How do you treat a lion’s mane jellyfish sting?

26 Jul 2017

Lion’s mane jellyfish in Dublin Bay. Image: Nigel Motyer

The bane of a sea swimmer’s life, jellyfish stings are a nightmare. But what if there was a fast way to treat a victim?

Jellyfish fill many roles on this planet. As a predator, they play a crucial part in the marine food chain. In aquariums, they remain the most beautiful species to observe.

They are muses for artists, models for computer desktop backgrounds and, unfortunately, painful inhabitants of our near-coast seas.

While most are harmless, a few pack quite a punch. There are the Portuguese man o’ war and box jellyfish, for example, which can kill humans with their toxins.

There’s also the mauve stinger, which inflicts more agony on Mediterranean swimmers than any other jellyfish, and the upside-down jellyfish, which invaded Europe through the Suez Canal.

King of the sea jungle

More common around the British Isles, though, is the wonderfully named lion’s mane jellyfish and, if you’ve ever come into contact with it, you’ll surely remember it.

It’s the largest known species of jellyfish and, given its striking orange or brown colour, it stands out among its transparent or white-ish pals.

Hundreds of bathers in the UK and Ireland are stung every year by jellyfish armed with 1,000 tentacles, which can reach several metres in length. The pain is much like a nettle sting, though it can last far longer.

However, a new study from researchers at NUI Galway and the University of Hawaii at Manoa, shows that the best first aid for a lion’s mane sting is to rinse it with vinegar to remove tentacles, and then immerse the affected area in hot water, at 45 degrees Celsius, or apply a heat pack, for 40 minutes.

Lion’s mane jellyfish in Dingle harbour. Photo: Nuala Moore

Lion’s mane jellyfish in Dingle Harbour. Image: Nuala Moore

That said, treatments for one jellyfish sting may not work on another.

“What most people don’t understand is that these jellyfish – the lion’s mane, the Portuguese man o’ war and a box jellyfish – are as different from each other as a dog and a snake,” said Dr Tom Doyle, lead author of the study and lecturer in zoology at the School of Natural Sciences at NUI Galway (NUIG).

“Therefore, when developing first aid treatment for a jellyfish sting, it is very important to test different treatments on these very different types of jellyfish.”

Apply vinegar

Interestingly, some of these findings go against what was previously thought. For example, earlier this year, the American Chemical Society advised sufferers to wash the painful area out with seawater, before applying vinegar.

Another approach is to apply cold packs to treat the sting. Doyle and his team, though, found otherwise for the lion’s mane jellyfish sting.

Cold packs induce “significant increases in venom delivery”, according to NUIG, whereas vinegar did not.

“Now that we have shown that vinegar and hot water work on these three jellyfish species, it will be much easier to standardise and simplify first aid for jellyfish stings where many different types of jellyfish occur,” said Doyle.

Deep dive

Jellyfish are pretty fascinating.

Last year, the US National Oceanic and Atmospheric Administration was diving in the Marianas Trench, thought to be the deepest part of the ocean, searching for new species of sea life.

On one of its trips, it captured footage of an amazing species at a depth of around 3,700ft, in what is aptly called the Enigma Seamount.

Scientists identified this hydromedusa as belonging to the Crossota genus, which are very small variants of what we see all over the world. They are often noted for their colourful heads (bells).

Gordon Hunt was a journalist with Silicon Republic