Invasion of killer jellyfish on British beaches poses 'serious threat' to children

A swarm of deadly tropical jellyfish has washed into British waters after being blown in by strong winds.

Eighteen Portuguese Men o' War have already been found off beaches in the South West in the last week, compared to just six recorded here since 2003.

A seven-year-old boy needed hospital treatment after he was stung on the leg by a Portuguese Man o' War, which marine experts say pose a particular threat to children.

They have 3ft tentacles that carry a poisonous sting capable of triggering fatal anaphylactic shocks.

Normally found in the Caribbean, the creatures, which are relatives of jellyfish, have been swept thousands of miles to Britain by strong south-westerly winds.

A dozen have been found in the sea off Dorset since last Thursday, including the one that stung the young boy at Charmouth.

Four have been found washed up dead on beaches in Devon while one has been found near Land's End, Cornwall, and another off the Isle of Wight.

Peter Richardson of the Marine Conservation Society said the tentacles carry a cocktail of toxins that can kill humans.

A rare Portuguese man-of-war jellyfish, which was discovered in a cove in Devon

He said: 'When people get stung they have different reactions. Some just feel an agonising sting, others come up in lesions while some can go into anaphylactic shock.

'Children in particular are at risk. Beach users should be aware that these animals can present a serious threat.'

Julie Hatcher of the Dorset Wildlife Trust said: 'They have been blown here from the Caribbean and there could still be more about. We wouldn't expect just the odd one or two, we would expect them to be here in numbers.'

Children play on the beach at Saunton Sand in North Devon