CaspAndyskoe mOre(Caspian) is the largest enclosed body of water on Earth. In size, the Caspian Sea is much larger than lakes such as Superior, Victoria, Huron, Michigan, and Baikal. According to formal characteristics, the Caspian Sea is an endorheic lake. However, given its large size, brackish waters and a regime similar to the sea, this body of water is called a sea.
According to one hypothesis, the Caspian Sea (among the ancient Slavs – the Khvalynsk Sea) received its name in honor of the Caspian tribes who lived BC in its south- west coast.
The Caspian Sea washes the shores of five states: Russia, Azerbaijan, Iran, Turkmenistan and Kazakhstan.
The Caspian Sea is elongated in the meridional direction and is located between 36°33΄ and 47°07΄ N latitude. and 45°43΄ and 54°03΄ E. (without Kara-Bogaz-Gol Bay). The length of the sea along the meridian is about 1200 km; average width – 310 km. The northern coast of the Caspian Sea is bordered by the Caspian lowland, the eastern coast by deserts Central Asia; in the west the Caucasus Mountains approach the sea, in the south the Elburz ridge stretches near the coast.
The surface of the Caspian Sea is located significantly below the level of the World Ocean. Its current level fluctuates around -27...-28 m. These levels correspond to a sea surface area of 390 and 380 thousand km 2 (without the Kara-Bogaz-Gol Bay), a water volume of 74.15 and 73.75 thousand km 3, average depth approximately 190 m.
The Caspian Sea is traditionally divided into three large parts: the Northern (24% of the sea area), the Middle (36%) and the Southern Caspian (40%), which differ significantly in morphology and regime, as well as the large and isolated Kara-Bogaz-Gol Bay. The northern, shelf part of the sea is shallow: its average depth is 5–6 m, maximum depths are 15–25 m, the volume is less than 1% of the total water mass of the sea. The Middle Caspian is an isolated basin with an area of maximum depths in the Derbent depression (788 m); its average depth is about 190 m. In the South Caspian, the average and maximum depths are 345 and 1025 m (in the South Caspian depression); 65% of the sea's water mass is concentrated here.
There are about 50 islands in the Caspian Sea with a total area of approximately 400 km2; the main ones are Tyuleniy, Chechen, Zyudev, Konevsky, Dzhambaysky, Durneva, Ogurchinsky, Apsheronsky. The length of the coastline is approximately 6.8 thousand km, with islands - up to 7.5 thousand km. The shores of the Caspian Sea are diverse. In the northern and eastern parts they are quite rugged. Here are the large bays of Kizlyarsky, Komsomolets, Mangyshlaksky, Kazakhsky, Kara-Bogaz-Gol, Krasnovodsky and Turkmensky, many bays; off the west coast - Kyzylagachsky. The largest peninsulas are Agrakhansky, Buzachi, Tyub-Karagan, Mangyshlak, Krasnovodsky, Cheleken and Apsheronsky. The most common shores are accumulative; areas with abrasion shores are found along the contour of the Middle and Southern Caspian Sea.
Over 130 rivers flow into the Caspian Sea, the largest of which are the Volga , Ural, Terek, Sulak, Samur, Kura, Sefidrud, Atrek, Emba (its flow enters the sea only in high-water years). Nine rivers have deltas; the largest are located at the mouths of the Volga and Terek.
The main feature of the Caspian Sea, as an endorheic reservoir, is instability and a wide range of long-term fluctuations in its level. This most important hydrological feature of the Caspian Sea has a significant impact on all its other hydrological characteristics, as well as on the structure and regime of river mouths and coastal zones. In the Caspian Sea level varied in the range of ~200 m: from -140 to +50 m BS; at -34 to -20 m BS. From the first third of the 19th century. and until 1977, sea level dropped by about 3.8 m - to the lowest level in the last 400 years (-29.01 m BS). In 1978–1995 The level of the Caspian Sea rose by 2.35 m and reached -26.66 m BS. Since 1995, a certain downward trend in level has been dominant - to -27.69 m BS in 2013.
