Two critically-endangered angel sharks have been captured, fitted with electronic tags and released in Tralee Bay in Co Kerry, allowing scientists to track their movements and habitats for a year.
It is the first time angel sharks have been tagged in Irish waters in over a decade, and the first time ever they have been fitted with electronic tags. Researchers at the Marine Institute, based in Galway, say the move is a crucial step in the conservation of one of the most endangered shark species in Europe.
Angel sharks have been listed as critically endangered by the International Union for Conservation of Nature. They are a protected species and cannot be fished commercially.
They can grow to around two-and-a-half metres in length and weigh up to 80 kilos. The have a lifespan of up to 35-40 years.
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Angel sharks are found in waters from North Africa to Norway, but they have become vulnerable and sightings are now extremely rare.
Tralee Bay has been described by the Marine Institute as one of the last strongholds for the angel shark species in Irish waters.
Historically, catches of angel shark were quite common in the bay, but since the late 1960s their numbers have declined dramatically.
Very little is known about the reasons for that, about the habitats of the shark species, their movements, breeding and feeding grounds. The reason why they are attracted to the waters off the west coast of Ireland are similarly a mystery.
Two years ago, the Marine Institute initiated a research project in Tralee Bay for angel shark and for a number of other endangered species, including the sting ray, the undulate ray and the extremely rare white skate.
The research project is funded by the Department of Marine and the EU and is headed up by marine scientist, Dr Ross O'Neill. He asked local fishermen to help; they work closely together.
The work of the last two years has now paid dividends - not once, but twice.
Local fisherman Michael Peter Hennessy was on his fishing boat, Lady K, just north of the Maharees in Tralee Bay when he captured two angel sharks in the space of a week - one male, one female - and carefully got them on board.
The male measured 1.25 metres, while the female was just under a metre. It wasn't possible to estimate their age, as they are a slow-growing animal.
Dr Ross O'Neill, a licensed tagger with the Marine Institute, was aboard the Lady K on both occasions and attached pop-off satellite archival tags to the sharks, before releasing them - unharmed - back into the water.
In research terms, the electronic tagging of the two sharks was almost like a lottery win to Ross O'Neill.
"It was amazing," he told RTÉ News. "We always thought we would struggle to get one of them, and then to get two is the cherry on top of our research work down there. It's kind of like winning the Lotto. They are rare, so to be there to tag them was quite unique."
The electronic tags will remain attached to the two sharks for the next year, all the time storing data on water depth and temperature, along with the time of dawn, dusk and maximum light each day.
At the end of 12 months, the tags will automatically detach from the sharks and float to the surface. At that stage they will begin transmitting the stored data back to Dr O'Neill and the scientists at the Marine Institute in Galway, allowing them to plot where the sharks have been over the past year.
Given that so little is known about the movement of angel sharks, where they feed and where they breed, the information gleaned from the electronic data is regarded as crucial in developing a conservation plans for the species.
"This is a landmark moment for marine conservation in Ireland," Dr O'Neill said. "The angel shark is an incredibly rare species, making this recent encounter and successful tagging of two specimens in Tralee Bay all the more important. The tagging will allow us to track their movements and better understand how we can protect this species from further decline. It's an exciting development, not just for Irish marine life but for global conservation efforts.
"This will help us build up a picture of what kind of migration they undertake, where they go offshore and what their optimal habitats are. It will also allow us to model where, potentially, they exist in Europe."
Dr O'Neill paid tribute to fisherman Michael Peter Hennessy, who captured both sharks, and to others in the fishing community in the area who are collaborating in the research project.
"The success of our research relies on buy-in from all stakeholders - they are a vital cog in the work we are doing," he said.
This was echoed by Marine Institute Chief Executive, Dr Rick Officer.
"The tagging project has been made possible through close co-operation between scientists, local fishermen and coastal communities, who have been instrumental in reporting sightings and providing assistance during the tagging process," Dr Officer said. "Our successful tagging of these angel shark highlights the importance of collaborative community involvement in marine conservation efforts."
As scientists from the Marine Institute wait for the electronic tags to begin transmitting data to them in a year's time, they will be busy with other projects in Tralee Bay: they are developing the local crayfish fishery, as well as studying other species there, such as ray and skate.
