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109-555: Swedish shipbuilder Swede Ship Marine have built four 24 m Amphibious Troop Transport Vessel and one 25 m Fast Supply Vessel for the UAE Navy (delivered between 2003 and 2005). Three additional vessels are being built by Swede Ship Marine for the UAE Navy (see Future Navy ). The origins of the UAE Navy begin with the Abu Dhabi Defence Force (ADDF) which established a Sea Wing in 1967. The initial fleet gave Abu Dhabi

218-749: A Darwin Point is reached. One such point exists at the northwestern end of the Hawaiian Archipelago; see Evolution of Hawaiian volcanoes#Coral atoll stage . However, reefs in the Persian Gulf have adapted to temperatures of 13 °C (55 °F) in winter and 38 °C (100 °F) in summer. 37 species of scleractinian corals inhabit such an environment around Larak Island . Deep-water coral inhabits greater depths and colder temperatures at much higher latitudes, as far north as Norway. Although deep water corals can form reefs, little

327-709: A Portuguese force led by commander Antonio Correia invaded Bahrain to take control of the wealth created by its pearl industry. On April 29, 1602, Shāh Abbās , the Persian emperor of the Safavid Persian Empire , expelled the Portuguese from Bahrain, and that date is commemorated as National Persian Gulf day in Iran . With the support of the British fleet, in 1622 'Abbās took the island of Hormuz from

436-569: A combination of fresh and salt water for growth, and act as nurseries for many crabs, small fish, and insects; these fish and insects are the source of food for many of the marine birds that feed on them. Mangroves are a diverse group of shrubs and trees belonging to the genus Avicennia or Rhizophora that flourish in the salt water shallows of the Persian Gulf, and are the most important habitats for small crustaceans that dwell in them. They are as crucial an indicator of biological health on

545-644: A continental shelf, and not around a volcanic island, Darwin's principles apply. Development stopped at the barrier reef stage, since Australia is not about to submerge. It formed the world's largest barrier reef, 300–1,000 m (980–3,280 ft) from shore, stretching for 2,000 km (1,200 mi). Healthy tropical coral reefs grow horizontally from 1 to 3 cm (0.39 to 1.18 in) per year, and grow vertically anywhere from 1 to 25 cm (0.39 to 9.84 in) per year; however, they grow only at depths shallower than 150 m (490 ft) because of their need for sunlight, and cannot grow above sea level. As

654-642: A few coral reefs . Compared to the Red Sea, the coral reefs in the Persian Gulf are relatively few and far between. This is primarily connected to the influx of major rivers, especially the Shatt al-Arab (Euphrates and Tigris), which carry large amounts of sediment (most reef-building corals require strong light) and causes relatively large variations in temperature and salinity (corals in general are poorly suited to large variations). Nevertheless, coral reefs have been found along sections of coast of all countries in

763-605: A giant field across the territorial median line (North Field in the Qatari sector; South Pars Field in the Iranian sector). Using this gas, Qatar has built up a substantial liquefied natural gas (LNG) and petrochemical industry. In 2002, the Persian Gulf nations of Bahrain, Iran, Iraq, Kuwait, Qatar, Saudi Arabia, and the UAE produced about 25% of the world's oil, held nearly two-thirds of the world's crude oil reserves , and about 35% of

872-723: A limited brown-water patrolling and protecting capability in the waters of the Persian Gulf and in the littoral region of the Northern Emirates in the Gulf of Oman. This included protection of the UAE's significant offshore oil and gas facilities. With the formation of the United Arab Emirates on 2 December 1971 and the unification of the UAE Armed Forces on 6 May 1976, the ADDF Sea Wing became

981-412: A pinhead to 12 inches (30 cm) across. Reef-building or hermatypic corals live only in the photic zone (above 70 m), the depth to which sufficient sunlight penetrates the water. Coral polyps do not photosynthesize, but have a symbiotic relationship with microscopic algae ( dinoflagellates ) of the genus Symbiodinium , commonly referred to as zooxanthellae . These organisms live within

1090-496: A pseudo-atoll. These can be distinguished from real atolls only by detailed investigation, possibly including core drilling. Some platform reefs of the Laccadives are U-shaped, due to wind and water flow. Atolls or atoll reefs are a more or less circular or continuous barrier reef that extends all the way around a lagoon without a central island. They are usually formed from fringing reefs around volcanic islands. Over time,

1199-433: A rapidly subsiding bottom can overwhelm coral growth, killing the coral and the reef, due to what is called coral drowning . Corals that rely on zooxanthellae can die when the water becomes too deep for their symbionts to adequately photosynthesize , due to decreased light exposure. The two main variables determining the geomorphology , or shape, of coral reefs are the nature of the substrate on which they rest, and

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1308-423: A zone extending from approximately 30° N to 30° S of the equator. Tropical corals do not grow at depths of over 50 meters (160 ft). The optimum temperature for most coral reefs is 26–27 °C (79–81 °F), and few reefs exist in waters below 18 °C (64 °F). When the net production by reef building corals no longer keeps pace with relative sea level and the reef structure permanently drowns

