Australia’s Toxic Doom-Inducing Jellyfish Season Has Officially Begun

This week, two children were stung by Irukandji jellyfish, marking the start of the season for these deadly psychotropic Cnidaria. Luckily both survived, thanks to speedy medical intervention, but don't let the administration of analgesics comfort you: The last 12 months have been peppered with worrying news about the species in Australia.

The Irukandji, native to northern waters of Australia, is one of the ocean's deadliest critters. Measuring just one cubic centimeter, their sting contains a neurotoxin that induces an overwhelming feeling of impending doom. As marine biologist and jellyfish expert Lisa-Ann Gershwin explains, "It's not that you're afraid, it's that you absolutely believe you're going to die and you just want to get it over with. Some people describe it as being afraid they're not going to die."

A medical superintendent by the name of Jack Barnes was the first person to discover the connection between the symptoms and the jellyfish in 1961 when he stung himself, his nine-year-old son, and a local lifesaver on purpose to observe the symptoms. He described the psychological effects as "dreadful anxiety and wretchedness."

But it's not just the worst trip ever. Irukandji stings bring on a huge rush of adrenaline that pushes blood pressure to dangerous levels. They cause sweating, vomiting, and excruciating back and kidney pain. Dennis Hayles was stung at Low Isles in Queensland, and once described the physical symptoms that set in after only ten minutes: "I was convulsing… It felt like I had all these electric hairs in my throat and every time I time I tried to breathe in, I just choked and was vomiting up this foamy stuff."

Hayles survived, but other victims haven't been so lucky. Over the years, Irukandji have claimed at least 70 lives—although the exact number is hard to know given the weird way in which they kill. The initial sting feels more like a mosquito bite, not worthy of reporting at all, with death coming later in the form of a heart attack or stroke.

Don't stress too much though, you'll never see the little guys coming. "The jellyfish bodies and tentacles are invisible in water. It's like a diamond dropped into a glass of water; you just can't see them," notes Lisa-Ann.

Given that their smallness prevents them from being seen, the discovery of a huge one off the coast of Western Australia could be seen as good news. Then again, it is a massive, deadly, doom-inducing jellyfish, so probably not. Measuring in at a foot, the creature is thought to be part of a newly-discovered larger Irukandji species that can be as large as 50 centimeters, not including tentacles.

Until now, Irukandji blooms have stayed away from more populated regions, with South East Queensland and New South Wales considered to be stinger free. "It's very clear that that is no longer true," says Lisa-Ann. "There have been nine events of highly dangerous jellyfish in southern waters."

So is climate change bringing these psychedelic stingers to beaches all over Australia? It would take time as their whole habitat would need to make the shift. However, as Macquarie University Professor, Rob Harcourt, told the Daily Telegraph last year, as winters get warmer, "animals being swept down in the EAC (East Australian Current) are more likely to survive.''

A more immediate threat from the changing climate is an observed increase in jellyfish numbers and toxicity brought on by warmer water. So while Irukandji may not arrive at Bondi Beach this week, when they do finally get there they'll be larger in number and even more deadly than usual.

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