During major events, the northern coast of the Caspian Sea shifted to the Samara Luka on the Volga, and perhaps further. During maximum transgressions, the Caspian Sea turned into a drainage lake: excess water flowed through the Kuma-Manych depression into the Sea of Azov and further into the Black Sea. In extreme regressions South coast The Caspian Sea shifted to the Absheron threshold.
Long-term fluctuations in the level of the Caspian Sea are explained by changes in the structure of the water balance of the Caspian Sea. Sea level rises when the incoming part of the water balance (primarily the water flow of rivers) increases and exceeds the outgoing part, and decreases if the influx of river water decreases. The total water flow of all rivers averages 300 km 3 /year; while the five largest rivers account for almost 95% (the Volga gives 83%). During the period of the lowest sea level, in 1942–1977, the river flow was 275.3 km 3 /year (of which 234.6 km 3 /year was the Volga runoff), precipitation - 70.9, underground flow - 4 km 3 /year, and evaporation and outflow into the Kara-Bogaz-Gol Bay are 354.79 and 9.8 km 3 /year. During the period of intense sea level rise, in 1978–1995, - respectively 315 (Volga - 274.1), 86.1, 4, 348.79 and 8.7 km 3 /year; in the modern period - 287.4 (Volga - 248.2), 75.3, 4, 378.3 and 16.3 km 3 /year.
Intra-annual changes in the level of the Caspian Sea are characterized by a maximum in June–July and a minimum in February; the range of intra-annual level fluctuations is 30–40 cm. Surge level fluctuations occur throughout the sea, but they are most significant in the northern part, where, with maximum surges, the level can rise by 2–4.5 m and the edge “retreat” by several tens kilometers inland, and during surges it will drop by 1–2.5 m. Seiche and tidal level fluctuations do not exceed 0.1–0.2 m.
Despite the relatively small size of the reservoir, there is strong excitement in the Caspian Sea. The highest wave heights in the Southern Caspian Sea can reach 10–11 m. Wave heights decrease in the direction from south to north. Storm waves can develop at any time of the year, but they are more frequent and more dangerous in the cold half of the year.
In the Caspian Sea as a whole, wind currents predominate; nevertheless, on the estuary shores of large rivers, they play a significant role katabatic currents. In the Middle Caspian, cyclonic water circulation predominates, in the Southern Caspian - anticyclonic. In the northern part of the sea, patterns of wind currents are more irregular and depend on the characteristics and variability of the wind, bottom topography and coastal contours, river flow and aquatic vegetation.
Water temperature is subject to significant latitudinal and seasonal changes. In winter, it varies from 0–0.5 o C at the ice edge in the north of the sea to 10–11 o C in the south. In summer, the water temperature in the sea averages 23–28 o C, and in shallow coastal waters in the Northern Caspian Sea it can reach 35–40 o C. At depths, a constant temperature is maintained: deeper than 100 m it is 4–7 o C.
In winter, only the northern part of the Caspian Sea freezes; in severe winter - the entire Northern Caspian and coastal zones of the Middle Caspian. Freeze-up in the Northern Caspian lasts from November to March.
Water salinity changes especially sharply in the northern part of the sea: from 0.1‰ at the mouth shores of the Volga and Ural to 10–12‰ on the border with the Middle Caspian. In the Northern Caspian Sea, the temporal variability of water salinity is also great. In the middle and southern parts of the sea, salinity fluctuations are small: it is generally 12.5–13.5‰, increasing from north to south and from west to east. The highest water salinity is in the Kara-Bogaz-Gol Bay (up to 300‰). With depth, water salinity increases slightly (by 0.1–0.3‰). The average salinity of the sea is about 12.5‰.
More than a hundred species of fish live in the Caspian Sea and the mouths of the rivers flowing into it. There are Mediterranean and Arctic invaders. The fish species are goby, herring, salmon, carp, mullet and sturgeon. The latter include five species: sturgeon, beluga, stellate sturgeon, thorn and sterlet. The sea can produce up to 500–550 thousand tons of fish annually, if overfishing is not allowed. Of the marine mammals, the endemic Caspian seal lives in the Caspian Sea. 5–6 million waterfowl migrate through the Caspian region annually.
