Osprey Reef Osprey Reef Osprey Reef is a submerged atoll in the Coral Sea, northeast of Queensland, Australia. It is part of the Northwestern Group of the Coral Sea Islands. Osprey Reef is roughly oval in shape, measuring , and covers around . It has a perimeter of . The central lagoon is only deep. The reef sits atop a seamount in deep water. It is an isolated location some from other reefs. The almost vertical reef walls, which rise from a depth of about , are home to a dwarf form of "Nautilus pompilius" that is isolated from other nautilus populations
Coral reef cannot grow above sea level. As the name implies, coral reefs are made up of coral skeletons from mostly intact coral colonies. As other chemical elements present in corals become incorporated into the calcium carbonate deposits, aragonite is formed. However, shell fragments and the remains of coralline algae such as the green-segmented genus "Halimeda" can add to the reef's ability to withstand damage from storms and other threats. Such mixtures are visible in structures such as Eniwetok Atoll. Since Darwin's identification of the three classical reef formations – the fringing reef around a volcanic island becoming a barrier reef and