Living Mesophotic Coral Gardens Discovered off Benin After Six Decades

A 2026 study published in *Frontiers in Marine Science* reports that mesophotic coral ecosystems—deep, dimly lit reefs around 54 m (177 ft) depth—are thriving off the coast of Benin in the Gulf of Guinea. Researchers identified two hard-bottom patches spanning roughly 7 km (4.3 mi) and documented vibrant octocoral colonies, black corals, and eight fish species inhabiting the sites.

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During the early 1960s, fisheries surveys detected apparent coral formations at 52–56 m depth near Benin, but reliance on dredging and primitive sonar led scientists to conclude the reefs were dead. For the next 60 years no follow-up investigations were conducted, leaving the area classified as a “coral graveyard” in global assessments of reef loss linked to warming oceans.

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Between April and December 2025, the team employed modern side-scan sonar to map the seafloor, revealing the two reef patches. Underwater cameras and a remotely operated vehicle captured video showing at least six octocoral morphologies, two types of black coral, and fish such as golden African snapper (*Lutjanus fulgens*), blackbar soldierfish (*Myripristis jacobus*), Guinean angelfish (*Pseudupeneus prayensis*), three-banded butterflyfish (*Chaetodon robustus*), and two damselfish species. The researchers note that the reefs consist of isolated rocky outcrops rather than a continuous structure, a pattern common to mesophotic habitats worldwide.

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He emphasized that the discovery underscores the need for further exploration and potential protection of these understudied habitats, especially as bottom-trawling and climate change intensify pressures on continental-shelf ecosystems.

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• “I still remember seeing those first images. It was a mix of excitement and disbelief, because after all this time thinking about this reef, suddenly there was something real in front of us,” — Zinzindohoué. Mesophotic

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• “I think what we found is probably not an exception," said Zinzindohoué.” — Gérard Zinzindohoué

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