The Great Barrier Reef is probably the best-known coral reef in the world. Stretching some 1,800 miles along Australia's east coast, the brightly colored reef is the only living thing on earth that is visible from space. The reef is home to more than 400 different types of coral, over 1,500 species of fish, 200 types of birds and 20 kinds of reptile. It lies between 15 and 150 kilometers off shore, and in some places is up to 65 kilometers wide. Since 1981, it has been a UNESCO designated World Heritage Site. UNESCO describes the reef as "a site of remarkable variety and beauty."
Located off the coast of Western Australia, Rowley Shoals is a small chain of coral atolls. The three atolls, named Mermaid Reef, Clerke Reef and Imperieuse Reef, rise from the sea bed some 440 meters below sea level. The atolls have shallow lagoons rich with sea life, including 233 species of coral and 688 species of fish. The coral reefs can be seen at low tide, but disappear from view at high tide, leaving only the sandy islands of Clerke and Imperieuse visible above the water.
The Abrolhos Islands lie around 60 kilometers west of the town of Geraldton on the Midwest coast. Clustered into three main groups---Wallabi, Easter and Pelsaert---they spread across 100 kilometers of ocean. The islands support coral formation because they lie in the south-flowing Leeuwin Current, which brings warm water from the Indian Ocean and maintains a water temperature of between 20 and 22 degrees Celsius in the winter months. In addition to tropical marine life, the islands are also important as a breeding site for seabirds. The Western Australia Department of Fisheries has identified more than 90 different species whose survival is aided by the fact that the islands have no introduced predators.
The largest coral reef in the western Australian coral reef system, Ningaloo Reef stretches for some 300 kilometers along Australia's west coast. At its central length, it is 200 kilmeters, making it the second longest continuous stretch of reef in the world. The reef itself is home to more than 200 types of coral, 500 fish species and more than 600 species of mollusk. Like the Abrolhos Islands, the Ningaloo Reef owes its existence to the warm waters of the Leeuwin Current, which support the diversity of its marine environment. The area is also unusual because it is the location for an annual gathering of whale sharks. The Ningaloo coast was put forward for UNESCO listing as a World Heritage Site in 2008.
