New weapon a ainst star s
Scientists find vinegar to be effective in culling the crown- ofthorns starfish.
A THORNY starfish which preys on corals have found its match – and it’s just simple household vinegar.
In a breakthrough in the war against the crown- of- thorns starfish, scientists from James Cook University in Australia found that injecting the coral- eating pest with vinegar kills it just as effectively as the current drug, which can be expensive and difficult to source. The animals are breeding at epidemic levels and are one of the primary reasons for the decline in live coral.
Researcher Lisa BostromEinarsson said vinegar had been tried unsuccessfully before, but scientists refined the process which resulted in a 100% kill rate. “Currently, divers use 10ml or 12ml of ox bile to kill each starfish. It is expensive, requires permits and has to be mixed to the right concentration. We used 20ml of vinegar, which is half the price and can be bought off the shelf at any local supermarket.”
The starfish in the trial were all dead within 48 hours of being injected. They were then fed on by fish in the lab trials with no ill- effect, but this needed to be backed up by large- scale field trials to be sure the process is totally safe for other marine life. “There’s no reason to think it won’t work or it’ll be dangerous, but we have to be sure,” said Bostrom- Einarsson.
She said the findings could have big implications for developing countries without the means to acquire and use the current drugs. Scientists say while the process may greatly help slow down the starfish outbreak, killing the starfish individually was never going to save coral reefs by itself.
“It has been estimated there are between four and 12 million of the starfish on the Great Barrier Reef alone and each female produces around 65 million eggs in a single breeding season. They managed to kill around 350 000 last year with two full- time boat crews. While it would take an insane effort to cull them all that way, we know that sustained efforts can save individual reefs,” BostromEinarsson said.
She said other researchers were working on population- level controls of the animal, but killing the starfish one by one was the only method available at the moment. Sea trials of the vinegar method will begin by the end of the year. – James Cook University