Lion’s mane jellyfish extends tentacles to west coast of Ireland

Andrew Hamilton

More lion’s mane jellyfish than cuckoos have been recorded on the west coast of Ireland this year, in what may represent a seismic shift in our natural environment.

Massive and sometimes dangerous lion’s mane jellyfish are normally confined to the east coast, commonly in waters north of Dublin, and confirmed sightings on the western seaboard are virtually non-existent.

Figures obtained from the National Biodiversity Data Centre show that there have been 157 recorded sightings of lion’s mane jellyfish this year in Donegal, Sligo, Mayo, Galway, Clare, and Kerry, compared to just 122 recorded sightings of cuckoos.

There were 61 lion’s mane sightings in Galway alone, where the lion’s mane jellyfish was the most commonly recorded wild animal by the National Biodiversity Data Centre.

According to jellyfish expert, Damien Haberlin of the Centre for Marine and Renewable Energy at University College Cork, marine scientists are at a loss to explain why this is happening.

“It is highly unusual in our experience. A lot of lion’s mane on the west coast is a very unusual thing. In fact, up to about two years ago, we would have told people that you don’t get lion’s mane on the west coast. But this year that sort of thinking has been proven totally wrong,” he said.

“We have been getting reports of lion’s mane from all over the country. Up to now, the thinking was that lion’s mane were pretty much restricted to the Irish Sea and you’d hardly get any of them below Dublin.

“This year has blown that out of the water. We just don’t know what’s going to happen. Maybe next year it will go back to a more normal distribution.

“I don’t have a ready answer as to why we are seeing them all over the country.”

The spread of lion’s mane has been seen by some as a result of climate change but this is not something that has yet been proven.

“Climate change and the warming sea will have an effect [on the environment]. But trying to predict with any level of certainty what that effect will be is difficult,” said Mr Haberlin.

“One thing that we do know is that a lot of zoo plankton has shifted its position about 1,000 kilometres northward over the past 30 or 40 years. So species that would have been restricted to the south coast of Ireland are now found way up around the north of Scotland. That is absolutely down to climate change.

“If you saw this happening on land, if a species of plant suddenly started growing 1,000km north of where it traditionally grows, that would be newsworthy in a very big way.”

According to Mr Haberlin, relatively little is known about the movement and habits of Irish jellyfish.

and the sector is very much under-funded at present. “We don’t have year to year sampling that we can refer to to try and answer these sorts of questions. This is something that we are pressing for, this sort of work needs funding,” he said.