Caspian Sea
The Caspian Sea, like the Black Sea, Namak Lake, and Lake Urmia, is a remnant of the ancient Paratethys Sea. It became landlocked about 5.5 million years ago due to tectonic uplift and a fall in sea level. During warm and dry climatic periods, the landlocked sea almost dried up, depositing evaporitic sediments like halite that were covered by wind-blown deposits and were sealed off as an evaporite sink when cool, wet climates refilled the basin. (Comparable evaporite beds underlie the Mediterranean.) Due to the current inflow of fresh water, the Caspian Sea is a freshwater lake in its northern portions, and is most saline on the Iranian shore, where the catchment basin contributes little flow. Currently, the mean salinity of the Caspian is one third that of Earth's oceans. The Garabogazköl embayment, which dried up when water flow from the main body of the Caspian was blocked in the 1980s but has since been restored, routinely exceeds oceanic salinity by a factor of 10.
Caspian turtle
"Mauremys caspica" occurs in large numbers in almost any permanent freshwater body within its range. It also lives in irrigation canals and is quite tolerant of brackish water. The turtles at one Iraq site lacked the ability to swim. Instead, they would crawl out of the water periodically to breathe and then slide back in again. A captive from there could not be induced to swim. Reed thought this behavior to be an adaptation to the extreme variability in the supply of surface water in the area.