With 994mi (1,600km) of reef and 4970sqmi (8,000km2) of coral formations, New Caledonia is surrounded by the largest lagoon in the world. In the Southern Province of Grande-Terre, marine protected areas have been set up on 44,300 hectares from Bourail to the Sarcelle pass to preserve the habitat biodiversity and encourage the repopulation of the adjacent unprotected areas. This monitoring of the lagoon space has made it possible to double the number of fish species around the protected perimeters.