Corals that can stand up to climate change

By Jude Dineley 25 February 2013
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Experts are detecting corals best placed to survive a warmer world, and hope to use them to recolonise damaged reefs.

CORALS THAT COPE BEST with climate change and pollution can now be spotted using new techniques that pick out genetic markers of coral toughness.

The research, reported last week in the journal BMC Genetics, says powerful new genetics tools are allowing researchers to make smart decisions about which corals should be used to restore damaged reefs.

“If we get to a point in the future when we’re going to lose reefs and we need to restore them, we need to think about which corals to preserve,” says Dr Petra Lundgren, lead author and geneticist from the Australian Institute of Marine Science in Townsville, Queensland.

The research marks the first time scientists have looked for genetic markers that point to the most resilient corals. The researchers used these signs to find the corals best equipped to survive temperature increases associated with climate change, and murky waters caused by cyclones and industrial activities, like dredging.

Finding the toughest types of coral

DNA sequencing techniques fast and efficient enough to rapidly scan coral genes have not previously existed, and little is known about the genomes of coral species.

“We were pretty much starting from scratch,” says Petra.

Petra and her colleagues used a DNA search technique which tracked the genes in hundreds of coral samples from two common species. The corals were taken from 27 sites along the Great Barrier Reef, covering a range of water temperatures and murkiness.

The researchers looked for gene variants in corals extracted from warmer or murkier waters. What surfaced were mutations in the species genes, which had resulted in tougher corals with better immune systems.

Hardy corals to conserve the Great Barrier Reef

The results, researchers say, are a step towards an insurance policy against the future destruction of coral reefs.

“If in the future we need to restore coral populations, we can make sure that we use the most robust strains of corals to do so,” say Petra.

Dr Bill Leggat, a coral geneticist at James Cook University, Townsville, says the new techniques will be valuable for protecting corals on the Great Barrier Reef. “If we can protect those reefs where hardier corals are found, we can minimise other pressures and they can act as a source of corals for other reefs,” he says.