These Coral Reefs Off West Africa Were Long Presumed Dead. Scientists Just Found Them Alive and Teeming With Life

In the 1960s, government-requested fish surveys detected a coral reef barrier off the coast of Benin in West Africa, but it was presumed to be dead. Now, however, researchers have taken a second look and found a flourishing coral ecosystem, they report in a study published on July 19 in the journal Frontiers in Marine Science. Their observations provide the first documented evidence of living low-light coral communities on the Gulf of Guinea’s continental shelf.

What’s more, the reefs’ rediscovery is a testament to scientific endurance and sheds light on an understudied marine region. The project began in January 2025, thanks to a National Geographic Explorers grant, reports Inside Climate News’ Johnny Sturgeon. However, the team hit roadblocks when trying to purchase sonar equipment from a supplier in Europe.

Additionally, since Benin doesn’t own a permanent research vessel, the scientists had to make do with small fishing boats to travel roughly 14 miles offshore. Nevertheless, they persisted. Between April and December 2025, the team conducted sonar mapping, underwater drone surveys and deployed stationary video recorders to see what was going on in a 4.3-mile stretch of the suspected 24-mile-long coral reef barrier mapped in the 60s.

The data revealed a patchwork of corals about 177 feet below the surface at a depth called the mesophotic zone, where little sunlight reaches. Additionally, the video surveys captured eight fish species, including golden African snappers, blackbar soldierfish, West African goatfish and Guinean angelfish, using the corals for shelter and feeding. Although the team did not estimate how many individual fish were living there, the observations hint that the habitat supports a diverse assemblage of animals, the researchers write in the paper.

It was a “really undisturbed environment,” Zinzindohoué tells ABC News’ Julia Jacobo. And it was a really big moment for us because it was some things we have never seen.” They were looking at a mesophotic coral garden, an ecosystem that differs from shallow coral reefs by living in deeper and darker waters and sometimes forming various chunks of coral communities instead of a continuous reef structure. It’s the first verified documentation of a living mesophotic coral ecosystem on the Gulf of Guinea continental shelf, Zinzindohoué says in a statement.

Mesophotic coral ecosystems Because these ecosystems are quite deep, little has been known about them until recently, thanks to technological developments. Scientists suspect that mesophotic corals could help replenish degraded shallow-water coral ecosystems because they share common species. If we were able to find this reef again after 60 years, how many others are still undocumented or simply forgotten?” Luiz Rocha, curator of fishes at the California Academy of Sciences, agrees.