Watch out for bluebottle jellyfish as water warms up

Local surf lifesavers say it is time to keep an eye out for bluebottle jellyfish as water temperatures rise. Photo/File

Local lifeguards say it is time to keep an eye out for bluebottle jellyfish - with sea temperatures up to four degrees warmer than usual for this time of year.

Surf Life Saving NZ national lifesaving manager and Omanu surf club's Allan Mundy said it was a "very expected" time of year to see the jellyfish around local beaches.

"Water temperatures have been warmer and when the temperature gets to around 19 or 20 degrees you'll see waves of bluebottles coming in."

Bluebottle jellyfish, also known as Portuguese man o' war, can vary in size and Mundy said their appearance could attract many to take a closer look.

"They really are beautiful, they're cobalt blue and look like a little plastic bag, underneath is a darker purple-blue with an acorn-shaped bag with tentacles."

He said at high tide the bluebottles could settle on the sand but could still sting, which could have a punch.

"Little girls could be walking along and see how pretty they are and go to pick them up."

Mundy recommended keeping away from the jellyfish because their tentacles could stretch up a metre long.

"If you do see them in the water think twice about going in."

Tauranga marine ecologist Professor Chris Battershill said the "fascinating" species was not a serious concern for the public, however, people prone to allergic reactions should be cautious of the stingers, especially when they washed ashore.

"Their tentacles can dry up but they can remain viable. There is a spear in one of the glands which work as a mechanic trigger, it can be set off when something touches them."

Battershill said many people thought vinegar the best remedy to treat a sting but the best course of action is to wash the sting with warm sea water.

Papamoa Surf Lifesaving Club chairman Andrew Hitchfield said he had not heard of any sightings of bluebottles at Papamoa.

He said he had seen jellyfish eggs while swimming at Mount Maunganui beach yesterday morning, however he was not sure what species they were.

Hitchfield said it was normally common to see bluebottle jellyfish later in the summer months, but the temperature of the water was about four degrees warmer than this time last year.

"As the water heats up we will be seeing more of them."

Mount Maunganui Surf Club general manager Glenn Bradley had not received any reports of jellyfish sightings around Mount main beach.

He said it was important parents kept an eye on their children to make sure they stayed away from the bluebottles.

If you see a bluebottle jellyfish
- Stay a metre away from them if you do see one in the water or washed ashore
- Keep children and dogs away from them because they can still sting after they wash ashore

What to do if you do get stung
- Remove the stinger if possible, Chris Battershill recommends wearing gloves or a wet towel to make sure you do not get re-stung
- Washing the sting with warm sea water or urine is best
- Next best thing is to wash the sting with fresh water
- Do not wash the sting with vinegar
- Keep the sting clean and do not touch or scratch it
- If you require help call 0800poison