This satellite image shows Fiji's second-largest island, Vanua Levu, and the Cakaulevu Reef that shelters the island's northern shore. Also called the Great Sea Reef, Cakaulevu shines turquoise through clear, shallow waters. It is the third longest continuous barrier reef in the world, behind the Great Barrier Reef in Australia and the Mesoamerica Reef off Central America. When combined with the nearby Pascoe Reef, Cakaulevu Reef is about 200 km (120 mi) long. On its own, the Cakaulevu Reef covers 202,700 sq km (77,200 sq mi). The first systematic survey of the reef (in 2004) revealed a diverse marine population, including unique mangrove ecosystems and endemic fish. Twelve threatened species live within the reef: 10 fish species, the green turtle, and the spinner dolphin. All of this marine life has traditionally supported the native population, and currently some 70,000 people depend on the reef. After seeing fish populations decline in recent decades, local leaders created a series of marine protected areas in 2005 where fishing is prohibited. Where the ban has been enforced, fish populations have rebounded and spilled over into areas where fishing is permitted. Photo courtesy of NASA.