Coral reef islands and atolls. The reef face is the zone above the reef floor or the reef drop-off. This zone is often the reef's most diverse area. Coral and calcareous algae provide complex habitats and areas that offer protection, such as cracks and crevices. Invertebrates and epiphytic algae provide much of the food for other organisms. A common feature on this forereef zone is spur and groove formations that serve to transport sediment downslope. The reef flat is the sandy-bottomed flat, which can be behind the main reef, containing chunks of coral. This zone may border a lagoon and serve as
Lihou Reef National Nature Reserve Lihou Reef National Nature Reserve Lihou Reef National Nature Reserve is a former marine protected area covering an area of 8440 kmin the Australian Coral Sea Islands Territory that was incorporated into the new Coral Sea Commonwealth Marine Reserve in December 2012. Together with the Coringa-Herald National Nature Reserve, from which it is separated by about 100 km of open ocean, it forms the Coral Sea Reserves Ramsar Site, designated on 16 August 2002, listing it under the Ramsar Convention as a wetland of international importance. Lihou Reef and its cays were discovered by Lieutenant John Lihou, R.N., on 23