Swimming has been regularly interrupted on beaches along the Aquitaine coast since the end of July, and just like last year at the same time, due to the presence in the water of Portuguese man o' war, a marine invertebrate with stinging tentacles, with local authorities calling for caution.
“ The sting can be very painful and cause serious effects. Never touch it, even if it's dead." , warns the prefecture of Pyrénées-Atlantiques on Facebook, while the regional press has reported temporary closures from the Arcachon basin to the Basque coast.
“ All the beaches on the Landes coast are affected, but there haven't been any mass strandings.“,” Julien Lalanne, of the Joint Syndicate for the Management of Landes Bathing Areas (SMGBL), told AFP on Tuesday, calling for avoid psychosis" . " Last summer, they arrived suddenly and left just as suddenly." added the rescuer.
Read also Portuguese man o' war, which are highly irritating, are appearing on the beaches of the Southwest.
A fascinating marine creature with formidable tentacles
Originating from tropical waters, Portuguese man o' war, recognizable by their bluish color, are carried by the wind towards the beaches. The Portuguese man o' war (Physalia physalisThe Portuguese man o' war, also called the Portuguese man o' war or sea bladder, is a siphonophore, that is, a marine organism made up of a colony of small, specialized individuals called polyps, which function together as a single living being. It belongs to the group of cnidarians, aquatic animals possessing stinging cells called cniocytes, used for defense and to capture their prey.
It lives primarily on the surface of tropical and subtropical seas in the Atlantic and Indian Oceans, but can be carried by currents and wind to European coasts. Its float, called a pneumatophore, allows it to remain at the surface and move with the water's currents. Its long tentacles, which can reach several tens of meters in length, contain nematocysts capable of releasing venom to capture prey and defend itself.
From stings that are sometimes very painful to possible complications
Although not fatal, their stings sometimes cause "very acute" pain and require the mobilization of lifeguards who, unable to monitor swimming, are forced to temporarily raise the purple or red flag.
The protocol is well-established: rescuers relieve the pain by applying shaving foam to the stings, then scrape off the remaining tentacles with a credit card, before rinsing everything with vinegared seawater. To prevent injuries, they use nets to catch these unpredictable creatures and try to locate schools of them offshore on jet skis.
Interviewed by AFP in 2025, a doctor from the poison control center at the Bordeaux University Hospital estimated that serious complications – muscle tetany, or even respiratory distress, which can lead to drowning – occur “in 8 to 10% of cases.” Seven out of ten patients describe pain lasting one to two hours, “worse than childbirth without an epidural,” she specified.
What to do if stung by a Portuguese man o' war.
The right actions :
Get out of the water immediately to avoid another sting.
Rinse the affected area with seawater (never fresh water).
If possible, use vinegared seawater (1/4 food vinegar and 3/4 seawater), preferably lukewarm.
Consult a doctor if the pain persists 30 minutes after the sting.
Watch for the appearance of symptoms: A sting can sometimes cause more serious reactions such as: feeling unwell or losing consciousness; an accelerated heart rate and blood pressure; dizziness; abdominal pain or vomiting.
If these symptoms appear, you should contact the local first aid station or call the SAMU (15).
Gestures to absolutely avoid :
Do not rub the stung area with your hand.
Do not cut the wound, suck out the venom, or apply urine.
Do not rinse with fresh water, as this may cause further release of venom from tentacles remaining on the skin.
Do not apply any ointment or gel, even hydroalcoholic.
(Source: Nouvelle-Aquitaine Regional Health Agency)
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