"Lyra Reef Lyra Reef is a remote submerged coral atoll, about in diameter, extending over an area of . It lies about north-east of New Ireland in the Bismarck Archipelago of Papua New Guinea, and north-east of Simberi Island, the closest island, and about the same distance north-west of the Nuguria Islands. The depths around the perimeter of the reef are generally less than and in places are less than . The least depth is on its north side. Within the reef, in the lagoon, there are depths of exceeding . A gap on the north-west side of the reef"
"Atoll An atoll (, , , , or ), sometimes called a coral atoll, is a ring-shaped coral reef including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. The coral of the atoll often sits atop the rim of an extinct seamount or volcano which has eroded or subsided partially beneath the water. The lagoon forms over the volcanic crater or caldera while the higher rim remains above water(s) or at shallow depths that permit the coral to grow and form the reefs. For the atoll to persist,"
"National Geographic Society defines lagoons as a ""shallow body of water protected from a larger body of water (usually the ocean) by sandbars, barrier islands, or coral reefs."" There are two different types of lagoons: coastal lagoons and atoll lagoons. Coral reefs are one of the most well-known marine ecosystems within the world. The largest being that of the Great Barrier Reef. These reefs are composed of large coral colonies of a variety of species living together. The corals form multiple symbiotic relationships with the organisms around them. The deep sea contains up to 95% of the space occupied by"
"Coral island A coral island is a type of island formed from coral detritus and associated organic material. They occur in tropical and sub-tropical areas, typically as part of coral reefs which have grown to cover a far larger area under the sea. Coral reefs are some of the oldest ecosystems on the planet. Over geological time forming massive reefs made of limestone. The reef environment supports more plant and animal species than any other habitat. Coral reefs are vital for life for multiple aspects some of which include structure, ecology, and nutrient cycles which all support biodiversity in the"
"Pseudo-atoll A pseudo-atoll, like an atoll, is an island that encircles a lagoon, either partially or completely. A pseudo-atoll differs from an atoll as established by several authorities, such as how it is formed (not by subsidence, nor by coral). It is considered a preferable term to ""near-atoll"". There is a need for rigorous definition of ""pseudo-atoll"" before it can be accepted as a general term. Alexander Agassiz gave the term pseudo-atoll to ""any ring-shaped reefs not formed as a result of subsidence"". while Norman D. Newell and J. Keith Rigby called such reefs non-coral. and ""We conclude that almost-atoll"
"are small with low elevation above sea level. Thus they are at threat from storms and rising sea levels. Coral island A coral island is a type of island formed from coral detritus and associated organic material. They occur in tropical and sub-tropical areas, typically as part of coral reefs which have grown to cover a far larger area under the sea. Coral reefs are some of the oldest ecosystems on the planet. Over geological time forming massive reefs made of limestone. The reef environment supports more plant and animal species than any other habitat. Coral reefs are vital for"
"a protective area, or it may lie between the reef and the shore, and in this case is a flat, rocky area. Fish tend to prefer it when it is present. The reef lagoon is an entirely enclosed region, which creates an area less affected by wave action and often contains small reef patches. However, the ""topography of coral reefs is constantly changing. Each reef is made up of irregular patches of algae, sessile invertebrates, and bare rock and sand. The size, shape and relative abundance of these patches changes from year to year in response to the various factors"
"enclosing a lagoon in which there are no promontories other than reefs and islets composed of reef detritus"" or ""in an exclusively morphological sense, [as] a ring-shaped ribbon reef enclosing a lagoon"". Most of the world's atolls are in the Pacific Ocean (with concentrations in the Tuamotu Islands, Caroline Islands, Marshall Islands, Coral Sea Islands, and the island groups of Kiribati, Tuvalu and Tokelau) and Indian Ocean (the Atolls of the Maldives, the Lakshadweep Islands, the Chagos Archipelago and the Outer Islands of the Seychelles). The Atlantic Ocean has no large groups of atolls, other than eight atolls east of"
