The Environment Ministry and a local diving association have confirmed the discovery of one of the nation's largest single-species colonies of coral.
The coral, which was discovered in Nagura Bay west of Ishigakijima island, Okinawa Prefecture, measures about 70 meters in circumference and is about 10 meters high.
Located two to three kilometers off the coast of Ishigakijima island on a slope seven to 13 meters underwater, the Pavona clavus coral colony has an oval shape and is between 17 meters and 24 meters wide.
Local divers say the water in Nagura Bay is somewhat murky, and the coral in the area was not well known.
The colony was accidentally discovered during the local diving association's work to eliminate crown-of-thorns starfish in 2013.
The ministry and the association conducted detailed research between July and December last year.
The newly discovered colony is located 10 kilometers from the Sekisei Lagoon, and during last year's survey, many other coral were discovered in Nagura Bay.