A Basking Shark tagged off County Clare on the western seaboard of Ireland this year was recently re-sighted off the west coast of Scotland. The shark was tagged on 25 April 2020 with a numbered red coloured tag off Kilkee and was re-sighted nearly 600km further north on 19 August 2020 near Hyskier Lighthouse in the Sea of the Hebrides. This re-sighting record, 116 days after the tag was deployed confirms the connectivity between Irish and Scottish waters.

Image: Bernt Popp

Dr Simon Berrow of the Irish Basking Shark Group who tagged the shark off west Clare in April said “we have long been aware that sharks in Irish waters are moving north through the early summer along the west coast and into Scottish waters, but this is the longest duration between re-sightings of our simple shark tags, which is fantastic and encouraging”.

The tagged shark was observed by snorkelling with Basking Shark Scotland. Founder Shane Wasik said “This is the third Irish tag we have recorded in recent years and it gives us a great sense of purpose to contribute to this Irish conservation led research project. The passenger were very excited to discover the tag and were so pleased to hear about the match from IBSG group. We welcome future scientific collaboration to assist in the understanding of this species and work towards protection over their entire Atlantic migration”.

“The Irish Basking Shark Group have tagged over 500 individual sharks since 2008 and it’s not unexpected that we are getting regular records from movements between Donegal and Scotland, but to get a re-sighting after from Co Clare after such a long period and distance demonstrates that other areas of Ireland also share this shark population,” said Dr Emmett Johnston, who works closely with Dr Berrow on the long-running Irish shark tagging project.

Basking sharks first appear in inshore Irish waters in the early spring between April and May, but generally appear later off the west coast of Scotland. This is thought to be linked to the later zooplankton bloom further north off Scotland, which are the sharks main prey.

This research is important to demonstrate that these sharks cross international boundaries and any management needs to consider their whole range. Basking sharks are protected under a suite of legislation in the UK including Scotland and Northern Ireland. The Sea of the Hebrides is also proposed as a Marine Protected Area for basking sharks by the Scottish government. No such measures exist for Ireland but Dr Berrow commented positively that “major collaborations are now underway in Irish waters that will provide vital information on how best to conserve these magnificent sharks while they are in our care”.

For information on the Irish Basking Shark Groupplease visit their website by clicking here.

For more information about Basking Shark Scotland visit their website by clicking here.