Galway city council have issued a warning to swimmers as Portuguese man o’wars have been spotted in the waters around the city.
The man o’war has been spotted by people down at Blackrock and Ladies Beach in Salthill.
Often referred to as a jellyfish, the man o’war (or man-of-war) is actually a colony of many creatures called polyps that are tied together.
The man-of-war can grow up to 30cm long, with a 15cm a float above the water, and has a distinctive silver, blue colour with a reddish tinge on the underwater section.
Its tentacles are far larger than the rest of its body, stretching for an average 10 metres through the water, and deliver a dangerous venom.
A sting from a man o’war is not usually fatal to humans, though it can cause swelling of the airways, fever, and breathing difficulties.
If you experience any swelling, breathing difficulties, chest tightness, or heart palpitations, seek medical attention immediately
Otherwise if stung, remove the tentacles with a gloved hand or stick, then bathe the affected area in warm water at 45 degrees for about 20 minutes.
Man o’war tentacles are particularly dangerous as they remain venomous for days after the creature is dead, or after detaching from its body and drifting through the water.
In the past two years there have been unprecedented numbers of man o’wars seen in Irish waters.
There were over 700 sightings in 2016 alone, the worst infestation in a century according to Irish Water Safety.
This year has been an unusual one for jellyfish and jellyfish-like creatures in and around Galway as the man o’war isn’t the only strange visitor to the area.
Lion’s man jellyfish have been spotted along the west coast in record numbers this year, with at least 61 reported sightings in Galway alone.
Marine experts remain baffled by the upsurge in numbers of this stranger to Atlantic waters.