Resources of the Caspian Sea. A brief description of. Rivers flowing into the Caspian Sea: list, description, characteristics

This is how the Mediterranean Sea was formed, which then included the current Azov, Black and Caspian Seas. On the site of the modern Caspian, a huge Caspian lowland was formed, the surface of which was almost 30 meters below the water level in the World Ocean. When the next rise of land began to take place at the place where the Caucasus Mountains were formed, the Caspian Sea was finally cut off from the ocean, and in its place a closed drainless reservoir was formed, which today is considered the largest inland sea on the planet. However, some scientists call this sea a giant lake.
A feature of the Caspian Sea is the constant fluctuation of the level of salinity of its water. Even in different areas of this sea, the water has different salinity. This was the reason for the predominance of fish and crustaceans in the Caspian Sea, which more easily tolerate fluctuations in water salinity.

Since the Caspian is completely isolated from the ocean, its inhabitants are endermics, i.e. always live in its water area.

The fauna of the Caspian Sea can be conditionally divided into four groups.

The first group of animals includes the descendants of ancient organisms that inhabited Tethys about 70 million years ago. These animals include Caspian gobies (golovach, Knipovich, Berg, bubyr, pugolovka, Baer) and herring (Kessler, Brazhnikov, Volga, brazil, etc.), some mollusks and most crustaceans (long-sexed crayfish, orthemia crustacean, etc.). Some fish, mainly herring, periodically enter the rivers flowing into the Caspian to spawn, many never leave the sea. Gobies prefer to live in coastal waters, often found in estuaries.
The second group of animals of the Caspian Sea is represented by arctic species. penetrated into the Caspian Sea from the north in the postglacial period. These are such animals as the Caspian seal (Caspian seal), fish - Caspian trout, white salmon, nelma. Of the crustaceans, this group is represented by mysid crustaceans, similar to small shrimps, tiny sea cockroaches, and some others.
The third group of animals inhabiting the Caspian includes species that independently or with the help of humans migrated here from the Mediterranean Sea. These are molluscs mitisyaster and abra, crustaceans - amphipods, shrimp, Black Sea and Atlantic crabs and some types of fish: golden mullet (sharp nose), needle fish and Black Sea kalk (flounder).

And, finally, the fourth group - freshwater fish that penetrated into the Caspian Sea from fresh rivers and turned into marine or anadromous, i.e. periodically rising into the rivers. Some of the typically freshwater fish also occasionally enter the Caspian. Among the fish of the fourth group are catfish, pike perch, barbel, red-lipped asp, Caspian fish, Russian and Persian sturgeon, beluga, stellate sturgeon. It should be noted that the Caspian Sea basin is the main habitat of sturgeons on the planet. Almost 80% of all sturgeons in the world live here. Barbels and fish are also valuable commercial fish.

As for sharks and other fish that are predatory and dangerous to humans, they do not live in the Caspian Sea-Lake.

Is it correct to call the Caspian a sea?

It is known that the sea is part of the oceans. From this geographically correct point of view, the Caspian cannot be considered a sea, because it is separated from the ocean by huge land masses. The shortest distance from the Caspian to the Black Sea, the closest of the seas included in the system of the World Ocean, is 500 kilometers. Therefore, it would be more correct to speak of the Caspian as a lake. This is the world's largest lake, often referred to simply as the Caspian or lake-sea.

The Caspian has a number of features of the sea: its water is salty (however, there are other salt lakes), the area is not much inferior to the area of ​​such seas as the Black, Baltic, Red, North, and even exceeds the area of ​​Azov and some others (however, the Canadian Lake Superior also has a huge area , like the three Seas of Azov). In the Caspian, fierce storm winds and huge waves are frequent (and this is not uncommon in Baikal).

So all the same, the Caspian Sea is a lake? That's Wikipedia says it. Yes, and the Great Soviet Encyclopedia answers that no one has yet been able to give an exact definition of this issue - "A generally accepted classification does not exist."

Do you know why this is very important and fundamental? And here's why...

The lake belongs to internal waters - the sovereign territories of coastal states, to which the international regime does not apply (the principle of non-intervention of the UN in the internal affairs of states). But the water area of ​​the sea is divided differently, and the rights of coastal states are completely different here.

In terms of its geographical position, the Caspian itself, in contrast to the land territories surrounding it, has not been the object of any targeted attention from the coastal states for many centuries. Only at the beginning of the XIX century. between Russia and Persia, the first treaties were concluded: Gulistan (1813) 4 and Turkmanchay (1828), summing up the results of the Russian-Persian war, as a result of which Russia annexed a number of Transcaucasian territories and received the exclusive right to keep a navy in the Caspian sea. Russian and Persian merchants were allowed to freely trade on the territory of both states and use the Caspian Sea to transport goods. The Turkmanchay Treaty confirmed all these provisions and became the basis for maintaining international relations between the parties until 1917.

After the October Revolution of 1917, in a note of the new Russian government that came to power on January 14, 1918, it renounced its exclusive military presence in the Caspian Sea. The agreement between the RSFSR and Persia of February 26, 1921 declared invalid all agreements concluded before it by the tsarist government. The Caspian Sea became a body of water for common use by the parties: both states were granted equal rights of free navigation, except in cases where the crews of Iranian ships could include citizens of third countries using the service for unfriendly purposes (Article 7). The 1921 agreement did not provide for a maritime border between the parties.

In August 1935, the following treaty was signed, the parties to which were new subjects of international law - the Soviet Union and Iran, which acted under the new name. The parties reaffirmed the provisions of the 1921 agreement, but introduced into the agreement a new concept for the Caspian - a 10-mile fishing zone, which limited the spatial limits for its participants to conduct this fishery. This was done in order to control and conserve the living resources of the reservoir.

In the context of the outbreak of World War II, unleashed by Germany, an urgent need arose to conclude a new treaty between the USSR and Iran on trade and navigation in the Caspian. The reason for this was the concern of the Soviet side, caused by Germany's interest in intensifying its trade relations with Iran and the danger of using the Caspian Sea as one of the stages of the transit route. The treaty between the USSR and Iran10, signed in 1940, protected the Caspian Sea from such a prospect: it repeated the main provisions of the previous agreements, which provided for the presence in its waters of ships of only these two Caspian states. It also included a provision for its indefinite validity.

