Carp are the most widely farmed fish globally, predominantly in Asia. Their welfare in intensive production systems is an increasingly important concern as fish sentience gains scientific recognition.
The welfare of farmed carp affects a larger number of individual animals than almost any other farmed species, yet they receive comparatively little welfare attention. Intensive pond systems frequently experience oxygen crashes during warm weather, causing mass mortalities preceded by acute hypoxic distress. Disease outbreaks, including koi herpesvirus, cause significant mortality and likely suffering in affected fish. The sheer scale of carp farming means that even modest improvements in water quality management, stocking density, and slaughter methods could reduce suffering for an enormous number of animals. Live transport and sale of carp, common in parts of Asia and Eastern Europe, creates additional welfare challenges that deserve industry and regulatory attention.