A coral reef presumed dead for 60 years has been found thriving in the Gulf of Guinea, off Benin’s coast, according to research published in Frontiers in Marine Science. The discovery, made using sonar and underwater drones, reveals a mesophotic ecosystem teeming with eight coral species and eight fish types, challenging assumptions about marine biodiversity in West Africa.
Scientists first detected signs of a coral reef off Benin’s coast in the 1960s, but limited technology led them to assume it was dead. Decades later, a team led by Gérard Zinzindohoué of the Benin Fisheries and Oceanological Research Institute used high-resolution sonar and the National Geographic Exploration Technology Lab’s Deep Sea Camera System to confirm the reef’s survival. The findings, published in Frontiers in Marine Science, mark the first recorded living mesophotic coral ecosystem on the Gulf of Guinea’s continental shelf.
The Rediscovery After Six Decades
The reef’s reappearance began with a sonar survey, which revealed rocky structures 54 meters (177 feet) below the surface. The first thing that gave us hope was our first deployment of the sonar. We were seeing nothing but sand and sediment, and suddenly we could see some rocky structure,
Zinzindohoué said, describing the moment. The team followed up with an underwater drone and deep-sea cameras, capturing footage of a really undisturbed environment
where everything was alive,
he noted.
The ecosystem, located along an 11.5-kilometer (7.1-mile) surveyed area of seabed, consists of scattered coral patches rather than a continuous reef. Unlike typical shallow reefs, it does not always form a single continuous reef structure. Instead, it can appear as patchy or scattered coral communities,
Zinzindohoué explained. The team identified eight coral species, including six octocorals and two black corals, as well as eight fish species such as golden African snappers and Guinean angelfish.
A Breakthrough for West African Marine Research
The discovery highlights the underexplored marine ecosystems of West Africa, where ocean science is not well developed,
Zinzindohoué said. Right now, on the coast of West Africa, and particularly in Benin, ocean science and marine research are not well developed.
The findings could spur further exploration, as the team suspects other undetected reefs exist. If we were able to find this reef again after 60 years, how many others are still undocumented or simply forgotten?
he asked.
Despite the confirmation of a living reef, questions remain. Future expeditions will focus on broader surveys and coral sampling to reconstruct the reef’s history.
Implications for Climate Resilience
The reef’s survival raises hopes for marine resilience. The absence of coral bleaching in the surveyed area suggests the ecosystem may possess unique adaptations.
The discovery also underscores the need for conservation in a region where marine resources are under pressure. We hope that, through this result, people will start to look at the ocean differently,
Zinzindohoué said. And that it might inspire others to do more ocean research and focus on the protection and conservation of marine ecosystems.
What Comes Next for the Reef?
While the immediate focus is on confirming the reef’s full extent, the findings have broader implications. Without further data, the reef’s status as a continuous barrier remains unproven.
The team’s next steps include expanding surveys along the Gulf of Guinea’s continental shelf and analyzing the reef. For now, the rediscovered reef stands as a testament to nature’s capacity for resilience—and a call to deepen marine research in one of the world’s most underexplored regions.
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