Common carp have been farmed for over 2,000 years and remain the most farmed fish globally by volume, yet welfare standards for this ancient aquaculture species are virtually absent.
Common carp welfare has received almost no systematic attention despite their status as the world's most-farmed fish by volume. In live fish markets, carp are transported without water in bags for extended periods, experiencing progressive hypoxia and stress. Live sale means fish remain alive until purchased — hours or days in poor conditions. Slaughter is frequently by asphyxiation in containers or on surfaces, a prolonged and potentially distressing process lasting many minutes. Pond-based aquaculture systems have variable water quality, with dense ponds experiencing seasonal hypoxia events causing acute distress. Simple welfare improvements — adequate transport oxygenation and rapid stunning before slaughter — could meaningfully reduce suffering across billions of animals.