Fish are increasingly recognised as sentient animals capable of experiencing pain and fear. Pre-slaughter stunning reduces suffering substantially but is not yet universal in commercial fisheries.
Fish killed without stunning die slowly through asphyxiation on deck, gill removal while conscious or evisceration while alive. These methods can cause minutes to hours of suffering. For farmed species especially, pre-slaughter stunning is technically feasible and is increasingly mandated by high-welfare certification schemes. Consumer demand for humanely killed fish can drive supply chain improvement.