The collapse of the Soviet Union radically changed the regional situation in the former Soviet space, in particular in the Caspian region. Among the large number of new problems, the problem of the Caspian Sea has also arisen. Instead of two states - the USSR and Iran, which previously bilaterally resolved all emerging issues of maritime navigation, fishing and the use of its other living and non-living resources, now there are five of them. Of the former, only Iran remained, Russia took the place of the USSR on the rights of succession, the remaining three are new states: Azerbaijan, Kazakhstan, Turkmenistan. They used to have access to the Caspian, but only as republics of the USSR, and not as independent states. Now, having become independent and sovereign, they have the opportunity to participate on an equal footing with Russia and Iran in the discussion and decision-making in the consideration of all the above issues. This was also reflected in the attitude of these states to the Caspian, since all five states that had access to it showed equal interest in the use of its living and non-living resources. And this is logical, and most importantly, justified: the Caspian Sea is rich in natural resources, both fish stocks and black gold - oil and blue fuel - gas. Exploration and production of the last two resources have long been the subject of the most heated and protracted negotiations. But not only them.

In addition to the presence of rich mineral resources, about 120 species and subspecies of fish live in the waters of the Caspian Sea, here is the world gene pool of sturgeons, the extraction of which, until recently, accounted for 90% of their total world catch.

Due to its location, the Caspian has traditionally and long been widely used for navigation, acting as a kind of transport artery between the peoples of the coastal states. On its shores there are such large seaports as the Russian Astrakhan, the capital of Azerbaijan Baku, the Turkmen Turkmenbashi, the Iranian Anzali and the Kazakh Aktau, between which trade, cargo and passenger sea transport routes have long been laid.

And yet, the main object of attention of the Caspian states is its mineral resources - oil and natural gas, to which each of them can lay claim within the boundaries that should be determined by them collectively on the basis of international law. And for this, they will have to divide between themselves both the Caspian Sea and its bottom, in the bowels of which its oil and gas are hidden, and develop rules for their extraction with minimal damage to a very fragile environment, primarily the marine environment and its living inhabitants.

The main obstacle in resolving the issue of the beginning of a wide extraction of the mineral resources of the Caspian Sea for the Caspian states continues to be its international legal status: should it be considered a sea or a lake? The complexity of the issue lies in the fact that these states themselves must solve it, and so far no agreement has been observed in their ranks. But at the same time, each of them seeks to start extracting Caspian oil and natural gas as soon as possible and make their sale abroad a permanent source of funds to form their budget.

Therefore, the oil companies of Azerbaijan, Kazakhstan and Turkmenistan, without waiting for the end of the settlement of existing disagreements on the territorial division of the Caspian Sea, have already begun active production of its oil, in the hope of ceasing to be dependent on Russia, turning their countries into oil producers and, in this capacity, begin to build their own long-term trading relations with neighbors.

However, the issue of the status of the Caspian Sea remains unresolved. Regardless of whether the Caspian states agree to consider it a “sea” or a “lake”, they will have to apply the principles corresponding to the choice made or develop their own in this case to the territorial division of its water area and bottom.

Kazakhstan was in favor of recognizing the Caspian as a sea. Such recognition will make it possible to apply to the division of the Caspian the provisions of the 1982 UN Convention on the Law of the Sea on Internal Waters, the Territorial Sea, the Exclusive Economic Zone, and the Continental Shelf. This would allow the coastal states to gain sovereignty over the subsoil of the territorial sea (Article 2) and exclusive rights to explore and develop the resources of the continental shelf (Article 77). But the Caspian cannot be called a sea from the position of the UN Convention on the Law of the Sea of ​​1982, since this body of water is closed and has no natural connection with the oceans.

In this case, the option of sharing its water area and bottom resources is also excluded.

In the treaties between the USSR and Iran, the Caspian Sea was considered as a border lake. With the legal status of a "lake" given to the Caspian Sea, it is supposed to be divided into sectors, as is done with respect to border lakes. But there is no rule in international law obliging states to do just that: division into sectors is an established practice.

The Russian Foreign Ministry has repeatedly made statements that the Caspian is a lake, and its waters and subsoil are the common property of the coastal states. Iran also considers the Caspian Sea as a lake from the position fixed in the treaties with the USSR. The country's government believes that this status implies the creation of a consortium for the unified management of production and use of its resources by the Caspian states. Some authors also share this opinion, for example, R. Mammadov believes that with such a status, the extraction of hydrocarbon resources in the Caspian Sea by these states should be carried out jointly.

In the literature, there has been a proposal to give the Caspian Sea the status of a “sui generis” lake, and in this case we are talking about a special international legal status of such a lake and its special regime. Under the regime is assumed the joint development by states of their own rules for the use of its resources.

Thus, the recognition of the Caspian Sea as a lake does not require its mandatory division into sectors - each coastal state has its own part. In addition, there are no norms in international law on the division of lakes between states: this is their good will, behind which certain internal interests may be hidden.

At present, all the Caspian states recognize that the modern legal regime was established by the established practice of its use, but now the Caspian is in actual common use not by two, but by five states. Even at the meeting of foreign ministers held in Ashgabat on November 12, 1996, the Caspian states confirmed that the status of the Caspian Sea could be changed only with the consent of all five coastal states. Later, this was also confirmed by Russia and Azerbaijan in a joint statement dated January 9, 2001 on the principles of cooperation, as well as in the Declaration on cooperation in the Caspian Sea signed between Kazakhstan and Russia dated October 9, 2000.

But in the course of numerous Caspian negotiations, conferences and four summits of the Caspian states (Ashgabat summit on April 23-24, 2002, the Tehran summit on October 16, 2007, the Baku summit on November 18, 2010 and Astrakhan on September 29, 2014), the consent of the Caspian countries it has not been possible to achieve.

