Mackerel, herring, and other small pelagic fish are caught in enormous quantities with minimal consideration of their welfare during capture, handling, and death.
Small pelagic fish are social schooling species with complex collective behaviour and demonstrable stress responses. Capture in purse seines exposes them to progressive oxygen depletion, crushing by the weight of the school, and prolonged stress before death. While individual fish welfare research has focused on larger, farmed species, the scale of small pelagic capture — measured in hundreds of billions of individual fish — makes this one of the most numerically significant welfare challenges in global fisheries.