Benin Coast, Benin – A coral reef once believed to be dead has been discovered alive and thriving off the coast of Benin after researchers used modern sonar surveys and underwater imaging systems.

The reef was first identified in surveys from the 1960s, which suggested a possible deep-water coral reef more than 50 meters below the surface but assumed it was no longer alive.

Researchers from the Institut de Recherches Halieutiques et Océanologiques du Bénin used sonar to survey 11.5 kilometers of seabed. Two signals appeared to show possible reef structures, leading the team to investigate further with an underwater drone and the Deep Sea Camera System.

The footage revealed a seemingly healthy mesophotic coral ecosystem with eight types of coral and eight species of fish living around the corals.

“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,” said Gérard Zinzindohoué, lead author of the research article.

The discovered ecosystem is made up of patches of coral growing in rocky areas rather than one continuous reef barrier. Scientists said it is the first confirmed record of a living mesophotic coral ecosystem on the Gulf of Guinea continental shelf.

Researchers noted that coral samples have not yet been collected, meaning species identifications still need confirmation. More studies will be needed to understand the reef’s history and determine whether other undocumented coral systems may exist in the region.

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