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Coral reefs host a unique and fragile ecosystem that is under threat from human activities and global warming. In line with TotalEnergies' commitments to supporting biodiversity, our Research & Development teams have been working, since 2016, on a solution for the fast and effective rehabilitation of coral reefs in French Polynesia and Qatar. To find out more, we spoke to Philippe Blanc, who heads up TotalEnergies’ Environmental Monitoring, Impact Analysis and Restoration of Marine Environments R&D unit.

Why are coral reefs - “the rainforests of the sea” - so important to marine biodiversity?

Philippe Blanc: Coral reefs are built on a symbiotic relationship between sea animals (scleractinian corals) and micro-algae (zooxanthellae). They occupy less than 0.1% of the ocean floor but are home to 25% of all marine species, illustrating their crucial role in marine biotopes.

Primarily located in shallow coastal areas, coral reefs provide a wide range of ecosystem services (see below) and play a key role in protecting shorelines from erosion and waves. By trapping carbon in their calcium carbonate skeletons throughout their lifespan, corals also create a vast carbon sink that helps reduce the amount of carbon dioxide (CO2) in the atmosphere.

Severe bleaching has affected corals in the Middle East, in certain seas in Asia and in the Pacific Ocean. What solutions can TotalEnergies offer to counter this loss of biodiversity?

P. B.: In response to the lack of a realistic and sustainable operational solution for the large-scale restoration of coral reefs, we launched the REEF program. REEF is part of our efforts to reduce the environmental impact of our operations. But it’s important to recognize that certain global phenomena will continue to have a decisive impact on ecosystem health and development.

And let’s not forget that coral reef restoration is still in its infancy. The traditional approach, which was used at Yemen LNG in the early 2000s, involved taking cuttings and transferring the corals from one area to another. This method works but it requires many onsite diving hours, which represent a significant cost and a considerable safety risk for the teams involved. The translocation of corals from nurseries (known as “coral gardening”) is another technique currently in use.

New methods are also being developed, such as the sexual propagation approach, which is based on larval capture and rearing. However, this method has only been tested to date on a small number of species. Sinking manmade structures to enhance natural recolonization is relatively infrequent.

Can you tell us a bit more about the REEF project?

P. B.: Initiated in 2016 in partnership with Seaboost, the REEF project aims to restore coral reefs by using an innovative solution to passively catalyze the coral colonization process. The solution is based on the development of an artificial object (a REEF module) whose characteristics (structure, shape, roughness, porosity, pH, materials, etc.) encourage the spontaneous settlement of coral larvae (planulae), as well as their survival and development.

Once the REEF module has been colonized by the coral, it is relocated to a damaged area to enable reseeding (i.e. the release of larvae by the coral colonies located on the REEF module). This produces a domino effect, triggering the restoration of large swathes of coral reefs over long distances.

Various test phases will be carried out through to 2021 on the island of Moorea in French Polynesia, in cooperation with island environmental research center CRIOBE. These tests will enable us to assess the biocompatibility and performance levels of the different materials and surfaces chosen, so that we can build artificial structures capable of encouraging coral settlement, development and growth. Our research work is crucial in determining the properties required to optimize the settlement and survival of coral colonies on the REEF modules, in terms of both quantity and diversity.

In 2021, as part of a trial developed in collaboration with Qatar University and the TotalEnergies Research Center - Qatar (TRC-Q), we will submerge 18 REEF modules at water depths of 20 meters. After around two years, some of the colonized modules will be relocated to test their mobility. The trial will be included in a thesis on coral restoration and underwater monitoring.

What hopes do you have for the world’s coral reefs, thanks to the REEF program?

P. B.: Designed specifically for the large-scale restoration of coral reefs, this type of movable structure could be placed in coral sanctuaries for colonization as a preventive measure, and then transferred to a damaged area when needed.

The aim is to facilitate recolonization and a gradual build-up of resilience — two objectives that generally require many years to achieve and may even be impossible without human intervention. Little by little, we hope that degraded coral reefs will recover and reclaim their role in biodiversity.

REEF modules have been designed so that they can be produced, installed and maintained by local communities. They therefore contribute to social and industrial development, while also generating a net positive impact for the communities concerned.


Photo Credits: Coral Reef Image Bank