Perfect stinger conditions
THERE have been unwanted visitors at Noosa's beaches over recent weeks as swarms of bluebottles made their presence felt.
Lifesavers and lifeguards have been busy treating stings as northeasterly winds have pushed the marine creatures onshore.
A University of the Sunshine Coast graduate research ecologist said a "perfect storm” of conditions has caused a bumper bluebottle season.
Letricia Delaney, who studied Queensland jellyfish trends for Honours research in 2016, said multiple factors had aligned ahead of last week's 13,000 bluebottle stings across the coast.
These included warm water, wind direction and huge numbers of holiday swimmers.
"We found there tends to be a longer stinger season during the El Nino weather cycle, which usually lasts one year and is associated with warmer waters,” she said.
"But larger 20-year natural cycles in global jellyfish abundance also occur, the cause of which is still unknown.
"On top of this, climate change is intensifying our hot summers.”
Ms Delaney said bluebottles were "passive floaters” and their location was entirely determined by wind, waves and currents.
Strong offshore winds drove many onshore in the past week, particularly on north-facing beaches like Noosa.
The stingers mostly feed on small fish, crustaceans and molluscs and, in turn, are eaten by the blue dragon nudibranch, which stores the stinging cells for its own defences.
Ms Delaney studied jellyfish after observing hundreds wash up onto Sunshine Coast beaches during one summer but said this season has topped previous summers as a recorded breaker for stings.
"Unfortunately, it is likely to continue as we predict a longer stinger season in Queensland this summer,” she said.
She said several stings by Carukia barnesi, a type of irukandji jellyfish in the waters on the west-side of Fraser Island for the third year in a row, suggest the species had established there.
However, as "small and delicate creatures” she said they were unlikely to thrive in surf beaches.
"There is currently disagreement between scientists as to whether this species of irukandji will thrive further south and more research into this area is needed. We should have more answers in the coming years,” she said.
"The fact is that we humans are changing the climate, which is supporting an increase in the abundance and location of some jellyfish species, resulting in negative impacts to tourism and health industries - another reason why we must reduce our carbon emissions.”