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SYDNEY - Forget the sharks, it's the tiny bluebottle jellyfish that could get you if you decide to take a cooling swim in the surf during Australia's hot summer.
At least 30,000 swimmers suffered painful stings from the jellyfish called "blueys" on the country's east coast in 2006, double the number of the previous year.
"They come in invasions called armadas," Lisa-Ann Gershwin, marine stinger adviser with Australia's Surf Life Saving Association, told Reuters.
"They are driven by the wind onto our beaches where they will invade for a couple of days and then they're just gone."
Bluebottle jellyfish, which have a bright blue translucent body and long tentacles, invaded the Gold Coast tourist beaches in tropical Queensland state earlier in January, stinging some 1200 swimmers in one weekend.
The jellyfish measure around 10-15cm and have stinging tentacles sometimes metres long. Their whispy tentacles often wrap around swimmers legs, arms or bodies, sometimes breaking off, causing a sharp, painful sting and welts.
Gershwin said the more than doubling of jellyfish stings in 2006 may have been due to warmer ocean temperatures.
"Periodically we do get large spikes in population numbers -- its the natural thing that jellyfish do," said Gershwin.
"I think what we are seeing is the natural ebb and flow but it may be an increase due to warmer temperatures or warmer temperatures may in fact drive them further south," she said.
"Numbers are closely tied with environmental changes and last year was obviously a very aggressive year for them, whereas this year has been a really good year to date."
The bluebottle sting is not fatal, but years of household remedies such as rubbing sand on the welt have seen swimmers inadvertently worsen the sting.
Lifesavers say the best treatment is to simply rinse the area immediately with seawater to remove the almost invisible stinging cells and apply ice to alleviate the pain.
"The stings are able to be treated on the spot and with the right treatment most people will only suffer temporary stinging pain for 30 minutes or so," said Brett Moore from New South Wales state Surf Life Saving.
Beaches along the eastern seaboard state of New South Wales, the country's most populous state, accounted for 26,000 stings in 2006, while the other eastern state of Queensland had 4,256.
Moore said the 2006 spike was largely due to two weekends when prevailing winds drove bluebottle jellyfish onto Sydney beaches at a time of soaring temperatures and a major surf life saving competition, ensuring beaches were crowded.
- REUTERS