A basking shark tagged off Co Clare earlier this year has been re-sighted off the west coast of Scotland.
The shark was tagged on 25 April 2020 with a numbered, red-coloured tag off Kilkee.
It was re-sighted nearly 600km further north on 19 August 2020 near Hyskier Lighthouse in the Sea of the Hebrides.
Researchers say the re-sighting record, 116 days after the tag was deployed, "confirms the connectivity between Irish and Scottish waters."
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.
Founder of Basking Shark Scotland, 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 passengers were very excited to discover the tag and were so pleased to hear about the match from IBSG. We welcome future scientific collaboration to assist in the understanding of this species and work towards protection over their entire Atlantic migration."
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 off Scotland.
Dr Emmett Johnston, who works closely with Dr Berrow on the long-running Irish shark tagging project, said:
"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 from Co Clare after such a long period and distance demonstrates that other areas of Ireland also share this shark population."