Shining Light on Brazil’s Secret Coral Reef

The massive, previously unstudied reef is unlike any other known on Earth

Researchers sort through finds recovered from trawling in the central section of the Amazon reef. (F. Moraes, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro)

By Rachel Nuwer

Ask anyone to picture a coral reef and they almost certainly think of sun-dappled aquatic communities in clear, turquoise waters. While that is the norm for the majority of the world’s reefs, there are striking exceptions—one of which can be found in the muddy waters off northern Brazil’s coast, where the Amazon River meets the sea.

Researchers previously had a vague idea of the reef’s existence, but until now they had no inkling of just how large and diverse it truly is. The most extensive study to date, published today in Science Advances, reveals that the reef covers an area larger than Delaware—some 3,600-square miles, stretching from the French Guiana border to Brazil’s Maranhão State—and likely supports many species previously unknown to science. The reef is so odd, in fact, that its discoverers believe it may constitute an entirely new type of ecological community.

“This is something totally new and different from what is present in any other part of the globe,” says Fabiano Thompson, an oceanographer at the Universidade Federal do Rio de Janeiro in Brazil. “But until now, it’s been almost completely overlooked.”  Read more.