Coral reef to form fringing reefs, and can eventually grow become a barrier reef. Where the bottom is rising, fringing reefs can grow around the coast, but coral raised above sea level dies. If the land subsides slowly, the fringing reefs keep pace by growing upwards on a base of older, dead coral, forming a barrier reef enclosing a lagoon between the reef and the land. A barrier reef can encircle an island, and once the island sinks below sea level a roughly circular atoll of growing coral continues to keep up with the sea level, forming a central lagoon. Barrier reefs
Coral reef fish wriggle into crevices and holes and extract prey inaccessible to other reef sharks. On the other hand, they are rather clumsy when attempting to take food suspended in open water. The whitetip reef shark does not frequent very shallow water like the blacktip reef shark, nor the outer reef like the grey reef shark. They generally remain within a highly localized area. An individual shark may use the same cave for months to years. The daytime home range of a whitetip reef shark is limited to about , and at night this range increases to . The whitetip reef shark