Coral bleaching: what can we do about it?

It seems unthinkable that the Great Barrier Reef could be in mortal danger. Yet at the University of Sydney we are thinking about it – and exploring ways to protect it.

On the frontline of the battle to save the Reef is Associate Professor Will Figueira. “I personally was stunned by the eerie vision of reefs with white corals popping out everywhere that we saw when we jumped in for our first field work dive,” he says with concern. “It was much more extensive than I had imagined.”

Associate Professor Figueira is talking about the effects of an intense coral bleaching event in 2016.

To assess the damage to the Reef, he worked with a team of reef experts, including another highly experienced marine biologist, Professor Maria Byrne. Collectively they documented the reef destruction and found that the 2016 event was the worst on record, devastating about two-thirds of the coral along a 700 kilometre stretch of the Great Barrier Reef, north of Port Douglas. Previously beautiful and abundant parts of the Reef had become wastelands.

When the team's study was published in the influential journal Nature in March 2017, it alarmed not just the scientific community, but anyone who relied on the Reef for their livelihood, or just loved it for itself.

Now our researchers are looking at ways to protect the Reef, and they’re using 3D mapping and printing to do it.

3D maps gives us the most detailed view possible of the delicate reef ecosystem. And significantly, they can also be used to produce realistically detailed sections of artificial reef, using 3D printing technology. These artificial structures can then be put in place where reefs have eroded, helping to rejuvenate the reef and therefore provide shelter to other reef creatures who would otherwise leave the area. Only by maintaining the whole reef ecosystem will the conditions be right for the coral to return.

The technology is in place and the 3D-printed reef has been tested for resilience in reef environments.  So far, the team has mapped about 14.5 hectares of reef and established a library of 40 models of coral. This mapping has helped form a basis of understanding of how to restore these reefs and now Figueira hopes to plant some of the reefs on the Great Barrier Reef this year. The pilot program would cost about $150,000, and more funding would allow the rehabilitation of more reefs.

There is good reason to think that more catastrophic bleaching events will occur in future, leading to coral death. Without action, it is possible we are saying a slow goodbye to the Great Barrier Reef.

University researchers are leaders in the fight to make sure the reef survives. Figueira is cautiously hopeful, though local solutions cannot fix the bigger picture.

“The fate of our reefs is linked inextricably with our ability to rise to the not inconsiderable challenge of reducing global emissions and dealing effectively with our role as drivers of climate change,” Figueira says.