More than 5000 people were stung by bluebottles on Queensland's Gold and Sunshine coasts over the weekend as weather drove a wall of jellyfish onto the shore.
Conditions eased on Monday but remnants of the bluebottle armada still dot the beaches and more than 300 people were treated for stings, mostly at the Sunshine Coast.
The latest figure for the weekend is almost double initial estimates released by Surf Life Saving Queensland and includes people treated by council lifeguards.
Across Queensland, but mostly in the southeast, 22,282 people sought treatment for bluebottle stings between December 1 and January 7, compared to 6831 in the same period last year.
That was a "hell of a lot" of people stung, Australian Marine Stinger Advisory Service director Lisa-ann Gershwin says.
"Wow, that is unusual," she said.
"The numbers I have seen published are 25,000 to 45,000 per year for the whole of Australia," Dr Gershwin said.
"Those figures, the 22,282, are for about five weeks and that's just one teeny tiny smidgen of Australia, so that is a lot."
Thousands were treated by lifesavers and several people reportedly suffered anaphylactic shock and were treated by paramedics.
In a matter of hours on Sunday, 476 bluebottle stings were treated on the Gold Coast and 461 on the Sunshine Coast.
Unusually strong northeasterly swell conditions pushed the bluebottles onshore.
Dr Gershwin said the striking blue jellyfish lived in armadas in the middle of the ocean and had trailing tentacles and a keel-like crest that acts like a sail.
"When you look at a bluebottle, and you see the bubble and the blue fringes and the long blue tentacles, that is actually a colony, that is not an individual.
"Those colonies also live in these armadas - sort of a population of the colonies - in the middle of the open ocean.
"Bluebottles have definitely been fairly active lately, pretty much throughout southeast Queensland," Dr Gershwin said.
"They get picked up by the wind and blown as long as the wind keeps going or until they hit land and strand on the beaches
"Some of the bluebottle sails are right-handed and some are left-handed, across the body, so when the wind comes up it only grabs the ones with the sail going the right way for that particular breeze.
"It's nature's way of making sure the population never becomes extinct."
Dr Gershwin is a co-creator of The Jellyfish App for species identification.
Surf Life Saving Queensland said people stung should remove stingers, take a very hot shower and apply ice.
Australian Associated Press