The economy of the Caspian Sea is associated with oil and gas production, shipping, fishing, seafood, various salts and minerals (Kara-Bogaz-Gol Bay), and the use of recreational resources. The explored oil resources in the Caspian Sea amount to about 10 billion tons, the total resources of oil and gas condensate are estimated at 18–20 billion tons. Oil and gas production is carried out on an ever-increasing scale. The Caspian Sea is also used by water transport, including along the river-sea and sea-river routes. The main ports of the Caspian Sea: Astrakhan, Olya, Makhachkala (Russia), Aktau, Atyrau (Kazakhstan), Baku (Azerbaijan), Noushehr, Bandar-Anzeli, Bandar-Torkemen (Iran) and Turkmenbashi (Turkmenistan).
Economic activities and hydrological features of the Caspian Sea create a number of serious environmental and water management problems. Among them: anthropogenic pollution of river and sea waters (mainly with petroleum products, phenols and surfactants), poaching and reduction of fish stocks, especially sturgeon; damage to the population and coastal economic activities due to large-scale and rapid changes in the level of the reservoir, the impact of numerous dangerous hydrological phenomena and hydrological-morphological processes.
The total economic damage for all Caspian countries associated with the rapid and significant recent rise in the level of the Caspian Sea, the flooding of part of the coastal land, and the destruction of coastlines and coastal structures, amounted to an estimated amount of 15 to 30 billion US dollars. Urgent engineering measures were required to protect the coast.
A sharp drop in the level of the Caspian Sea in the 1930s–1970s. resulted in less damage, but it was still significant. Navigable approach channels became shallow, the shallow seaside at the mouths of the Volga and Ural became heavily overgrown, which became an obstacle to the passage of fish into the rivers to spawn. Fish passages had to be built through the mentioned seashores.
Among the unresolved problems is the lack of an international agreement on the international legal status of the Caspian Sea, the division of its waters, bottom and subsoil.
The Caspian Sea is the object of many years of research by specialists from all Caspian states. Such domestic organizations as the State Oceanographic Institute, the Institute of Oceanology of the Russian Academy of Sciences, the Hydrometeorological Center of Russia, the Caspian Research Institute of Fisheries, the Faculty of Geography of the Moscow State University took an active part in the study of the Caspian Sea. state university and etc.
The Caspian Sea is the largest lake on our planet, which is located in a depression of the earth’s surface (the so-called Aral-Caspian Lowland) on the territory of Russia, Turkmenistan, Kazakhstan, Azerbaijan and Iran. Although they consider it as a lake, because it is not connected with the World Ocean, but by the nature of the formation processes and history of origin, by its size, the Caspian Sea is a sea.
The area of the Caspian Sea is about 371 thousand km 2. The sea, stretching from north to south, has a length of about 1200 km and an average width of 320 km. The length of the coastline is about 7 thousand km. The Caspian Sea is located 28.5 m below the level of the World Ocean and its greatest depth is 1025 m. There are about 50 islands in the Caspian Sea, mostly small in area. The large islands include such islands as Tyuleniy, Kulaly, Zhiloy, Chechen, Artem, Ogurchinsky. There are also many bays in the sea, for example: Kizlyarsky, Komsomolets, Kazakhsky, Agrakhansky, etc.
The Caspian Sea is fed by more than 130 rivers. Largest quantity water (about 88% of the total flow) is brought by the rivers Ural, Volga, Terek, Emba, which flow into the northern part of the sea. About 7% of the runoff comes from large rivers Kura, Samur, Sulak and small ones flowing into the sea on the west coast. The rivers Heraz, Gorgan, and Sefidrud flow into the southern Iranian coast, bringing only 5% of the flow. Not a single river flows into the eastern part of the sea. The water in the Caspian Sea is salty, its salinity ranges from 0.3‰ to 13‰.
