The UK’s leading marine charity has received several reports in the last week of Portuguese man o’ war washing up on beaches. There have been sightings at Newgale in Pembrokeshire, Portmelon and Porthloo on the Isles of Scilly and Gwithian, Pendeen, Porth, Holywell Bay, Polzeath, Hayle and Tolcarne beaches in Cornwall. This week, Perranporth beach in north Cornwall was temporarily closed as a precaution due to the number of specimens found.
Dr Peter Richardson, MCS Head of Ocean Recovery, says they’ve also been reported recently in Ireland: “Portuguese man o’ war are ocean-going animals, propelled by the wind on their inflatable sail as they fish the depths with their stinging tentacles. Recent persistent winds have blown them from the Atlantic onto our shores.”
Portuguese man o’ war (Physalia physalis) are only occasionally reported in UK waters, but this is the second consecutive year they have turned up in numbers. Last year they were spotted in September on beaches in the South West UK, with significant strandings of the species also reported in in 2009 and 2012.
The Portuguese Man o’ War isn’t a jellyfish but is closely related, and consists of a floating colony of hydrozoans – several tiny marine organisms living together and behaving collectively as if one animal. A purple float, shaped a little like a Cornish pasty, is visible on the water’s surface whilst blue, tentacle-like ‘fishing polyps’ hang below; these can be tens of metres in length.
“It’s the tentacle-like polyps that can give an agonising and potentially lethal sting,” says Dr Richardson. “Because a stranded Portuguese Man o’ war looks a bit like a deflating purple balloon with blue ribbons attached, children will find it fascinating. So, if you’re visiting west coast beaches in the next few weeks it’s well worth making sure you know what these animals look like and that no one picks them up. The stings can be unbelievably painful and in rare cases, fatal. We’d like people to report any sightings of Portuguese man o’ war to our website so we get a better idea of the extent of the strandings.”