Red warning flags have been put up on four of the most popular beaches in Dublin because of an unusually high showing of jellyfish in the recent warm weather.
Dublin County Council has erected red flags at Seapoint, Sandycove, the Forty Foot and Killiney beaches, and people are being warned about swimming.
Three people were treated in St Michael's Hospital in Dún Laoghaire yesterday for jellyfish stings.
These jellyfish include colonies of the exceptionally large Lion's Mane (Cyanea capillata). Great numbers of the more common purple jellyfish (Aurelia aurata) were also reported on Dublin beaches and spotted in Kerry and Donegal.
Earlier in the week, bathers on Banna Strand in Kerry were also being warned to beware of the Lion's Mane. Its bell can reach eight-foot wide with long tentacles of up to 100 feet. Juveniles are pink, turning red as they mature into reddish brown or purple adults.
The venom in the tentacles of the Lion's Mane is a powerful toxin and a large number of stings could kill an adult. However, John Joyce of the Marine Institute said it is unlikely jellyfish stings would kill unless the victim is very old, very young or suffering from a medical condition. Even dead jellyfish found lying on beaches are capable of stinging.
Mr Joyce advises anyone stung to contact the lifeguard, who normally carries an antihistamine cream to relieve the pain.
Other jellyfish found on Irish beaches are the Portuguese Man of War and the Small Blue (Valeta) also called the Wind Sailor.