Shores of the Caspian Sea
The shores have different landscapes. The shores of the northern part of the sea are low and flat, surrounded by low-lying semi-desert and somewhat elevated desert. In the south, the shores are partly low-lying, they are bordered by a small coastal lowland, behind which the Elburz ridge runs along the coast, which in some places comes close to the shore. In the west, the Greater Caucasus ranges approach the coast. In the east there is an abrasion coast, carved out of limestone, and semi-desert and desert plateaus approach it. The coastline changes greatly due to periodic fluctuations in water levels.
The climate of the Caspian Sea is different:
Continental in the north;
Moderate in the middle
Subtropical in the south.
At the same time, there are severe frosts and snowstorms on the northern shore, while fruit trees and magnolias bloom on the southern shore. In winter, strong storm winds rage at sea.
On the coast of the Caspian Sea there are big cities, ports: Baku, Lankaran, Turkmenbashi, Lagan, Makhachkala, Kaspiysk, Izberbash, Astrakhan, etc. 
The fauna of the Caspian Sea is represented by 1809 species of animals. More than 70 species of fish are found in the sea, including: herring, gobies, stellate sturgeon, sturgeon, beluga, white fish, sterlet, pike perch, carp, bream, roach, etc. Of the marine mammals, only the smallest in the world, the Caspian seal, is found in the lake. not found in other seas. The Caspian Sea lies on the main migratory route of birds between Asia, Europe and the Middle East. Every year, about 12 million birds fly over the Caspian Sea during migration, and another 5 million usually winter here.
Vegetable world
The flora of the Caspian Sea and its coast includes 728 species. Basically, the sea is inhabited by algae: diatoms, blue-greens, red, characeae, brown and others, of the flowering ones - rupee and zoster.
The Caspian Sea is rich in natural resources; many oil and gas fields are being developed in it; in addition, limestone, salt, sand, stone and clay are also mined here. The Caspian Sea is connected by the Volga-Don Canal with the Sea of Azov, and shipping is well developed. A lot is caught in the reservoir different fish, including more than 90% of the world's sturgeon catch.
The Caspian Sea is also a recreation area; on its shores there are holiday homes, tourist centers and sanatoriums.
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Many place names can be misleading to people who are not keen on geography. Could it be that an object designated as a sea on all maps is actually a lake? Let's figure it out.
The history of the appearance of the Caspian Sea?
14,000,000 years ago, the Sarmatian Sea existed on the planet. It included modern, Black, Caspian and Sea of Azov. About 6,000,000 years ago, due to the rise of the Caucasus Mountains and the decrease in water levels in the Mediterranean Sea, it divided, forming four different seas.
The Caspian is inhabited by many representatives of the fauna of Azov, which once again confirms that these reservoirs were once one whole. This is one of the reasons why the Caspian Sea is considered a lake.
The name of the sea comes from the ancient tribes of the Caspian Sea. They inhabited its shores in the first millennia BC and were engaged in horse breeding. But over the many hundreds of years of its existence, this sea has had many names. It was called Derbentsky, Saraisky, Girkansky, Sigai, Kukkuz. Even in our time, for residents of Iran and Azerbaijan, this lake is called Khazar.
Geographical location
Two parts of the world - Europe and Asia - are washed by the waters of the Caspian Sea. The coastline covers the following countries:
- Turkmenistan
- Russia
- Azerbaijan
- Kazakhstan
The length from north to south is about one thousand two hundred kilometers, the width from west to east is about three hundred kilometers. The average depth is about two hundred meters, the greatest depth is about a thousand kilometers. The total area of the reservoir is more than 370,000 square kilometers and is divided into three climatic and geographical zones:
- Northern
- Average
- Southern Caspian
The water area includes six large peninsulas and about fifty islands. Their total area is four hundred square kilometers. The most large islands– Dzhambaisky, Ogurchinsky, Chechen, Tyuleniy, Konevsky, Zyudev and Absheron Islands. About one hundred and thirty rivers flow into the Caspian Sea, including the Volga, Ural, Atrek, Sefirud, Terek, Kura and many others.
