Basking sharks are the world's second-largest fish and are vulnerable to bycatch and boat strikes. Their slow reproduction makes each welfare harm a conservation concern.
Basking shark welfare is threatened by bycatch and vessel collisions. Entanglement in fishing gear causes drowning and entrapment-related injuries. Propeller strikes leave deep parallel lacerations that can become infected or impair swimming. Given basking sharks' very slow reproduction, each individual that suffers welfare harm from human activity represents a significant conservation and welfare cost. Research using tagging shows basking sharks have complex migration routes — protecting them requires international cooperation across their range. Encounter guidelines for recreational vessels reduce collision risk during feeding aggregations at the surface.