From the article:

In the 1960s, fishing surveyors off West Africa’s Benin coast hauled up heads of coral in their nets. Employed by local governments to assess fish diversity and discover potentially trawlable seabeds in the sandy-bottomed Gulf of Guinea, the researchers shrugged off the discovery at the time, burying the find in a brief paragraph in a 130-something-page report.

With no surveys since, the scientists who followed had lost track of exactly where the reefs might lie. And as mass bleaching events and overfishing slashed the world’s coral reef area by more than 50 percent since the 1950s, local oceanographers had written off any remnants of a possible reef as dead.

More than six decades on, the mystery has been solved as a team of Beninese scientists rediscovered the healthy reef teeming with marine life. At least eight coral types and eight fish species have formed a thriving ecosystem on this long-forgotten site.