More productive so far is cooperation at the bilateral and trilateral levels. Back in May 2003, Russia, Azerbaijan and Kazakhstan signed an agreement on the junction of the lines of delimitation of adjacent sections of the bottom of the Caspian Sea, which was based on previous bilateral agreements. In the current situation, Russia, by its participation in these agreements, seemed to confirm that the agreements between the USSR and Iran are outdated and do not correspond to existing realities.

In the Agreement of July 6, 1998 between the Russian Federation and the Republic of Kazakhstan on the delimitation of the bottom of the northern part of the Caspian Sea in order to exercise sovereign rights to subsoil use, the delimitation of the sea bottom between adjacent and opposite sides along a modified median line was announced on the basis of the principle of justice and agreement of the parties. At the bottom of the section, the states have sovereign rights, but their common use of the water surface is preserved.

Iran perceived this agreement as separate and violating the previous Treaties with the USSR of 1921 and 1940. However, it should be noted that in the preamble of the 1998 agreement, to which Russia and Kazakhstan were parties, the agreement was considered as a temporary measure pending the signing of the convention by all the Caspian states.

Later, on July 19 of the same year, Iran and Russia made a joint statement in which they proposed three possible scenarios for the delimitation of the Caspian Sea. First: the sea should be shared on the basis of the condominium principle. The second scenario boils down to dividing the water area, waters, bottom and subsoil into national sectors. The third scenario, which is a compromise between the first and second options, suggests dividing only the bottom between the coastal states, and considers the water surface to be common and open to all coastal countries.

The existing options for the delimitation of the Caspian Sea, including those mentioned above, are possible only if there is good political will on the part of the parties. Azerbaijan and Kazakhstan have clearly expressed their position from the very beginning of the process of multilateral consultations. Azerbaijan considers the Caspian Sea to be a lake and, therefore, it should be divided. Kazakhstan proposes to consider the Caspian as a closed sea, referring to the 1982 UN Convention (Articles 122, 123), and, accordingly, stands for its division in the spirit of the Convention. Turkmenistan has long supported the idea of ​​joint management and use of the Caspian, but foreign companies already developing resources off the coast of Turkmenistan have influenced the policy of its president, who began to object to the establishment of a condominium regime, supporting the position of dividing the sea.

Azerbaijan was the first of the Caspian states to start using the hydrocarbon resources of the Caspian under the new conditions. After the signing of the "Deal of the Century" in September 1994, Baku expressed a desire to declare the sector adjacent to it an integral part of its territory. This provision was also enshrined in the Constitution of Azerbaijan, adopted in order to exercise sovereign rights to subsoil use, Moscow, July 6, 1998 at a referendum on November 12, 1995 (Article 11). But such a radical position from the very beginning did not correspond to the interests of all other coastal states, especially Russia, which expresses fears that this will open access to the Caspian Sea to countries in other regions. Azerbaijan agreed to a compromise. In the Agreement between the Russian Federation and Azerbaijan on the delimitation of adjacent sections of the Caspian Sea in 2002, a provision was fixed in which the division of the bottom was carried out using the median line, and the water area of ​​the reservoir remained in joint use.

Unlike Azerbaijan, which expressed a desire to completely divide the Caspian, Iran proposes to leave its bowels and water for joint use, but does not object to the option of dividing the Caspian into 5 equal parts. Accordingly, each member of the Caspian five would be allocated 20 percent of the total territory of the reservoir.

Russia's point of view was changing. For a long time Moscow insisted on the establishment of a condominium, but wanting to build a long-term policy with neighbors who did not benefit from considering the Caspian as the property of five coastal states, it changed its position. This then prompted the states to start a new stage of negotiations, at the end of which, in 1998, the above Agreement was signed, where Russia declared that it was “ripe” for the division of the Caspian Sea. Its main principle was the position "the water is common - we divide the bottom."

Taking into account the fact that some of the Caspian states, namely Azerbaijan, Kazakhstan and Russia, have reached agreements on the conditional delimitation of spaces in the Caspian, it can be concluded that they are actually satisfied with the already established regime with the division of its bottom along a modified median line and the joint use of the surface reservoir for navigation and fishing.

However, the lack of complete clarity and unity in the position of all countries of the coast prevents the Caspian states themselves from developing oil production. And oil is of key importance to them. There are no unequivocal data regarding their reserves in the Caspian Sea. According to the US Energy Information Agency in 2003, the Caspian was ranked second in oil reserves and third in gas reserves. The data of the Russian side is different: they speak of an artificial overestimation by Western experts of the energy resources of the Caspian Sea. Differences in assessments are due to the political and economic interests of regional and external players. The data distortion factor was the geopolitical significance of the region, with which the foreign policy plans of the US and the EU are connected. Zbigniew Brzezinski back in 1997 expressed the opinion that this region is the "Eurasian Balkans".

The Caspian Sea is located on the border of Europe and Asia and is surrounded by the territories of five states: Russia, Azerbaijan, Iran, Turkmenistan and Kazakhstan. Despite the name, the Caspian is the largest lake on the planet (its area is 371,000 km2), however, the bottom, composed of the oceanic crust, and salt water, together with its large size, give reason to consider it a sea. A large number of rivers flow into the Caspian Sea, for example, such large ones as the Volga, Terek, Ural, Kura and others.

Relief and depth of the Caspian Sea

According to the bottom relief, the Caspian Sea is divided into three parts: southern (the largest and deepest), middle and northern.

In the northern part, the depth of the sea is the smallest: on average, it is from four to eight meters, and the maximum depth here reaches 25 m. The northern part of the Caspian Sea is limited by the Mangyshlak Peninsula and occupies 25% of the entire area of ​​the reservoir.

The middle part of the Caspian is deeper. Here the average depth becomes equal to 190 m, while the maximum is 788 meters. The area of ​​the middle Caspian is 36% of the total, and the volume of water is 33% of the total volume of the sea. It is separated from the southern part by the Absheron Peninsula in Azerbaijan.