1417-516: Is 989 kilometres (615 miles), with Iran covering most of the northern coast and Saudi Arabia most of the southern coast. The Persian Gulf is about 56 km (35 mi) wide at its narrowest, in the Strait of Hormuz. Overall, the waters are very shallow, with a maximum depth of 90 metres (295 feet) and an average depth of 50 metres (164 feet). Countries with a coastline on the Persian Gulf are (clockwise, from north): Iran; Oman 's Musandam exclave ;

1526-470: Is a diverse cradle for many species who depend on each other for survival. However, the Persian Gulf is not as biologically diverse as the Red Sea . Overall, the wildlife of the Persian Gulf is endangered from both global factors, and regional, local negligence. Most pollution is from ships; land generated pollution counts as the second most common source of pollution. Along the mediterranean regions of

1635-454: 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

1744-578: 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 change from year to year in response to the various factors that favor one type of patch over another. Growing coral, for example, produces constant change in the fine structure of reefs. On a larger scale, tropical storms may knock out large sections of reef and cause boulders on sandy areas to move. Coral reefs are estimated to cover 284,300 km (109,800 sq mi), just under 0.1% of

1853-470: Is destroyed, or occupied by man-made structures. This has had a negative impact on the crustaceans that rely on the mangrove, and in turn on the species that feed on them. The Persian Gulf and its coastal areas are the world's largest single source of petroleum, and related industries dominate the region. Safaniya Oil Field , the world's largest offshore oilfield , is located in the Persian Gulf. Large gas finds have also been made, with Qatar and Iran sharing

1962-445: Is directly attached to a shore, or borders it with an intervening narrow, shallow channel or lagoon. It is the most common reef type. Fringing reefs follow coastlines and can extend for many kilometres. They are usually less than 100 metres wide, but some are hundreds of metres wide. Fringing reefs are initially formed on the shore at the low water level and expand seawards as they grow in size. The final width depends on where

2071-498: Is home to many islands such as Bahrain, an Arab state. Geographically, the biggest island in the Persian Gulf is Qeshm island , belonging to Iran and located in the Strait of Hormuz . Other significant islands in the Persian Gulf include Greater Tunb , Lesser Tunb and Kish administered by Iran, Bubiyan administered by Kuwait, Tarout administered by Saudi Arabia, and Dalma administered by UAE. In recent years, there has also been

2180-523: Is known about them. The northernmost coral reef on Earth is located near Eilat , Israel . Coral reefs are rare along the west coasts of the Americas and Africa , due primarily to upwelling and strong cold coastal currents that reduce water temperatures in these areas (the Humboldt , Benguela , and Canary Currents , respectively). Corals are seldom found along the coastline of South Asia —from

2289-430: Is negatively affected by new developments along the Persian Gulf coastline, particularly the construction of artificial islands by Arab states and pollution from oil spills caused during the "Persian Gulf war" and various other natural and artificial causes. Uncontrolled hunting has also had a negative impact on the survival of dugongs. After Australian waters, which are estimated to contain some 80,000 dugong inhabitants,

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2398-408: Is now the Iranian province of Bushehr , is an example of such commercial port. Siraf, was also significant in that it had a flourishing commercial trade with China by the fourth century, having first established connection with the far east in 185 AD. Portuguese influence in the Persian Gulf lasted for 250 years; however, since the beginning of the 16th century, Portuguese dominance contended with

2507-613: Is of Cenozoic origin and related to the subduction of the Arabian Plate under the Zagros Mountains . The current flooding of the basin started 15,000 years ago due to rising sea levels of the Holocene glacial retreat . The International Hydrographic Organization defines the Persian Gulf's southern limit as "The Northwestern limit of Gulf of Oman". This limit is defined as "A line joining Ràs Limah (25°57'N) on

2616-418: Is often the reef's most diverse area. Coral and calcareous algae provide complex habitats and areas that offer protection, such as cracks and crevices. Invertebrates and epiphytic algae provide much of the food for other organisms. A common feature on this forereef zone is spur and groove formations that serve to transport sediment downslope. The reef flat is the sandy-bottomed flat, which can be behind

2725-567: Is still a deficit of 416 cubic kilometres (100 cu mi) per year. This difference is supplied by currents at the Strait of Hormuz . The water from the Persian Gulf has a higher salinity, and therefore exits from the bottom of the Strait, while ocean water with less salinity flows in through the top. Another study revealed the following numbers for water exchanges for the Persian Gulf: evaporation = –1.84 m (6.0 ft)/year, precipitation = 0.08 m (0.26 ft)/year, inflow from

2834-517: Is used by the International Hydrographic Organization . The dispute in naming has become especially prevalent since the 1960s. Rivalry between Iran and some Arab states, along with the emergence of pan-Arabism and Arab nationalism , has seen the name "Arabian Gulf" become predominant in most Arab countries. Names beyond these two have also been applied to or proposed for this body of water. The region of

2943-682: The Al Qasimi tribe. This led to the British mounting the Persian Gulf campaign of 1819 . The campaign led to the signing of the General Maritime Treaty of 1820 between the British and the Sheikhs of what was then known as the ' Pirate Coast '. From 1763 until 1971, the British Empire maintained varying degrees of political control over some of the Persian Gulf states, including the United Arab Emirates (originally called

