RISING sea temperatures could make dangerous irukandji and box jellyfish a problem in Northern Rivers waters, a CSIRO scientist has warned.
CSIRO research scientist, Dr Lisa-ann Gershwin, says more research is needed into the jellyfish. She warned higher ocean temperatures from global warming may stimulate jellyfish to breed faster, grow faster and live longer.
"What you don't want happening is that all of a sudden it's a huge problem and no one sees that coming," she said.
Symptoms of an irukandji jellyfish sting include severe pain, vomiting, anxiety and in rare cases can cause pulmonary oedema (fluid in the lungs), hypertension or toxic heart failure that can be fatal.
A box jellyfish sting can be fatal in as little as three minutes.
Dr Gershwin said contrary to popular belief, instances of "tropical" jellyfish like the irukandji in places like Moreton Bay, Fraser Island, Newcastle and Sydney were likely to be from local populations rather than tropical species migrating south.
"We have irukandji that are already south and have always been south because that's their species, that's their habitat," she said.
"A little bit of change is probably enough to stimulate the local ones to get a little rambunctious long before the big swarms up north will be able to migrate south.
"So it's important to identify what conditions stimulate irukandji to be more active, where they are occurring and how that interacts without beach usage," she said. "It's a matter of doing the research."
Dr Gershwin said the fact stings from box and irukandji jellyfish were in rare was evidence the populations were not out of control.
"I think there's enough of a possibility that it could become a problem with warmer waters that we should be looking into it."
Dr Daniel Bucher, a senior lecturer in marine biology and fisheries at Southern Cross University, said it was difficult to predict how Northern Rivers waters would be influenced by a general increase in ocean temperatures, and the jellyfish populations that came with warmer warmers.
"It's really hard to tell in this particular area because our coastal water temperatures are influenced by the East Australian Current (EAC) so we get huge fluctuations in temperatures," he said.
"Certainly we might be getting more frequent periods of warmer water but we could just as easily get cooler.
"No one's really got a good handle on what's going to happen when it (EAC) gets warmer and stronger, if that happens."
CSIRO is currently developing an early warning system that will predict when and where irukandji jellyfish blooms are likely to occur.