Sea or lake?
The official name used in documentation and cartography is the Caspian Sea. But is this true?
In order to have the right to be called a sea, any body of water must be connected to the world's oceans. In the case of the Caspian Sea, this is not reality. The Caspian Sea is separated by almost 500 km of land from the nearest sea, the Black Sea. This is a completely enclosed body of water. The main differences between the seas:
- The seas can be fed by waterways - rivers.
- The external seas are directly connected to the ocean, that is, they have access to it.
- Inland seas are connected to other seas or oceans by straits.
The Caspian received the right to be called a sea primarily because of its impressive size, which is more typical of seas rather than lakes. In area it surpasses even Azov. Also no small role was played by the fact that not a single lake washes the shores of five states at once.
It is worth noting that the structure of the Caspian Sea bottom is of the oceanic type. This happened due to the fact that it was once part of the ancient World Ocean.
Compared to other seas, the percentage of salt saturation in it is very weak and does not exceed 0.05%. The Caspian Sea is fed only by rivers flowing into it, like all lakes on the globe.
Like many seas, the Caspian is famous for its powerful storms. The height of the waves can reach eleven meters. Storms can occur at any time of the year, but they are most dangerous in autumn and winter.
In fact, the Caspian Sea is the largest lake in the world. Its waters are not subject to international maritime laws. The territory of waters is divided between countries on the basis of laws adopted for lakes, and not for seas.
The Caspian Sea has rich mineral resources such as oil and gas. Its waters are inhabited by more than one hundred and twenty species of fish. Among them are the most valuable sturgeons, such as stellate sturgeon, sturgeon, sterlet, beluga, and thorn. 90% of the world's sturgeon catch comes from the Caspian Sea.
Interesting features:
- Scientists around the world have not yet come to a clear conclusion as to why the Caspian Sea is considered a lake. Some experts even suggest considering it a “lake-sea” or an “inland” sea, like the Dead Sea in Israel;
- The deepest point of the Caspian Sea is more than one kilometer;
- Historically, it is known that the total water level in the reservoir has changed more than once. The exact reasons for this are still not understood;
- It is the only body of water separating Asia and Europe;
- The largest water artery feeding the lake is the Volga River. It is this that carries the bulk of the water;
- Thousands of years ago the Caspian Sea was part of the Black Sea;
- In terms of the number of fish species, the Caspian Sea is inferior to some rivers;
- The Caspian Sea is the main supplier of the most expensive delicacy - black caviar;
- The water in the lake is completely renewed every two hundred and fifty years;
- The territory of Japan is smaller than the area of the Caspian Sea.
Ecological situation
Intervention into the ecology of the Caspian Sea regularly occurs due to the extraction of oil and natural resources. There are also interventions in the fauna of the reservoir, cases of poaching and illegal fishing of valuable fish species are frequent.
The water level in the Caspian Sea is falling every year. This is due to global warming, due to the influence of which the water temperature on the surface of the reservoir increased by one degree and the sea began to actively evaporate.
It is estimated that water levels have fallen by seven centimeters since 1996. By 2015, the level of the fall was about one and a half meters, and the water continues to fall.
If this continues, in a century the shallowest part of the lake may simply disappear. This will be the part that washes the borders of Russia and Kazakhstan. If global warming intensifies, the process may accelerate and this will happen much earlier.
It is known that long before the onset of global warming, the water level in the Caspian Sea underwent changes. The water kept rising and then falling. Scientists still cannot say exactly why this happened.
The Caspian Sea is one of the most amazing closed bodies of water on Earth.
Over the centuries, the sea has changed more than 70 names. The modern one came from the Caspians - tribes inhabiting the central and southeastern part of Transcaucasia 2 thousand years BC.
Geography of the Caspian Sea
The Caspian Sea is located at the junction of Europe and Asia and geographical location is divided into the Southern, Northern and Middle Caspian. The middle and northern part of the sea belongs to Russia, the southern to Iran, the eastern to Turkmenistan and Kazakhstan, and the southwestern to Azerbaijan. For many years, the Caspian states have been dividing the Caspian waters among themselves, and quite sharply at that.