3052-614: The Arabian Peninsula . It is connected to the Gulf of Oman in the east by the Strait of Hormuz . The Shatt al-Arab river delta forms the northwest shoreline. The Persian Gulf has many fishing grounds, extensive reefs (mostly rocky, but also coral ), and abundant pearl oysters , however its ecology has been damaged by industrialization and oil spills . The Persian Gulf is in the Persian Gulf Basin , which

3161-475: The Late Cretaceous (100–66 Ma), when reefs formed by a group of bivalves called rudists existed; one of the valves formed the main conical structure and the other, much smaller valve acted as a cap. Measurements of the oxygen isotopic composition of the aragonitic skeleton of coral reefs, such as Porites , can indicate changes in sea surface temperature and sea surface salinity conditions during

3270-739: The Mesoamerican Barrier Reef System and the New Caledonian Barrier Reef . Barrier reefs are also found on the coasts of Providencia , Mayotte , the Gambier Islands , on the southeast coast of Kalimantan , on parts of the coast of Sulawesi , southeastern New Guinea and the south coast of the Louisiade Archipelago . Platform reefs, variously called bank or table reefs, can form on the continental shelf , as well as in

3379-592: The Middle Cambrian (513–501 Ma ), Devonian (416–359 Ma) and Carboniferous (359–299 Ma), owing to extinct order Rugosa corals, and Late Cretaceous (100–66 Ma) and 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 related to sponges ) and in

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3488-563: The Nile in the west, as well as Sind waterway, in India. The Achaemenid high naval command had established major naval bases located along Shatt al-Arab river, Bahrain, Oman, and Yemen. The Persian fleet would soon not only be used for peacekeeping purposes along the Shatt al-Arab but would also open the door to trade with India via Persian Gulf. Following the fall of Achaemenid Empire, and after

3597-541: The Trucial States ) and at various times Bahrain, Kuwait, Oman, and Qatar through the British Residency of the Persian Gulf . The Persian Gulf was a battlefield of the 1980–1988 Iran–Iraq War , in which each side attacked the other's oil tankers . It is the namesake of the 1991 Gulf War , the largely air- and land-based conflict that followed Iraq 's invasion of Kuwait . The United States' role in

3706-610: The United Arab Emirates ; Saudi Arabia; Qatar , on a peninsula off the Saudi coast; Bahrain , an island nation; Kuwait ; and Iraq in the northwest. Various small islands also lie within the Persian Gulf, some of which are the subject of territorial disputes between the states in the region. Exclusive economic zones in the Persian Gulf: Countries by coastline length : The Persian Gulf

3815-450: The collared kingfishers were raised by conservationists over real estate development by the United Arab Emirates and Oman. Estimates from 2006 showed that only three viable nesting sites were available for this ancient bird, one located 80 miles (129 km) from Dubai, and two smaller sites in Oman. Such real estate expansion could prove devastating to this subspecies. A UN plan to protect

3924-417: 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 to form fringing reefs, and can eventually grow to become a barrier reef. Where the bottom is rising, fringing reefs can grow around the coast, but coral raised above sea level dies. If the land subsides slowly,

4033-627: The " Persian Corridor ". Britain utilized the Persian Gulf as the entry point for the supply chain in order to make use of the Trans-Iranian Railway . The Persian Gulf therefore became a critical maritime path through which the Allies transported equipment to Soviet Union against the Nazi invasion . The piracy in the Persian Gulf was prevalent until the 19th century. Many of the most notable historical instances of piracy were perpetrated by

4142-521: The Arabian Sea, including the Persian Gulf, the Red Sea , the Gulf of Kutch , the Gulf of Suez , the Gulf of Aqaba , the Gulf of Aden , and the Gulf of Oman , dolphins and finless porpoises are the most common marine mammals in the waters, while larger whales and orcas are rarer today. Historically, whales had been abundant in the Persian Gulf before commercial hunts wiped them out. Whales were reduced even further by illegal mass hunts by

4251-522: The CMN Group's Combattante BR70 design). 4 MM-40 SSM 1 × 6 Mistral SAM 1 × 76 mm 2 × 40 mm guns — commissioned 1990 The UAE Navy has several naval bases: Until 2014, 12 Ghannatha Phase II class fast missile landing crafts will be commissioned. The first unit was launched in July 2012. Another 12 were upgraded from Ghannatha Phase I class 4 Falaj 2 class patrol vessel (based on

4360-416: The Gulf of Aqaba), omura's whale , minke whale , and orca also swim into the Persian Gulf, while many other large species such as blue whale , sei , and sperm whales were once migrants into the Gulf of Oman and off the coasts in deeper waters, and still migrate into the Red Sea, but mainly in deeper waters of outer seas. In 2017, waters of the Persian Gulf along Abu Dhabi were revealed to hold

4469-738: The Indian Ocean, for example, in the Maldives , the Chagos Islands , the Seychelles and around Cocos Island . The entire Maldives consist of 26 atolls. Coral reef ecosystems contain distinct zones that host different kinds of habitats. Usually, three major zones are recognized: the fore reef, reef crest, and the back reef (frequently referred to as the reef lagoon). The three zones are physically and ecologically interconnected. Reef life and oceanic processes create opportunities for

