Disease outbreaks in farmed shrimp — particularly early mortality syndrome and white spot disease — cause mass mortality events under conditions that may involve aversive experience for millions of individuals.
Shrimp disease welfare sits at the intersection of scale and uncertainty — mass mortality events involving billions of individuals under potentially aversive disease conditions, in animals whose capacity for distress during illness remains scientifically contested. The behavioral changes observed in shrimp with WSSV — reduced activity, congregation at edges, loss of coordination before death — are consistent with aversive states in animals whose nervous systems can detect and respond to harmful stimuli. Whether this constitutes suffering in a morally relevant sense remains uncertain, but the precautionary significance of billions of individuals dying under disease conditions in concentrated production systems is substantial. Prevention-focused management that maintains pond conditions reducing disease susceptibility — stable water quality, appropriate stocking density, and pathogen-free inputs — serves both economic and potential welfare interests simultaneously.