Team ofĀ researchersĀ from CSIRO, Australia's National Science Agency, theĀ AustralianĀ Institute of Marine Science (AIMS) and the University of Melbourne isolated the microalgae fromĀ coralĀ and cultured them in the specialist symbiont lab at AIMS. Using a technique called "directed evolution", they then exposed the cultured microalgae to increasingly warmer temperatures over a period of four years.
Corals with increasedĀ heatĀ tolerance have the potential to reduce the impact ofĀ reefĀ bleachingĀ from marineĀ heatĀ waves, which are becoming more common under climate change.
The team made theĀ coralĀ more tolerant to temperature-inducedĀ bleachingĀ by bolstering theĀ heatĀ tolerance of its microalgal symbionts-tiny cells of algae that live inside theĀ coralĀ tissue.
This assisted them to adapt and survive hotter conditions. The microalgae were exposed to temperatures that are comparable to the ocean temperatures during current summer marineĀ heatĀ waves causingĀ coralĀ bleachingĀ on the Great BarrierĀ Reef.
TheĀ researchersĀ then unveiled some of the mechanisms responsible for the enhancedĀ coralĀ bleachingĀ tolerance.
Professor Madeleine van Oppen, of AIMS and the University of Melbourne, said, "We found that theĀ heatĀ tolerant microalgae are better at photosynthesis and improve theĀ heatĀ response of theĀ coralĀ animal. These exciting findings show that the microalgae and theĀ coralĀ are in direct communication with each other."
