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 and atolls do not usually form complete circles, but are broken in places by storms. Like sea level rise, a rapidly subsiding bottom can overwhelm coral growth, killing the coral and the reef, due to what is called "coral drowning". Corals that rely on zooxanthellae can die when the water becomes too deep for their symbionts to adequately photosynthesize, due to decreased light exposure. The two main variables determining the geomorphology, or shape, of coral reefs are the nature of the substrate on which they rest, and the history of the change in sea level relative to that substrate. The