Heat Resistant Coral – Discovery into the Resistance of Bleaching

By Jonny Dawson

In this post, we will take a look at a research study made by our Director of Science, Jonny Dawson. We hope this gives you further insight into coral bleaching and the discoveries being made to combat it.

The ocean provides one of clearest indications on the state of global climate change, with it being estimated to absorb over 90% of the heat generated from greenhouse gases. Analysis has shown that the past 10 years have represented the top 10 warmest years on record within the ocean.

Rising sea temperatures are seen to have the largest influence on coral bleaching events, with temperature fluctuations of only 1o C (2o F) resulting in bleaching. As the impact on coral reefs from elevated sea temperatures continues to be demonstrated throughout the world’s oceans, scientists in Australia have recently come up with a potential solution.

Researchers from CSIRO, Australia's national science agency, the Australian Institute of Marine Science (AIMS) and the University of Melbourne have made significant strides in the push to save the world’s reefs by successfully developing a heat resistance coral. In May 2020, researchers published a study showcasing the development of a lab-grown strain of coral microalgae symbionts (tiny cells of algae that live inside the coral tissue) which are more tolerant to heat.

Using a technique called “directed evolution”, the microalgae symbiont was increasingly subjected to warmer temperatures over a four-year period, helping them to adapt and survive within a hotter environment. Once the microalgae were reintroduced into the coral larvae, the newly established organism had an elevated heat tolerance and as was more efficient at photosynthesis; demonstrating the development of a coral with enhanced climate resilience.

It is believed that these findings may help in the effort to restore coral reefs suffering from mass mortalities as a result of marine heatwaves.

Professor Claudia Vickers (SynBio FSP Director Associate Professor) stated that:

‘This breakthrough provides a promising and novel tool to increase the heat tolerance of corals and is a great win for Australian science.’

Although further work needs to be done, this appears to represent a significant movement in the pursuit of saving the world’s coral reefs.