Armadas of alien-like sea creatures have been washing up on Australian beaches thanks to the warm weather but experts warn people should look but not touch.
Jellyfish expert Dr Lisa-ann Gershwin said bluebottles had been washing up on beaches across New South Wales, Victoria, South Australia and Tasmania in “gobsmacking numbers” over the last few months thanks to the warmer weather.
“They’re having a really fun time this year and they’re definitely terrorising us this year,” Gershwin said. “They’re really strange alien creatures. There’s no two ways about it.
“It doesn’t have any equal to people, or animals, or corals, or things we understand intuitively. It’s just their own brand of weirdness in such a cool way.”
A population of bluebottles on the move is known as an “armada” and the species is evolutionarily descended from jellyfish in the same way humans are related to monkeys or apes. They are also the closest known relative of the Portuguese man o’ war and distantly to Porpita porpita, a marine organism with a circular float but no sail.
Every bluebottle population floats freely on the surface of the ocean, made up of “an unbelievable number” of individual “colonies”. These colonies are what are commonly referred to as “bluebottles” but are actually a collection of semi-autonomous parts fused together.
Each colony is also either left-handed or right-handed, with the sail on top of the animal angled one way or the other.
When a breeze picks up at just the right angle, it will carry off only a small number of colonies at any given time, ensuring the whole population isn’t lost in one gust.
Even more weirdly, every individual bluebottle colony is a hermaphrodite with both male and female reproductive organs, and each of the autonomous components is responsible for its own function such as feeding, stinging or reproduction.
Gershwin said that for humans it would be as if each arm and leg operated entirely independently, with each limb having its own critical job required to keep the whole alive.
Bluebottles themselves are preyed upon by Glaucus, otherwise known as the “sea lizard” or “Pokémon slug”. Glaucus are often washed up on shore with the bluebottle, and looks like a lizard but is actually a sea slug that feeds on the colony and “steals” its stingers for its own defence.
Gershwin said there was a still much to learn about the biology of this “amazing feat of nature” as it was difficult to track down where they originate and then to study them before they complete their lifecycle.
However, what is known is the complex changes brought by climate change are likely to create ideal breeding environments for bluebottles and other jellyfish species which already reproduce “faster than rabbits”.
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While they may flourish, fish, crustaceans and other marine life will struggle with warmer waters, lower oxygen levels and acidifying oceans.
If someone finds a bluebottle washed up on the beach, Gershwin encouraged people to look but warned they should not touch, poke or stomp on the animals as even in death they can sting.
“These things bloody hurt,” she said.
Bluebottles excrete a microscopic mucus on their tentacles that is invisible and cannot be felt when touched but which contains thousands of stinging cells that are “armed and dangerous” as they inject venom into the skin on contact.
Even where a person uses a stick to poke at the creature, it will collect the microscopic film which can then be found by a dog or other animal when left behind.
There have also been cases where young children stomped on the animals and the venom has splashed into the eyes of someone watching.
Gershwin, who once allowed herself to be stung 80 times to test various methods at treating the stings, said the pain was “excruciating” with the closest comparable feeling akin to being splashed with scalding hot cooking oil.
“I let my curiosity overwhelm my common sense,” she said. “It was, hands down, the stupidest thing I’ve ever done. Let me go on record: I paid a big price for it. I was in a lot of pain and I was very swollen. I do not recommend anyone do the same.”
If someone is stung, Gershwin says the advice from the Australian Resuscitation Council is to first wash the sting in ocean water to clean off any stinging cells, before cleansing with either very hot water – as hot as a person can stand it before pulling away – or very cold water “for the pain”.
Even if nothing is done, however, the pain will resolve in 30 minutes on its own.
Gershwin said people shouldn’t “run screaming” but take a moment to appreciate the “fascinating creatures”.
“This is nature standing up on her haunches and showing off with a brightly coloured, frilly dress,” she said. “But also: don’t touch.”