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4578-501: The Italian Diciotti class) are on order, 2 being outfitted with 550 tons - 4 MM-40 Exocets - 6 Mica VL SAM (with an additional 4 to be produced in the future, grand total 8) One 26 m Offshore Patrol Vessel, one 24 m Amphibious Troop Transport Vessel and one 24 m Patrol Vessel are under construction for the UAE Navy. On 1 July 2022, United Arab Emirates Navy signed a Memorandum of Understanding (MoU) with PT PAL Indonesia for

4687-714: The Lakhum tribe , who lived in what is now Yemen, migrated north and founded the Lakhmid Kingdom along the southern coast. Occasional ancient battles took place along the Persian Gulf coastlines, between the Sassanid Persian empire and the Lakhmid Kingdom, the most prominent of which was the invasion led by Shapur II against the Lakhmids, leading to Lakhmids' defeat, and advancement into Arabia, along

4796-628: The Middle East adjacent to the Gulf. The world's oldest known civilization ( Sumer ) developed along the Persian Gulf and southern Mesopotamia . The oldest evidence in the world for seagoing vessels has been found at H3 in Kuwait, dating to the mid-sixth millennium BC, when the Gulf was part of an extensive trade network that involved the Ubaid settlements in Mesopotamia and communities along

4905-452: The Middle East are located in this region. The wildlife of the Persian Gulf is diverse, and entirely unique because of the Persian Gulf's geographic distribution and its isolation from the international waters only breached by the narrow Strait of Hormuz . The Persian Gulf has hosted some of the most magnificent marine fauna and flora, some of which are near extirpation or at serious environmental risk. From corals, to dugongs , Persian Gulf

5014-442: The Persian Gulf by the United Arab Emirates and Oman also raised concerns that habitats of species such as the hawksbill turtle , greater flamingo , and booted warbler may be destroyed. The dolphins that frequent the Persian Gulf in northern waters around Iran are also at risk. Recent statistics and observations show that dolphins are at danger of entrapment in purse seine fishing nets and exposure to chemical pollutants; perhaps

5123-496: The Persian Gulf grew in the second half of the 20th century. On July 3, 1988, Iran Air Flight 655 was shot down by the U.S. military (which had mistaken the Airbus A300 operating the flight for an Iranian F-14 Tomcat ) while it was flying over the Persian Gulf, killing all 290 people on board. The United Kingdom maintains a profile in the region; in 2006 alone, over 1 million British nationals visited Dubai . In 2018,

5232-626: The Persian Gulf has been inhabited since the Paleolithic . During most of the Last Glacial Period (115,000–11,700 years Before Present ), due to lowered sea levels (reaching around 125 metres (410 ft) metres below present values during the Last Glacial Maximum ) combined with the shallow depth of the Gulf (on average around 35 metres (115 ft) and at max around 100 metres (330 ft) metres depth) most of

5341-422: The Persian Gulf in recent years. Aside from direct damage to the coral, the construction waste creates "traps" for marine life in which they are trapped and die. The result has been a dwindling population of the coral, and as a result a decrease in number of species that rely on the corals for their survival. A great example of this symbiosis are the mangroves in the Persian Gulf, which require tidal flow and

5450-529: The Persian Gulf was called Pūdīg , which comes from Avestan : Pūitika , lit.   'cleansing', a name mentioned in Bundahishn . The body of water is historically and internationally known as the Persian Gulf. Arab governments refer to it as the Arabian Gulf or The Gulf, and other countries and organizations have begun using Arabian Gulf. The name Gulf of Iran (Persian Gulf)

5559-635: The Persian Gulf was called many different names. The Assyrians called it the "Bitter Sea". In 550 BC, the Achaemenid Empire established the first ancient empire in Persis ( Pars , or modern Fars , also known as Persia), in the southwestern region of the Iranian plateau . Consequently, in the Greek sources, the body of water that bordered this province came to be known as the "Persian Gulf". In

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5668-455: The Persian Gulf was exposed as dry land, forming a flat floodplain where a number of rivers converged. This region may have served as an environmental refuge for early humans during periodic hyperarid climate oscillations. The modern marine Gulf was formed when sea level rose during the early Holocene , from around 12,000 to 6,000 years ago. The flooding of the Gulf may have stimulated the development of Neolithic farming cultures in regions of

5777-448: The Persian Gulf. Corals are vital ecosystems that support multitude of marine species, and whose health directly reflects the health of the Persian Gulf. Recent years have seen a drastic decline in the coral population in the Persian Gulf, partially owing to global warming but mostly to irresponsible dumping by Arab states like the UAE and Bahrain. Construction garbage such as tires, cement, and chemical by products have found their way to

5886-580: The Persian Gulf. Persian naval forces laid the foundation for a strong Persian maritime presence in Persian Gulf, that started with Darius I and existed until the arrival of the British East India Company , and the Royal Navy by mid-19th century AD. Persians were not only stationed on islands of the Persian Gulf, but also had ships often of 100 to 200 capacity patrolling empire's various rivers including Shatt-al-Arab , Tigris , and

