Basking Shark Welfare and Marine Protection in UK Waters

Basking sharks are the world second largest fish and visit UK waters seasonally to feed on plankton. Their welfare and conservation are threatened by bycatch, boat strikes, and historical harpoon hunting.

Key Facts

Basking sharks can reach lengths of 12 metres — the second largest fish in the ocean after whale sharks
They filter approximately 2,000 tonnes of water per hour through their enormous gill arches to collect zooplankton
UK waters off Cornwall, Ireland, and the Hebrides are important seasonal feeding and potentially breeding aggregation areas
Basking sharks were hunted commercially in the UK until the 1990s — Norwegian vessels took significant numbers off Scottish coasts
They are listed on Schedule 5 of the Wildlife and Countryside Act and CITES Appendix II
Boat strikes and propeller injuries cause visible scarring on many individuals — a welfare and population health concern
Entanglement in creel and net fisheries kills basking sharks that cannot surface to breathe
The Shark Trust runs the UK Basking Shark Project monitoring seasonal aggregations and individual identification by fin photogrammetry

Welfare Considerations

Basking shark welfare is shaped primarily by human maritime activities. Vessel strikes from speedboats and yachts cause serious trauma — the scars documented on individual basking sharks include deep propeller lacerations that take years to heal, if they heal at all. Entanglement in creel lines causes drowning — sharks cannot breathe without swimming continuously. Historical hunting reduced populations significantly and recovery has been slow. The development of marine protected areas that encompass basking shark aggregation zones and restrictions on vessel speed near feeding groups represent the most direct welfare and conservation interventions available.

What You Can Do

Observe basking sharks from a minimum distance of 100 metres and switch off boat engines near feeding groups
Submit basking shark sightings to the Shark Trust national recording scheme
Support campaign calls for marine protected areas encompassing known basking shark aggregation areas
Advocate for creel fishery regulations requiring escape gaps that reduce basking shark entanglement risk
Donate to Shark Trust basking shark research and protection programmes
Engage with boating and water sports communities about basking shark encounter guidelines