"The only way to visit the island is with a private yacht or by chartered expedition from Rarotonga, and visitors require permits from the park authorities before being permitted to land. Suwarrow Suwarrow (also called Suvorov, Suvarou, or Suvarov) is an island in the northern group of the Cook Islands in the south Pacific Ocean. It is about south of the equator and north-northwest of the capital island of Rarotonga. Suwarrow is a roughly quadrilateral-shaped coral atoll, in circumference, with over 20 small islets (motu) surrounding a central lagoon . Cyclones have often created storm surges which sweep over the"
"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,"
"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"
"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"
"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"
"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"
"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"
"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"
"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"
"two lagoon systems, the north and south lagoons which are bounded by narrow reef platforms. It is a almost triangular northern and southern atoll-like reefs separated by a deep channel that is open to the west. The channel runs east to west from deep with a fine white sand bottom, numerous mounds and patches of branching corals under the deep blue water. The north lagoon is an enclosed triangular coral reef platform partly exposed during low tide. It is relatively shallow with depths of about . While the south lagoon is an inverted triangular coral platform enclosed on two sides"
"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"
"a medium-sized coralline atoll circled by a regular coral reef, similar to those in the neighboring Maldives. The diameter of the lagoon, known as ""Baie de Peros Banhos"" in French, is just above 20 km. The circling reef is sunken on its southeastern rim. All islands are flat and sandy and the largest ones are covered with coconut trees. The largest and most important island in the group is Île du Coin. It was home to the Perch Settlement from where the coconut plantations of the Atoll were run. This island was the main port of the atoll and had"
"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"
"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"
"Kiritimati Kiritimati, or Christmas Island, is a Pacific Ocean raised coral atoll in the northern Line Islands. It is part of the Republic of Kiribati. The name ""Kiritimati"" is a respelling of the English word ""Christmas"" in the Kiribati language, in which the combination ""ti"" is pronounced ""s"", and the name is thus pronounced . The island has the greatest land area of any coral atoll in the world, about ; its lagoon is roughly the same size. The atoll is about in perimeter, while the lagoon shoreline extends for over . Kiritimati comprises over 70% of the total land"
"other coral larvae to attach to and grow on. These corals can form into three different structures; fringing reefs, which are reefs that are close to the shore, barrier reefs, which are reefs that are alongside the shore and is separated by deep water, and an atoll reef which is a coral reef that circles a lagoon or body of water. As stated, the coral reefs such as fringing reefs, deep reefs, patch reefs and spur and groove formation are distributed over three islands in the Virgin Islands which are St. Croix (Salt River Bay National Historical Park and Ecological"
"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"
"Cay A cay ( or ), also spelled caye or key, is a small, low-elevation, sandy island on the surface of a coral reef. Cays occur in tropical environments throughout the Pacific, Atlantic and Indian Oceans (including in the Caribbean and on the Great Barrier Reef and Belize Barrier Reef). The 1492 indigenous people of Bahamas were called ""Lucayan"", an Anglicization of the Spanish ""Lucayos"", derived in turn from the Taíno ""Lukku-Cairi"" (which the people used for themselves), meaning ""people of the islands"". The Taíno word for ""island"", ""cairi"", became ""cayo"" in Spanish and ""cay"" in English (spelled ""key"" in"
"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"
"atoll has, besides the four larger islands, some 40 smaller islands and rocks, all inside the lagoon, as well as a few very small islets at the West Channels between Grand Terre Island and Picard Islands, the largest of those being Îlot Magnan. More Islands (unspecified location, but sizes are included under ""Other Islands"": The atoll reflects both fossil and geomorphological features, the former is the source of the biodiversity seen today. The atoll is made of reef limestone of Pleistocene age (with irregular coral formations called ""champignon"", made up of two layers of varying stages of crystallization ) and"
"Ulong Island Ulong is a major island and channel of western Palau. It is sometimes called Aulong and originally written Oroolong in English. Ulong is regarded by many as one of the best drift dives in the world. Ngerumekaol Pass (also known as Ulong Channel) partially cuts through the reef near the Island. The channel stretches about , with an average width of and leads into a coral reef lagoon. There are sharks within the currents of the channel and Ulong Corner. The channel contains giant clams and one of the largest known patches of green lettuce coral in the"
"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"
"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"
"island. The island is almost entirely surrounded by reefs: there are three narrow boat passages through the reefs on the northern side. The best entrance is the center one, located 350 meters north of the eastern end of Cato Island; it has a conspicuous rock at half tide on its eastern side. The island lies on the western end of an oval-shaped reef enclosing a lagoon. The lagoon contains numerous coral heads. The sea breaks over the reef in all weather. The reef lies on Cato Bank, which falls away steeply on all sides. Hutchison Rock , with a depth"
"pseudo-atoll, has two small islands, which are gradually undergoing coastal erosion, and appear as just small sandstone ridges exposed only at low tide. The underwater banks extend over north-south and east-west and occupy a total area of about . With a shallow coral ring, it appears as an incomplete atoll. To the west of the coral ring, however, it is deep. North Island ( fr. Île du Nord ) is small and flat with an area of . It has a derelict automatic lighthouse on the north point. and is occasionally visited by tourists in charter yachts. It was formed"
"Microatoll A microatoll is a circular colony of coral, dead on the top but living around the perimeter. Growth is mainly lateral, as upward growth is limited by exposure to air. Microatolls may be up to in diameter. They are named for their resemblance to island atolls formed during the subsidence of volcanic islands, as originally suggested by Darwin (1842). They act as natural recorders of sea level, which allows the monitoring of sea level changes in response to global warming. They have also been used to quantify and date changes in relative sea level in seismically active areas, and"
"Coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically live in compact colonies of many identical individual polyps. Corals species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton. A coral ""group"" is a colony of myriad genetically identical polyps. Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in length. A set of tentacles surround a central mouth opening. An exoskeleton is excreted near the base. Over many generations, the colony thus creates a large skeleton"
"biodiversity (more than 500 species), and the boundaries based on the area of greatest biodiversity for coral reef fishes. The 2013 documentary film ""Journey to the South Pacific"" tells the story of Coral Triangle conservation against the backdrop of island life. 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"
"A fringing reef forms around an extinct volcanic island as the island and ocean floor subsides. As the subsidence continues, the fringing reef becomes a barrier reef and ultimately an atoll reef. Darwin predicted that underneath each lagoon would be a bedrock base, the remains of the original volcano. Subsequent research supported this hypothesis. Darwin's theory followed from his understanding that coral polyps thrive in the tropics where the water is agitated, but can only live within a limited depth range, starting just below low tide. Where the level of the underlying earth allows, the corals grow around the coast"
"Bay. Immediately to the west of Flag Hill is an airstrip. The island is surrounded by submerged coral reef. This is narrow along the west, north and east shores, giving way to open ocean to the west and north. Beyond the reef on the east side of the island lies Pigeon Island Anchorage, the main passage and anchorage for Pigeon Island, a small island to the south that is used as a seasonal camp for the Western Rock Lobster fishery. To the south, the reef is extensive, and much of it is high enough that a person may wade from"
"a sequence of gradual subsidence of what started as an oceanic volcano. He reasoned that a fringing coral reef surrounding a volcanic island in the tropical sea will grow upwards as the island subsides (sinks), becoming an ""almost atoll"", or barrier reef island, as typified by an island such as Aitutaki in the Cook Islands, Bora Bora and others in the Society Islands. The fringing reef becomes a barrier reef for the reason that the outer part of the reef maintains itself near sea level through biotic growth, while the inner part of the reef falls behind, becoming a lagoon"
"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"