Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps are like tiny sea anemones, to which they are closely related. Unlike sea anemones, coral polyps secrete hard carbonate exoskeletons which support and protect their bodies. Reefs grow best in warm, shallow, clear, sunny and agitated waters.
Often called “rainforests of the sea”, coral reefs form some of the most diverse ecosystems on Earth. They occupy less than 0.1% of the world's ocean surface, about half the area of France, yet they provide a home for 25% of all marine species, including fish, mollusks, worms, crustaceans, echinoderms, sponges, tunicates and other cnidarians. Paradoxically, coral reefs flourish even though they are surrounded by ocean waters that provide few nutrients. They are most commonly found at shallow depths in tropical waters, but deep water and cold water corals also exist on smaller scales in other areas.
Coral reefs deliver ecosystem services to tourism, fisheries and shoreline protection. The annual global economic value of coral reefs has been estimated at US$ 375 billion. However, coral reefs are fragile ecosystems, partly because they are very sensitive to water temperature. They are under threat from climate change, ocean acidification, blast fishing, cyanide fishing for aquarium fish, overuse of reef resources, and harmful land-use practices, including urban and agricultural runoff and water pollution, which can harm reefs by encouraging excess algal growth.
Other articles related to "coral reef, reefs, corals, reef, coral reefs, coral":
... by marine organisms, there were almost always reefs ... Ma), owing to order Rugosa extinct corals, and Late Cretaceous (100–65 Ma) and all Neogene (23 Ma–present), owing to order Scleractinia corals ... Not all reefs in the past were formed by corals those in the Early Cambrian (542–513 Ma) resulted from calcareous algae and archaeocyathids (small animals with conical shape, probably ...
... Coral Reef Adventure is a 70mm American documentary film released in 2003 to IMAX theaters ... and Howard Hall explore the declining reefs and failing health of the world's oceans ... From Australia's Great Barrier Reef, to a friend's coral reef-sustained village in Fiji, the diving expeditions show a range of coral reefs, from flourishing ...
... marine sanctuaries—Channel Islands, Gulf of the Farallones, Gray's Reef, and Looe Key ... Ocean Conservancy is attempting to halt current and future coral reef damage in two key ways through changing policy and by building resiliency ... The coral are very sensitive to changes in water temperature and quality caused by global warming, and many times these changes result in disease and death of ...
... In the beginning, the goal was simple to engage the diving community in coral reef conservation ... Today, CORAL's mission of uniting communities to save coral reefs has dramatically broadened the scope of its work and has provided extensive opportunities to have an even greater impact around the globe ... In 1995 CORAL started their first website to help expand coral reef communication and news ...
... Coral reef, of the fringing and hermatypic types, exist along the coast around Ras Mohammad close to the shoreline ... More than 220 species of coral are found in the Ras Mohammad area, 125 of them soft coral ... The coral reefs are located 50 to 100 cm below the sea surface, and they have a width of 30 to 50 m in most places ...
Famous quotes containing the words reef and/or coral:
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