How farmed Atlantic salmon are handled, crowded, and killed at harvest has major welfare implications for millions of individual fish in commercial operations.
Farmed salmon slaughter involves welfare trade-offs that have received increasing scientific and regulatory attention. Pre-slaughter crowding, pumping, and handling cause measurable stress responses in fish. CO2 narcosis, once thought humane, is now understood to be aversive — fish exhibit escape behavior and show signs of distress. Percussion and electrical stunning can render fish insensible rapidly, but require capital investment and operational changes that many facilities have resisted. Consumer demand for welfare-certified salmon is driving industry adoption of better practices.