Italian holidaymakers are having to cope with the arrival of swarms of jellyfish to some coastal areas, after braving the recent invasions of 'toxic algae'.
Large groups of jellyfish have appeared at beaches in the northern region of Liguria, at resorts around the Sicilian city of Messina and in parts of the Adriatic Sea near Trieste.
The species in question is the Pelagia noctiluca, which glow in the dark and packs a painful sting, hence its common name, the mauve stinger.
The jellies have come while several resorts are still battling with invasions of Ostreopsis ovata - the "toxic seaweed" that caused authorities to ban bathing on beaches near the northwestern city of Genoa and at Fregene near Rome. Experts say the recent heat wave and rising sea temperatures caused by climate change are factors behind both phenomena.
"It is a sign that the sea is under stress," said Silvio Greco, the Commissioner of the Central Institute for Scientific and Technological Research Applied to the Sea (ICRAM).
Greco explained that Pelagia noctiluca have also turned up on beaches in France and Croatia and that other jellyfish with less powerful stings have appeared in larger-than-usual numbers in other parts of Italy.
Experts claim it is normal for certain species of marine life to "bloom" in this way occasionally, but they believe the increased frequency of this type of phenomena is an effect of global warming.
Climate change is evident in the arrival of tropical species of fish in the increasingly warm Mediterranean too, they say.
"Until recently, these blooms were considered cyclical events which take place every 12 years or so," commented Alessandro Lucchetti, a marine biologist with the National Research Council (CNR).
"They occurred in 1992 and in 2003, but since then they have happened every year in different parts of the Mediterranean.
"This year's bloom is probably also down to the increase in surface temperatures, which creates ideal conditions for the jellyfish to breed".
Lucchetti explained that the resorts affected will have to wait for strong currents to come along to sweep the jellies away.
Jellyfish are slow swimmers which tend to drift wherever the water takes them, so they are unable to move away of their own accord.
Health Ministry officials have stressed that, like the algae, the jellyfish are a nuisance but do not represent a serious threat to holidaymakers' health.
They recommend people who get stung bathe the wound in salt water, not freshwater, and use cortisone-based creams.