5995-441: The Portuguese; much of the trade was diverted to the town of Bandar 'Abbās , which he had taken from the Portuguese in 1615 and had named after himself. The Persian Gulf was therefore opened to a flourishing commerce with the Portuguese, Dutch, French, Spanish and the British merchants, who were granted particular privileges. The Ottoman Empire reasserted itself into Eastern Arabia in 1871. Under military and political pressure from

6104-473: The Soviet Union and Japan in the 1960s and 1970s. Along with Bryde's whales , these once common residents can still can be seen in deeper marginal seas such as Gulf of Aden, Israel coasts, and in the Strait of Hormuz . Other species such as the critically endangered Arabian humpback whale , (also historically common in Gulf of Aden and increasingly sighted in the Red Sea since 2006, including in

6213-426: The Strait = 33.66 m (110.4 ft)/year, outflow from the Strait = -32.11 m (105.3 ft)/year, and the balance is 0 m (0 ft)/year. Data from different 3D computational fluid mechanics models, typically with spatial resolution of 3 kilometres (1.9 mi) and depth each element equal to 1–10 metres (3.3–32.8 ft) are predominantly used in computer models. Before being given its present name,

6322-473: The Strait of Hormuz. Writing the water balance budget for the Persian Gulf, the inputs are river discharges from Iran and Iraq (estimated to be 2,000 cubic metres (71,000 cu ft) per second), as well as precipitation over the sea which is around 180 mm (7.1 in)/year in Qeshm Island . The evaporation of the sea is high, so that after considering river discharge and rain contributions, there

6431-460: The UAE Navy and continued to expand with naval facilities at Abu Dhabi port in 1975 as well as other facilities at the far west of Abu Dhabi Emirate and on the eastern coast of Fujairah at Khor Fakkan . The Iran-Iraq War (1980-1988) and especially the 1986 ' tanker war ' in the Persian Gulf culminated in the 25 November 1986 attack of Abu Dhabi's Abu Al Bukhoosh offshore oil platforms by Iranian aircraft. These incidents led to further expansion of

6540-589: The UAE's Navy assets in this period. The 1990s and 2000s saw further consolidation. In 2001, the UAE Coast Guard , which had been under the control of the UAE Ministry of Interior since 1976, was transferred to the control of the Navy. This change was likely in response to increased concern over the possibility of terrorist attacks on critical infrastructure in the UAE's littoral zone and on its islands in

6649-588: The UK opened a permanent military base, HMS  Jufair , in the Persian Gulf, the first since it withdrew from East of Suez in 1971 and is developing a support facility in Oman. Eight nations have coasts along the Persian Gulf: Bahrain , Iran , Iraq , Kuwait , Oman , Qatar , Saudi Arabia , and the United Arab Emirates . The Persian gulf's strategic location has made it an ideal place for human development over time. Today, many major cities of

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6758-599: The UV radiation and allowing them to better adapt to warmer water temperatures. In the event of UV or thermal damage, if and when repair occurs, it will increase the likelihood of survival of the host and symbiont. This leads to the idea that, evolutionarily, clade A is more UV resistant and thermally resistant than the other clades. Clades B and C are found more frequently in deeper water, which may explain their higher vulnerability to increased temperatures. Terrestrial plants that receive less sunlight because they are found in

6867-616: The addition of artificial islands for tourist attractions , such as The World Islands in Dubai and The Pearl Island in Doha . Persian Gulf islands are often also historically significant, having been used in the past by colonial powers such as the Portuguese and the British in their trade or as acquisitions for their empires. The Persian Gulf is connected to the Indian Ocean through

6976-1188: The area of France, yet they provide a home for at least 25% of all marine species , including fish , mollusks , worms , crustaceans , echinoderms , sponges , tunicates and other cnidarians . Coral reefs flourish in ocean waters that provide few nutrients. They are most commonly found at shallow depths in tropical waters, but deep water and cold water coral reefs exist on smaller scales in other areas. Shallow tropical coral reefs have declined by 50% since 1950, partly because they are sensitive to water conditions. They are under threat from excess nutrients (nitrogen and phosphorus), rising ocean heat content and acidification , overfishing (e.g., from blast fishing , cyanide fishing , spearfishing on scuba ), sunscreen use, and harmful land-use practices, including runoff and seeps (e.g., from injection wells and cesspools). Coral reefs deliver ecosystem services for tourism, fisheries and shoreline protection . The annual global economic value of coral reefs has been estimated at anywhere from US$ 30–375 billion (1997 and 2003 estimates) to US$ 2.7 trillion (a 2020 estimate) to US$ 9.9 trillion (a 2014 estimate). Though

7085-482: The book of Nearchus known as Indikê (300 BC), the word "Persikon kolpos" is mentioned for multiple times meaning "Persian gulf". During the years 550 to 330 BC, coinciding with the sovereignty of the Achaemenid Persian Empire over the Middle East area, especially the whole part of the Persian Gulf and some parts of the Arabian Peninsula , the name of "Persian ( Pars ) Sea" is widely found in

7194-445: The coast of Arabia and Ràs al Kuh (25°48'N) on the coast of Iran (Persia)". This inland sea of some 251,000 square kilometres (96,912 sq mi) is connected to the Gulf of Oman in the east by the Strait of Hormuz ; and its western end is marked by the major river delta of the Shatt al-Arab , which carries the waters of the Euphrates and the Tigris . In Iran , this is called "Arvand Rud" (lit. Swift River ). Its length

