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Portuguese Man O'War Jellyfish is Largest Infestation In A Hundred Years – Water Safety

29th September 2016
A Portuguese man o’ war beached in the Bahamas A Portuguese man o’ war beached in the Bahamas Credit: James St John/Wikimedia

Irish Water Safety (IWS) is alerting the public to exercise caution on our south, west and northwest coastline over the next few days due to jellyfish arriving on our shores, as previously reported by Afloat.ie. 

IWS says Ireland has experienced tropical maritime air for almost two months now with very little northerly winds, in addition sea water temperatures are approximately 15 degrees Celsius, consequently we have seen one of the largest infestations of the Portuguese Man o'war land on our western seaboard in over a hundred years.

There is a new moon on Saturday which will give us spring tides which will mean that we will have larger exposed areas of coastline where we are likely to see these most venomous siphonophores or to most of us Jellyfish. Surfers, kite surfers, swimmers, kayakers, divers and walkers need to keep a vigilant eye open for these creatures which give a very strong sting and to some people can cause anaphylactic shock or seizures. Local Authorities from Cork, Kerry, Clare, Galway, Mayo and Donegal have reported them on their shores mainly in south and southwest facing bays. There have been reports of in excess of 80 landing on the South Harbour in Cape Clear an in excess of 20 on Keel Bay in Achill. They have been known to kill people such is the severity of their stings.

  • Ensure you don't get stung yourself when aiding others.
  • Remove any attached tentacles with a gloved hand, stick or towel.
  • Do not rub the affected area, this may result in further venom release.
  • Rinse the affected area with sea-water (do not use fresh water, vinegar or urine)
  • Apply a "dry cold pack" to the area (i.e place a cold pack or ice inside a plastic bag & then wrap this package in a t-shirt or other piece of cloth).
  • Seek medical attention if there is anything other than minor discomfort (Please note: The sting can cause anaphylactic shock, if you are feeling unwell go to A&E for treatment).

Members of the public should report the sightings of these two jellyfish to the relevant Local Authority or local Water Safety Development Officer

Published in Marine Wildlife

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Marine Wildlife Around Ireland One of the greatest memories of any day spent boating around the Irish coast is an encounter with marine wildlife.  It's a thrill for young and old to witness seabirds, seals, dolphins and whales right there in their own habitat. As boaters fortunate enough to have experienced it will testify even spotting a distant dorsal fin can be the highlight of any day afloat.  Was that a porpoise? Was it a whale? No matter how brief the glimpse it's a privilege to share the seas with Irish marine wildlife.

Thanks to the location of our beautiful little island, perched in the North Atlantic Ocean there appears to be no shortage of marine life to observe.

From whales to dolphins, seals, sharks and other ocean animals this page documents the most interesting accounts of marine wildlife around our shores. We're keen to receive your observations, your photos, links and youtube clips.

Boaters have a unique perspective and all those who go afloat, from inshore kayaking to offshore yacht racing that what they encounter can be of real value to specialist organisations such as the Irish Whale and Dolphin Group (IWDG) who compile a list of sightings and strandings. The IWDG knowledge base has increased over the past 21 years thanks in part at least to the observations of sailors, anglers, kayakers and boaters.

Thanks to the IWDG work we now know we share the seas with dozens of species who also call Ireland home. Here's the current list: Atlantic white-sided dolphin, beluga whale, blue whale, bottlenose dolphin, common dolphin, Cuvier's beaked whale, false killer whale, fin whale, Gervais' beaked whale, harbour porpoise, humpback whale, killer whale, minke whale, northern bottlenose whale, northern right whale, pilot whale, pygmy sperm whale, Risso's dolphin, sei whale, Sowerby's beaked whale, sperm whale, striped dolphin, True's beaked whale and white-beaked dolphin.

But as impressive as the species list is the IWDG believe there are still gaps in our knowledge. Next time you are out on the ocean waves keep a sharp look out!