Swimmers and beach goers are being urged to stay away from some beaches in the south and east of Ireland after the appearance of dangerous jellyfish.
Lion’s Mane jellyfish have been spotted on Irish beaches forcing the possible cancelation of an Ironman event in Sandycove.
The organisers tweeted that they "are aware of the jellyfish situation in Sandycove".
“Athlete safety is paramount. We will continue to monitor and take action if necessary", they added.
A warning was issued by Dún Laoghaire-Rathdown County Council earlier this week.
“We have raised the red warning flag in Sandycove and erected signs warning swimmers of the presence of jellyfish in the water and washed up on the beach,” it said.
"Bathers are advised not to enter the water due to the presence of these jellyfish whose sting can be dangerous and cause serious symptoms including nausea, vomiting and respiratory distress."
A Portuguese Man O'War jellyfish was also found by lifeguards yesterday afternoon at Ballybunion beach, Co Kerry. Stings from either jellyfish can cause blisters, irritation, cramps and in some serious cases may even affect respiratory and heart function.
People are urged to seek medical attention if a sting results in anything other than mild discomfort.
The return of the summer weather this weekend will encourage plenty of people to go to the beach.
Sunday and Monday appear at this stage to be the best days to plan any outdoor activities with warm dry weather, good sunny spells and high temperatures of 20 to 23 degrees.
Bathers,pls only swim in identified bathing areas that are lifeguarded & ask them for info about possible jellyfish pic.twitter.com/zL4aId2r7K— FingalCountyCouncil (@Fingalcoco) August 12, 2016
WARNING - JELLYFISH Be extremely vigilant for dangerous Lion's Mane jellyfish at our beaches pic.twitter.com/dagHEt5wXi— Meath County Council (@meathcoco) August 9, 2016