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Learn about the world's largest coral reef system, its biodiversity, threats, history and culture. Find out how to visit, explore and protect this natural wonder of the world.
Oct 19, 2023 · Learn about the biodiversity, threats, and conservation of the Great Barrier Reef, a coral reef off the coast of Australia. Find out how climate change, pollution, and pests affect the reef and what you can do to help.
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Great Barrier Reef, complex of coral reefs, shoals, and islets in the Pacific Ocean off the northeastern coast of Australia that is the longest and largest reef complex in the world. The Great Barrier Reef extends in roughly a northwest-southeast direction for more than 1,250 miles (2,000 km), at an offshore distance ranging from 10 to 100 miles (1...
The reef actually consists of some 2,100 individual reefs and some 800 fringing reefs (formed around islands or bordering coastlines). Many are dry or barely awash at low tide; some have islands of coral sand, or cays; and others fringe high islands or the mainland coast. In spite of this variety, the reefs share a common origin: each has been formed, over millions of years, from the skeletons and skeletal waste of a mass of living marine organisms. The “bricks” in the reef framework are formed by the calcareous remains of the tiny creatures known as coral polyps and hydrocorals, while the “cement” that binds these remains together is formed in large part by coralline algae and bryozoans. The interstices of this framework have been filled in by vast quantities of skeletal waste produced by the pounding of the waves and the depredations of boring organisms.
European exploration of the reef began in 1770, when the British explorer Capt. James Cook ran his ship aground on it. The work of charting channels and passages through the maze of reefs, begun by Cook, continued during the 19th century. The Great Barrier Reef Expedition of 1928–29 contributed important knowledge about coral physiology and the ecology of coral reefs. A modern laboratory on Heron Island continues scientific investigations, and several studies have been undertaken in other areas.
The reef has risen on the shallow shelf fringing the Australian continent, in warm waters that have enabled the corals to flourish (they cannot exist where average temperatures fall below 70 °F [21 °C]). Borings have established that reefs were growing on the continental shelf as early as the Miocene Epoch (23.0 million to 5.3 million years ago). Subsidence of the continental shelf has proceeded, with some reversals, since the early Miocene.
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The water environment of the Great Barrier Reef is formed by the surface water layer of the southwestern Pacific Ocean. The reef waters show little seasonal variation: surface-water temperature is high, ranging from 70 to 100 °F (21 to 38 °C). The waters are generally crystal-clear, with submarine features clearly visible at depths of 100 feet (30 metres).
Learn about the Great Barrier Reef, the world's largest coral reef complex in the Pacific Ocean off northeastern Australia. Discover its geography, biodiversity, history, and current challenges from climate change and human activities.
- The Editors of Encyclopaedia Britannica
1 day ago · Learn how to visit and protect one of the world's natural wonders, with tips on tours, islands, diving, wildlife and more. Explore the best destinations, experiences and accommodation options on the Great Barrier Reef.
17 hours ago · The Great Barrier Reef is the largest coral reef system in the world. It is 344,400 km2 and extends to Queensland’s coast, Australia, securing the classification of a UNESCO World Heritage site. In this world-famous reef, more than 1,500 fish species and 411 hard coral species are found to be thriving, which makes it the most expansive range ...
Learn about the world's largest coral reef system, its biodiversity, threats, and conservation efforts. Find out how to visit, explore, and photograph this natural wonder in Australia.
Jun 20, 2018 · Learn about the Great Barrier Reef, the largest coral reef system on Earth, and its diverse marine life. Find out how to get there, when to go, and how to explore this natural wonder by boat, plane, or helicopter.