Lake or sea?
In fact, the Caspian Sea is the world's largest lake, but has a number of marine characteristics. These include: a large body of water, strong storms with high waves, high and low tides. But the Caspian Sea does not have a natural connection with the World Ocean, which makes it impossible to call it a sea. At the same time, thanks to the Volga and artificially created channels, such a connection appeared. The salinity of the Caspian Sea is 3 times lower than the usual sea salinity, which does not allow the reservoir to be classified as a sea.
There were times when Caspian seas was truly part of the oceans. Several tens of thousands of years ago the Caspian Sea was connected to the Sea of Azov, and through it to the Black and Mediterranean. As a result of long-term processes occurring in the earth's crust, the Caucasus Mountains were formed, which isolated the reservoir. The connection between the Caspian and Black Seas was carried out for a long time through the strait (Kuma-Manych depression) and gradually ceased.
Physical quantities
Area, volume, depth
The area, volume and depth of the Caspian Sea are not constant and directly depend on the water level. On average, the area of the reservoir is 371,000 km², the volume is 78,648 km³ (44% of all world lake water reserves).
(The depth of the Caspian Sea in comparison with lakes Baikal and Tanganyika)
The average depth of the Caspian Sea is 208 m; the northern part of the sea is considered the shallowest. The maximum depth is 1025 m, noted in the South Caspian depression. In terms of depth, the Caspian Sea is second only to Baikal and Tanganyika.
The length of the lake from north to south is about 1200 km, from west to east on average 315 km. The length of the coastline is 6600 km, with islands - about 7 thousand km.
Shores
Basically, the coast of the Caspian Sea is low-lying and smooth. In the northern part it is heavily indented by the river channels of the Urals and Volga. The swampy shores here are located very low. The eastern shores adjoin semi-desert zones and deserts and are covered with limestone deposits. The most winding shores are in the west in the area of the Absheron Peninsula, and in the east in the area of the Kazakh Bay and Kara-Bogaz-Gol.
Sea water temperature
(Temperature of the Caspian Sea in different time of the year)
The average winter water temperature in the Caspian Sea ranges from 0 °C in the northern part to +10 °C in the southern part. In Iranian waters, the temperature does not drop below +13 °C. With the onset of cold weather, the shallow northern part of the lake is covered with ice, which lasts for 2-3 months. The thickness of the ice cover is 25-60 cm, at especially low temperatures it can reach 130 cm. In late autumn and winter, drifting ice floes can be observed in the north.
In summer, the average sea surface temperature is + 24 °C. In most parts the sea warms up to +25 °C…+30 °C. Warm water and beautiful sandy, occasionally shell and pebble beaches create excellent conditions for a full-fledged beach holiday. In the eastern part of the Caspian Sea, near the city of Begdash, abnormally low water temperatures remain in the summer months.
Nature of the Caspian Sea
Islands, peninsulas, bays, rivers
The Caspian Sea includes about 50 large and medium-sized islands, total area of which is 350 km². The largest of them are: Ashur-Ada, Garasu, Gum, Dash and Boyuk-Zira. The largest peninsulas are: Agrakhansky, Absheronsky, Buzachi, Mangyshlak, Miankale and Tyub-Karagan.
(Tyuleniy Island in the Caspian Sea, part of the Dagestan Nature Reserve)
The largest bays of the Caspian include: Agrakhansky, Kazakhsky, Kizlyarsky, Dead Kultuk and Mangyshlaksky. In the east is salt Lake Kara-Bogaz-Gol, previously a lagoon connected to the sea by a strait. In 1980, a dam was built on it, through which water from the Caspian goes to Kara-Bogaz-Gol, where it then evaporates.
130 rivers flow into the Caspian Sea, located mainly in its northern part. The largest of them are: Volga, Terek, Sulak, Samur and Ural. The average annual drainage of the Volga is 220 km³. 9 rivers have delta-shaped mouths.