The deepest and largest part of the Caspian Sea is the southern one. It occupies 39% of the total area, and its share of the total water volume is 66%. Here is the South Caspian depression, in which the deepest point of the sea is located - 1025 m.

Islands, peninsulas and bays of the Caspian Sea

In total, there are about 50 islands in the Caspian Sea, almost all of them are uninhabited. Due to the lesser depth of the northern part of the sea, most of the islands are located there, among them the Baku archipelago belonging to Azerbaijan, the Seal Islands in Kazakhstan, as well as many Russian islands off the coast of the Astrakhan region and Dagestan.

Among the peninsulas of the Caspian Sea, the largest are Mangyshlak (Mangistau) in Kazakhstan and Absheron in Azerbaijan, where such large cities as the country's capital Baku and Sumgayit are located.

Gulf of Kara-Bogaz-Gol Caspian Sea

The coastline of the sea is heavily indented, and there are many bays on it, for example, Kizlyar, Mangyshlak, Dead Kultuk and others. Special mention deserves the Kara-Bogaz-Gol Bay, which is actually a separate lake connected to the Caspian Sea by a narrow strait, thanks to which a separate ecosystem and higher salinity of water are preserved in it.

Fishing in the Caspian Sea

Since ancient times, the Caspian Sea has attracted the inhabitants of its shores with its fish resources. About 90% of the world's sturgeon production is mined here, as well as such fish as carp, bream, and sprat.

Caspian Sea video

In addition to fish, the Caspian is extremely rich in oil and gas, the total reserves of which are about 18-20 million tons. Salt, limestone, sand and clay are also mined here.

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Yes, geography can sometimes break my brain quite a bit. You look at the map and see the name - "Caspian Sea". What a normal person would think in such a situation - yes, of course, it would not occur to him that we are talking about ... a lake! So now I'll tell you why the Caspian Sea is not a sea, but a lake, how did it happen and what is this strange whirlwind with names.

The sea is not the sea

Yes, the Caspian Sea is a geographical object, the essence of which does not really coincide with its name.

The fact is that by name it is a sea, but in fact it is a lake. They called it the sea due to the large size and salinity of the water. After all, people did not want to delve into geographical nuances - the name appeared a long time ago.

Only really Caspian lake has no outlet to the ocean. And this is one of the most important conditions for which a body of water is called a sea. It turns out that without access to the ocean, the Caspian is considered a lake. Big, salty and very similar to the sea - but still a lake.

So, once again I will list what a reservoir should have in order for it to be considered a sea:

A lake is not a lake

The Caspian Sea-Lake, however, is different from other lakes. It is indeed very large - so much so that it washes the territory five different countries. In addition, it has about fifty fairly large islands.

Yes and water there salty. However, by maritime standards, all the same not enough- which again inclines us towards the fact that this is a lake.

And the abundance of waters of the Caspian decreases over the years. Long time it replenished the Volga, but in recent years it she becomes shallow- respectively, the water level in the Caspian Sea is also decreasing. So, perhaps in a hundred or two years it will turn into a regular-sized lake if global warming does not stop.

Throughout the world, the Caspian Sea is unanimously considered a lake. Even his water territory is divided not according to those international laws that were invented for marine areas, but lake legislation.

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In a huge number of books I read about the Caspian Sea, its greatness and how local people love and respect it. And indeed, I was very surprised when I once found myself on the shore of this sea. But after a while I began to hear that it is called a lake. I was wondering why is this happening? And then I delved into literature in order to understand the situation.

Why the Caspian is a lake

There is one main reason why people no longer consider this beautiful body of water to be the sea - the lack of access to the ocean. Usually the sea must have a strait connecting it with a larger part of a huge water reservoir - the oceans. For example, we can recall the Sea of ​​\u200b\u200bAzov, with its Kerch Strait, or the Black Sea following it, with the Bosphorus Strait. A series of such straits and seas leads them to the Atlantic Ocean.

But the Caspian Sea is a unique case. There is not a single drain from it. Even the Angara River flows out of the great Baikal.

The only weighty argument for the fact that the Caspian is a sea is its salinity. But the numbers speak against it. The average percentage of water salinity here is 12.9%, while in other seas this figure is 35%.

Where does the Caspian Sea draw water from?

In this, the largest, as I figured out, lake on the planet, five great rivers flow at once:

• Samur;
• Volga;
• Ural;
• Terek;
• Kura.

At the confluence of the rivers, the water is almost fresh, but closer to the south, the lake saturates it with its own salt reserves.

Fluctuations in the level of the Caspian Sea

The locals told me that the Caspian is fickle. The water level is extremely variable. This is due to the change in the level of the rivers, the internal sources of this sea-lake. Climate plays a big role. At the moment, the height of the Caspian Sea is steadily growing, reaching almost 26 meters below sea level. For comparison: 20 years ago, this figure was almost two meters lower.

This has pros and cons. On the one hand, navigation is improving, and on the other, pastures and fields are flooded.

The inhabitants of the coast love the Caspian, despite its unusual nature and stormy character. I liked him very much too!

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Many names, not only toponyms, have always surprised me with their seeming groundlessness. Guinea pigs are not guinea pigs, bats are not related to rodents, and the Caspian Sea is generally a lake.

I didn't say "apparently" for nothing. Every name has a backstory. And often very interesting.

How the sea became a lake

The Caspian Sea is not so undeservedly called the sea. Once it really was part of the ocean.

It even rests in the bed of the earth's crust ocean type.

The Caspian is brackish although the salinity of the water is variable. Near the mouth of the Volga, which flows into it, the salinity of the water is minimal. The size of the Caspian in no way inferior to the sea. Its surface area: 371,000 km².

The main reason why Caspian considered to be lake, it is his isolation from the oceans. He has nothing to do with him.

But it was many years ago.

It all started with Sarmatian Sea, which existed more than 13 million years ago. It was loosely associated with by sea mediterranean, but later lost this connection and began to desalinate. Then it briefly restored contact with the sea, but then lost it again.

