These gentle giants of the seas can be spotted round the Lizard coastline in the summer. Look out for their dorsal and tail fins above the waves.
Photo: Greg Skomal

Scientific name: Cetorhinus maximus

Other common names: Bone Shark, Elephant Shark

Cornish name: Morvleydh omdesi

Conservation status: IUCN, Northeast Atlantic population is Red-listed; protected in the EU and UK – it is illegal to disturb, kill or injure them.

What to look for:

• Appearance: Large shark, usually seen below the water surface with mouth wide open as it filters its plankton food. The dorsal fin and tail can often be seen above the water surface. Mottled grey to brown in colour.
• Size: Up to 12 m in length.
• Where: Coastal waters round the UK; globally in all temperate seas.
• When: Late spring and summer.
• Similar species: Some other sharks, but no others this size are found round the UK coastline.

Late spring and summer bring Basking Sharks to Cornwall’s waters. These giant filter-feeders are attracted here by the plankton blooms of the summer months: this greater productivity is encouraged by warmer waters from the Atlantic.

It’s hard to believe for such a large animal (this is the second-largest fish in the world – only the Whale Shark is larger) that we know very little about them. We can only estimate how long they live or dates of sexual maturity from comparison with related species. Although we know they move to deeper waters in the winter, very little is known of their behaviour in the colder months. If you come across one on boat trips, you will probably get to see its massive mouth, held wide open to take in seawater and filter out its plankton food through five extensive gill slits. 

Did you know…?

…The southwest of England is one of five Basking Shark ‘hotspots’ on the west coast of Britain and Ireland, where the waters are particularly warm, and therefore productive, in the summer.

…Basking Sharks will swim thousands of kilometres in pursuit of plankton blooms.

 

Published: May 2015 (updated April 2020)
Author: Amanda Scott
Photo: Greg Skomal / NOAA Fisheries Service / Public Domain