Bluebottles back on beaches

Bluebottles have been sighted on Nelson beaches, riding the waves and washing up on shore – and potentially delivering a nasty sting to unsuspecting swimmers and walkers.

What may surprise some people is that the famed and perhaps dreaded creature, otherwise known as a Portuguese man o’ war, isn’t a jellyfish at all.

The Nelson City Council’s group manager for environmental management, Mandy Bishop, said bluebottles (Physalia physalis) were regular visitors to Nelson waters and could be found floating out on the ocean and, on occasion, at local beaches.

They are not jellyfish but belong to an order of animals called siphonophores, she said.

Each individual bluebottle is not a single animal but a colony of co-operating multicellular organisms that drift along the ocean’s surface. The wind pushes them along by their crests, or “sails”.

Persistent onshore winds blow them through the water onto beaches.

Although their tentacles could deliver a painful sting, they were not usually dangerous, Bishop said, and wearing a rash vest or wetsuit would provide some protection for swimmers.

Auckland Museum curator of marine biology Clinton Duffy said the foraging predator could be found in every ocean in the world. It was usually seen in its biggest numbers in spring, when the “whole pelagic environment is kicking off”, and through the summer.

As to how bad the pain level of the sting was, that depended entirely on how much tentacle was involved, he said.

Duffy said it felt similar to a “very painful bee sting” and advised those with allergies to bee stings to be cautious around bluebottles.

Should you be stung, the worst thing to do was try to rub it off, he said. That would just trigger more stinging cells to fire.

“You have to carefully peel them off and try to avoid rubbing or brushing them off.”

The Nelson City Council advises people to keep their dogs away from bluebottles and to seek veterinary advice if a dog ingests the animals.

Here are some steps from the council for treating a bluebottle sting, whether for humans or dogs.

1. Flush the stung area with seawater, or fresh water if seawater is unavailable, to remove the tentacles.
2. If tentacles are still attached, use a dry towel to remove them. Wear gloves if you have some.
3. Soak the stung area in heated tap water for 15 to 20 minutes. Have it as hot as the person can bear without causing skin burns, and no more than 45C. A shower can be used for stings to the torso. You can repeat this for up to two hours after the injury. Make sure to limit this to 15 to 20 minutes at a time with breaks between to allow cooling of the skin.
4. Take pain relief following hot water soaking.
5. Seek medical assistance if symptoms reflect an allergic reaction, as with any sting.

By Warren Gamble, Nelson Mail