Atlantic mackerel are fast-swimming pelagic fish whose welfare during commercial capture is affected by crowding stress, exhaustion, and the physiological trauma of net hauling and handling.
The welfare of Atlantic mackerel during commercial capture is compromised primarily by the extreme physical stress of net capture and crowding. In purse seine operations, millions of fish are compressed into decreasing net volumes, causing crushing pressure, oxygen depletion, and extreme physiological stress. Ram ventilators like mackerel suffer particularly from forced cessation of swimming. Research on fish nociception suggests mackerel likely experience something analogous to pain and distress during capture. Death by crowding and asphyxiation in holds is slow and may be aversive. More humane slaughter methods including electrical stunning applied to whole catches in the net are technically feasible and would reduce suffering considerably. Consumer choice of mackerel caught by hook-and-line or small-scale methods, where fish are dispatched rapidly, represents a welfare improvement over industrial seine operations.