Irish scientists first to tag Lion’s Mane jellyfish
Last month, warning signs were placed by local authorities at beaches and bathing spots in Dublin warning that the giant jellyfish were in the water. Swimmers who have been stung by the jellyfish in the last few weeks said they did not see anything but what looked like seaweed in the water.
UCC researchers found a way of attaching a tag to the underside of the jellyfish in among the hundreds of metre-long tentacles.
“As crazy as it sounds, tracking these jellyfish is one of the only ways we can learn how much time they spend at the surface and whether or not they are residents or just passing through,” said Dr Tom Doyle from UCC’s Coastal Marine Resources Centre.
Dr Doyle is involved in an EU project, the EcoJel project, to track the migration of jellyfish in European waters and better understand their movements and overall ecology.
“A bad encounter with a Lion’s Mane may result in severe pain for five or six hours, weeping skin and back pains,” he said.
All of the jellyfish were tagged near the Forty Foot, a deep seawater inlet in Dún Laoghaire, and followed for up to eight hours.
The jellyfish either went north or south along the coast. One jellyfish hugged the coastline from the Forty Foot to Bullock Harbour and along to Sorrento Point, never moving more than 20 metres from shore.
“This is a great success as only three weeks ago we had no idea of where they went and how they behaved,” he said.
“We now know that these jellyfish are residents, moving about with the ebb and flow of the tide,” said Dr Doyle.
The jellyfish, a cold-water species, are now dying off and washing up on shorelines in large numbers.
Dr Doyle said it was a first to tag the creatures and they had stopped tagging them until early next year.
The project was featured on a Facebook page called The Big Jellyfish Hunt in a bid to encourage people to report sightings of the creature.
The Lion’s Mane jellyfish is capable of reaching a bell diameter of 2.5m.