"a lagoon, which often extends more than a hundred metres to the reef, then slopes steeply to deep water. The reef fronts the shore to the north of the island, making the lagoon there unsuitable for swimming and water sports, but to the south east, particularly around Muri, the lagoon is at its widest and deepest. This part of the island is the most popular with tourists for swimming, snorkelling and boating. Agricultural terraces, flats and swamps surround the central mountain area. Along the southeast coast off Muri Beach are four small coral islets within a few hundred metres of"
"Coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Coral belongs to the class ""Anthozoa"" in the animal phylum ""Cnidaria"", which includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons that support and protect the coral. Most reefs grow best in warm, shallow, clear, sunny and agitated water. Often called ""rainforests of the sea"", shallow coral reefs form some of Earth's most diverse ecosystems. They occupy"
"infer a region's paleoclimate. Coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Coral belongs to the class ""Anthozoa"" in the animal phylum ""Cnidaria"", which includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons that support and protect the coral. Most reefs grow best in warm, shallow, clear, sunny and agitated water. Often called ""rainforests of the sea"", shallow coral reefs form some of Earth's most"
"around . At the outer edge of the reef shelf, the bottom slopes very steeply into deep water, at some locations dropping to more than within of the shore. In the lagoon, numerous coral heads present hazards to navigation. The shallow reef shelf surrounding the island on the ocean side offers no ocean-side anchorage. The channel and anchorage areas in the northern half of the lagoon are dredged, along with the pre-1971 ship turning basin. Significant saltwater wetlands called barachois exist in the southern half of the lagoon. These small lagoons off of the main lagoon are filled with seawater"
"Coral Sea Islands The Coral Sea Islands Territory is an external territory of Australia which comprises a group of small and mostly uninhabited tropical islands and reefs in the Coral Sea, northeast of Queensland, Australia. The only inhabited island is Willis Island. The territory covers , most of which is ocean, extending east and south from the outer edge of the Great Barrier Reef and includes Heralds Beacon Island, Osprey Reef, the Willis Group and fifteen other reef/island groups. Cato Island is the highest point in the Territory. The Coral Sea Islands were first charted in 1803. In the 1870s"
"of the southern islet, built by the Japan Marine Science and Technology Center in 1988, which appears as a rectangle of . The platform has a helicopter landing pad and a large three-story building with a marine investigation facility and a meteorological station. The rocks are in the western part of a lagoon surrounded by a submerged coral reef, over which the waves break, and that extends east-west and north-south, with an area of roughly 5 km² within the rim of the reef. The lagoon is 3 to 4.6 meters deep, but there are numerous coral heads of lesser depths"
"and by private aquarium hobbyists. Coral reef farming is the extracting of part of a coral colony or free-floating larva from a reef and growing them in a nursery until adulthood. It is commonly referred to as the ""gardening method"" and has been compared to silviculture as a management practice that mimics natural ecosystems. Adult corals can be transplanted onto a reef, usually a damaged area. Coral is farmed for conservation reasons in the Philippines, Solomon Islands, Palau, Fiji, Marshall Islands and Japan. Land-based coral farming occurs in public aquariums in North America and Europe. Coral is an important foundation"
"barrier reef. The lagoon floor is covered with thick sand deposits and thickets of staghorn Acropora. The reef is protected by Ngaruangel Reserve. There is one small, barren and uninhabited islet, Ngaruangel Island, in the center of the eastern rim of the atoll, at its easternmost point. Ngaruangel Island is long north-south, and from wide in the south to in the north. There is a sand spit attached to the island, pointing southwest into the lagoon, long and wide. The total area of the island is . The islet consists almost entirely of pieces of rough coral rock thrown up"
"expedition in 1897. The third expedition in 1898 was led by Alfred Edmund Finckh. On January 6, 2009, U.S. President George W. Bush announced the creation of the Pacific Remote Islands Marine National Monument, covering several islands and atolls under U.S. jurisdiction. Atoll An atoll (, , , , or ), sometimes called a coral atoll, is a ring-shaped coral reef including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. The coral of the atoll often sits atop the rim of an extinct seamount or volcano which has"
