For the past two years the Argyll Islands, off the West Coast of Scotland have had the UK’s highest reported sightings of basking shark. Every summer they are sighted off the west coast, and we occasionally encounter them on our boat trips. These huge fish are the third largest fish in the sea.
They feed on plankton, and it is during this activity that they are seen at the surface during the summer months, and from this they derive their name. They disappear at other times of the year, and where they go had been a mystery until recent scientific studies, using miniaturised computers attached to the shark’s fin, found that they stay in British waters throughout the winter. They hold the record for the broadest foraging range of any shark, and make regular vertical dives to a depth of up to 1000 metres, following vertical layers of plankton in the water column.
One tagged shark was found to have travelled from the English Channel to the west coast of Scotland in 2½ months. The results of the research showed that Basking Sharks are indeed truly British sharks, and throughout the entire year never leave our coastal waters.
The harmless basking shark can be readily differentiated from our other big shark, the porbeagle shark, as you are likely to see the nose, dorsal fin and tail at the surface at the same time.