7303-448: The coast. The fringing reefs of the Red Sea are "some of the best developed in the world" and occur along all its shores except off sandy bays. Barrier reefs are separated from a mainland or island shore by a deep channel or lagoon . They resemble the later stages of a fringing reef with its lagoon but differ from the latter mainly in size and origin. Their lagoons can be several kilometres wide and 30 to 70 metres deep. Above all,

7412-416: The coastal plains had become continental islands . As sea level rise continued, water topped most of the continental islands. The corals could then overgrow the hills, forming cays and reefs. Sea level on the Great Barrier Reef has not changed significantly in the last 6,000 years. The age of living reef structure is estimated to be between 6,000 and 8,000 years. Although the Great Barrier Reef formed along

7521-499: The compiled written texts. At the same period, there is the inscription and engraving of Darius the Great, which belongs to the fifth century BC: King Darius says: I ordered to dig this ( Canal of the Pharaohs ) canal from the river that is called Nile ( Pirâva ) and flows in Egypt ( Mudrâyâ ), to the sea that begins in Persia ( Pârsa ). Therefore, when this canal had been dug as I had ordered, ships went from Egypt through this canal to Persia, as I had intended. In Sassanian times,

7630-451: The coral animals. Coral that loses a large fraction of its zooxanthellae becomes white (or sometimes pastel shades in corals that are pigmented with their own proteins) and is said to be bleached , a condition which, unless corrected, can kill the coral. There are eight clades of Symbiodinium phylotypes . Most research has been conducted on clades A–D. Each clade contributes their own benefits as well as less compatible attributes to

7739-412: The coral. Most reefs grow best in warm, shallow, clear, sunny and agitated water. Coral reefs first appeared 485 million years ago, at the dawn of the Early Ordovician , displacing the microbial and sponge reefs of the Cambrian . Sometimes called rainforests of the sea , shallow coral reefs form some of Earth's most diverse ecosystems. They occupy less than 0.1% of the world's ocean area, about half

7848-415: The corals shelter the zooxanthellae, averaging one million for every cubic centimetre of coral, and provide a constant supply of the carbon dioxide they need for photosynthesis. The varying pigments in different species of zooxanthellae give them an overall brown or golden-brown appearance and give brown corals their colors. Other pigments such as reds, blues, greens, etc. come from colored proteins made by

7957-529: The deep sea away from continental shelves , around oceanic islands and atolls . The majority of these islands are volcanic in origin. Others have tectonic origins where plate movements lifted the deep ocean floor. In The Structure and Distribution of Coral Reefs , Charles Darwin set out his theory of the formation of atoll reefs, an idea he conceived during the voyage of the Beagle . He theorized that uplift and subsidence of Earth's crust under

8066-637: The eastern tip of India ( Chennai ) to the Bangladesh and Myanmar borders —as well as along the coasts of northeastern South America and Bangladesh, due to the freshwater release from the Amazon and Ganges Rivers respectively. Significant coral reefs include: When alive, corals are colonies of small animals embedded in calcium carbonate shells. Coral heads consist of accumulations of individual animals called polyps , arranged in diverse shapes. Polyps are usually tiny, but they can range in size from

8175-462: The entire Gulf coast. For most of the early history of the settlements in the Persian Gulf, the southern shores were ruled by a series of nomadic tribes. During the end of the fourth millennium BC , the southern part of the Persian Gulf was dominated by the Dilmun civilization. For a long time, the most important settlement on the southern coast of the Persian Gulf was Gerrha . In the second century

8284-479: The exchange of seawater , sediments , nutrients and marine life. Most coral reefs exist in waters less than 50 m deep. Some inhabit tropical continental shelves where cool, nutrient-rich upwelling does not occur, such as the Great Barrier Reef . Others are found in the deep ocean surrounding islands or as atolls, such as in the Maldives . The reefs surrounding islands form when islands subside into

8393-733: The fall of the Parthian Empire , the Sassanid Empire ruled the northern half and at times the southern half of the Persian Gulf. The Persian Gulf, along with the Silk Road , were important trade routes in the Sassanid Empire. Many of the trading ports of the Persian empires were located in or around Persian Gulf. Siraf , an ancient Sassanid port that was located on the northern shore of the Persian Gulf, located in what

8502-401: The floor often supports seagrass meadows which are important foraging areas for reef fish. The reef drop-off is, for its first 50 m, habitat for reef fish who find shelter on the cliff face and plankton in the water nearby. The drop-off zone applies mainly to the reefs surrounding oceanic islands and atolls. The reef face is the zone above the reef floor or the reef drop-off. This zone

8611-403: The fringing reef, barrier reef, atoll and table reef based on Stoddart, D.R. (1969). Spalding et al. list four main reef types that can be clearly illustrated – the fringing reef, barrier reef, atoll, and "bank or platform reef"—and notes that many other structures exist which do not conform easily to strict definitions, including the "patch reef". A fringing reef, also called a shore reef,

