Carp is the most widely produced freshwater fish globally and the dominant farmed fish in Eastern Europe, but welfare standards for its production are significantly less developed than for salmon.
Carp welfare receives far less scientific and regulatory attention than salmon or trout despite being produced in much larger volumes. Extensive pond culture allows more naturalistic behavior than intensive systems, but harvest and post-harvest handling create concentrated welfare events. Traditional live carp sale at Christmas markets in central Europe involves holding fish in small containers for extended periods without adequate water quality or space - a culturally embedded practice that causes significant suffering. Transport stress in carp has been well-documented, with crowding, oxygen depletion, and handling causing physiological stress that impairs immune function and recovery. The welfare case for improving carp slaughter methods is strong - live chilling and CO2 narcosis used in some operations are not reliably humane.