Basking Shark Welfare: Gentle Giants and Boat Strike Risk

Basking sharks are the second largest fish in the world and filter-feed on zooplankton near the ocean surface. Their surface-feeding behaviour makes them highly vulnerable to boat strikes.

Key Facts

Basking sharks can reach 12 metres in length and filter thousands of litres of water per hour
They are legally protected in UK and Irish waters but still face risks from boat traffic
Basking sharks aggregate in Scottish and Irish coastal waters in summer where boat strikes occur
Despite protection, basking sharks are still illegally finned in some parts of their range
Their slow reproductive rate means populations recover very slowly from any mortality

Welfare Considerations

Boat strikes on basking sharks cause traumatic blunt force injuries and propeller lacerations. Surface-feeding animals are particularly at risk because they are not actively evading vessels. Propeller injuries to the dorsal fin and body cause severe lacerations that can become infected. Even non-lethal encounters cause stress and disruption to feeding. Legal protection has not eliminated mortality from boat strikes, and enforcement of approach distances in aggregation areas is inconsistent.

What You Can Do

Maintain at least 100 metres distance from basking sharks when boating
Report basking shark sightings and boat strike incidents to the Shark Trust
Support speed restriction areas in known basking shark aggregation zones
Donate to basking shark research that informs better protection of aggregation areas