Marine biologists report that the numbers of poisonous jellyfish around the coasts of Spain have tripled.

The worst effected areas are the Costa Brava, the Costa Dorada and the Costa del Sol. Overfishing is being blamed by some: they say it has reduced the numbers of fish which feed on the jellyfish.

Off the coast of La Manga in the south-east the sea had turned a milky blue from the proliferation of jellyfish.