The menace of the méduse, looking out for jellyfish

Of all God’s creatures among us, some seem less admirable than others: snakes, wasps, cockroaches, and moths. In the nautical field, the méduse (jellyfish) romps home unchallenged … by several lengths. The villain along our Riviera coasts, the Pelagia noctiluca (mauve stinger), stings thousands of bathers every year. Finally modern science and computer modelling are being harnessed, financed by the Conseil Général, to combat this age-old menace. If nothing were done, our vital summer tourist industry could be threatened with out-of-bounds beaches and infested yacht anchorages. Yacht cooling-water intakes can also become obstructed by these unwelcome creatures. The Oceanographic Laboratory of Villefranche-sur-Mer is investigating jellyfish habits, and how to predict the movement of swarms near our beaches, since it will never be possible to eradicate them.

Menace of the MéduseMedazur posts Jellyfish sightings throughout the summer, as illustrated in this 2012 prediction. Regional forecasts will be available in June, but you’ll have to wait until July 1 for local warnings.P. noctiluca is actually increasing its activity, apparently because increased pollution run-off from the land provides more plankton to feed on, while over-fishing is reducing the number of predators like swordfish, sunfish, tuna and turtles. Changing these factors would be a very long-term aim, but forecasting risky areas gave promising results in a trial campaign in summer 2012, ending September 7th. From mid-June, 48-hour forecasts with maps will be issued daily based on measured sea-currents, wind, plankton count, temperature, salt level and pollutants. Go to and click on “Previsions-d-echouage”. These bulletins will also be available for iPhones and iPads with the new Jellyfish Report app (see below). People are encouraged to report sightings by SMS from anywhere along the Coast to improve data input.

Should prediction fail, many local beaches (and mega-yachts) will try to protect bathers with anti-jellyfish nets, but these are expensive and liable to damage, so a sharp lookout is still necessary. Wear a mask and snorkel (and even a combinaison – a wetsuit – which protects from stings) and KEEP CALM. If stung, apply vinegar or seawater – not fresh. No ice or rubbing, consult a pharmacist if needed, and keep an antihistamine handy.