A huge Porbeagle shark, the biggest of its kind ever caught off Irish waters, has been landed and tagged off the coast of Donegal.
An international team of scientists led by Trinity College Dublin tagged and released the record-breaking 2.8 metre shark.
The female specimen, estimated to weigh 400-500lb, is the largest ever recorded in Irish waters and likely to be between 25 and 30 years old.
Three local anglers worked together to catch the giant fish.
It was then transferred to the scientists’ vessel so the team could quickly measure it, attach two different types of satellite tags and take samples to examine.
Nick Payne, shark biologist and assistant professor in Trinity's School of Natural Sciences, said this was a significant moment in the exploration of sharks.
“It is exciting to see such huge porbeagles in Irish waters. The conservation status of porbeagles has been really concerning in this part of the world, with the European population considered critically endangered.
“There’s evidence that the Donegal coast may act as a globally important reproductive area for this species, with lots of very large female sharks appearing here for a short period in spring.”
Last week was the first trip in a new research collaboration between Trinity, Inland Fisheries Ireland (IFI), and local shark anglers, together with leading scientists from James Cook University (Australia), University of Miami, and US non-profit Beneath the Waves.
Dr Payne added: “this was an incredible start to an important new project, where we will work with the local shark angling community to learn as much as we can about porbeagle movements and their reproductive dynamics in Irish waters. If this is an important breeding location then we need to know about it, so we can monitor and conserve the animals as best we can when they visit our shores.”
Overfishing saw severe declines in porbeagle stocks since the 1930s, and commercial fishing by EU vessels has been prohibited under EU regulations since 2010.
The International Council for Exploration of the Sea considers there to be just a single stock in the northeast Atlantic, with tagging data showing individual porbeagle sharks can migrate long distances throughout the region.
"If we are to see recovery of the European porbeagle population it is especially important to monitor reproductive areas. If Ireland is a key breeding site then we really have a global responsibility to protect porbeagles using this area," Dr Payne said.
The shark, which the team have nicknamed Danu, was handled and tagged safely and released in a healthy condition.
One of her satellite tags will transmit a wealth of information on her migration history and ocean conditions encountered, before detaching in several months.
A second tag provides near real-time data on her location whenever her fin breaks the water surface – a trait of porbeagles.
Dr Payne said that Danu had already covered a lot of ground and was almost at the Hebrides in Scotland 48 hours after her release.