8720-463: The fringing reefs keep pace by growing upwards on a base of older, dead coral, forming a barrier reef enclosing a lagoon between the reef and the land. A barrier reef can encircle an island, and once the island sinks below sea level a roughly circular atoll of growing coral continues to keep up with the sea level, forming a central lagoon. Barrier reefs and atolls do not usually form complete circles but are broken in places by storms. Like sea level rise ,

8829-607: The governor of the Ottoman Vilayet of Baghdad , Midhat Pasha , the ruling Al Thani tribe submitted peacefully to Ottoman rule. The Ottomans were forced to withdraw from the area with the start of World War I and the need for troops in various other frontiers. In World War II , the Western Allies used Iran as a conduit to transport military and industrial supply to the USSR, through a pathway known historically as

8938-419: The growth of the coral. This technique is often used by climate scientists to infer a region's paleoclimate . Since Darwin's identification of the three classical reef formations – the fringing reef around a volcanic island becoming a barrier reef and then an atoll – scientists have identified further reef types. While some sources find only three, Thomas lists "Four major forms of large-scale coral reefs" –

9047-548: The history of the change in sea level relative to that substrate. The approximately 20,000-year-old Great Barrier Reef offers an example of how coral reefs formed on continental shelves. Sea level was then 120 m (390 ft) lower than in the 21st century. As sea level rose, the water and the corals encroached on what had been hills of the Australian coastal plain. By 13,000 years ago, sea level had risen to 60 m (200 ft) lower than at present, and many hills of

9156-666: The island erodes away and sinks below sea level. Atolls may also be formed by the sinking of the seabed or rising of the sea level. A ring of reefs results, which enclose a lagoon. Atolls are numerous in the South Pacific, where they usually occur in mid-ocean, for example, in the Caroline Islands , the Cook Islands , French Polynesia , the Marshall Islands and Micronesia . Atolls are found in

9265-690: The local powers and the Ottoman Empire. Following the arrival of the English and the Dutch, the Safavid Empire allied with the newcomers to contest Portuguese dominance of the seas in the 17th century. Portuguese expansion into the Indian Ocean in the early 16th century following Vasco da Gama 's voyages of exploration saw them battle the Ottomans up the coast of the Persian Gulf. In 1521,

9374-418: The main reef, containing chunks of coral. This zone may border a lagoon and serve as 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

9483-484: The mainland. Unlike fringing and barrier reefs which extend only seaward, platform reefs grow in all directions. They are variable in size, ranging from a few hundred metres to many kilometres across. Their usual shape is oval to elongated. Parts of these reefs can reach the surface and form sandbanks and small islands around which may form fringing reefs. A lagoon may form In the middle of a platform reef. Platform reefs are typically situated within atolls, where they adopt

9592-461: The mangroves as a biological reserve was ignored by the emirate of Sharjah, which allowed the dredging of a channel that bisects the wetland and construction of an adjacent concrete walkway. Environmental watchdogs in Arabia are few, and those that do advocate the wildlife are often silenced or ignored by developers of real estate many of whom have governmental connections. Real estate development in

9701-461: The most alarming sign is the "mass suicides" committed by dolphins off Iran's Hormozgan province, which are not well understood, but are suspected to be linked with a deteriorating marine environment from water pollution from oil, sewage, and industrial run offs. The Persian Gulf is home to over 700 species of fish, most of which are native. Of these 700 species, more than 80% are reef associated. These reefs are primarily rocky, but there are also

9810-423: The most lucrative world supply of oil, and the lack of cooperation between Arab states and Iran, have had a negative impact on the survival of many marine species, including dugongs. The Persian Gulf is also home to many migratory and local birds. There is great variation in color, size, and type of the bird species that call the Persian Gulf home. Concerns regarding the endangerment of the kalbaensis subspecies of

9919-400: The name "patch reefs" and often span a diameter of just a few dozen meters. In instances where platform reefs develop along elongated structures, such as old and weathered barrier reefs, they tend to arrange themselves in a linear formation. This is the case, for example, on the east coast of the Red Sea near Jeddah . In old platform reefs, the inner part can be so heavily eroded that it forms

10028-528: The name implies, coral reefs are made up of coral skeletons from mostly intact coral colonies. As other chemical elements present in corals become incorporated into the calcium carbonate deposits, aragonite is formed. However, shell fragments and the remains of coralline algae such as the green-segmented genus Halimeda can add to the reef's ability to withstand damage from storms and other threats. Such mixtures are visible in structures such as Eniwetok Atoll . The times of maximum reef development were in

10137-415: 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

10246-528: The oceans formed the atolls. Darwin set out a sequence of three stages in atoll formation. A fringing reef forms around an extinct volcanic island as the island and ocean floor subside. 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

10355-535: The oceans' surface area. The Indo-Pacific region (including the Red Sea , Indian Ocean , Southeast Asia and the Pacific ) account for 91.9% of this total. Southeast Asia accounts for 32.3% of that figure, while the Pacific including Australia accounts for 40.8%. Atlantic and Caribbean coral reefs account for 7.6%. Although corals exist both in temperate and tropical waters, shallow-water reefs form only in

10464-490: The offshore outer reef edge formed in open water rather than next to a shoreline. Like an atoll, it is thought that these reefs are formed either as the seabed lowered or sea level rose. Formation takes considerably longer than for a fringing reef, thus barrier reefs are much rarer. The best known and largest example of a barrier reef is the Australian Great Barrier Reef . Other major examples are

