Great Barrier reef is a largest living structure on earth that is extremely diverse. Is 2300 km in length and can be even seen from outer space. Moreover it has 600 types of soft and hard corals, over 100 species of jellyfish, 3000 types of molluscs, 500 species of worms, 1625 types of fish, 133 varieties of sharks and rays, and more than 30 species of whales and dolphins. In addition to that the Great Barrier Reef extends over 14 degrees of latitude, that vary from shallow estuarine areas to deep ocean waters. Which also contributed to its inscription in 1981 into the World Heritage Reef. The region has two main seasons: a winter period/dry season of warm temperatures and low rainfall (20°C / 68°F), and a summer/green period of balmy temperatures and high precipitation (up to 31°C / 90°F). East Australian Current the major current running along the east coast southward. Furthermore the structure of individual reefs varies greatly yet two main classes may be defined: platform or patch reefs, resulting from radial growth; and wall reefs, resulting from elongated growth, often found in areas of strong water currents. There is also a handful fringing reefs when the reef growth is established on subtidal rock of the mainland coast/ continental islands. All in all the Great Barrier Reef is a remarkable site with a large part of it protected by the GBR Marine Park, that covers 99% of the territory.