6.5 - 5.2 million years ago formed Pontic Sea, which is smaller in area. Which, moreover, was soon divided into several unconnected reservoirs. The resulting Balakhani lake can be considered a grandmother Caspian Sea. It gained and lost access to the sea several more times, raised and lowered the water level, changed in size, until finally something appeared. Caspian Sea as we see it now.

How to consider the Caspian Sea: the sea or the lake

And the disputes here are not so much between geographers, but between politicians.

The Caspian washes the territories at once five states:

• Kazakhstan;
• Russia;
• Turkmenistan;
• Iran;
• Azerbaijan.

But Caspian Sea is not only important transport node, but also a storehouse of various natural resources, among which:

• oil;
• gas;
• fish, including sturgeon.

And here comes the problem with legal status of the Caspian. If you count it by sea, then when using it, states should focus on United Nations Convention on the Law of the Sea 1982. But the procedure for the use of international rivers and lakes, as a rule, is established by the coastal states themselves, concluding appropriate agreements.

Full agreement between the countries has not yet been reached.

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I rested somehow in the camp. It's no secret that almost every day there are competitions for the entertainment of children and youth. So. Was we have quiz. Question: "Which lake is the largest?" One guy of about fifteen was the first to raise his hand and answer: "Baikal." The strangest thing was that his answer was counted as correct! How so? Isn't the Caspian Sea the largest lake? Now I will explain to you.

How to distinguish the sea from the lake

I will list several signs by which a body of water is defined as a sea.

1. Rivers can flow into the sea.

2. The outer sea has direct access to the ocean.

3. If the sea is inland, then it is connected by straits with other seas or directly with the ocean.

Is the Caspian Sea suitable for the parameters of the sea

Need to check, does the Caspian Sea have signs of a sea. into it really rivers flow, but they flow into many bodies of water: seas, lakes, oceans, and other rivers. The Caspian Sea is surrounded from all sides dry land. Is it really inland sea? Then it should be connected to the Black or Azov seas some strait. Strait Same No. Exactly due to the lack of access to the World Ocean, the Caspian Sea is considered a lake.

“But why was it then called the sea, if it is a lake?”- you ask. Answer very simple: because of his large size and salinity. Indeed, The Caspian Sea is several times larger than the Sea of ​​Azov and almost the same size as the Baltic Sea..

Great! The quiz issue has been resolved. Soap judge!!!

Well then I told, that the Caspian Sea In fact - lake. Now I want to you provide small collection of interesting facts about this lake.

1. The Caspian Sea is below sea level (-28 m), which once again proves that this is a lake.

2. BC around the lake area lived nomadic Caspian tribes,in honor of which he was nicknamed the Caspian.

3. It the deepest enclosed body of water on the planet.

4. Many believe that the name of the group "Caspian cargo" is related to the Caspian Sea. In a way they are right No). In fact the expression "Caspian cargo" can refer to any illegal cargo.

5.Caspian Sea Fine suitable for tourism. Under the USSR, a large number of sanatoriums were built here. Today same here you can see many hotels, water parks and beaches.

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The Caspian Sea is inland and is located in a vast continental depression on the border of Europe and Asia. The Caspian Sea has no connection with the ocean, which formally allows it to be called a lake, but it has all the features of the sea, since it had connections with the ocean in past geological epochs.

The area of ​​the sea is 386.4 thousand km2, the volume of water is 78 thousand m3.

The Caspian Sea has a vast drainage basin, with an area of ​​about 3.5 million km2. The nature of landscapes, climatic conditions and types of rivers are different. Despite its vastness, only 62.6% of its area is in waste areas; about 26.1% - for drainless. The area of ​​the Caspian Sea itself is 11.3%. 130 rivers flow into it, but almost all of them are located in the north and west (and the eastern coast does not have a single river reaching the sea at all). The largest river in the Caspian basin is the Volga, which provides 78% of the river water entering the sea (it should be noted that more than 25% of the Russian economy is located in the basin of this river, and this undoubtedly determines many other features of the waters of the Caspian Sea), as well as the Kura River , Zhaiyk (Ural), Terek, Sulak, Samur.

In physical and geographical terms and according to the nature of the underwater relief, the sea is divided into three parts: northern, middle and southern. The conditional boundary between the northern and middle parts runs along the line of Chechen Island–Cape Tyub-Karagan, between the middle and southern parts - along the line of Zhiloy Island–Cape Kuuli.

The shelf of the Caspian Sea, on average, is limited to depths of about 100 m. The continental slope, which begins below the edge of the shelf, ends in the middle part at about 500–600 m, in the southern part, where it is very steep, at 700–750 m.

The northern part of the sea is shallow, its average depth is 5–6 m, the maximum depths of 15–20 m are located on the border with the middle part of the sea. The bottom relief is complicated by the presence of banks, islands, furrows.

The middle part of the sea is a separate basin, the region of maximum depths of which - the Derbent depression - is shifted to the western coast. The average depth of this part of the sea is 190 m, the greatest is 788 m.

The southern part of the sea is separated from the middle part by the Apsheron threshold, which is a continuation of the Greater Caucasus. Depths above this underwater ridge do not exceed 180 m. The deepest part of the South Caspian basin with a maximum sea depth of 1025 m is located east of the Kura delta. Several underwater ridges up to 500 m high rise above the bottom of the basin.

The shores of the Caspian Sea are diverse. In the northern part of the sea, they are quite strongly indented. Here are the bays of Kizlyar, Agrakhan, Mangyshlak and many shallow bays. Notable peninsulas: Agrakhansky, Buzachi, Tyub-Karagan, Mangyshlak. Large islands in the northern part of the sea are Tyuleniy, Kulaly. In the deltas of the Volga and Ural rivers, the coastline is complicated by many islets and channels, which often change their position. Many small islands and banks are located on other parts of the coastline.

The middle part of the sea has a relatively flat coastline. On the western coast, on the border with the southern part of the sea, the Apsheron Peninsula is located. To the east of it, islands and banks of the Apsheron archipelago stand out, of which the largest is Zhiloy Island. The eastern shore of the Middle Caspian is more indented, the Kazakh Bay stands out here with the Kenderli Bay and several capes. The largest bay of this coast is Kara-Bogaz-Gol.