"Coral reefs are the largest structures created by living organisms, and contain abundant and highly complex microbial communities. A coral ""head"" is a colony of genetically identical polyps, which secrete an exoskeleton near the base. Depending on the species, the exoskeleton may be hard, based on calcium carbonate, or soft and proteinaceous. Over many generations, the colony creates a large skeleton that is characteristic of the species. Diverse forms of life take up residence in a coral colony, including photosynthetic algae such as ""Symbiodinium"", as well as a wide range of bacteria including nitrogen fixers, and chitin decomposers, all of"
"Reef A reef is a bar of rock, sand, coral or similar material, lying beneath the surface of water. Many reefs result from abiotic processes (i.e. deposition of sand, wave erosion planing down rock outcrops, and other natural processes), but the best known reefs are the coral reefs of tropical waters developed through biotic processes dominated by corals and coralline algae. Artificial reefs (e.g. shipwrecks) sometimes have a role in enhancing the physical complexity of featureless sand bottoms, in order to attract a diverse assemblage of organisms, especially algae, and fish. Earth's largest and most famous reef is the Great"
"Lagoon A lagoon is a shallow body of water separated from a larger body of water by barrier islands or reefs. Lagoons are commonly divided into coastal lagoons and atoll lagoons. They have also been identified as occurring on mixed-sand and gravel coastlines. There is an overlap between bodies of water classified as coastal lagoons and bodies of water classified as estuaries. Lagoons are common coastal features around many parts of the world. Lagoons are shallow, often elongated bodies of water separated from a larger body of water by a shallow or exposed shoal, coral reef, or similar feature. Some"
"continued erosion or subsidence must be at a rate slow enough to permit reef growth upwards and outwards to replace the lost height. The word ""atoll"" comes from the Dhivehi (an Indo-Aryan language spoken on the Maldive Islands) word ""atholhu"" (Dhivehi: , ), meaning an administrative subdivision. Its first recorded use in English was in 1625 as ""atollon"". Charles Darwin recognized its indigenous origin and coined, in his ""The Structure and Distribution of Coral Reefs"", the definition of atolls as ""circular groups of coral islets"" that is synonymous with ""lagoon-island"". More modern definitions of ""atoll"" describe them as ""annular reefs"
"island is circled by a broad fringing reef, which, off the western coast swings sharply away from the shore to enclose the lagoon. The precipitous sides of the central mass are scored by three shallow terraces, marking pauses in the uplift of the island; but these are not readily observed, being smothered under the dense vegetation that clothes the whole towering structure. It is a former atoll, specifically called a “Guyot”. This is an extinct volcano that has become overgrown by coral reefs to form an atoll. The flat top was once at sea level, which is why the summit"
"or epicontinental (as the Belize reefs or the Florida Keys). Geologically speaking, reef rocks can be classified as massive boundstones. The internal lagoon, as the name suggests, is the part of platform behind the reef. It is characterised by shallow and calm waters. Sediments are composed of reef fragments and hard parts of organisms. If the reef is epicontinental there can be also a terrigenous contribution. In some lagoons (e.g., the Florida Bay) green algae produce great volumes of carbonate mud. Rocks here are mudstones to grainstones depending on the energy of the environment. The slope is the outer part"
"traditional owners groups agreed to cease the hunting of dugongs in the area in 2011 due to their declining numbers, partially accelerated by seagrass damage from Cyclone Yasi. Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, Australia. The Great Barrier Reef can be seen from outer space and is the world's biggest single structure made by living organisms. This reef structure is composed"
"coast, while estuaries are usually drowned river valleys, elongated perpendicular to the coast. When used within the context of a distinctive portion of coral reef ecosystems, the term ""lagoon"" is synonymous with the term ""back reef"" or ""backreef"", which is more commonly used by coral reef scientists to refer to the same area. Coastal lagoons are classified as inland bodies of water. Many lagoons do not include ""lagoon"" in their common names. Albemarle and Pamlico sounds in North Carolina, Great South Bay between Long Island and the barrier beaches of Fire Island in New York, Isle of Wight Bay, which"
