One of the world's deadliest jellyfish is wreaking havoc on Queensland's southeastern coast. So far this summer, 22 people have been hospitalised with suspected stings from the Irukandji: a thumbnail-sized, hyper-toxic invertebrate whose venom can induce sweating, vomiting, excruciating pain, and brain haemorrhages. It's also been known to trigger hellish psychedelic trips and feelings of impending doom, according to those who've been caught on the rough end of it. Describing the feeling of a sting to VICE in 2015, marine biologist and jellyfish expert Lisa-Ann Gershwin explained that: "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."
The amount of people who are thought to have fallen prey to the Irukandji this season is almost double the 10-year average, according to the ABC—and experts aren't quite sure what's causing the spike. But before we get into the reasons as to why this might be happening, let’s talk about what a run-in with this dreaded jellyfish actually does to a person.
For starters, there’s something called “Irukandji syndrome”: a potentially fatal condition that usually kicks in about 20 minutes after the sting and triggers a range of unpleasant symptoms—from feelings of dysphoria through to vomiting, sweating, and intense back and kidney pain. Dennis Hayles, who was stung by an Irukandji jellyfish in Queensland in 2013, recalls that the after effects “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."
Others speak of the aforementioned head trip: a crushing sense of doom that is triggered by the jellyfish’s highly potent neurotoxin. And then, of course, there’s the real possibility that the sting will actually kill you. Irukandji’s hyper-toxic venom—which it administers by injecting its stingers into its prey—is so potent that it can cause fatal brain haemorrhages and cardiac arrest. In 2016, two French tourists died within minutes of each other from a suspected jellyfish sting while snorkelling on the Great Barrier Reef. Speaking to the ABC at the time, cardiologist Dr Ross Walker said "it's highly likely they were stung by Irukandji.”
The surge in Irukandji-related incidents—along with the 5,000 reported cases of bluebottle stings in the past week and 22,282 reported cases in the past five weeks—has experts like Dr Gershwin calling 2019 "the year of the jellyfish"
“So far this season… there have been 22 hospitalisations from Irukandji,” she told NewsCorp. “In the past 10 years, the annual average for the whole season up to January 5, had been 10. This is more than double the decade-old annual average. There have been no other years in that period where we’ve seen 22 hospitalisations up to that point.”
So why are we seeing such a notable spike this season? One popular theory is that rising sea temperatures are allowing Irukandji to venture further afield than ever before. Early last year, experts caught a specimen off Fraser Island, about 250 kilometres north of Brisbane, and subsequently issued a warning for anyone looking to take a dip on Queensland’s southeastern coast to beware of the toxic jellyfish. In the past few weeks, at least 10 people have been hospitalised as a result of what are thought to be Irukandji encounters on Fraser.
Despite the sharp increase in stings, however, Dr Gershwin isn’t convinced that the Irukandji population around Fraser and southeast Queensland is on the rise. Indeed, she suggests that the deadly little critters have always been in these areas—and that it may well be some other factor that’s resulting in so many run-ins with them.
"It is nothing new—we've found them south of Fraser Island for more than 100 years," she told the ABC. "Certainly we are getting more stings in the database. [But] We really don't have the evidence in place yet to be able say that it's the species that's more common, the awareness that's more common, the reporting that's more common, or the people in the water that are more common.
"We simply don't know what factors are responsible for the increase in stings that are being reported."