South of the Absheron Peninsula are the islands of the Baku archipelago. The origin of these islands, as well as some banks off the eastern coast of the southern part of the sea, is associated with the activity of underwater mud volcanoes lying at the bottom of the sea. On the eastern shore are the large bays of Turkmenbashi and Turkmensky, and near it is the island of Ogurchinsky.

One of the most striking phenomena of the Caspian Sea is the periodic variability of its level. In historical times, the Caspian Sea had a lower level than the World Ocean. Fluctuations in the level of the Caspian Sea are so great that for more than a century they have attracted the attention of not only scientists. Its peculiarity is that in the memory of mankind its level has always been below the level of the World Ocean. Since the beginning of instrumental observations (since 1830) of the sea level, the amplitude of its fluctuations has been almost 4 m, from -25.3 m in the eighties of the XIX century. to -29 m in 1977. In the last century, the level of the Caspian Sea has changed significantly twice. In 1929 it stood at a mark of about -26 m, and since it had been close to this mark for almost a century, this position of the level was considered as a long-term or secular average. In 1930, the level began to decline rapidly. Already by 1941, it had dropped by almost 2 m. This led to the drying up of vast coastal areas of the bottom. The decrease in the level, with its small fluctuations (short-term insignificant rises in the level in 1946-1948 and 1956-1958), continued until 1977 and reached the mark of -29.02 m, i.e., the level took the lowest position for last 200 years.

In 1978, contrary to all forecasts, the sea level began to rise. As of 1994, the level of the Caspian Sea was at -26.5 m, that is, in 16 years the level has risen by more than 2 m. The rate of this rise is 15 cm per year. The level increment in some years was higher, and in 1991 it reached 39 cm.

The general fluctuations in the level of the Caspian Sea are superimposed by its seasonal changes, the average long-term of which reaches 40 cm, as well as surge phenomena. The latter are especially pronounced in the Northern Caspian. The northwestern coast is characterized by large surges created by the prevailing, especially in the cold season, storms of eastern and southeastern directions. Over the past decades, a number of large (more than 1.5–3 m) surges have been observed here. A particularly large surge with catastrophic consequences was noted in 1952. Fluctuations in the level of the Caspian Sea cause great damage to the states surrounding its water area.

Climate. The Caspian Sea is located in the temperate and subtropical climatic zones. Climatic conditions change in the meridional direction, since the sea stretches for almost 1200 km from north to south.

In the Caspian region, various circulation systems interact, however, easterly winds prevail throughout the year (the influence of the Asian high). The position at rather low latitudes provides a positive balance of heat inflow, so the Caspian Sea serves as a source of heat and moisture for passing air masses for most of the year. The average annual temperature in the northern part of the sea is 8–10°С, in the middle part - 11–14°С, in the southern part – 15–17°С. However, in the northernmost parts of the sea, the average January temperature is from –7 to –10°C, and the minimum temperature during arctic air intrusions is up to –30°C, which determines the formation of the ice cover. In summer, rather high temperatures dominate over the entire region under consideration - 24–26°С. Thus, the Northern Caspian is subject to the most sharp temperature fluctuations.

The Caspian Sea is characterized by a very small amount of precipitation per year - only 180 mm, and most of it falls on the cold season of the year (from October to March). However, the Northern Caspian differs in this respect from the rest of the basin: here the average annual precipitation is less (only 137 mm for the western part), and the distribution over the seasons is more even (10–18 mm per month). In general, we can talk about the proximity of climatic conditions to arid ones.

Water temperature. The distinctive features of the Caspian Sea (great differences in depths in different parts of the sea, the nature of the bottom relief, isolation) have a certain influence on the formation of temperature conditions. In the shallow North Caspian, the entire water column can be considered as homogeneous (the same applies to shallow bays located in other parts of the sea). In the Middle and South Caspian, surface and deep masses separated by a transitional layer can be distinguished. In the Northern Caspian and in the surface layers of the Middle and Southern Caspian, the water temperature varies over a wide range. In winter, temperatures vary from north to south from less than 2 to 10°С, the water temperature near the western coast is 1–2°С higher than near the eastern one, in the open sea the temperature is higher than near the coasts: by 2–3°С in the middle part and by 3–4°С in the southern part of the sea. In winter, the temperature distribution is more uniform with depth, which is facilitated by the winter vertical circulation. During moderate and severe winters in the northern part of the sea and shallow bays on the east coast, the water temperature drops to freezing.

In summer, the temperature varies in space from 20 to 28°C. The highest temperatures are observed in the southern part of the sea; temperatures are also quite high in the well-warmed shallow North Caspian. The zone of distribution of the lowest temperatures is adjacent to the east coast. This is due to the rise of cold deep waters to the surface. Temperatures are also relatively low in the poorly heated deep-water central part. In the open areas of the sea, in late May–early June, the formation of a temperature jump layer begins, which is most clearly expressed in August. Most often it is located between 20 and 30 m in the middle part of the sea and 30 and 40 m in the south. In the middle part of the sea, due to the surge near the eastern coast, the shock layer rises close to the surface. In the bottom layers of the sea, the temperature during the year is about 4.5°C in the middle part and 5.8–5.9°C in the south.

Salinity. Salinity values ​​are determined by such factors as river runoff, water dynamics, including mainly wind and gradient currents, the resulting water exchange between the western and eastern parts of the Northern Caspian and between the Northern and Middle Caspian, the bottom topography, which determines the location of waters with different salinity, mainly along the isobaths, evaporation, which ensures the shortage of fresh water and the inflow of more saline ones. These factors collectively affect the seasonal differences in salinity.

The Northern Caspian can be considered as a reservoir of constant mixing of river and Caspian waters. The most active mixing occurs in the western part, where both river and Central Caspian waters directly enter. In this case, horizontal salinity gradients can reach 1‰ per 1 km.