10573-451: The open ocean, in fact anywhere where the seabed rises close enough to the surface of the ocean to enable the growth of zooxanthemic, reef-forming corals. Platform reefs are found in the southern Great Barrier Reef, the Swain and Capricorn Group on the continental shelf, about 100–200 km from the coast. Some platform reefs of the northern Mascarenes are several thousand kilometres from

10682-429: The polyps' tissues and provide organic nutrients that nourish the polyp in the form of glucose , glycerol and amino acids . Because of this relationship, coral reefs grow much faster in clear water, which admits more sunlight. Without their symbionts, coral growth would be too slow to form significant reef structures. Corals get up to 90% of their nutrients from their symbionts. In return, as an example of mutualism ,

10791-851: The post- 9/11 world, and the effectiveness of the Coast Guard in countering this threat. Another change in the Navy's force structure in the 2000s was the expansion of its amphibious capability and the formation of the UAE Navy Marines (subsequently merged with the UAE Presidential Guard ). Since 2015, the UAE Navy has been operating in the Yemen region in response to the Civil War there. 2 × Rheinmetall MLG 27 27 mm guns 21x RIM-116 RAM SAM 8 × MM40 Block 3 Exocet anti-ship missiles 1 AS-565 helo (based on

10900-420: The precise condition under which corals flourish. The light is sufficient for photosynthesis by the symbiotic zooxanthellae, and agitated water brings plankton to feed the coral. The off-reef floor is the shallow sea floor surrounding a reef. This zone occurs next to reefs on continental shelves. Reefs around tropical islands and atolls drop abruptly to great depths and do not have such a floor. Usually sandy,

11009-614: The purchase one 163 meters version of Makassar-class LPD which planned to start the construction at 2024. The First Steel Cutting ceremony for Landing Platform Dock 163M – Al Maryah Project was carried out on 28 February 2024. Persian Gulf The Persian Gulf , sometimes called the Arabian Gulf , is a mediterranean sea in West Asia . The body of water is an extension of the Indian Ocean located between Iran and

11118-412: The sea bed begins to drop steeply. The surface of the fringe reef generally remains at the same height: just below the waterline. In older fringing reefs, whose outer regions pushed far out into the sea, the inner part is deepened by erosion and eventually forms a lagoon . Fringing reef lagoons can become over 100 metres wide and several metres deep. Like the fringing reef itself, they run parallel to

11227-539: The shallow water tropical coral reefs are best known, there are also deeper water reef-forming corals, which live in colder water and in temperate seas. Most coral reefs were formed after the Last Glacial Period when melting ice caused sea level to rise and flood continental shelves . Most coral reefs are less than 10,000 years old. As communities established themselves, the reefs grew upwards, pacing rising sea levels . Reefs that rose too slowly could become drowned, without sufficient light. Coral reefs are also found in

11336-669: The southern shorelines. During the seventh century the Sassanid Persian empire conquered the whole of the Persian Gulf, including southern and northern shores. Between 625 BC and 226 AD, the northern side was dominated by a succession of Persian empires including the Median , Achaemenid , Seleucid and Parthian empires. Under the leadership of the Achaemenid king Darius the Great (Darius I), Persian ships found their way to

11445-437: The surface of the water, as the corals are to biological health of the Persian Gulf in deeper waters. Mangroves' ability to survive the salt water through intricate molecular mechanisms, their unique reproductive cycle, and their ability to grow in the most oxygen-deprived waters have allowed them extensive growth in hostile areas of the Persian Gulf. However, with the advent of artificial island development, most of their habitat

11554-424: The survival of their coral hosts. Each photosynthetic organism has a specific level of sensitivity to photodamage to compounds needed for survival, such as proteins. Rates of regeneration and replication determine the organism's ability to survive. Phylotype A is found more in the shallow waters. It is able to produce mycosporine-like amino acids that are UV resistant , using a derivative of glycerin to absorb

11663-408: The waters off Qatar, Bahrain, UAE, and Saudi Arabia make the Persian Gulf the second most important habitat for the species, hosting some 7,500 remaining dugongs. However, the current number of dugongs is dwindling, and it is not clear how many are currently alive or what their reproductive trend is. Ambitious and uncalculated construction schemes, political unrest, ever-present international conflict,

11772-618: The world's natural gas reserves. The oil-rich countries (excluding Iraq ) that have a coastline on the Persian Gulf are referred to as the Persian Gulf States . Iraq's egress to the Persian Gulf is narrow and easily blockaded, consisting of the marshy river delta of the Shatt al-Arab , which carries the waters of the Euphrates and the Tigris rivers, where the east bank is held by Iran. Coral reef A coral reef

11881-520: The world's largest population of Indo-Pacific humpbacked dolphins . One of the more unusual marine mammals living in the Persian Gulf is the dugong ( Dugong dugon ). Also called "sea cows", for their grazing habits and mild manner resembling livestock, dugongs have a life expectancy similar to that of humans and they can grow up to 3 metres (9.8 feet) in length. These gentle mammals feed on sea grass and are closer relatives of certain land mammals than are dolphins and whales . Their simple grass diet

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