Recently my wife and I saw an item on the TV about the Irukandji jellyfish, which was said to be moving south as waters warm. I thought it was the 7.30 Report, but can’t find it. Googling reveals that the same tale was being told in 2010.
Here’s the distribution map from Australian Venom Research Unit:
You won’t have much chance of seeing these things coming. This photo from the Courier Mail gives some idea of the size, but the bell can be up to 2cm and the tentacles up to a metre:
This article tells us the Irukandji is thought to be the most venomous creature on earth, 100 times more potent than a cobra and 1000 times more potent than a tarantula. Not as quick to kill you, though, as the larger box jellyfish which has a similar distribution. So far:
Australia has only had two confirmed deaths from irukandji and though the real figure could be higher, there have been 71 cases of death from box jellyfish sting.
Apparently in terms of sting to death the box jellyfish beats everything. It can be 20-30 cm across the bell, weigh up to 6 kg with tentacles up to two metres. The effect of the tentacles can be seen on this photo of a 10-year old girl, who was stung more than 20 kilometres up the Calliope River which empties into the sea just north of Gladstone:
The incidence of irukandji is not high from Rockhampton south, but the season in NQ has extended from about two months to six months. Irukanji have recently been found at Fraser Island, which would be about 100 km north of Noosa. As the Calliope River episode shows, the box jellyfish can be found in shallow waters and can survive as far inland as the tides go.
Less is known about the Irukandji, but appear to arrive in certain weather conditions.
As yet, scientists don’t know where the irukandji live most of the time, or where they breed.
“No reports of finding breeding sites have turned out to be true,” Dr Gershwin said.
That’s Dr Lisa-ann Gershwin, director of the Australian Marine Stinger Advisory Service and Australia’s only dedicated box jellyfish expert.
She says the choices will be wear a full body suit or stay out of the water!
“And look out for clusters of what looks like crushed glass or ice at the high tide line … they’re salps or weird jellyfish creatures that hang out with irukandji.
“If you see that on the beach, that’s the highest risk factor we know,” she said.
And expect to find them at Surfers paradise within 30 to 40 years.
Update: See also Dr Lisa-ann Gershwin’s comment.
Also her book Stung! On Jellyfish Blooms and the Future of the Ocean. It seems that jellyfish are taking over the oceans. We are past a tipping point on the way to a really yucky ocean with a vastly depleted range of fish species.