Flora and fauna
The Caspian Sea is home to about 450 species of phytoplankton, including algae, aquatic and flowering plants. Of the 400 species of invertebrates, worms, crustaceans and molluscs predominate. There are a lot of small shrimp in the sea, which are the object of fishing.
More than 120 species of fish live in the Caspian Sea and its delta. Fishing objects include sprat (“Kilkin fleet”), catfish, pike, bream, pike perch, kutum, mullet, roach, rudd, herring, white fish, pike perch, goby, grass carp, burbot, asp and pike perch. Stocks of sturgeon and salmon are currently depleted, however, the sea is the largest supplier of black caviar in the world.
Fishing in the Caspian Sea is allowed all year round, with the exception of the period from late April to late June. There are many fishing bases with all amenities on the coast. Fishing in the Caspian Sea is a great pleasure. In any part of it, including in large cities, the catch is unusually rich.
The lake is famous for its wide variety of waterfowl. Geese, ducks, loons, gulls, waders, eagles, geese, swans and many others fly to the Caspian Sea during the migration or nesting period. The largest number of birds - over 600 thousand individuals - is observed at the mouths of the Volga and Ural, in the Turkmenbashi and Kyzylagach bays. During the hunting season, a huge number of fishermen come here not only from Russia, but also from countries near and far abroad.
The Caspian Sea is home to the only mammal. This is the Caspian seal or seal. Until recently, seals swam close to the beaches, everyone could admire the amazing animal with round black eyes, and the seals behaved very friendly. Now the seal is on the verge of extinction.
Cities on the Caspian Sea
The largest city on the Caspian Sea coast is Baku. The population of one of the most beautiful cities in the world is over 2.5 million people. Baku is located on the picturesque Absheron Peninsula and is surrounded on three sides by the waters of the warm and oil-rich Caspian Sea. Less big cities: the capital of Dagestan is Makhachkala, the Kazakh Aktau, the Turkmen Turkmenbashi and the Iranian Bender-Anzeli.
(Baku Bay, Baku - a city on the Caspian Sea)
Interesting Facts
Scientists are still arguing about whether to call a body of water a sea or a lake. The level of the Caspian Sea is gradually decreasing. The Volga delivers most of the water to the Caspian Sea. 90% of black caviar is mined in the Caspian Sea. Among them, the most expensive is the albino beluga caviar “Almas” ($2 thousand per 100 g).
In developing oil fields Companies from 21 countries take part in the Caspian Sea. According to Russian estimates, hydrocarbon reserves in the sea amount to 12 billion tons. American scientists claim that a fifth of the world's hydrocarbon reserves are concentrated in the depths of the Caspian Sea. This is more than the combined reserves of oil-producing countries such as Kuwait and Iraq.
The Caspian Sea is a special body of water, since its nature is still debated. Some scientists believe that this is the largest lake on our planet, others call it an endorheic sea.
The unique fossil and biological resources of the Caspian Sea are shared among five coastal states: Russia, Iran, Kazakhstan, Turkmenistan and Azerbaijan. But in addition to natural resources, this sea is fraught with many dangers. Oil and gas production poisons the ecosystem, industrial wastewater pollutes the coast, and dangerous microorganisms are regularly found in water samples.
Mining of oil and gas
Today, active hydrocarbon production is underway throughout the Caspian Sea. Back in 1820, the first well was drilled on the Absheron shelf. The news that oil had been found near Baku caused a real boom. The development of the mining industry has progressed by leaps and bounds. Moreover, according to geologists, about 20 billion tons of hydrocarbons are hidden in the depths of the Caspian Sea.
The extraction of oil and gas condensate has led to a real environmental problem. We are not just talking about associated pollution and chemical spills as a result of man-made disasters, but also about the use nuclear charges during the construction of gas storage facilities.
