Sivash Sea (sēväsh') or Putrid Sea, Rus. Gniloye More, salt lagoon, c.1,000 sq mi (2,590 sq km), S Ukraine, extending along the northeastern coast of the Crimea. It is separated-except at the Genichesk Strait-from the Sea of Azov by the Arabat Tongue, a narrow sandspit c.70 mi (110 km) long; the Perekop Isthmus separates it from the Black Sea in the north. The sea is a complex system of shallow inlets, straits, and sandbars. The water, which has a salt content of up to 20%, has been the source of table salt and of several chemicals, including bromine.