Basking sharks are the second largest fish in the world, filter-feeding in plankton-rich UK coastal waters in summer. They face welfare threats from boat strikes and illegal harassment by poorly managed wildlife watching operations.
Basking sharks struck by propellers suffer severe lacerations that are often documented through scarring on surviving individuals. Propeller strikes can be immediately fatal. Boats that approach too closely disrupt filter feeding and cause these slow-moving fish to dive, interrupting foraging during the brief productive summer season when they must accumulate energy reserves. Responsible watching from appropriate distances allows observation without welfare impact.