Caspian Sea
The sea has a surface area of 371,000 km (143,200 sq mi) (not including the detached lagoon of Garabogazköl) and a volume of 78,200 km(18,800 cu mi). It has a salinity of approximately 1.2% (12 g/l), about a third of the salinity of most seawater.
Caspian Depression
The southern region of the depression, or the north coast of the Caspian Sea, is characterized by large development of damp sites resulting from tidal phenomena. The depression is also home to a large number of insect species, with several thousand different species likely living in the region around the Caspian Sea. Studies have shown that water pollution, mostly coming from the Volga River, poses a serious threat to the biodiversity of the Caspian Depression. Water pollution is contributed mainly by industrial, agricultural, and household discharges.