Instruct: Given a question, retrieve documents that can help answer the question.
Query: Is the Caspian Sea saltwater?
The sea has a surface area of 371,000 km2 (143,200 sq mi) (not including the detached lagoon of Garabogazköl) and a volume of 78,200 km3(18,800 cu mi). It has a salinity of approximately 1.2% (12 g/l), about a third of the salinity of most seawater.
The Caspian turtle (Mauremys caspica), although found in neighboring areas, is a wholly freshwater species. The zebra mussel is native to the Caspian and Black Sea basins, but has become an invasive species elsewhere, when introduced. The area has given its name to several species, including the Caspian gull and the Caspian tern. The Caspian seal (Pusa caspica) is the only aquatic mammal and is endemic to the Caspian Sea, being one of very few seal species that live in inland waters, but it is different from the those inhabiting freshwaters due to the hydrological environment of the sea.
The five littoral states build consensus on legally binding governance of the Caspian Sea through Special Working Groups of a Convention on the Legal Status of the Caspian Sea.[57] In advance of a Caspian Summit, 51st Special Working Group took place in Astana in May 2018 and found consensus on multiple agreements: Agreements on cooperation in the field of transport; trade and economic cooperation; prevention of incidents on the sea; combating terrorism; fighting against organized crime; and border security cooperation.[58]
The word Caspian is derived from the name of the Caspi, an ancient people who lived to the southwest of the sea in Transcaucasia.[3] Strabo wrote that "to the country of the Albanians belongs also the territory called Caspiane, which was named after the Caspian tribe, as was also the sea; but the tribe has now disappeared".[4] Moreover, the Caspian Gates, which is the name of a region in Iran's Tehran province, possibly indicates that they migrated to the south of the sea. The Iranian city of Qazvin shares the root of its name with that of the sea. In fact, the traditional Arabic name for the sea itself is Baḥr al-Qazwin (Sea of Qazvin).[5]
Baku, which is the starting point of all sea routes of Azerbaijan, is the largest port of the Caspian Sea. Azerbaijan has access to the oceans along the Caspian Sea-Volga-Volga-Don Canal, and the Don-Sea of Azov. Along with the Volga-Don Canal, the Azerbaijani vessels have the opportunity to enter the world ocean through the Volga-Baltic and White Sea-Baltic canals. Moreover, oil tankers are being transported through the Caspian Sea. Baku Sea Trade Port and Caspian Shipping Company CJSC, have a big role in the sea transportation of Azerbaijan. The Caspian Sea Shipping Company CJSC, along with the transport fleet, also includes a specialized fleet and shipyards. The transport fleet consists of 51 vessels, including 20 tankers, 13 ferries, 15 universal dry cargo vessels, 2 Ro-Ro vessels, as well as 1 technical vessel and 1 floating workshop. The specialized fleet includes 210 vessels, including 20 cranes, 25 towing and supplying vehicles, 26 passenger, two pipe-laying, six fire-fighting, seven engineering-geological, two diving and 88 auxiliary vessels.[44]
In July 1919, the Astrakhan-Caspian Military Flotilla was combined with the Volga Military Flotilla (Волжская военная флотилия, or Volzhskaya voyennaya flotiliya) and renamed to the Volga-Caspian Military Flotilla (Волжско-Каспийская военная флотилия). On May 1, 1920, the Soviets established the Caspian Fleet, which comprised three auxiliary cruisers, ten torpedo boats, four submarines and other ships. Together with the Caspian Fleet, there was the Red Fleet of the Soviet Azerbaijan, stationed in Baku, as well. Both fleets completed the conquest of the Caspian Sea from the White Army. In July 1920, Caspian and Azerbaijani fleets were combined into the Naval Forces of the Caspian Sea ("Морские Силы Каспийского моря", or Morskiye Sily Kaspiyskogo morya) and would later be renamed to the Caspian Flotilla on June 27, 1931.
The Black Sea-Caspian Steppe is an informal name for that part of the Eurasian Steppe that extends south between the Black and Caspian Seas. It is usually treated as part of the Pontic-Caspian steppe which includes the area north of the Black and Caspian Seas, but there is some reason to treat it as a distinct place. Its natural boundaries are the Sea of Azov and Black Sea on the west, the Caucasus Mountains on the south and the Caspian Sea on the east. Its northern boundary may be taken as the triangle formed by the lower Don River and Volga River which are about 60 km apart to the west of Volgograd. This article excludes the north slope of the Caucasus which is not steppe and has a distinct geography and history.
The Caspian Depression (, Caspian Lowland) or Pricaspian/Peri-Caspian Depression/Lowland is a low-lying flatland region encompassing the northern part of the Caspian Sea, the largest enclosed body of water on Earth. It is the larger northern part of the wider Aral-Caspian Depression around the Aral and Caspian seas.
