Scientists find active coral communities in reef system presumed dead decades ago
Scientists have found an active coral community that may belong to a deep-sea coral reef system that was assumed to have died out decades ago, according to new research.
A living coral garden located about 54 meters (177 feet) below the surface of the Gulf of Guinea, off the coast of West Africa’s Benin, was detected using sonar technology and deep-sea cameras, according to an article published in the journal earlier this week. Frontiers in Marine Sciences.
Heat-resistant ‘super corals’ offer hope against climate change: Scientists
Gerard Zinzindohoue, a scientist at the Benin Research Institute of Fisheries and Oceanology and lead author of the paper, told ABC News that in the 1960s, the Benin government funded researchers to study what types of fish species were found in the area, including seabeds and hydrology.
The researchers were able to collect a coral reef sample, but a potential reef system was assumed to be dead because its ecological status was unknown, according to the article. Zinzindohoue said that because corals were not the focus of the study, only a short paragraph was written in the 100-page report.
Gerard Zinzindohoue/COREB – PHOTO: Representative images of mesophotic coral communities in Area 1.
However, he said that this determination was not enough to satisfy Zinzindohoue’s curiosity.
“One hope is that even if the reef is dead, it may still be important to the microorganisms living in the ecosystem.”
This time, researchers were equipped with modern technology. They first used side-scan sonar, a detection system used to detect and image objects on the seafloor.
At first they collected only rocky sediments from the seafloor. However, Zinzindohoue said that when they detected a rocky structure, they activated the National Geographic Deep Sea Camera System, which provided close evidence of the ecosystem observed in the sonar image.
Largest coral bleaching event on record affects 84% of world’s reefs: NOAA
To get a closer look at the ecosystem, the researchers used an underwater drone. Describing the scene as “a truly pristine environment,” Zinzindohoue said they saw numerous species of coral moving in the current and numerous fish surrounding the reef structures.
“Everything was alive,” Zinzindohoue said. “And that was a really big moment for us because it was stuff we’d never seen before.”
Şebnem Coşkun/Anadolu via Getty Images – PHOTO: A view showing coral reefs in the Red Sea off Sharm el-Sheikh, Egypt, May 28, 2026.
According to the article, the community consisted of six octocols (a type of soft coral) and two types of black corals, forming a coral garden rather than a structured reef. At least eight associated reef fish species were also identified.
Zinzindohoue also said researchers did not observe any bleaching within the reef system.
How will Florida’s planned coral ‘baby boom’ help strengthen the coastal reef system?
This is the first confirmed existence of a mesophotic coral reef system (or a reef system that needs light to survive but lives in deeper waters where sunlight is not available) on the continental shelf of the Gulf of Guinea, Zinzindohoue said.
According to the article, mesophotic coral ecosystems along the West African coastline, particularly on the continental shelf of the Gulf of Guinea, remain poorly documented.
Gerard Zinzindohoue/COREB – PHOTO: Representative of reef-associated fish species observed in the coral garden.
Zinzindohoue said the next step will be to collect samples from the reef and further investigate its current state.
No physical samples have been taken so far, and the idea of a long, continuous coral barrier is “not supported” by the acoustic data collected for the study, according to the paper.
Zinzindohoue said it will be important to study these reefs and their resilience, especially as climate change and sea warming threaten reefs around the world.
“Today we are experiencing the effects of climate change in oceans around the world, particularly in West Africa and Benin,” he said. “So we really want to continue researching.”