The eastern part of the Northern Caspian is characterized by a more uniform salinity field, since most of the river and sea (Middle Caspian) waters enter this area of ​​the sea in a transformed form.

According to the values ​​of horizontal salinity gradients, in the western part of the Northern Caspian, a river-sea contact zone can be distinguished with water salinity from 2 to 10‰, in the eastern part from 2 to 6‰.

Significant vertical salinity gradients in the Northern Caspian are formed as a result of the interaction of river and sea waters, with runoff playing a decisive role. The intensification of vertical stratification is also facilitated by the unequal thermal state of the water layers, since the temperature of the surface desalinated waters coming from the coast in summer is 10–15°C higher than that of the bottom ones.

In the deep basins of the Middle and South Caspian, salinity fluctuations in the upper layer are 1–1.5‰. The largest difference between the maximum and minimum salinity was noted in the area of ​​the Apsheron threshold, where it is 1.6‰ in the surface layer and 2.1‰ at the 5 m horizon.

The decrease in salinity along the western coast of the South Caspian in the 0–20 m layer is caused by the runoff of the Kura River. The influence of the Kura runoff decreases with depth; at the horizons of 40–70 m, the range of salinity fluctuations is no more than 1.1‰. Along the entire western coast to the Absheron Peninsula stretches a strip of desalinated water with a salinity of 10–12.5‰ coming from the Northern Caspian.

In addition, salinity increases in the South Caspian due to the removal of saline waters from bays and inlets on the eastern shelf under the action of southeasterly winds. In the future, these waters are transferred to the Middle Caspian.

In the deep layers of the Middle and South Caspian, salinity is about 13‰. In the central part of the Middle Caspian, such salinity is observed at horizons below 100 m, and in the deep part of the South Caspian, the upper boundary of waters with increased salinity drops to 250 m. Obviously, vertical mixing of waters is difficult in these parts of the sea.

Surface water circulation. Currents in the sea are mainly wind-driven. In the western part of the Northern Caspian, currents of the western and eastern quarters are most often observed, in the eastern - southwestern and southern. The currents caused by the runoff of the Volga and Ural rivers can be traced only within the estuarine coast. The prevailing current velocities are 10–15 cm/s; in the open areas of the Northern Caspian, the maximum velocities are about 30 cm/s.

In the coastal areas of the middle and southern parts of the sea, currents of the northwestern, northern, southeastern, and southern directions are observed in accordance with the wind directions; eastward currents often occur near the eastern coast. Along the western coast of the middle part of the sea, the most stable currents are southeast and south. Current velocities are on average about 20–40 cm/s, the maximum ones reach 50–80 cm/s. Other types of currents also play a significant role in the circulation of sea waters: gradient, seiche, inertial ones.

ice formation. The Northern Caspian is covered with ice annually in November, the area of ​​the freezing part of the water area depends on the severity of the winter: in severe winters, the entire Northern Caspian is covered with ice, in soft ice it stays within the 2–3 meter isobath. The appearance of ice in the middle and southern parts of the sea falls on December-January. Near the eastern coast, ice is of local origin, near the western coast - most often brought from the northern part of the sea. In severe winters, shallow bays freeze off the eastern coast of the middle part of the sea, coasts and landfast ice form off the coast, and drift ice spreads to the Absheron Peninsula in abnormally cold winters off the western coast. The disappearance of the ice cover is observed in the second half of February–March.

Oxygen content. The spatial distribution of dissolved oxygen in the Caspian Sea has a number of regularities.
The central part of the Northern Caspian is characterized by a fairly uniform distribution of oxygen. An increased oxygen content is found in the areas of the pre-estuary seashore of the Volga River, a lower one - in the southwestern part of the Northern Caspian.

In the Middle and South Caspian, the highest oxygen concentrations are confined to coastal shallow areas and pre-estuary seashores of rivers, with the exception of the most polluted areas of the sea (Baku Bay, Sumgait region, etc.).

In the deep-water regions of the Caspian Sea, the main pattern is preserved in all seasons - a decrease in oxygen concentration with depth.
Due to the autumn-winter cooling, the density of the waters of the North Caspian increases to a value at which it becomes possible for the flow of North Caspian waters with a high oxygen content along the continental slope to significant depths of the Caspian Sea.

The seasonal distribution of oxygen is mainly related to the annual course and seasonal ratio of production-destruction processes occurring in the sea.

In spring, the production of oxygen in the process of photosynthesis quite significantly covers the decrease in oxygen due to a decrease in its solubility with an increase in water temperature in spring.

In the areas of the estuarine coasts of the rivers feeding the Caspian Sea, in spring there is a sharp increase in the relative oxygen content, which in turn is an integral indicator of the intensification of the photosynthesis process and characterizes the degree of productivity of the mixing zones of sea and river waters.

In summer, due to significant warming of water masses and activation of photosynthesis processes, the leading factors in the formation of the oxygen regime in surface waters are photosynthetic processes, in near-bottom waters - biochemical oxygen consumption by bottom sediments.

Due to the high temperature of the waters, the stratification of the water column, the large influx of organic matter and its intense oxidation, oxygen is quickly consumed with its minimal entry into the lower layers of the sea, as a result of which an oxygen deficiency zone is formed in the Northern Caspian. Intensive photosynthesis in the open waters of the deep-water regions of the Middle and South Caspian covers the upper 25-meter layer, where oxygen saturation is more than 120%.

In autumn, in the well-aerated shallow water areas of the Northern, Middle and Southern Caspian, the formation of oxygen fields is determined by the processes of water cooling and the less active, but still ongoing process of photosynthesis. The oxygen content is rising.

The spatial distribution of nutrients in the Caspian Sea reveals the following patterns:

• increased concentrations of biogenic substances characterize the areas of pre-estuary seashores of rivers that feed the sea and shallow areas of the sea subject to active anthropogenic influence (Baku Bay, Turkmenbashi Bay, water areas adjacent to Makhachkala, Fort Shevchenko, etc.);
• The Northern Caspian, which is a vast mixing zone of river and sea waters, is characterized by significant spatial gradients in the distribution of nutrients;
• in the Middle Caspian, the cyclonic nature of the circulation contributes to the upwelling of deep waters with a high content of nutrients into the overlying layers of the sea;
• in the deep water areas of the Middle and South Caspian, the vertical distribution of nutrients depends on the intensity of the convective mixing process, and their content increases with depth.

