Jellyfish in Sardinia: which ones, where and what (actually) to do if stung
The mauve one that stings, the harmless “fried egg”, the by-the-wind sailor that isn’t a jellyfish at all: recognise them at a glance, and the right protocol after contact — no ammonia, no myths.
It is the most-clicked search of the summer, second only to the weather: “jellyfish today?”. The truth is less dramatic than the headlines: in the Sardinian sea the unpleasant encounters come down to a few species, almost all recognisable at a glance — and snorkellers start with an advantage: with a mask you see them long before someone swimming eyes-shut.
The three you should know by sight
The mauve stinger (Pelagia noctiluca) is the one that matters: small, pink-violet, speckled, with long thin tentacles. It is the only genuinely stinging one among the common species, and it arrives in swarms, carried by currents and wind: if you see two, assume twenty.
The fried-egg jellyfish (Cotylorhiza tuberculata) is the big harmless one of late summer: a yellow dome with a tuft at the centre, often escorted by tiny fish. Watch it, photograph it, don’t touch it (out of respect, not danger). The by-the-wind sailor (Velella velella), finally, is not even a jellyfish: the blue flotillas blown ashore in spring are drifting colonies, practically harmless to skin.
The protocol after a sting
If contact happens: get out calmly and rinse only with seawater — never fresh water, which makes the remaining stinging cells fire. Lift off any filaments with the edge of a rigid card, not with your fingers. Then the thing that works: heat (warm sand, warm seawater) or an astringent gel from the pharmacy.
Myths to retire: no ammonia, no urine, no alcohol — they only irritate. Strong burning fades in 10–20 minutes; if general symptoms appear (breathing difficulty, spreading reaction, feeling unwell) it is a case for emergency services — rare, but worth knowing.
Living with them as a snorkeller
Two habits cut encounters almost to zero: check the downwind side (mauve stingers pile up where the wind pushes, often in the “sheltered” corner of the bay) and wear a rash guard, which covers 90% of exposed skin. And if the swarm is there, the right choice is the simplest: change cove. The wind that brought them today will take them away tomorrow.
