Every summer, holidaymakers dread the appearance of jellyfish on the beaches. The stings, which are not fatal in France, are nevertheless painful and can cause burning and itching. Learn the right reflexes to relieve them.

Jellyfish : what to do in case of sting ?

To the great displeasure of holidaymakers, jellyfish are inviting themselves more and more often on our beaches, and logically the frequency of their stings is increasing. And the summer of 2021 is no exception to the rule: pelagic jellyfish, those that are the most stinging, have made their return to the Côte Bleue west of Marseille since July 23.

What does the pain feel like after a jellyfish sting?

The jellyfish has stinging cells, called cnidocytes, present on the tentacles, but also sometimes on the whole jellyfish.which, in contact with a "predator", send a venomous liquid.

The pain caused by the jellyfish sting is similar to an electric discharge. It is immediately accompanied by a burning sensation, of varying intensity depending on the person and the species, followed by itching. If you have all these symptoms, you have probably been stung by a jellyfish.

How to react in case of a sting?


  •     Get out of the water immediately: the pain could make you panic and you could drown.

  •     Carefully remove the fragments of tentacles remaining on the skin with a thin object such as a knife or a piece of cardboard.

  •     You can also put wet sand on the area, scraping lightly, to remove the stinging filaments more easily without breaking them.

  •     Rinse the wound thoroughly with sea water. Do not use fresh water as it may rekindle the pain.

  •     You can also approach the wound with a heat source such as a cigarette butt. Indeed, the venom of the jellyfish is thermolabile: it dissolves with heat.

  •     Vinegar is also a solution, especially since it is readily available at beach first aid stations. It contains acetic acid which allows to detach the filaments without making them burst.

  •     Consult a doctor in case of a sting on the face or an allergic reaction (especially breathing difficulties).

  •     Inform the authorities of the presence of jellyfish. They will take care of alerting the bathers.

Afterwards, at home

  •     When you get home, disinfect the wound with a sterile compress soaked in antiseptic.

  •     In case of a moderate reaction, apply an antihistamine ointment available without a prescription.

  •     If the burning sensation persists after 48 hours, consult a doctor who can prescribe a corticoid cream.

  •     In all cases, monitor the evolution of your sting in the following days.  
  • For people with an allergic background, vigilance is required: a strong allergic reaction can occur after several stings. 

What not to do after a jellyfish sting

  •     Do not rinse the sting with fresh water (no need to rush to the beach shower) as this will burst the remaining cells and release the venom.
  •     Do not suck on the wound to suck out the stinging fluid.
  •     Do not apply alcohol.
  •     Do not cut the wound or cause it to bleed.
  •     Do not apply a tourniquet.
  •     Most doctors advise against urinating on the wound because of the risk of superinfection.
  •     Do not touch a dead jellyfish washed up on the beach because the stinging cells continue to sting. 

Why a resurgence of jellyfish?

Oceans depopulated by fish under the surge of jellyfish, would Jules Verne's prediction in "Twenty Thousand Leagues Under the Sea" be right? Scientists tend to think so since the last few years, all of which have been decreed "years of jellyfish".

This proliferation is due to a complex and still poorly understood combination of climatic factors and human actions:

  •     overfishing of tuna, the main predator of jellyfish, but also overfishing of small fish such as sardines and herring which, by feeding on jellyfish eggs and larvae, contribute to regulate their development;
  •     the decrease in the presence of natural predators of jellyfish: tuna, but also the leatherback sea turtle (which no longer finds places to lay its eggs), the sunfish (Mola-mola)
  •     ecological dysfunctions due to global warming: jellyfish multiply with pollution and the increase in water temperature. 

What species do we find in France?

There are more than 1,000 species of jellyfish. The jellyfish, eaten dried in Asia, is also a great predator for humans. The most deadly ones, like the cynanea capillata which can reach 40 meters in length, remain exotic monsters, haunting the Australian coasts. There is therefore no risk of coming face to face with such an animal on French beaches. But vigilance is still necessary: if the jellyfish is not aggressive, its stings are often painful.

To consult, this map which lists over the last 48 hours the locations of jellyfish on the Mediterranean: the portal of observation of jellyfish in the Mediterranean (map of the coastline).

Three species mainly pullulate on our hexagonal shores:

  •     the Aurelia jellyfish (Aureliaaurita) lives mainly in the Channel and the North Sea. It is distinguished by its blue or pink color and its hundred tentacles, slightly stinging;
  •     the sea lung or rhizostomapulmo jellyfish makes its nest in the Atlantic. It is characterized by its bluish reflections and its four weakly stinging arms, which divide themselves into eight arms welded at the end;
  •     the pelagic jellyfish or Pelugia noctiluca, orange or purple, is spotted with red. This is why it is also called the "purple jellyfish". Attracted by warm waters, it evolves in the Mediterranean Sea. But it begins to gain the coasts of the Atlantic because of global warming. It is by far the most stinging of the three.

Consisting of 97% water and 3% dry matter, the jellyfish belongs to the planktonic category. Devoid of skeleton, brain, lungs and blood, it has a gelatinous and transparent aspect. It consists of a cap called "umbrella" and tentacles, lined with mini suckers that, in contact with a body, release a very irritating toxin. The jellyfish lives at the bottom of the water. To feed, it goes up to the surface, propelled by its tentacles. There, it is carried away by the marine currents to strand on our beaches.

How to react in case of a jellyfish invasion on the beach?

In case of a strong jellyfish proliferation on our coasts, the access to the affected beaches is generally forbidden. We can also find the red flag "swimming prohibited" which indicates, among other things, a pullulation of jellyfish.

Some cities on the French Riviera had installed anti-jellyfish nets. An experiment that did not prove conclusive, deemed too expensive or not effective enough. According to France 3 Provence-Alpes-Côte d'Azur in 2020, only five beaches would still be equipped.