Carp are the most farmed fish globally by volume, with traditional pond culture systems that vary enormously in welfare quality across different production regions and intensities.
Carp welfare spans a wide spectrum depending on production system. Extensive pond culture with low stocking densities and natural food allows a degree of natural behavior expression that intensive systems cannot match. At the high-intensity end, crowded carp in recirculating or net cage systems show chronic stress indicators and fin damage. The live trade, which involves transporting carp in buckets and holding them in market tanks with minimal water, is a significant welfare concern. Air exposure during handling and processing causes hypoxia and stress responses. Traditional systems that have sustained carp production for centuries in Europe are often gentler welfare-wise than modern intensive alternatives.