There are five million lakes on Earth. They occupy 1.8% of the entire land area. The largest lake in the world in the world is known as the Caspian Sea. It attracts the attention of scientists and tourists from around the world.
Geographical position
To the question "which lake is the largest in area" the answer may be ambiguous. Among the possible options are called Upper, Victoria, Huron, but only the Caspian Sea can be the correct answer, called the sea only because of its historical origin and gigantic size.
The Caspian is located on the Eurasian continent at the junction of two parts of the world - Asia and Europe. The total area of this reservoir is 321 thousand square kilometers. In addition to water resources, these include islands (about 350 square kilometers) and the peninsula. The largest of them are Uch-Kosa (Dagestan), Tyub-Karagan (Kazakhstan), Ashur-Ada (Iran), Kur dashi (Azerbaijan) and others.
Five states have full access to the waters of the Caspian Sea. These are Russia, Azerbaijan, Iran, Kazakhstan and Turkmenistan. The longest coastline is about 2320 kilometers and belongs to the territory of Kazakhstan. For comparison: the Russian Federation has the shortest coastline among all countries — only 695 kilometers.
The sea coast is distinguished by its low position and smooth structure. The only place where you can meet the elevations is in the west. There, the coasts are quite winding.
The largest lake in area has no connection with the World Ocean, although about 130 rivers flow into it. The largest of them is the Russian Volga.
Along the eastern shores of the Caspian, there is the salt lake Kara-Bogaz-Gol, which was a sea lagoon with a small strait until 1980. Then a dam and dam were built there, but the lake began to dry quickly and the strait was returned to its place.
Cities such as Baku, Turkmenbashi (Krasnovodsk), Avaza, Aktau, Derbent sheltered the largest lake in Eurasia on its shores.
Physiography
The volume of the Caspian Sea is about 44% of the world's lake water reserves. Its area varies depending on the water level, which often changes, but averages 321,000 square kilometers.
The depth of the Caspian is completely uneven. In the north, the pond is very shallow and only four meters from the surface to the bottom. But there is also the South Caspian Depression, the lower point of which lies at around 1025 meters.
The water temperature is also different and depends on the territorial location. The warmest period for the Caspian begins in August, when the reservoir warms up to 26 ° C. However, in the south and in places of shallow water it can grow up to 32 ° C.
The largest lake in size is salt. But it has specifics, which allows water to differ in composition from oceanic. First of all, it is connected with continental drains. Rivers bring a large amount of calcium, carbonates and sulfates to the Caspian. Salinity increases from the mouth of the Volga to the southeast.
The bottom relief separates the North, Middle and South Caspian with the help of rapids (Mangyshlak, Absheron). Basically it is a muddy surface, shell sands and bedrock in some places (the deepest).
The climatic conditions of the Caspian Sea determine the continental, temperate and subtropical zones. Therefore, the lowest temperatures in this region stayed at -8 ° C, the highest + 26 ° C. A record of + 44 ° C in the south of the lake was also recorded.
Animal world
The Earth’s largest lake in comparison with other water bodies is not particularly rich in species, of which there are about 1800. Of these, only 101 species are fish. The Caspian Sea is the habitat of valuable commercial fish, including sturgeons. And although the Caspian is considered a shallow lake, its inhabitants are considerable in size. So, beluga fish reaches a length of 4 meters.
The largest lake in Eurasia is isolated from the oceans, so there you will not find mollusks, jellyfish, polyps, etc. typical of the sea. But this is a house for the Caspian seal (seal), which is on the verge of extinction. She waits for winter on the ice of the Northern Caspian, and in summer she can set off on a trip to the upper Volga or the Urals.
Vegetable world
A total of 728 species representing the flora inhabit the Caspian. The basis is algae and phytoplankton.
The flora of the Caspian Sea is fully consistent with its shallow nature. Of the flowering there grow only two representatives. This is a seaside and rupee. The second name of the seaside is sea grass. It is perennial, with long leaves of bright green color. The flower looks like an ear.
Ruppia loves brackish water, so it does not occur in fresh water. In appearance, this plant resembles an overgrown rhizome. Appears on the surface of the water only during flowering, preferring to rest at the bottom the rest of the time. Ruppia propagates vegetatively, as well as with the help of fish and birds, which eat its fruits.
Thus, the largest lake in the world does not differ in the richness of flora and fauna. To a greater extent, small populations are associated with the economic activities of people and the general environmental situation in the region.
Natural resources
The largest lake has large oil and gas reserves. The first attempts to develop deposits date back to 1820. It was then that the first well was drilled off the coast of Baku.
Half a century later, oil production was commercially available. Today, oil reserves in the Caspian Sea are estimated at ten million tons.
In addition to these two gold veins, the Caspian shares its reserves of salts, clay, sand and limestone.
Due to the presence of healing mud and mineral waters, the Caspian Sea has become a therapeutic relaxation area. However, it gained distribution only in Azerbaijan. Iran and Turkmenistan are somewhat isolated from the tourism business. And in Russia the competition of the Black Sea coast is too high .
The largest lake attracts the attention of fishermen. Almost 90% of the world fishing for sturgeon is mined here. Often illegal.
Environmental Safety
Ecological problems faced this region after the start of oil production. Well drilling, transportation of resources and much more threaten the marine environment with pollution and its partial change.
In November 2003, the Caspian littoral states signed the Framework Convention, which is designed to protect the Caspian Sea, protect its natural environment and monitor biological resources.
A particular problem is poaching, which reduces the population of fish and seals and does not allow for full legitimate prey.