The New Caledonian barrier reef is located in New Caledonia in the South Pacific, and is the longest continuous barrier reef in the world and the third largest after the Great Barrier Reef of Australia and the Mesoamerican Barrier Reef. The New Caledonian barrier reef surrounds Grande Terre, New Caledonia's largest island, as well as the Ile des Pins and several smaller islands, reaching a length of. The reef encloses a lagoon of, which has an average depth of. The reefs lie up to from the shore, but extend almost to the Entrecasteaux reefs in the northwest. This northwestern extension encloses the Belep Islands and other sand cays. Several natural passages open out to the ocean. The Boulari passage, which leads to Noumea, the capital and chief port of New Caledonia, is marked by the Amédée lighthouse.
Ecology
The reef systems of New Caledonia are considered to be the second largest in the world after the Great Barrier Reef of Australia, the longest continuous barrier reef in the world with a length of 1,600 km and its lagoon, the largest in the world with an area of 24,000 square kilometers. This ecosystem hosts along with Fiji, the world's most diverse concentration of reef structures, 146 types based on a global classification system, and they equal or even surpass the much larger Great Barrier Reef in coral and fish diversity. The reef has great species diversity with a high level of endemism, and is home to endangered dugongs ' with the third largest population, and is an important nesting site for green sea turtle'. In the lagoons of New Caledonia there are many water species ranging from plankton to larger fish and even sharks.
Environmental Threats
Most of the reefs are generally thought to be in good health. Some of the eastern reefs have been damaged by effluent from nickelmining on Grand Terre. Sedimentation from mining, agriculture, and grazing has affected reefs near river mouths, which has been worsened by the destruction of mangrove forests, which help to retain sediment. Some reefs have been buried under several metres of silt. In January 2002, the French government proposed listing New Caledonia's reefs as a UNESCO World Heritage Site. UNESCO listed New Caledonia barrier reef on the World Heritage List under the name The Lagoons of New Caledonia: Reef Diversity and Associated Ecosystems on 7 July 2008. The Lagoons were listed under three UNESCO categories:
There are 13 local management committees, composed of tourist operators, fishermen, politicians and chiefs of local tribes which work with the community to monitor the health of the lagoons.
Human Use
Scuba Diving is common, with several dive sites in the lagoon and around the reef. These include the Prony needle, the Shark Pit and the Cathedral.
