, biosecure hatcheries, probiotics) reduces both mass mortality and antibiotic resistance.