Probiotics Help Protect Red Sea Corals During Heat Wave

A field study at the Coral Probiotic Village in the Red Sea has shown that probiotic treatments can shield Acropora valida corals from the effects of extreme heat. Researchers from the King Abdullah University of Science and Technology (KAUST) observed this during a 2022 heat wave, when water temperatures rose 1.2°C above the seasonal average. Corals treated with the probiotics remained resilient, offering a potential path forward for conservation as rising temperatures threaten marine ecosystems around the world.

These ecosystems are essential to marine life, providing a home for roughly one-third of all species in the ocean. However, they are currently in a state of decline due to climate change and the warming waters that trigger coral bleaching. This process occurs when corals lose the algae in their tissues, causing them to turn white and eventually die if the thermal stress continues. Data from the Global Coral Reef Monitoring Network suggests that if global temperatures reach 1.5°C above pre-industrial levels, 70-90% of corals could face severe degradation by the year 2100.

At the Coral Probiotic Village, a site established by Peixoto in 2021, the research team tested different methods for improving coral health. They used syringes to apply two types of probiotics directly to the corals during the heat wave, then monitored their color and condition. The results indicated that both live probiotics and a heat-killed version, known as postbiotics, were effective at preventing bleaching. Because postbiotics are more shelf-stable and cost-effective, they may be easier to use in large-scale conservation projects.

The impact of these treatments reaches beyond the health of individual corals. Healthy reefs are fundamental to marine biodiversity, the productivity of fisheries, and the protection of coastlines from erosion. By helping coral populations survive, these interventions support the broader ecosystems and the human communities that rely on them for food and work. This research contributes to a wider international effort to find new ways to build reef resilience in a changing climate.

Future work will focus on the long-term consequences of these treatments and how they might be implemented on a larger scale. The research team remains hopeful that these findings will lead to more comprehensive strategies for protecting reefs globally. As environmental pressures on the oceans increase, the use of probiotics marks a notable step toward preserving coral reefs and the many species that depend on them.