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
Middleton Reef Middleton Reef Middleton Reef is a coral reef in the Tasman Sea. It is separated by a deep oceanic pass some 45 km wide from nearby Chan Reef, forming part of the Lord Howe Rise underwater plateau. It is around 220 km from Lord Howe Island and 555 km from the coast of New South Wales. In 1997 the Environment, Sport and Territories Legislation Amendment Bill 1996 included the reef in Australia's Coral Sea Islands Territory. It is among the southernmost platform reefs in the world. Despite its relatively high latitude, there is a wide variety of flora and fauna