Barrier Reef: Vinegar could curtail coral-eating starfish

Crown-of-thorns starfish feed on coral in the Great Barrier Reef.

Scientists have found a cheap new way to kill coral-eating starfish that are damaging the Great Barrier Reef.

The crown-of-thorns starfish is one of the main culprits in a massive coral cover decline on the reef.

A trial conducted by the Australian Institute of Marine Science (Aims) found that injecting the starfish with vinegar showed a 100% mortality rate.

Vinegar is cheaper and more accessible than ox bile, which is currently injected into the starfish.

Current eradication methods are limited to those that manually remove each starfish or lethally inject them.

"For that, vinegar is a great method. Vinegar can be bought at any supermarket and is roughly half the price," lead researcher Lisa Bostrom-Einarsson from James Cook University told the BBC's Rone McFarlane.

She said the method still needs further testing before it can be fully rolled out and used on the reef. Research needs to ensure that the vinegar does not harm other sea life.

Researcher Lisa Bostrom-Einarsson injecting vinegar into crown-of-thorns starfish in the Great Barrier Reef.

The method is not enough to save the Great Barrier Reef, she said, but could help save individual reefs in the meantime.

"The ideal would be to stop the cots (crown-of-thorns starfish) outbreaks from occurring altogether, but we still know relatively little about what causes them."

The past 30 years have seen a 50% drop in coral cover on the reef, according to researchers at Aims. Crown-of-thorns starfish, along with cyclones, have caused the most damage.

Research by Aims has suggested that increasingly frequent outbreaks of the starfish might be fuelled by nutrients from land-based agriculture.

Agricultural nutrients in the seawater cause an increase in the amount of phytoplankton, which the starfish larvae feed on.