Rediscovered Coral Reef Off Benin Coast Sparks Conservation Push

A team of Beninese scientists has rediscovered a thriving coral reef off the coast of Benin, sixty years after the site was first identified but subsequently lost to scientific record. Led by project lead Gérard Zinzindohoué, the discovery confirms the existence of a mesophotic coral ecosystem (MCE) at depths exceeding 175 feet, approximately 14 miles offshore in the Gulf of Guinea. The finding challenges previous assumptions that the region’s deep-water coral communities had been wiped out by climate-induced bleaching or human activity.

The reef was originally identified in the 1960s by fishing surveyors assessing fish diversity in the sandy-bottomed waters. However, the specific location was buried in a brief paragraph of a lengthy government report and lost to subsequent research. Zinzindohoué, who questioned the absence of local reefs after visiting Cape Verde in 2021, secured a $20,000 National Geographic Explorers grant in January 2025 to investigate the historical data. The project faced significant logistical hurdles, including equipment procurement issues and the lack of a permanent research vessel, requiring the team to utilise local fishermen and their pirogues to tow sonar equipment offshore.

Utilising sonar and high-resolution deep-sea camera footage provided by the National Geographic Exploration Technology Lab, the team verified the reef’s existence and health. The footage revealed a patchily scattered coral garden on a rocky substrate, hosting at least eight types of coral, including six types of soft coral and two black corals. The ecosystem also supports eight species of fish, such as golden African snappers, Monrovia doctorfish, and blackbar soldierfish.

Researchers have classified the site as a mesophotic coral ecosystem, which exists between 30 and 150 metres below the surface where light levels are lower but still support photosynthesis. These ecosystems are increasingly recognised for their ecological and climatic importance, serving as a bridge between shallow reefs and deeper benthic habitats. Zinzindohoué noted that the undisturbed nature of the site offers potential for carbon dating and paleoclimatic studies to better understand historical climate systems in the region.

Following the discovery, the team is moving to secure formal conservation status for the habitat. Houangninan Midinoudewa, an oceanographic researcher at the Benin Marine Conservation Club, is submitting an application to the International Union for Conservation of Nature (IUCN) to designate the area as an Important Shark and Ray Area. Based on local knowledge, the site is believed to be home to sawback angel sharks, silky sharks, brown skates, and marbled stingrays. The researchers plan to advocate for the establishment of a marine protected area to preserve the ecosystem and support local livelihoods.