Why we don't know if Irukandji jellyfish are moving south

January 22, 2019 by Kylie Pitt And Dean Jerry, The Conversation

Reports that Irukandji jellyfish might be moving south may be panicking people unnecessarily. It's almost impossible to tell where the tiny jellyfish are along our coast, but that could change with new technology that can "sweep" the ocean for traces of DNA.

Since the Christmas period nearly twice the usual number of people have suffered the excruciating consequences of being stung by Irukandji. The stings are rarely fatal, but can require medical evacuation and hospitalisation.

These reports of southward movement are almost a yearly tradition, often sensational, and accompanied by varying expert opinions about whether climate change is driving these dangerous tropical animals south, towards the lucrative beach tourism destinations of southeast Queensland.

But simply counting the number of Irukandji found, or the number of reported stings, tells us very little about where the species can be found.

A simple question but difficult answer

"Where are Irukandji located, and is that changing?", might seem like a straightforward question. Unfortunately, finding the answer is not easy. The only definitive way to determine where they are is to catch them – but that poses many challenges.

Irukandji are tiny (most are about 1cm in diameter) and transparent. Along beaches they are usually sampled by a person wading through shallow water towing a fine net. This is often done by lifeguards at beaches in northern Queensland to help manage risk.

Read more at: 

Irukandji warning: deadly jellyfish will be 'fired up' by north Queensland's big wet

Tiny creatures prefer calm, warm waters – with risk of stings increasing after rainfall

Australian Associated Press

Thu 27 Dec 2018 23.40 GMT

Irukandji jellyfish may be elusive during far north Queensland’s big wet but they’re set to come back in big numbers when the sun comes out.

After they forced the closure of two northern Queensland beaches last weekend, including Ellis Beach near Cairns when a teenage girl was admitted to hospital with stings to her upper body, no irukandji have been spotted in swimming areas since.

One of the world’s deadliest creatures, the tiny box jellyfish prefer calm, warm waters and tend to stay away during heavy rainfall, with some far north areas receiving up to 200mm since Boxing Day.

But the risk of irukandji stings will increase once the rain stops, according to a James Cook university toxicologist, Prof Jamie Seymour. “All this rain, it’ll fire all jellyfish up,” he said.

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Two children, six and 10, survive stings by Irukandji jellyfish on WA beach

Health officials say the intense pain generated by the Irukandji’s sting raises the victim’s blood pressure which can lead to death

Calla Wahlquist

theguardian.com, Wednesday 7 January 2015 06.23 GMT

Two children have been treated for the sting of a tiny jellyfish known for producing “a sense of impending doom” in its victims.

The children, a six-year-old girl and a 10-year-old boy, were stung by Irukandji jellyfish at Honeymoon Cove beach in far-north Western Australia on New Year’s Day and 4 January respectively.

A spokesman for the WA Country Health Service said both were taken to the emergency department of the Nickol Bay hospital and “responded well” to treatment.

Jamie Seymour, an associate professor from James Cook University and recognised expert in venomous Australian animals, said symptoms from the sting of the thumbnail-sized jellyfish take 20 minutes to develop and “range from a mild headache to death”. Usually, though, they present as “intense, overall pain”.

“[People get] stomach cramps, nausea, vomiting and pain coming in waves,” Seymour said. “But it’s not a wave that comes and goes, it’s a wave that builds up. It’s progressive. It peaks, and peaks again, and peaks again.”

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Giant jellyfish pops up in the north-west

An unusually huge toxic jellyfish has been found off the north-west coast of Western Australia.

The Keesingia gigas is one of two new species of Irukandji jellyfish recently discovered by scientist and Marine Stinger Advisory Services director Dr Lisa-Ann Gershwin.

Dr Gershwin says this jellyfish is of particular interest because it is so much larger than usual jellyfish causing Irukandji syndrome, resulting in pain, nausea, vomiting and in extreme cases, stroke and heart failure.

"It's just a whopping huge animal. We normally measure Irukandji in terms of size of your pinky or thumb nail—this one is more the size of an arm," Dr Gershwin says.

Dr Gershwin says the Keesingia gigas was first photographed in the 1980s but a specimen was only captured in 2013 near Shark Bay by marine scientist and Dr Gershwin's previous supervisor John Keesing, after whom the jellyfish is named.

Read more at:

New jellyfish discovered: giant venomous species found off Australia

WA specimen of new Irukandji jellyfish sparks particular scientific interest because it has no tentacles

Australian Associated Press

theguardian.com, Friday 8 August 2014 01.57 BST

A giant and extremely venomous jellyfish found off Western Australia’s north-west coast has researchers stumped because it appears to have no tentacles.

Keesingia gigas is one of two new species of Irukandji jellyfish recently discovered by the director of Marine Stinger Advisory Services, Lisa-ann Gershwin.

While Irukandji jellyfish are normally only the size of a fingernail, Keesingia gigas is the length of an arm and believed to cause the potentially deadly Irukandji syndrome.

The condition can cause pain, nausea, vomiting and in extreme cases, stroke and heart failure.

Gershwin said Keesingia gigas was first photographed in the 1980s, but a specimen was not captured until 2013, near Shark Bay by the marine scientist John Keesing, after whom the jellyfish is named.

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