The Caspian has characteristics common to both seas and lakes. It is often listed as the world's largest lake, although it is not a freshwater lake. It contains about 3.5 times more water, by volume, than all five of North America's Great Lakes combined. The Caspian was once part of the Tethys Ocean, but became landlocked about 5.5 million years ago due to plate tectonics.[11] The Volga River (about 80% of the inflow) and the Ural River discharge into the Caspian Sea, but it has no natural outflow other than by evaporation. Thus the Caspian ecosystem is a closed basin, with its own sea level history that is independent of the eustatic level of the world's oceans.
The lower part of the river flows through the Kura-Aras Lowland, which covers most of central Azerbaijan and abuts the Caspian Sea. The Kura is the third largest, after the Volga and Ural, of the rivers that flow into the Caspian. Its delta is the fourth largest among the rivers that flow into the Caspian Sea, and is divided into three main sections, or "sleeves", composed of sediment the river deposited during different periods of time. Before 1998, the river flowed all the way to the tip of the delta, where it discharged into the Caspian. In that year, the river escaped its channel and started to flow off to the west, leaving the last few kilometers abandoned. The course change is believed to be the result of a rise in the level of the Caspian Sea coupled with a major flood of the Kura.
The British Caspian Flotilla was a naval force of the Royal Navy established in the Caspian Sea in 1918. It was part of the allied intervention in the Russian Civil War. The flotilla initially reported to the Rear-Admiral Commanding, Black Sea, Caspian Sea and Sea of Marmora until 1919.
The Baku–Tbilisi–Ceyhan pipeline was built to transport crude oil and the Baku-Tbilisi-Erzurum pipeline was built to transport natural gas from the western side (Azerbaijani sector) of the Caspian Sea to the Mediterranean Sea bypassing Russian pipelines and thus Russian control. Following the construction of the pipelines, the United States and the European Union proposed extending them by means of the proposed Trans-Caspian Oil Pipeline and the Trans-Caspian Gas Pipeline under the Caspian Sea to oil and gas fields on the eastern side (Kazakhstan and Turkmenistan sectors) of the Caspian Sea. In 2007, Russia signed agreements with Turkmenistan and Kazakhstan to connect their oil and gas fields to the Russian pipeline system effectively killing the undersea route.
Iranrud Baku oil fields Caspians Ekranoplan, a ground effect plane which was developed on the Caspian Sea. Epoch of Extreme Inundations Framework Convention for the Protection of the Marine Environment of the Caspian Sea Shah Deniz gas field South Caucasus Pipeline Southern Gas Corridor Tengiz Field Trans-Caspian Gas Pipeline Trans-Caspian Oil Transport System Wildlife of Azerbaijan Wildlife of Iran Wildlife of Kazakhstan Wildlife of Russia
Soimonov made the first thorough hydrographic survey of the Caspian Sea between 1719 and 1727, building up on the survey previously done by Karl Van Verden during tsar Peter the Great's drive for reform and modernization at the beginning of the 18th century. He led the Caspian Expedition that explored the coasts of the sea. As a result of the survey Soimonov drew a set of maps of the Caspian for the 'Atlas of the Caspian Sea' "(Atlas Kapiiskago Moria)" and wrote the 'Pilot of the Caspian Sea'. Published in 1731 by the Russian Academy of Sciences, these became the first comprehensive report and the first modern maps of the Caspian in history. Between 1730 and 1738 he was employed as a cartographer for the Russian Admiralty Board, which had been established in 1718 by Peter I the Great.
To the south, the Pontic steppe extends to the Black Sea, except the Crimean and western Caucasus mountains' border with the sea, where the Crimean Submediterranean forest complex defines the southern edge of the steppes. The steppe extends to the western shore of the Caspian Sea in the Dagestan region of Russia, but the drier Caspian lowland desert lies between the Pontic steppe and the northwestern and northern shores of the Caspian. The Kazakh Steppe bounds the Pontic steppe on the southeast.
The Aral–Caspian Depression is a lowland depression straddling Europe and Asia around the Aral Sea and Northern Caspian Sea. The most northern part is called the Caspian Depression. The desert part to the east of the Caspian Depression and Caspian is called the Turan Depression. In Azerbaijan, the Kura-Aras Lowland is part of the Aral–Caspian Depression. 
This is a list of current and historic lighthouses and lightvessels in Russia. On saltwater, Russia has had lighthouses on the Black Sea, on the Baltic Sea in the Kaliningrad Oblast exclave, on the Gulf of Finland approaching St. Petersburg, on the Arctic Ocean (including a series of nuclear-powered ones), and on the Pacific Ocean. It has had lighthouses on freshwater of Lake Ladoga, on the Volga and Don Rivers, on the Caspian Sea, on Lake Baikal, in Siberia on the great Ob and Yenisey Rivers, and elsewhere.
