Black Sea, an inland body of water between Asia Minor and Europe, bordered by Ukraine, Russia, Georgia, Turkey, Bulgaria, and Romania. In the north, the Black Sea is connected with the Sea of Azov by the Strait of Kerch. In the southwest, it discharges into the Mediterranean Sea through the Bosporus, the Sea of Marmara, and the Dardanelles. Except in the northwest, where the coast is a sandy lowland, the Black Sea is almost entirely bordered by mountains. Among them are the Caucasus and Pontic ranges. The Crimean peninsula juts far into the Black Sea in the north.
The Black Sea's greatest length (east-west) is about 710 miles (1,140 km) and its greatest width about 390 miles (630 km). It covers an area of approximately 163,000 square miles (422,000 km 2 ), slightly more than five times that of Lake Superior. The sea is shallow in the northwest; it reaches its greatest depth—about 7,254 feet (2,211 m)—off the coast of Turkey.
The Black Sea is about half as salty as the ocean, mainly because of substantial precipitation on the sea and a great inflow of river water. Virtually no plant and animal life exists deeper than about 400 feet (120 m) below the surface because the water contains insufficient oxygen to support most marine life. Surface currents in the sea run counterclockwise in two large spirals, one in the eastern part and one in the west. Tides are insignificant. Fogs and winter storms are frequent.
The Black Sea is virtually ice-free in winter and is important to the adjoining countries for shipping. Ports include Odessa and Sevastopol in Ukraine; Novorossiysk in Russia; Batumi in Georgia; Trabzon and Samsun in Turkey; Varna in Bulgaria; and Constana in Romania. The sea is also the site of important naval bases and supports commercial fishing. During the 1980's and early 1990's, however, overfishing and pollution severely damaged commercial fishing on the Black Sea. The Crimea has many seaside resorts.
In ancient times Greeks and Romans were among those who colonized areas on the Black Sea, named Pontus Euxinus by the Romans. By the fifth century A.D., the sea had come under the control of the Byzantines. After their empire fell to the Ottoman Turks in 1453, the Black Sea was virtually closed to the West. In the 18th century, Russia conquered most of the territory on the sea's northern shore. Russia's desire to gain control of the sea's outlet to the Mediterranean led to the Crimean War (1853–56) and continued to be an issue well into the 20th century. The Montreux Convention (1936) guaranteed access to the Black Sea for merchant shipping of all nations (except for those at war with Turkey) but placed various restrictions on the passage of warships into and out of the sea.