Caspian Sea the east often changed course to empty into the Caspian through a now-desiccated riverbed called the Uzboy River, as did the Syr Darya farther north. The Caspian also has several small islands; they are primarily located in the north and have a collective land area of roughly . Adjacent to the North Caspian is the Caspian Depression, a low-lying region below sea level. The Central Asian steppes stretch across the northeast coast, while the Caucasus mountains hug the western shore. The biomes to both the north and east are characterized by cold, continental deserts. Conversely, the climate to the southwest
Caspian Sea The water level change within the Caspian Sea is an indirect reason for which plants may not get established. These affect aquatic plants of the Volga Delta, such as "Aldrovanda vesiculosa" and the native "Nelumbo caspica". About 11 plant species are found in the Samur River Delta, including the unique liana forests that date back to the Tertiary period. Reptiles native to the region include spur-thighed tortoise ("Testudo graeca buxtoni") and Horsfield's tortoise. The history of the Caspian sea is divided into two parts: a Miocene stage, determined by tectonic events that correlate with the closing of the Tethys Sea,