The history of the Caspian sea is divided into two parts: a Miocene stage, determined by tectonic events that correlate with the closing of the Tethys Sea, and a Pleistocene stage, that includes glaciation cycles and the creation of the present Volga River. During the first stage, the Tethys Sea had evolved into the Sarmatian Lake, that was created from the modern Black Sea and south Caspian, when the collision of the Arabian peninsula with Western Asia pushed up the Kopet Dag and Caucasus Mountains, setting definitive south and west boundaries to the Caspian basin. This orogeneic movement was continuous throughout the years, while Caspian was regularly disconnecting from the Black Sea. In the late Pontian, a mountain arch rose across the south basin and divided it in the Khachmaz and Lankaran Lakes (or early Balaxani). The period of restriction to the south basin was reversed during the Akchagyglian, when the lake expanded to more than three times its present area and established the first of a series of contacts with the Black Sea and with Lake Aral. A recession of the lake Akchagyl completed stage one.[31]
Tyuleny Island (Russian: Тюлений) is an uninhabited island in the Caspian Sea. It is located 47 km east of the Dagestan coastline, in the Caspian Sea, near the entrance to the Kizlyar Gulf.
The Caspian Sea, like the Black Sea, Namak Lake, and Lake Urmia, is a remnant of the ancient Paratethys Sea. It became landlocked about 5.5 million years ago due to tectonic uplift and a fall in sea level. During warm and dry climatic periods, the landlocked sea almost dried up, depositing evaporitic sediments like halite that were covered by wind-blown deposits and were sealed off as an evaporite sink when cool, wet climates refilled the basin. (Comparable evaporite beds underlie the Mediterranean.) Due to the current inflow of fresh water, the Caspian Sea is a freshwater lake in its northern portions, and is most saline on the Iranian shore, where the catchment basin contributes little flow.[9] Currently, the mean salinity of the Caspian is one third that of Earth's oceans. The Garabogazköl embayment, which dried up when water flow from the main body of the Caspian was blocked in the 1980s but has since been restored, routinely exceeds oceanic salinity by a factor of 10.[10]
Anadromous brown trout are widely distributed in Europe along the Atlantic and Baltic coasts, the United Kingdom and the coasts of Iceland. They do not occur in the Mediterranean Sea but are found in the Black and Caspian Seas and as far north as the Barents and Kara Seas in the Arctic Ocean. Brown trout introduced into freshwater habitats in Tasmania, Victoria, New Zealand, Falkland Islands, Kerguelen Islands, Chile and Argentina have established anadromous populations when there was suitable access to saltwater. Anadromous behavior has been reported in the Columbia river and its tributaries in the U.S. and in Canadian rivers on both the Pacific and Atlantic coasts.
The Rostov Nature Reserve is located in the south of the East European plain, in the Manych River valley. The dominant geological feature of the reserve is Lake Manych-Gudilo, a saltwater reservoir which is surrounded be dry steppe and semi-desert landscape. The lake is long and narrow, occupying a portion of the Manych trough between the Sea of Azov and the Caspian Sea; this long depression is the remains of what was once a sea connection between the Black and Caspian Seas.
The Garabogazköl Aylagy or Kara-Bogaz-Gol (, black (or mighty) strait lake) is a shallow inundated depression in the northwestern corner of Turkmenistan. It forms a lagoon of the Caspian Sea with a surface area of about . It is separated from the Caspian Sea proper, which lies immediately to the west, by a narrow, rocky ridge having a very narrow opening in the rock through which the Caspian waters flow, cascading down into Garabogazköl, leading to the Turkmen language name of the bay, "Mighty Strait Lake". The water volume of the bay fluctuates seasonally with the Caspian Sea; at times it becomes a large bay of the Caspian Sea, while at other times its water level drops drastically.
The Caspian Summit is a head of state-level meeting of the five littoral states.[55] The fifth Caspian Summit took place on August 12, 2018 in the Kazakh port city of Aktau. [55] The five leaders signed the ‘Convention on the Legal Status of the Caspian Sea’.[56]
Differences between the three regions are dramatic. The Northern Caspian only includes the Caspian shelf,[15] and is very shallow; it accounts for less than 1% of the total water volume with an average depth of only 5–6 metres (16–20ft). The sea noticeably drops off towards the Middle Caspian, where the average depth is 190 metres (620ft).[14] The Southern Caspian is the deepest, with oceanic depths of over 1,000 metres (3,300ft), greatly exceeding the depth of other regional seas, such as the Persian Gulf. The Middle and Southern Caspian account for 33% and 66% of the total water volume, respectively.[12] The northern portion of the Caspian Sea typically freezes in the winter, and in the coldest winters ice forms in the south as well.[16]