Ireland is currently in the midst of a Lion’s Mane jellyfish invasion, which has caused around five people to be hospitalized after being stung.

This particular variety of jellyfish are normally not due to arrive in Ireland’s waters for another few weeks, even months, yet they’re here far earlier than usual this year.

#DYK at full length tip to tip, these lions mane jellyfish can grow to be longer than a Blue Whale! #NationalWildlifeWeek pic.twitter.com/rdt3sLuwLv

— ParksCanadaVancouver (@ParksCanadaVan) April 12, 2018

Recently, 14-year-old Jack Dunne was swimming off the coast of County Louth when one of the jellyfish attached themselves to his shoulder and chest. His mother stated: “Its tentacles went around his legs and waist.”

“His friends rang me and when we got to the beach he was on his hands and knees and finding it hard to breathe… By the time we got to the hospital he was starting to lose the feeling in one of his legs with the pain.”

These jellyfish are unmistakably huge according to John Leech, the chief executive of Irish Water Safety.

He stated: “This year is the earliest and largest infestation of Lion’s Mane jellyfish in my experience.”

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They have been swarming in large numbers, as per Leech, because their natural predators are decreasing due to the prevalence of plastic pollution.

They have been found not only in Louth but also in Galway Bay and other parts of the Irish coast.

Swimmers are warned that these stings, in addition to causing pain comparable to that of Dunne’s, have a small chance of enacting anaphylactic shock for certain people.

Read More: Woman in emergency airlift after jellyfish mauling in Dublin

A diver with a giant Lions Mane Jellyfish.Twitter/@TwoPaddles