Bycatch - non-target species caught and discarded from commercial fisheries - causes enormous welfare impacts through capture stress, physical injury and mortality for billions of animals.
Bycatch welfare is measured in billions of individual animals experiencing drowning, crushing, hypoxia and traumatic injury annually. Even animals that are returned to the sea alive from surface-trawl fisheries experience severe physiological stress and often die from delayed capture effects. The welfare argument for bycatch reduction is unambiguous; the challenge is the scale and economic complexity of global fisheries. Effective reduction requires selective gear technology, area closures, real-time monitoring, and market incentives through certification and consumer choice. Turtle excluder devices, pingers and modified trawl designs have demonstrated that bycatch can be dramatically reduced without eliminating fishing viability.