Corals in the Great Barrier Reef have enough genetic variation to adapt to and survive the impacts of climate change for at least another century, according to research published this week in the journal PLOS Genetics.
Man-made greenhouse gas emissions have led to rises in ocean temperature and acidity — both of which have resulted in coral bleaching and death across the Great Barrier Reef. The compound influence of habitat destruction has taken a heavy toll on coral populations in recent years.
Previous estimates suggested that the reef could be dead by the middle of this century. However, scientists have now used genetic samples and computer models to show that genetic variations will help the coral survive for another 100 years or more.
“It means these corals will still go extinct if we do nothing,” says Mikhail Matz, associate professor in The University of Texas at Austin and lead researcher on the project. “But it also means we have a chance to save them. It buys us time to actually do something about global warming, which is the main problem.”
Matz and his colleagues used their model to analyze the present-day genetic diversity and larvae migration patterns of the common Acropora millepora, or staghorn coral. They determined that the species will become more sensitive to temperature changes and only specimens with heat-tolerance genes will cope.
As ocean waters warm, better-adapted corals will survive, while those unable to cope with the increased heat will die off. Over time, if incoming larvae supply genetic variants for increased resistance, the local population shifts to the more heat-resistant variety.
The researchers involved in the study plan to conduct further experiments to confirm that the model’s predictions match up with the evolution of coral species in the wild.