Carp are the world's most farmed fish by volume, yet their welfare during production, transport, and slaughter receives far less attention than other species. Improving carp welfare matters at an enormous scale.
Carp welfare is a largely neglected frontier in fish welfare science. The sheer scale — billions of individual fish — means even marginal welfare improvements have enormous impact. High stocking densities in ponds cause chronic crowding stress, fin damage, and elevated cortisol. Live transport in crowded, oxygen-depleted water causes acute suffering measured by physiological stress markers. The common practice of selling live carp at markets, where fish may remain in cramped tanks for days, extends the welfare burden. Slaughter by suffocation or CO₂ immersion without prior stunning causes distress. Current husbandry and slaughter practices are largely driven by tradition and cost rather than welfare evidence, but this is beginning to change as fish sentience research matures.