The world's newest marine sanctuary, announced this week, encompasses 18,000 square miles (over 46,000 square kilometers) of ocean around the central African nation of Gabon. (See "Gabon Announces World's Newest Underwater Reserve, Rich in Threatened Wildlife.")
The area is home to more than 20 species of sharks and rays, including threatened species like great hammerhead sharks, manta rays, whale sharks, and tiger sharks. (Read "Saving Africa's Eden" in National Geographic magazine.)
Its protection had been a major aim of National Geographic's Pristine Seas project, which conducted a marine survey of parts of the nation's almost 500-mile (800-kilometer) coastline in 2012.
"National Geographic's Pristine Seas project looks for the wildest places in the ocean, to inspire leaders to save them before it's too late; Gabon was probably the only such place left in West Africa," says National Geographic Explorer-in-Residence Enric Sala, leader of the Pristine Seas project.
In the pictures that follow, Sala and National Geographic photographer Michael "Nick" Nichols capture Gabon's vibrant underwater life. Above, an eel slithers through coral patches off an oil platform in Gabon in a picture shot by Sala.
—By Kennedy Warne and Linda Qiu, photo gallery by Nicole Werbeck