Common carp and related cyprinid species are the most widely farmed fish globally, primarily in Asia. Understanding their welfare challenges guides improvement in a sector producing billions of fish annually.
Carp welfare in aquaculture exists on a spectrum from traditional extensive polyculture systems — where carp live in relatively natural conditions at low densities — to intensive monoculture operations where welfare compromise is more significant. The paradox of carp welfare is that the species' hardiness, evolved over millennia of cultivation, is interpreted as meaning that suboptimal conditions are not harmful. As with other farmed fish, the ability to survive poor conditions does not mean those conditions cause no welfare harm. Research on carp stress responses shows that overcrowding, handling, poor water quality, and inhumane slaughter all produce physiological and behavioral indicators of distress. Improving carp welfare across the vast production volume involved requires practical, low-cost interventions appropriate for small-scale Asian aquaculture systems as well as larger industrial operations.