Irukandji jellyfish stings on rise prompt fears for southeast Queensland

A surge in stings from one of the world’s most lethal creatures has prompted fears that deadly jellyfish invisible to the naked eye are moving south.

Thea Dobbins shared what she remembers about being stung by an Irukandji jellyfish when she was a little girl.

The aquamarine waters of Queensland mesmerise thousands each year but lately a rising number of swimmers are paying an excruciating tax to play in the deep blue.

Often invisible to the naked eye, the waters of the Great Barrier Reef are home to the world’s most venomous creatures, the six species of cubozoan jellyfish. More commonly known as box jellyfish,a particularly horrendous sub-species is the Irukandji.

Over the past 12 months, there have been 39 recorded marine stings within the Mackay Whitsundays region – a staggering number when you consider it is almost double the year before.

Further, over the 32 years to 2016, there were on average seven Irukandji stings reported each year for the Whitsundays region alone.

With Irukandji already causing an annual $3bn dent via healthcare costs and tourism losses, some scientists are now scurrying to figure out whether the potentially-deadly creatures could migrate south, extending beyond the GBR and towards the heavily-populated southeast Queensland.

Stings have already been recorded around popular K’gari-Fraser Island on the Fraser Coast.

‘I remember collapsing on the ground’

One person who will never forget the Irukandji’s wrath is Thea Dobbins, 24, who was suspected to have been stung by one when she was about eight years old.

Thea Dobbins was just a little girl when she was stung by an Irukandji jellyfish.

It was a blue-sky morning during the September school holidays when Thea had asked her mum, Alexandra, if she could go to Bucasia Beach to build sandcastles with her older sister, Rachel.

Alexandra agreed if the girls stayed out of the water.

But young Thea thought she would be okay in a shallow puddle.

“I remember being in pretty striking pain … I wasn’t sure if I had been stung but I got upset pretty quickly,” Thea said.

Box jellyfish stings can cause what is nicknamed 'caterpillar tracks'. Picture: Thaikruea L.

“My sister told me I was a bit of a sook, and I was running to the house.

“From there the only thing I remember is collapsing on the ground before I got inside.

“Mum was a bit frantic.”

Thea said she can only remember parts of what happened next as she slipped “in and out of consciousness”.

“I don’t remember how long I was asleep for, I think the only reason I didn’t suffer bad health effects was because the doctor said the Irukandji was likely dead and was at the end of what was left.”

‘The pain is just so extreme’

Alexandra vividly remembers the drama of that “very scary” day, recalling it was “horrible to watch” her daughter in so much pain she seemed “delirious”.

She said Thea’s sting was the first and only time she’d ever had to phone an ambulance for any of her children.

“I put vinegar on her arm, and I put her in a cool bath, but she was still crying,” Alexandra said.

“She was in so much pain and her eyes were rolling … I didn’t know what to do and I couldn’t see any marks.

“I couldn’t calm her down … I didn’t know if she was going to pass out or stop breathing.

“I now know there was nothing more I could have done because the pain is just so extreme.”

Alexandra said growing up in Cairns had made her mindful of swimming in saltwater but her daughter’s experience had made her even more wary.

“I didn’t realise such a small amount of water was enough for it to happen,” she said.

“It was a sobering event.”

Thea Dobbins, now 24, said the pain from the sting was ‘excruciating’.

Irukandji hot spots

Like the Whitsundays, Cairns and Townsville are hot spots for Irukandji stings with 490 stings and 202 stings recorded respectively in the 32 years to 2016.

In the past 12 months, there were 28 presentations for marine stings across Cairns and Hinterlands, with incomplete data available for Townsville.

Across all three regions, most Irukandji stings occur in waters off the islands, with higher incidents during “periods of weak, westerly or north-westerly winds”.

“Slow wind speeds also led to more Irukandji stings, particularly in the Cairns region,” states a CSIRO report.

“Incoming tides were also associated with more Irukandji stings on beaches in the northern and central GBR, the majority of which were around low tide or over the early phase of the flood tide.”

