Groundbreaking research has uncovered remarkable diversity in heat tolerance within a single coral species on the Great Barrier Reef, offering new hope for the future of these vital ecosystems.
Unearthing an unseen side of Coral
The study, which was led by Ph. Now, research led by UTS D. candidate Melissa Naugle along with researchers from the University of Newcastle and other institutions has uncovered a previously undescribed gradient in heat tolerance in coral populations across the Great Barrier Reef. The researchers studied over 500 colonies of the table coral, Acropora hyacinthus and determined that heat-tolerant corals are not rare.
With coral reefs experiencing the fourth global mass bleaching event now underway, and unprecedented warm summer sea temperatures on Australia’s Great Barrier Reef, these findings are important. These could provide essential genetic resources for corals to survive and cope with the ongoing threats from climate change. As Dr. Line Bay, a co-author from the Australian Institute of Marine Science (AIMS) said, ‘The variation among these corals is what will fuel natural selection for future generations of more temperature tolerant corals. This variation is important for predicting how corals will acclimate to the warming climate.
Tapping Coral’s Capacity for Flexibility
These results have important implications for how we manage and protect coral reef ecosystems into the future. Corals of the Great Barrier Reef show together to withstand a heating planet, suggesting new restoration and conservation efforts such as the Reef Restoration and Adaptation Program (RRAP).
This work further validates the natural plasticity of corals to environmental change, as outlined by Dr Cedric Robillot, RRAP Executive Director, “and confirms the potential existence of naturally heat-hardy corals that can be a major focus for RRAP in operational scale reef restoration and conservation in a race against warming ocean temperatures now locked-in from global climate change.”
Perhaps the most promising method moves in this direction, as it involves using selective breeding to speed up coral adaptability to warmer water temperatures Co-author Dr Emily Howells, Senior Research Fellow at Southern Cross University says, “Heat tolerance variation could be utilised for restoration programs like selective breeding and potentially make adaptation faster, instead producing offspring that are more better suited to warmer waters. Although, she warns that this would only work if the heat tolerance variation is because of heritable gene variants.
The researchers are now using DNA sequencing data from the corals studied to identify gene variants linked with heat tolerance and gain a clearer picture of the genetic underpinnings of this trait. But this information can guide selective breeding efforts, and shed light on how well different corals populations can naturally adapt.
Conclusion
The extraordinary variability in heat tolerance of a single species on the Great Barrier Reef provides hope that coral reefs will be able to withstand climate change. Using the genetic tool of heat-tolerant corals, researchers and conservation efforts like RRAP can begin to build coral adaptive capacity amidst our changing climate reality. While saving and conserving coral reefs will take several fronts, this new research offers a promising start to ensuring the longevity of these invaluable natural treasures.