The waters of the Caspian Sea are practically poisoned with arsenic, lead, and mercury. In addition, the maximum permissible concentration (MPC) of heavy metals, copper, barium and zinc is significantly exceeded here. Phenols, volatile and non-volatile derivatives of hydrocarbons, cause especially great damage to the marine ecosystem. These substances are waste from oil refineries and are extremely toxic.
Another danger that threatens hydrocarbon production in the Caspian Sea, scientists consider the possibility of releasing large amounts of hydrogen sulfide into the water, which will inevitably cause ecological disaster. Already now, in the areas of wells, the level of water pollution with oil products ranges from 30 to 100 (!) MPC.
Spilled oil prevents the growth of phytoplankton and phytobenthos, blue-green algae, which reduces the food supply of sea inhabitants and reduces the amount of oxygen produced. An oil film can lead to the death of rare fish species, including sturgeon, waterfowl and other fauna.
Wastewater
Various pollutants enter the Caspian waters not only as a result of the work of oil and gas workers. The Volga and other rivers flowing into the sea annually bring thousands of tons of various waste into the Caspian Sea. Coastal cities often simply dump untreated sewage into the sea, and factories poison the water with waste chemicals.
For example, employees of the Dagestan department of Rospotrebnadzor do not recommend residents and tourists to swim in the sea near Derbent, Makhachkala, Izberbash and Kaspiysk. However, not all people are stopped by these warnings.
Almost half of Russia's industrial and agricultural enterprises are located in the Volga basin. This river flows through 15 regions of our country and poisons the Caspian Sea with pesticides, mineral fertilizers, nitrates, phosphates, heavy metal salts, and dioxins. According to scientists, the waters of the Volga mouth are firmly among the top ten most environmentally unfavorable water areas in the world.
Experts fear that such high levels of pollution in the rivers flowing into the Caspian Sea and problems in the sea itself could lead to the emergence of so-called oxygen-free zones. That is, under the influence of chemicals, the algae will finally die, there will be no one to produce oxygen, which will lead to the death of all the inhabitants of this area of the sea. The danger of the emergence of oxygen-free zones is especially relevant for the southern part of the Caspian Sea, where a noticeable imbalance in the balance between the synthesis and decomposition of organic substances has already been recorded.
Pathogenic bacteria
Some researchers fear that many dangerous viruses and bacteria that existed on our planet before the last ice age remained preserved in the depths of the sea. And active production of hydrocarbons can “let the genie out of the bottle,” which is very dangerous, because modern people there is no immunity from ancient pathogens. But most scientists are skeptical about such fears, because nothing like this has happened yet, although Caspian oil production has been going on for almost 200 years.
However, even fully studied microorganisms can cause significant harm to human health. From year to year, scientists discover Vibrio cholera and Escherichia coli in the waters of the Caspian Sea. According to the Dagestan department of Rospotrebnadzor, the number of pathogenic microorganisms in samples sea water sometimes exceeds the maximum permissible concentration by 28 (!) times.
In many samples, scientists discovered so-called rotaviruses, which cause acute intestinal infections that are quickly transmitted from person to person. This can provoke the emergence of mass outbreaks of the disease.
Experts say the main reason for the current situation is the banal discharge of human waste from the sewers of coastal cities without special cleaning and disinfection.
Caspian seal
Despite numerous media reports about mysterious predators, poisonous snakes and even sharks, which some tourists and local residents allegedly saw in the Caspian Sea, the inhabitants of this sea do not pose a particular danger to people. There aren't even stinging jellyfish here.
True, there is still one predator that can cause damage to human health if handled carelessly. This is the Caspian seal - a small seal that lives only in this sea. The body length of this animal does not reach 1.5 meters, its weight is about 50 kg. Compared to other seals, the Caspian seal is a real baby. But still a predator.
During the mating season, males become very aggressive; a female, fearing for her cub, can bite an unwary person. These animals have very sharp teeth; if you are unlucky, you may end up without fingers. The bite is painful and may become inflamed. Medical assistance in this case is mandatory.
However, who would stick their limbs into the jaws of wild predators? And the seals themselves try to avoid people, often suffering from poachers.
