Millions of dolphins are caught as bycatch in fishing nets each year. Drowning, injury, and entanglement cause significant welfare harms and population declines across dolphin species worldwide.
Dolphin bycatch causes profound welfare harms to highly intelligent, socially complex animals. Entanglement in nets causes panic, exhaustion, and injury as dolphins struggle to reach the surface to breathe. Drowning is the most common cause of death in entangled dolphins. Animals that are disentangled alive may suffer internal injuries and post-capture stress. Trawl capture causes physical trauma from the pressure and abrasion of the net. Given dolphin cognitive complexity — they demonstrate self-recognition, complex communication, and long-term social bonds — bycatch mortality and suffering has significant welfare implications beyond the individual animal. Bycatch reduction technologies including modified nets, pingers, and real-time monitoring are available but inconsistently deployed.