The dynamics of nutrient concentrations during the year in the Caspian Sea is influenced by such factors as seasonal fluctuations in the biogenic runoff into the sea, the seasonal ratio of production-destruction processes, the intensity of exchange between soil and water mass, ice conditions in winter in the Northern Caspian, the processes of winter vertical circulation in the deep sea areas.

In winter, a significant area of ​​the Northern Caspian is covered with ice, but biochemical processes are actively developing in the under-ice water and ice. The ice of the Northern Caspian, being a kind of accumulator of biogenic substances, transforms these substances entering the sea from and from the atmosphere.

As a result of the winter vertical circulation of waters in the deep-sea regions of the Middle and Southern Caspian in the cold season, the active layer of the sea is enriched with nutrients due to their supply from the underlying layers.

Spring for the waters of the North Caspian is characterized by a minimum content of phosphates, nitrites and silicon, which is explained by the spring outbreak of phytoplankton development (silicon is actively consumed by diatoms). High concentrations of ammonium and nitrate nitrogen, characteristic of the waters of a large area of ​​the Northern Caspian during floods, are due to intensive flushing by river waters.

In the spring season, in the area of ​​water exchange between the Northern and Middle Caspian in the subsurface layer, with the maximum oxygen content, the content of phosphates is minimal, which, in turn, indicates the activation of the photosynthesis process in this layer.

In the South Caspian, the distribution of nutrients in spring is basically similar to their distribution in the Middle Caspian.

In the summertime, the waters of the Northern Caspian reveal a redistribution of various forms of biogenic compounds. Here, the content of ammonium nitrogen and nitrates significantly decreases, while at the same time there is a slight increase in the concentrations of phosphates and nitrites and a rather significant increase in the concentration of silicon. In the Middle and South Caspian, the concentration of phosphates has decreased due to their consumption in the process of photosynthesis and the difficulty of water exchange with the deep water accumulation zone.

In autumn, in the Caspian Sea, due to the cessation of the activity of some types of phytoplankton, the content of phosphates and nitrates increases, and the concentration of silicon decreases, as an autumn outbreak of diatoms occurs.

Oil has been produced on the shelf of the Caspian Sea for more than 150 years.

Currently, large reserves of hydrocarbons are being developed on the Russian shelf, the resources of which on the Dagestan shelf are estimated at 425 million tons of oil equivalent (of which 132 million tons of oil and 78 billion m3 of gas), on the shelf of the Northern Caspian - 1 billion tons of oil .

In total, about 2 billion tons of oil have already been produced in the Caspian.

Losses of oil and products of its processing during extraction, transportation and use reach 2% of the total volume.

The main sources of pollutants, including oil products, entering the Caspian Sea are carry-over with river runoff, discharge of untreated industrial and agricultural effluents, domestic wastewater from cities and towns located on the coast, shipping, exploration and exploitation of oil and gas fields located at the bottom of the sea, transportation of oil by sea. 90% of pollutants with river runoff are concentrated in the Northern Caspian, industrial effluents are confined mainly to the area of ​​the Apsheron Peninsula, and increased oil pollution of the Southern Caspian is associated with oil production and oil exploration drilling, as well as active volcanic activity (mud) in zone of oil and gas bearing structures.

From the territory of Russia, about 55 thousand tons of oil products enter the Northern Caspian every year, including 35 thousand tons (65%) from the Volga River and 130 tons (2.5%) from the Terek and Sulak rivers.

The thickening of the film on the water surface up to 0.01 mm disrupts the processes of gas exchange and threatens the death of hydrobiota. Toxic for fish is the concentration of oil products 0.01 mg/l, for phytoplankton - 0.1 mg/l.

The development of oil and gas resources of the bottom of the Caspian Sea, the estimated reserves of which are estimated at 12–15 billion tons of standard fuel, will become the main factor in the anthropogenic load on the ecosystem of the sea in the coming decades.

Caspian autochthonous fauna. The total number of autochthons is 513 species or 43.8% of the entire fauna, which include herring, gobies, mollusks, etc.

arctic views. The total number of the Arctic group is 14 species and subspecies, or only 1.2% of the entire fauna of the Caspian (mysids, sea cockroach, white salmon, Caspian salmon, Caspian seal, etc.). The basis of the Arctic fauna is crustaceans (71.4%), which easily tolerate desalination and live at great depths of the Middle and South Caspian (from 200 to 700 m), since the lowest water temperatures (4.9– 5.9°C).

mediterranean views. These are 2 types of mollusks, needle-fish, etc. At the beginning of the 20s of our century, the mollusk mitilyastra penetrated here, later 2 types of shrimp (with mullets, during their acclimatization), 2 types of mullet and flounder. Some Mediterranean species entered the Caspian after the opening of the Volga-Don Canal. Mediterranean species play a significant role in the fish food base of the Caspian Sea.

Freshwater fauna (228 species). This group includes anadromous and semi-anadromous fish (sturgeon, salmon, pike, catfish, cyprinids, as well as rotifers).

sea ​​views. These are ciliates (386 forms), 2 species of foraminifera. There are especially many endemics among higher crustaceans (31 species), gastropod molluscs (74 species and subspecies), bivalve mollusks (28 species and subspecies) and fish (63 species and subspecies). The abundance of endemics in the Caspian Sea makes it one of the most unique brackish water bodies on the planet.

The Caspian Sea provides more than 80% of the world's sturgeon catch, most of which falls on the North Caspian.

To increase the catches of sturgeon, which dropped sharply during the years of sea level drop, a set of measures is being implemented. Among them - a complete ban on sturgeon fishing in the sea and its regulation in rivers, an increase in the scale of factory breeding of sturgeons.