Black Sea–Caspian Steppe Yeya and Kuban Rivers became the Black Sea Host Territory. In 1794 some Don Cossacks settled on the great bend of the Kuban. The Terek Cossacks were pushed west and became the Caucasus Line Cossack Host. In 1825 Volga Cossacks arrived in the center. Further north Cossack and peasant settlements were mixed. in the northeast the Kalmyks retained most of their land while the Nogais were pushed southeast to land south of the Kalmyks in what is now the Nogai Raion of Dagestan. Sources can be found in the linked articles. Black Sea–Caspian Steppe The Black Sea-Caspian Steppe is an
Black Sea is a marginal sea and is the world's largest body of water with a meromictic basin. The deep waters do not mix with the upper layers of water that receive oxygen from the atmosphere. As a result, over 90% of the deeper Black Sea volume is anoxic water. The Black Sea's circulation patterns are primarily controlled by basin topography and fluvial inputs, which result in a strongly stratified vertical structure. Because of the extreme stratification, it is classified as a salt wedge estuary. The Black Sea only experiences water transfer with the Mediterranean Sea, so all inflow and outflow occurs