Swimmers in NSW and Queensland are being warned to use caution after unprecedented numbers of brightly coloured, venomous blue dragons washed up on beaches in 2023.
Little is known about the usually elusive sea slugs, and it remains unclear whether the sudden influx is due to a population increase, warming waters, or altered ocean currents.
In January, hundreds were recorded washing up on Bondi and Maroubra beaches near Sydney, as well as Kurnell and Newcastle. While there have been blue dragon reports in 2018 and 2021, numbers appear to be much higher this year.
TikTok marine biology enthusiast Julian Obayd has documented them on the Gold Coast. "I've seen more dragons this year than any year previous. I would see maybe one or two a year now you'll see them all across the beach."
What does a blue dragon sting feel like?
While they appear cute and are usually docile, if provoked they can deliver a sting that can be much more potent than a bluebottle as they store up the venom of the many bluebottles they eat. This can result in nausea and vomiting, but the symptoms are rarely life-threatening.
Julian describes the pain as “the worst thing ever”. “I was trying to be a tough guy, I was trying to play it down. Truth is I wanted to cry,” he told Yahoo News Australia.
While he's now worked out methods to handle them without being stung, he wouldn't want others to emulate his behaviour. But he notes it is rare for blue dragons to sting humans when beached.
But blue dragons aren’t actually venomous
Blue dragons are usually only noticed when they're blown onto the shore along with prey species including bluebottles and blue buttons, a grouping referred to as a “blue fleet”.
University of the Sunshine Coast's Professor David Schoeman explains despite being able to inflict a “serious sting”, the species is not technically venomous.
Instead, they consumes the stinging cells of prey species, like bluebottles, and then stores it in its wings for defence. “In some sense this is a chimaera. It's an animal that has cells from different species."
What to do if you’re stung by a blue dragon
It’s thought some serious strikes attributed to bluebottles may have actually been inflicted by blue dragons.
Surf Live Saving Australia’s Dr Jaz Lawes recommends anyone harmed by a blue dragon should follow an amended version of first aid for bluebottle stings:
Do not allow rubbing of the sting area.
Rinse the area well with seawater (not freshwater)
Place the sting area in hot water — no hotter than the rescuer can comfortably tolerate for 20 minutes.
If the pain is unrelieved by heat, or if hot water is not available, apply cold packs or ice in a dry plastic bag.
Send for medical aid if symptoms persist.
What’s causing the blue dragons to wash up?
Blue dragons float upside down and use their foot to hold onto the underside of the surface of the sea, making them susceptible to the movements of currents.
Blue dragons usually live offshore, and Professor Schoeman said the chances of seeing them is very low, but occasionally very large numbers will be recorded. “I guess that’s their bad luck, your good luck, because they absolutely amazing little critters."
He believes it’s more common to see them in late summer during La Niña years because of the predominance of strong onshore winds. “They're not just local winds, they’re winds that blow from the deep ocean and carry on to shore,” he said.
Are blue dragon numbers increasing?
Blue dragons are a temperate water species and there has been some evidence of range extension in North America as local patches of water begin to warm.
Professor Schoeman notes that Australia’s east coast is a “hotspot” for climate warming and there is an intensification and southerly extension of the East Australian Current, making growth of blue dragon numbers possible. “We're seeing an increase in the frequency and intensity of marine heat waves throughout the world,” he said.
“By 2050, for much of the world's ocean, there will be a near-perpetual state of marine heatwave if we don't act swiftly,” he said. “You may be thinking that the waters of Bondi are warm now… but you're going to be getting big pulses of warm water for fairly long durations as climate change bites.”
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