Dangerous jellyfish appear in Wellington Harbour
Two species of stinging jellyfish have appeared in Wellington Harbour, one of which has recently been implicated in the death of a man in Auckland.
National Institute of Water and Atmospheric Research (Niwa) marine biologist Dennis Gordon said the two species, the spotted and lion's mane jellyfish, should be avoided, with the toxins from the latter indicated in the recent death.
"Lion's mane has a really bad stinger, so that's certainly to be avoided.
"I had a call from someone in Environmental Sciences and Research [ESR], and they were testing some toxins associated with the death of a person in Auckland. There was no guarantee it was the jellyfish, but the person had been stung multiple times."
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Gordon said this was an unusual case, and a stung person would likely have to suffer anaphylactic shock for any stings to be fatal.
Niwa became aware of the presence of the spotted jellyfish after a team member was stung on the face last week.
"She said it wasn't too painful – a kind of 'stinging-tingling' that lasted about 20 minutes. She did not get out of the water.
"The lion's mane is likely to be more painful, especially if you get multiple stings. She has seen both species in the harbour lately."
The lion's mane, which can grow up to a metre in width, is identifiable by its purple top. "It is one to look out for and it does seem to be in the harbour at the present time. In what numbers, I cannot say."
Although both species are no strangers to the harbour, Gordon said he was surprised to see them at this time of the year.
Some had washed up in Evans Bay, and there had been separate reports in Shelly Bay.
ESR said the Auckland death was being investigated by the coroner, and it could not comment further.
Australian Marine Stinger Advisory Services director Lisa-Ann Gershwin has experienced first-hand just how painful a lion's mane sting can be. "The sting they have can be a bit sharp, but mostly it's an ongoing raw burn kind of feel."
She said bluebottle jellyfish were the only stingers in New Zealand waters that delivered more of a punch.
Co-creator of The Jellyfish App, which allows users to identify and treat stings, Gershwin said she had been inundated with sightings of lion's mane swarms around New Zealand all year.
"I've been having reports of lion's manes going absolutely manic from New Zealand and Australia in August and September. That's a bit of a head scratcher – it's very early."
Warmer sea temperatures, favourable breeding conditions, and reduced predator numbers could be contributing to the blooming.
If swimmers found themselves surrounded by jellyfish, Gershwin said it was best to move slowly to avoid water flow pulling the stingers towards the body.
If stung, it is best to wash the area thoroughly with salt water.
"There is a slime coating that their sting leaves behind, and it is absolutely saturated with microscopic stinging cells. You rinse to get rid of those stinging cells."
Vinegar or urine could also be used to treat stings.
This comes a week after a large numbers of another species, named Aequorea forskalea, washed up on Lyall Bay after they were attracted by unusually warm water temperatures.