The Sea of Azov ( - Azovskoye more; - Azovs'ke more, ) is the world's shallowest sea, linked by the Strait of Kerch to the Black Sea to the south. It is bounded on the north by Ukraine, on the east by Russia and on the west by the Crimean peninsula. The Don River flows into it.

Geology and bathymetry

The sea is long and wide and has an area of . The main rivers flowing into it are the Don and Kuban; they ensure that the waters of the sea have comparatively low salinity and are almost fresh in places, and also bring in huge volumes of silt. To the west also lie the long Arabat Spit and the highly saline marshy inlets of the Sivash.

The Sea of Azov is the shallowest sea in the world with an average depth of and maximum depth of ; where silt has built up, such as the Gulf of Taganrog, the average depth is less than . The prevailing current in the sea is a counter-clockwise swirl. Salinity varies from 1 to 15 parts per thousand (compared to 30 to 40 for the oceans) across the sea and with season.

The shallowness and low salinity of the sea make it vulnerable to freezing during winter. Formation of sea ice can occur temporarily at any time from late December to mid-March. Under the present climate, the sea no longer freezes over, although during the 18th and 19th centuries and as far as the late 1970s, it was normally frozen over every year by early February.

The current name is popularly said to come from a Polovtsian prince named Azum or Asuf, who was killed defending a town in this region in 1067.

Hydrology and hydrochemistry

The current vertical profile of the Sea of Azov exhibits oxygenated surface waters and anoxic bottom waters, with the anoxic waters forming in a layer in thickness. The occurrence of the anoxic layer is attributed to seasonal eutrophication events associated with increased sedimantary input from the Don and Kuban Rivers. This sedimentary input stimulates biotic activity in the surfaces layers, which photosynthesize under aerobic conditions. Once expired, the dead organic matter sinks to the bottom of the sea where bacteria and microorganisms, using all available oxygen, consume the organic matter, leading to anoxic conditions. Studies have shown that in the Sea of Azov, the exact vertical structure is dependent on wind strength and sea surface temperature, but typically a 'stagnation zone' lies between the oxic and anoxic layers.
thumb|[[Great Cormorants on the Belosarayskaya Spit.]]

Fauna

Historically, the sea has had a rich variety of marine life, with over 80 fish and 300 invertebrate species identified. But diversity and numbers have been reduced by over-fishing and water-intense large-scale cultivation of cotton, causing increasing levels of pollution.

History

thumb|The Kerch peninsula
The Black Sea deluge theory dates the genesis of the Sea of Azov to 5600 BC, and there are traces of Neolithic settlement in the area now covered by it. In antiquity, it was known as Lake MæotisLordkipanidze, Otar (2000) Phasis: The River and City in Colchis Franz Steiner Verlag, Stuttgart, p. 25, ISBN 3-515-07271-3, the Maeotian Lake or the Maeotian Sea (Greek and Latin Palus Maeotis), after the tribe of Maeotae which inhabited the Maeotian marshes to the east from the sea.

Deluge theory

In 1997, William Ryan and Walter Pitman from Columbia University published a theory that a massive flood through the Bosporus occurred in ancient times. They claim that the Black and Caspian Seas were vast freshwater lakes, but then about 5600 BC, the Mediterranean spilled over a rocky sill at the Bosporus, creating the current communication between the Black and Mediterranean Seas. Subsequent work has been done both to support and to discredit this theory, and archaeologists still debate it. This has led some to associate this catastrophe with prehistoric flood myths.

Crimean War 1854-56

A naval campaign between the Allied navies of Britain and France against Russia took place in the Sea of Azov between May and November 1855. The British awarded a bar, 'Azoff', to the British Crimean War medal to commemorate the campaign.