The Caspian Sea is the most enclosed body of water on Earth, which is ranked as both lakes (endless reservoir) and seas (due to its very large size). Located on the Eurasian continent. Its length approximately from north to south is 1200 km, width from west to east - from 195 to 435 km.
The length of the coastline is estimated at about 6500-6700 km, with islands up to 7000 km. The area is approximately 371 thousand rubles. sq. km, maximum depth - 1025 m. More than 130 rivers flow into the Caspian Sea, of which the largest are the Volga, Ural, Terek, Sulak, Samur. The natural resources of the sea include over 500 species of plants and 854 species of fish, of which about 30 are of commercial importance: beluga, stellate sturgeon, sterlet, pike perch, sturgeon (about 90% of the world's sturgeon reserves), etc.
The forecasted hydrocarbon resources of the Caspian (oil and gas) are estimated at 18 billion tons of standard fuel, proven reserves - up to 4 billion tons. It is the second largest volume of oil and gas after the Persian Gulf.
The main pollution of the sea is undoubtedly oil. Oil pollution suppresses the development of phytobenthos and phytoplankton of the Caspian Sea, represented by blue-green and diatom algae,
reduce oxygen production and accumulate in bottom sediments. The increase also negatively affects the heat, gas, moisture exchange between the water atmosphere and the atmosphere. Due to the spread over large areas of the oil film, the evaporation rate decreases several times.