Black Sea which are largely responsible for regional precipitation inputs and influence Mediterranean Sea Surface Temperatures (SST's). The relative strength of these systems also limits the amount of cold air arriving from northern regions during winter. Other influencing factors include the regional topography, as depressions and storms systems arriving from the Mediterranean are funneled through the low land around the Bosphorus, Pontic and Caucasus mountain ranges acting as wave guides, limiting the speed and paths of cyclones passing through the region. There are some islands in the Black sea that belong to Bulgaria, Romania, Turkey, and Ukraine: The Black Sea is connected
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,