Photo: Manny Moreno // Unsplash
Coral bleaching has become an epidemic, as reefs around the world are negatively affected by rising water temperatures. Florida in particular has received a fair share of attention for it’s bathtub-like water, but Australia’s famous Great Barrier Reef has also been receiving a beating for almost a decade. A new study from Australia’s Southern Cross University has found a tool to prevent coral bleaching: shade.
“Despite being one of the best managed coral reef ecosystems in the world, the Great Barrier Reef is under imminent threat from climate change and has suffered four mass bleaching events since 2016,” Peter Butcherine, a research fellow at Australia’s Southern Cross University and lead author of the study published in Frontiers in Marine Science, told Newsweek. “This summer, 2023-24, there is an elevated bleaching risk due to the El Nino conditions, resulting in higher water temperature. In the future, the consequences of climate change, including more intense and frequent marine heatwaves and tropical storms, pose a significant risk to the Great Barrier Reef.”
Butcherine went on to say that, although efforts to reduce climate change are still required, they are now no longer enough to protect the Great Barrier Reef. That’s why Butcherine, along with his colleagues at the Cooling and Shading subprogram of the Reef Restoration and Adaptation Program (RRAP), started researching the utility of cooling down coral reefs by shading them.
The results were positive, with the researchers finding that even providing partial shade for a portion of the day was effective at combating bleaching. “We show that intermittent shading under controlled conditions can moderate light stress and slow bleaching,” Butcherine said in a release detailing the findings. “Reducing sunlight by 30 percent for four hours around solar noon can slow the onset of the bleaching response in some thermally-stressed shallow corals.”
The success of the study opens up the possibility for various different human interventions to aid the coral ecosystems. One possibility is the use of artificial coverings such as shade cloths, but the study cautions that “further research is necessary to investigate the indirect effects of these novel shading techniques.”
Another solution that may be able to provide shade with less of an impact on the coral ecosystem is artificial fog systems. “The fog generators under development require no in-water infrastructure, allowing them to be deployed relatively quickly and move freely between reefs,” said Butcherine. “However, more research and development is required before the current technologies can be ready for scaled-up deployment in the field. So far, our field trials have delivered some promising results and suggest we could create sufficient fog cover over tens of hectares of reef.”
