Johnson South Reef Johnson South Reef Johnson South Reef (; ), also known as Chigua Reef in China, Gạc Ma Reef in Vietnam and Mabini Reef in the Philippines is a reef in the southwest portion of the Union Banks in the Spratly Islands of the South China Sea. It is controlled by the People's Republic of China (PRC), but its ownership is disputed by the PRC, the Philippines, Taiwan, and Vietnam. Johnson South Reef lies adjacent to the Vietnamese-controlled Collins Reef (also known as Johnson North Reef) which lies to the northwest. It is naturally above water only at low tide. Prior
Apo Island species of coral can be found here, from tiny bubble corals to huge gorgonian sea fans and brain corals. Visitors and tourists pay a fee to enter Apo Island and to snorkel or dive in the marine sanctuary there. These fees are used to keep the sanctuary clean and in good condition. In 2003, Chicago's Shedd Aquarium opened a Wild Reef exhibit based on Apo Island's surrounding reef and marine sanctuary. In 2008, Sport Diver Magazine listed Apo Island as one of the top 100 diving spots in the world. As of 2017, the fish sanctuary, at the southeastern part