A giant starfish-eating snail could be unleashed to help save the Great Barrier Reef, officials said on Monday, with a trial under way to breed thousands of the rare species.

Predatory crown-of-thorns starfish, which munch coral, are naturally-occurring but have proliferated due to pollution and run-off at the struggling World Heritage-listed ecosystem. Their impact has been profound with a major study of the 2,300-km long reef’s health in 2012 showing coral cover halved over the past 27 years, with 42% of the damage attributed to the pest.

Hunting by scent

Now, Australian Institute of Marine Science (AIMS) research has shown they avoid areas where the Pacific triton sea snail — also known as the giant triton — is present.

The snails, which can grow to half a metre, have a well developed sense of smell and can hunt their prey by scent alone.

Research showed they were particularly fond of crown-of-thorns, but only eat a few each week, and with the snail almost hunted to extinction for their shells, there are not many left.

This led the government to announce on Monday funding to research breeding them. “The possibilities the triton breeding project opens up are exciting,” said Queensland federal MP Warren Entsch. “If successful, this research will allow scientists to closely look at the impact of giant tritons on crown-of-thorns behaviour and test their potential as a management tool to help reduce coral lost to outbreaks.” Giant tritons held at AIMS have laid numerous egg capsules. But they are so rare, almost nothing is known about their life cycle.

Jaggi Vasudev’s Rally for Rivers claims they will, but this is not based on the most nuanced science