"is mapped under three zones of reef flat, reef slope and lagoon. Next to the shore line are the fringing reefs where fish species of fin and shell fishes spawn, and are found in abundance. As of 1986, there were 45 coral species in the reef. These are threatened due to human interference and natural causes. Live coral is reported in less than 1% area. There are 9 species of live corals in the lagoon and reef slope area. The species of live corals reported are: ""Acropora formosa"" (staghorn coral), ""Acropora robusta"", ""Acropora"", ""Acropora subglabra"", ""Acropora tortuosa"", ""Acropora vaughani"", ""Favites"","
"on 23 December 1987, they were protected as the Elizabeth and Middleton Reefs Marine National Nature Reserve, which has an area of 1880 km. Automatic, unmanned weather stations are located on the following reefs or atolls: Lighthouses are located on following reefs or islands: Willis Island, the only inhabited island, has a number of structures. Coral Sea Islands The Coral Sea Islands Territory is an external territory of Australia which comprises a group of small and mostly uninhabited tropical islands and reefs in the Coral Sea, northeast of Queensland, Australia. The only inhabited island is Willis Island. The territory covers"
"Réunion's coral reef Réunion is an island located near the eastern coast of Madagascar in the Indian Ocean. Its coral reef covers a concentrated part of the western littoral. The coral reef is located between St Leu and St Gilles. It is more than long and ranges in width from in its northern part at St. Gilles to in the south. Since the island is close to the continental shelf, the sea becomes deep not far from the coast. The presence of nearby deeper ocean currents supports a rich biodiversity fauna and flora in the reef environment. Coral reefs are"
"as well as atolls. A fringing reef is a reef that is attached to an island. A barrier reef forms a calcareous barrier around an island resulting in a lagoon between the shore and the reef. An atoll is a ring reef with no land present. The reef front (ocean side) is a high energy locale whereas the internal lagoon will be at a lower energy with fine grained sediments. Ancient reefs buried within stratigraphic sections are of considerable interest to geologists because they provide paleo-environmental information about the location in Earth's history. In addition, reef structures within a sequence"
"Coral Triangle The Coral Triangle is a geographical term so named as it refers to a roughly triangular area of the tropical marine waters of Indonesia, Malaysia, Papua New Guinea, Philippines, Solomon Islands and Timor-Leste that contain at least 500 species of reef-building corals in each ecoregion. This region encompasses portions of two biogeographic regions: the Indonesian-Philippines Region, and the Far Southwestern Pacific Region. The Coral Triangle is recognized as the global centre of marine biodiversity and a global priority for conservation. It is also called the ""Amazon of the seas"" and covers of ocean waters. Its biological resources sustain"
"as in the Maldives. The reefs surrounding islands form when islands subside into the ocean, and atolls form when an island subsides below the surface of the sea. Alternatively, Moyle and Cech distinguish six zones, though most reefs possess only some of the zones. The reef surface is the shallowest part of the reef. It is subject to surge and tides. When waves pass over shallow areas, they shoal, as shown in the adjacent diagram. This means the water is often agitated. These are the precise condition under which corals flourish. The light is sufficient for photosynthesis by the symbiotic"
"world's premier coral reef research facility. Coconut Island is approximately , including of enclosed lagoons used to keep organisms being studied in captivity. Surrounding it are of coral reef, designated by the state of Hawai‘i as the Hawai‘i Marine Laboratory Refuge. It is part of the University of Hawaii at Manoa. It is the only research facility in the world built on a coral reef. The boundaries of the Hawaii Marine Laboratory Refuge surrounding the island start at the high-water mark on the island and go to twenty-five feet beyond the outer edges of the reefs, including sand and seawall"
"Reef aquarium A reef aquarium or reef tank is a marine aquarium that prominently displays live corals and other marine invertebrates as well as fish that play a role in maintaining the tropical coral reef environment. A reef aquarium requires appropriately intense lighting, turbulent water movement, and more stable water chemistry than fish-only marine aquaria, and careful consideration is given to which reef animals are appropriate and compatible with each other. Reef aquariums consist of a number of components, in addition to the livestock, including: Display tank: The primary tank in which the livestock are kept and shown. Stand: A"