Data shows most Irukandji stings in the Whitsundays occur around the islands. Just recently, a tourist was stung while swimming at Hamilton Island and required an emergency flight to Mackay Base Hospital for treatment.

Just recently, a 41-year-old man from New South Wales was swimming at Hamilton Island when an Irukandji jellyfish stung his face, causing considerable pain and Irukandji syndrome symptoms.

An RACQ CQ helicopter crew had to collect anti-venom before flying from Mackay to his rescue.

He was released from Mackay Base Hospital the next day; but not all Irukandji victims get off so lightly.

Box jellyfish stings can cause serious skin damage. The top left are marks left from the tentacle of a Chironex fleckeri (the largest of the box jellyfish) hours after a sting, the top right are scabs starting to form after 12 days, the bottom left is on day 24, and the bottom right is day 19. Pictures: Auerbach, Gupta, Van Hoesen and Zavala (top left) and Thaikurea, Siriariyaporn, Wutthanarungsan, and Smithsuwan (all other pictures).

Venom route similar to snakes

The Irukandji – which can range in size from about 1mm to a few centimetres, excluding the tentacles or arms – use their stinging cells to capture prey, for spatial competition, and for self-defence, says the University of Portugal’s Sara Cunha and Ricardo Dinis-Oliveria.

Those stinging cells pierce the human skin and release venom which “exerts its effect locally but can also enter the bloodstream … in a route similar to that of snake venoms, giving the distinctive 30 minute delay in the onset of symptoms”.

Symptoms may or may not include skin markings, lesions or necrosis, localised sweating, hypertension, an increased heart rate, intense pain, muscle cramping, back or abdominal pain, vomiting, nausea, anxiety, restlessness, shock, prolonged erections, acute renal failure, fluid in the lungs, bleeding or swelling in the brain, and death.

Thankfully, most Irukandji victims survive and go on to make full recoveries.

As the data shows, and as Advanced Care Paramedic Stephen Turner will attest to, most marine stings occur during the warmer summer months from November to May.

Mr Turner said most were suspected to be from Irukandji with paramedics carrying anti-venoms on board when and if they were needed.

The Irukandji – which can range in size from about 1mm to a few centimetres, excluding the tentacles or arms – use their stinging cells to capture prey, for spatial competition, and for self-defence, says the University of Portugal’s Sara Cunha and Ricardo Dinis-Oliveria.

“It’s important people are aware of the warning signs and what to do,” he said.

“If people are in doubt with what to do, QAS emergency medical dispatchers will be able to provide information over the phone.”

Avoid freshwater first aid at all costs

Mr Turner said anyone stung by a jellyfish should douse the sting in vinegar or ocean water if there was none.

“You want to make sure the leftover jellyfish stingers are off the skin,” he said.

“It’s important freshwater isn’t used because it can worsen the sting and cause more envenomation.”

Research shows venom can remain intact even after a jellyfish has died, with the commercial product Sting No More proving effective in the first aid treatment of Irukandji syndrome.

Box jellyfish stings can often go undetected for at least 30 minutes with one of the first symptoms being beads of sweat on the skin. Picture: Thaikruea L.

But whether southeast Queenslanders will ever have to worry about nearly-invisible killers in their patch of ocean remains to be seen with the scientific jury still out.

On the one hand, Irukandji were detected as far south as Hervey Bay for the first time in 2007 with research from Griffith University and James Cook University finding the jellyfish were “already capable of surviving the current summer pH and temperature conditions experienced in SEQ”.

On the other hand, the study showed juvenile Irukandji, or polyps, were more suited to the habitat of the GBR and thus unlikely to ever establish further south.

But in a different study from the Australian Institute of Tropical Health and Medicine, Dr Robert Courtney contradicts this, finding Irukandji thrives in water less salty and cooler than coral reefs.

And so while there is no unanimous ruling, perhaps the best advice is to avoid getting stung in the first place.

In reflecting on her experience, Thea says “it doesn’t how matter how deep the water is”, there is still a risk.

“I definitely feel more comfortable swimming in freshwater.”

For more information on what to do when you or someone gets stung by a jellyfish or how to prevent stings, visit the Surf Life Saving Queensland website.