Hebridean seas crucial for Scotland's basking sharks

NEW research has shown the plankton-rich waters off Scotland's west coast to be important to the survival of one of the largest fish in the sea.

A total of 61 of the ocean giants were tagged near the islands of Hyskier, Coll and Tiree as part of the study. Picture: contributed

The results of a pioneering three-year satellite tagging project have revealed the Sea of the Hebrides is a crucial feeding ground for migrating basking sharks.

A total of 61 of the ocean giants were tagged near the islands of Hyskier, Coll and Tiree as part of the study, a partnership between government agency Scottish Natural Heritage (SNH) and the University of Exeter that began in 2012.

It is the first time satellite tags have been used to track basking sharks in near real time.

Researchers say the sharks were particularly drawn to the waters around the Hebridean islands in summer, often returning each year to feed on the area’s plentiful plankton.

Project manager Suzanne Henderson, of SNH, said: “It has been really exciting to learn that the same individual basking sharks return in consecutive years to use Scottish waters.

“It’s something we thought happened, but we now have the first proof that this occurs.

“It really does emphasise that the Sea of the Hebrides is highly important for this migrating species.”

Protecting highly mobile species such as basking shark and whales is difficult due to the large areas they cover. This mean identifying and safeguarding areas where they feed or perform major life-cycle events can play a key role in their conservation.

The scientists say behaviour exhibited by the sharks suggests the region could also be important for breeding.

“As well as cruising around and feeding at the surface, the sharks can be seen showing courtship-like behaviours,” said Ms Henderson.

“These social behaviours suggest that the sharks return to the area not just to feed on the plankton bloom but for other reasons too, perhaps even to find a mate.”

SNH has recommended an area of the Sea of the Hebrides should be earmarked to conserve the sharks – and minke whales – as part of the country’s network of marine protected areas (MPAs),

Scottish environment secretary Richard Lochhead said: “The results of this valuable work will help us along the path of getting the MPA network right by ensuring the ecological processes and places basking shark depend upon are afforded the protection they need to endure.”