Common carp is the world's most farmed fish by volume, with production concentrated in Asia and Central Europe under welfare conditions that vary significantly between systems.
Common carp welfare in farmed systems ranges from extensive pond culture — where fish have relatively natural conditions and behaviour — to highly intensive recirculating systems where stocking density and water quality management are critical welfare determinants. The adaptability of carp to poor conditions has allowed intensive production to proceed without the obvious welfare failures seen in more sensitive species, but research demonstrates that carp in optimal conditions show distinct positive welfare states compared to those in poor conditions. Establishing carp-specific welfare standards as the industry grows would be more effective than retrospective reform.