Protecting and Restoring Resilience in Coral Reefs

KAUST researchers discover a new way to boost the health of coral, which could save the world’s most vulnerable ecosystems

KAUST researchers have shown that feeding beneficial bacteria to coral can help save them from some of the impacts of climate change. Having published their research based on studies in controlled settings, they are now applying their treatment to pocillopora, a dominant species of coral in the Red Sea — the first time that coral have been inoculated in their natural habitat. The team is led by Professor Raquel Peixoto, Associate Professor Erika Santoro and Research Scientist Helena Villela.

This research is crucial because coral reefs are biodiversity hotspots. Biodiversity is considered critical for human existence because a rich catalogue of organisms provides food for consumption and raw materials for production, and keeps ecologies healthy in balance with natural cycles, and resilient with respect to perturbations in those cycles.

Healthy coral contain algae in their tissue, which provide nutrients and up to 80% of the carbon compounds that the coral convert to energy. In an example of the symbiosis that makes biodiversity valuable, the algae convert coral waste for photosynthesis. However, because of increases in water temperatures due to climate change, the coral can react by expelling the algae. This is called coral bleaching because the coral loses its color in the process. If the algae do not return, then the condition is often fatal, leading to a slow death by starvation.

Coral reefs support about a quarter of all fish species, and millions of people rely on them for food, jobs and flood protection, as they buffer coastal communities from storm surges. Coral reefs are potentially the first major ecosystems that could collapse due to the acceleration of climate change, according to the US National Center for Atmospheric Research. Therefore, tools for restoration and adaptation are required within the next decades. KAUST’s discovery adds to that tool kit. The researchers found that atrisk corals that were fed probiotics — a mixture of bacteria beneficial to their health — experienced a 40% increase in survival rate because the extra bacteria triggered a process within the coral that altered their genetics and metabolism to mitigate bleaching and prevent mortality.

TONY CHAN President of KAUST

WE MUST CONTINUE TO TAKE ACTION TO PROTECT AND RESTORE CORAL REEFS. AT KAUST WE HAVE BEEN WORKING TO UNLOCK THE BASIS FOR RESILIENCE WITH THE HOPE THAT THE KNOWLEDGE ACQUIRED WILL HELP US CONSERVE CORAL REEFS, WHICH ARE AT RISK ACROSS THE WORLD’S OCEANS.

GREAT BARRIER REEF FOUNDATION

“Pioneering science such as KAUST’s provides hope for the future of coral reefs globally, which are coming under increasing pressure from climate change.”

In addition to observing the increased resilience of coral that received probiotics, the researchers tracked changes at the cellular level, where lipids and membranes responded positively. The study’s collection of data at the cellular and also physiological level of organisms makes it foundational work, said KAUST Professor Christian Voolstra, a collaborator with Peixoto since 2016 and the developer of the analytical frameworks that the study used to interpret its data.

The scientists began their work in Brazil at the Federal University of Rio de Janeiro and relocated to KAUST to continue through the university’s Red Sea Research Center. KAUST believes the sea’s coral reefs, mangroves, seagrasses, brine pools and other ecosystems hold untapped potential for scientific inquiry into areas such as evolutionary biology and adaptation in extreme environments.

While the discovery may prove crucial to saving coral reefs worldwide, those in the Red Sea off Saudi Arabia’s western coast are likely to be the first beneficiaries. Peixoto and her team are diving into the sea to treat coral in their natural environment. The probiotics are distributed in small beads placed on the coral that dissolve into the water around them, allowing them to be absorbed.

The work will shore up the health of a beloved region in the Kingdom and support tourism goals outlined under Vision 2030. In the form of the Red Sea Project, Saudi Arabia is developing one of the world’s most ambitious tourism projects, which aims to not only preserve but also enhance coral and biodiversity along the country’s Red Sea coast.