Ocean reefs form under water, and may be formed from, coral, rock, or sand. Generally the top of the reef is positioned from two to three feet below the surface. Coral reefs are located in shallow, clean ocean water.
Among the most amazing of this type is the Great Barrier Reef. It is actually a chain of much smaller reefs, and measures an astounding 1,250 miles across the ocean.
Located in the coral sea, which is an area of the Pacific ocean, around the northeastern coast of Australia, it creates a natural water break between the immense waves of the Pacific ocean and the coast of Australia.
Great Barrier Reef
The waters around it cover an area roughly the size of the state of Minnesota. There are reefs that may be found in much deeper waters, as low as 250 feet below the surface, but usually corals that thrive in such deep water don’t make such good reef builders.
The Great Barrier reef is the largest single structure made by a living organism, and can actually be seen from outer space.
It is also labled as one of the 7 natural wonders of the world. To limit human impact, much of it is protected by the Great Barrier Reef Marine Park, this prevents overuse by tourism or fishing.
The reef supports an amazing diversity of life including many endangered species, and some species that live exclusively in the reef.
Among the life that specifically live there, 30 species of dolphin, whale and porpoises have be recorded there, including the humpback whale, the dwarf Minke whale, and the Indo-pacific humpback dolphin.
Along with this a very large population of Dugongs reside within the protective waters of the reef. Six species of sea turtle make the reef their breeding grounds, the leatherback, the hawksbill, the loggerhead, the green sea turtle, the flatback and the olive ridley.
Great Barrier Reef Turtle
The main attraction seems to be the some 15 species of seagras that grow there, providing food and cover for the dugongs and turtles.
About 125 species of shark make their home on the reef, and over 200 species of bird use it for their feeding grounds. It is also one of the primary places on earth to find the giant clam.
The reef first became know to Europeans in 1770 when captain James Cook ran his ship aground there, causing much damage. After casting much of the cargo aside they succeeded in saving the boat during high tide.
Find out more about the Great Barrier Reef Turtle over at Wikipedia »