Stinging Lion’s mane jellyfish in Irish waters is larger this year

Several swimmers in the west have received hospital treatment for Lion’s mane stings

A number of people have been hospitalised after being stung by Lion's Mane jellyfish in Ireland during the hot spell. Research from NUI Galway and University of Hawaii suggests an effective treatment for the sting. Video:NUIG / Damien Haberlin

 

Sea swimmers may know that Lion’s mane jellyfish are the most venomous of the indigenous species in Irish waters, but they may not know that this season’s generation is far larger than usual.

Lion’s mane is also becoming more geographically spread than its normal Irish Sea habitat, with sightings in the Celtic Sea and Atlantic waters in recent weeks, Dr Tom Doyle has said.

Dr Doyle, zoology lecturer at University College Cork’s school of biological, earth and environmental sciences, has confirmed recent sightings of large adult Lion’s mane off Galway’s Blackrock swimming tower, Barna, Rinville near Oranmore, Traught near Kinvara, and Newquay, Co Clare.

The typical jellyfish lives in the water column for six to eight months, having been released as a juvenile in December

“It is not correct to say this is the first time they have been spotted on the west coast, as we had reports for the last two years, but they are particularly large and mature,” he noted.

Dr Doyle has received similar reports of large adult Lion’s mane jellyfish off Anglesey in Wales and Liverpool.

Some 17 dangerous and severely stinging jellyfish, known as lion’s mane have been removed by Dun Laoghaire Rathdown County Council from Sandycove Beach today. Photograph: Irish Water Safety
Several swimmers in the west have reportedly received hospital treatment for Lion’s mane stings, which can cause severe pain. File photograph: Irish Water Safety

“They normally prefer the Irish Sea as it is cooler, and the hotspots are the Forty Foot in south Dublin, and popular swimming places like Bettystown, Co Meath and Clogherhead, Co Louth, and right around to Donegal, ” he explained.

Stings

Several swimmers in the west have reportedly received hospital treatment for Lion’s mane stings, which can cause severe pain and lead to what Dr Doyle and colleagues call “dangerous systemic effects” including “Irukandji-like” syndrome. This syndrome, named after a type of box jellyfish, can involve symptoms ranging from severe headache and backache to abdominal pain, nausea, vomiting, and even cardiac arrest.

The lion’s mane jellyfish. Illustration by Michael Viney
The lion’s mane jellyfish. Illustration by Michael Viney

“The typical jellyfish lives in the water column for six to eight months, having been released as a juvenile in December, but we believe these jellyfish may have over-wintered and may be on their second season,” he said.

Dr Doyle is urging sea swimmers and coastal visitors to report any sightings with photographs if possible to the National Biodiversity Data Centre website and the Big Jellyfish Hunt Facebook page.

Winning photographer George Stoyle, from Muston, North Yorkshire, won the overall prize of £5,000 (€5,970) for his image of a huge lion’s mane jellyfish and its “hitchhikers”. He said: “As I approached cautiously I noticed that a number of juvenile fish had taken refuge inside the stinging tentacles.” Photograph: George Stoyle/BWPA/PA Wire
September 2016, British Wildlife Photography Awards: Winning photographer George Stoyle, from Muston, North Yorkshire, won the overall prize of £5,000 for this image of a huge lion’s mane jellyfish and its “hitchhikers”. Photograph: George Stoyle/BWPA/PA Wire

Dr Doyle is co-author of a recent paper on jellyfish stings which recommends vinegar and 45-minute immersion in hot water as the best treatment, rather than rinsing in seawater which may make a sting worse.

He is currently researching trends in jellyfish abundance as part of the EU CERES project to examine how climate change will influence Europe’s most important fish and shellfish resources.