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Box jellyfish mass stranding potentially lethal, says expert

By Ben Collins
Posted , updated 
A box jellyfish washed up on Cable Beach in Broome.
One of what the Shire of Broome has called large numbers of potentially deadly box jellyfish, which have caused the closure of Cable Beach.(

ABC Kimberley: Ben Collins

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Large numbers of potentially deadly box jellyfish stranding on Broome's Cable Beach are not easily explained according to jellyfish expert Dr Lisa-ann Gershwin.

"They don't normally wash up, they're pretty good at not getting stranded," Dr Gershwin told Vanessa Mills on ABC Kimberley Local Radio.


"They've got good vision, and even though they don't have a brain, they somehow figure out how to not get stranded.

"It's a big mystery actually," she said.

Cable Beach, an iconic West Australian tourism attraction, has been closed for the past four days, due to what the Shire of Broome described as, "large numbers of the potentially deadly stingers".

A cyclone that recently formed off the Kimberley coast could be responsible for the jellyfish stranding, though Dr Gershwin said that would be unusual.

"It's possible that they could get killed by bad weather and then blown up, or they could get blown up while they're alive and healthy but disoriented," she said.

"But those are both fairly unusual, we don't see that happening very often."

Dr Gershwin said the danger posed by box jellyfish should not be underestimated.

"These box jellyfish are lethal, absolutely dangerous," she said

"They're the world's most venomous animal, actually."

The jellyfish actively hunt fish, can swim at up to two metres per second and have image forming eyes on the corners of their cube-shaped body.

Broome box jellyfish unknown entity

Box jellyfish are found throughout the world's tropical, and some temperate, marine environments.

As many as 40 deaths are attributed to the jellyfish annually in the Philippines, and there have been 64 deaths recorded in Australian waters since 1983.

But not all species of box jellyfish are deadly, and Dr Gershwin said it was not known how dangerous Broome's stingers were.

Box jellyfish found in deep water off WA's Kimberley
Scientists are still learning about box jellyfish, with this one found in deep water off WA's Kimberley by CSIRO scientists. May 19, 2015.(

Supplied: CSIRO


"In the Broome region we have very large box jellyfish, but there's some debate as to whether they are dangerous or not," she said.

"We don't have any fatalities ever recorded in Western Australia from these, only in the Territory and in Queensland.

"And it does appear that they are a different species."

Until more is known about box jellyfish in the Kimberley tourist town, Dr Gershwin said they must be treated as potentially lethal.

"We obviously take the precaution and treat them as if they could be dangerous, until we're definitely sure that that's not the case," she said.

Dr Gershwin warned that dead box jellyfish on the beach still posed a risk. The tentacles can fire their stinging cells independently from the animal's nervous system.

"Even if they're dried out, believe it or not, if they then get rehydrated they'll fire off again," she said.

"So they are absolutely still armed and dangerous even if the animals are dead."

Camel train at Broome's Cable Beach
Camels are more commonly found on Cable Beach than box jellyfish. (file)(

Supplied: Tourism WA

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