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Swimmers face jellyfish threat

WebMD UK Health News
Medically Reviewed by Dr Sheena Meredith

2nd August 2013 - Bathers are being advised to take care in the sea because of a surge in the number of jellyfish off parts of the UK coastline. In the latest incident 4 people - including a young boy - were stung by jellyfish on Thursday afternoon in Anglesey.

Holyhead Coastguard was called to Lligwy Beach and advised holidaymakers to keep out of the water. "We were there to check they didn’t have any adverse effects such as anaphylactic shock," a coastguard spokesman told the Daily Post. "Jellyfish stings can be dangerous. In this case it was just painful for them."

Jellyfish are mushroom-shaped creatures that often float near the surface and have long, thin tentacles on the underside of their bodies. The tentacles are covered with small poisonous sacs called nematocysts, which if touched produce a nasty sting.

Hot weather brings out the jellies

Marine experts say the increase in moon, compass, blue and lion's mane jellyfish is down to the onset of warm weather. The Marine Conservation Society says the highest concentration of jellyfish is being seen off the coast of Devon and Cornwall, North Wales and the North West of England.

Lion's mane jellyfish have a particularly nasty sting, and these are the jellies being sighted in North Wales.

Normally jellyfish numbers begin increasing in spring, but the cold start to the season delayed the onset of jellyfish blooms appearing. "The scarcity of jellyfish reports before June was unusual and could well be linked to the exceptionally cold spring," explains Dr Peter Richardson, a jellyfish expert at the Society.

He is asking the public to report any sightings for inclusion in the charity's National Jellyfish Survey - now in its 10th year.

However, the Marine Conservation Society is urging anyone taking part in the survey to "look but don't touch!"


For bathers unfortunate enough to have too close an encounter with a jellyfish, the symptoms are severe pain, an itchy rash, and welts where the tentacles have touched the skin.

In rare cases, a serious reaction to a jellyfish sting can result in breathing difficulties, coma or even death. The NHS advises dialling 999 if someone stung by a jellyfish is very young or elderly or has:

Most jellyfish stings, though, can be treated without medical help.

First, remove any remaining tentacles from the skin using tweezers or a clean stick. The affected area should be soaked in vinegar for between 15 to 30 minutes to prevent further toxins from being released. Unless you happen to be standing next to a fish and chip shop, the best alternative is likely to be close at hand - seawater.

Do not be tempted to use fresh water as this could lead the nematocysts to release more venom.

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