Portuguese Man-of-War’s warning issued - “unlikely” to come this far north say IWS

Irish Water Safety is warning members of the public that Portuguese man-of-wars have landed on Irish beaches in Waterford and Cork and may land on other shores particularly Kerry.

Irish Water Safety is warning members of the public that Portuguese man-of-wars have landed on Irish beaches in Waterford and Cork and may land on other shores particularly Kerry.

However, the CEO of Irish Water Safety John Leech told democrat.com that it was “unlikely” that the stinging giants would make it as far north as Donegal beaches:

“It’s unlikely, but it is possible. I have no records of them going any further north than Galway Bay, but they have been recorded as far north as the Hebrides, it is possible. I would urge people using the waters off Donegal Bay and elsewhere along the west coat to be vigilant. The weekend forecast is good and who knows how far north they might travel, so caution is advised,” he said.

By Michael Daly

Man-of-wars are found, sometimes in groups of 1,000 or more, floating in warm waters throughout the world’s oceans. They have no independent means of propulsion and either drift on the currents or catch the wind with their gas filled floats. To avoid threats on the surface, they can deflate their air bags and briefly submerge.

The stinging, venom-filled nematocysts in the tentacles of the Portuguese man-o-war can paralyse small fish and other prey. Detached tentacles and dead specimens (including those that wash up on shore) can sting just as painfully as the live creature in the water and may remain potent for hours or even days after the death of the creature or the detachment of the tentacle.

Stings usually cause severe pain to humans, leaving whip-like, red welts on the skin that normally last 2 or 3 days after the initial sting, though the pain should subside after about an hour. However, the venom can travel to the lymph nodes and may cause, depending on the amount of venom, a more intense pain. A sting may lead to an allergic reaction. There can also be serious effects, including fever, shock, and interference with heart and lung function. Stings may also cause death, although this is extremely rare. Medical attention may be necessary, especially if pain persists or is intense, there is an extreme reaction, the rash worsens, a feeling of overall illness develops, a red streak develops between swollen lymph nodes and the sting, or either area becomes red, warm and tender.


There have been sightings in Tramore, Ardmore Inchydoney and Schull so far. With a promising weather forecast for the weekend swimmers, surfers and families enjoying the beach are at a high risk of encountering them. Other aquatic users will be at a lesser risk and there is a risk that they may drift further north depending on wind direction.

The Portuguese Man-of-War is an Invertebrate and Carnivore. The dimensions are Float, 12 in (30 cm) long, 5 in (12.7 cm) wide; tentacles, up to a maximum of 165 ft (50 m) long.

It is not a jellyfish, it is a siphonophore, which is an animal made up of a colony of organisms working together.

It is most commonly found in the tropical and subtropical regions of the Pacific and Indian oceans and in the northern Atlantic Gulf Stream.


The best treatment for a Portuguese man-o-war sting is:

To avoid any further contact with the Portuguese man-o-war, carefully remove any remnants of the creature from the skin (taking care not to touch them directly with fingers or any other part of the skin to avoid secondary stinging);

Apply salt water to the affected area (not fresh water, which tends to make the affected area worse)

Then follow up with the application of hot water (45 °C/113 °F) to the affected area, which eases the pain of a sting by denaturing the toxins.

If eyes have been affected, to irrigate with copious amounts of room temperature tap water for at least 15 minutes, and if vision blurs or the eyes continue to tear, hurt, swell, or show light sensitivity after irrigating, or there is any concern, to see a doctor as soon as possible.

Vinegar is not recommended for treating stings. Vinegar dousing increases toxin delivery and worsens symptoms of stings from the nematocysts of this species. Vinegar has also been confirmed to provoke hemorrhaging when used on the less severe stings of nematocysts of smaller species.

Further details at http://www.iws.ie/guides-page52707.html