Thermally sensitive corymbose Acropora corals were the focal coral taxon for a recent study. An international team of scientists warns that coral adaptation to global warming may be overwhelmed without rapid reductions in global greenhouse gases.
Professor Peter Mumby from The University of Queensland's School of the Environment collaborated with Dr. Liam Lachs from Newcastle University's Coralassist Lab in the United Kingdom. They modeled the consequences of various global development scenarios and fossil fuel usage on coral populations.
Professor Mumby stated, "If we don't achieve commitments to reduce greenhouse gas emissions, our world is expected to warm by 3 to 5 degrees by the end of this century." He added that under such warming levels, natural selection may not be sufficient for the survival of sensitive coral species.
The research indicated that marine heatwaves are causing mass coral bleaching mortality events across shallow tropical reefs, with increasing frequency and intensity due to climate change.
The team studied corals in Palau in the western Pacific Ocean to develop an eco-evolutionary simulation model. This model incorporates new experimental data on the thermal and evolutionary biology of thermally sensitive corals in the Acropora genus, simulating population trajectories under various future climate scenarios.
Lead author Dr. Lachs noted that current climate policies are on track for 3 degrees of warming. Their results suggest that some coral populations might adapt and survive, although he cautioned about the uncertainty in the 'evolvability' of coral populations.
Dr. Lachs emphasized the urgent need for climate-smart management of coral reefs, stating, "We need management actions that can maximize the natural capacity for genetic adaptation, whilst also exploring whether it will be possible to further boost adaptation rates in wild populations with targeted interventions."
He mentioned that experimental approaches could include planting selectively bred corals for heat tolerance. "We can still have fairly healthy corals in the future, but this requires more aggressive reductions in global emissions and strategic approaches to coral reef management," he concluded.
The findings are published in the journal Science.