382 



BIOLOGY OF THE SEAS OF THE U.S.S.R. 



Scientific Industrial Expedition, under the leadership of N. M. Knipovitch, 

 which worked for six years (1922-28), the expedition of the Hydrographic 

 Directorate, of the Sevastopol Biological Station and the Hydrological 

 Institute, under the leadership of Yu. M. Schokalsky and, finally, the expedi- 

 tions of the Hydrographic Directorate in the ship Hydrograph in 1932 and 

 1935. 



At present hydrological investigations of the Black Sea are being carried 

 out by the Sevastopol Biological Station of the Academy of Sciences of the 

 u.s.s.r., by the Karadag Biological Station of the Ukrainian Academy of 

 Sciences, by the Novorossiysk Biological Station of Rostov University, by 

 the Scientific Fisheries and Biological Station of Georgia, and by the 

 Azov-Black Sea Scientific Investigation Institute of Fisheries and Oceano- 

 graphy. 



III. PHYSICAL GEOGRAPHY AND HYDROLOGY 



Situation and size 



The Black Sea is situated between 46° 32-5' and 40° 55-5' N latitude and 

 between 27° 27' and 41° 42' E longitude. To the northeast the Black Sea is 

 connected with the Sea of Azov by the Kerch Strait and to the southwest with 

 the Sea of Marmora through the Bosporus. The greatest length of the Sea is 

 1,149 km. Its greatest width is 611 km. The Black Sea is characterized by the 



Fig. 183. Bottom topography of Black Sea (Archangelsky and 

 Strahov). 



absence of coastal features, by its small number of bays and inlets, by the 

 almost complete absence of islands and by its very steep shores (Fig. 183), 

 except for the northwestern part of the Sea (Karkinitsk Bay). The surface 

 of the Black Sea is 423,488 km 2 , its volume 537,000 km 3 , its greatest depth 

 2,245 m, its average depth 1,271 m. The 100 m isobath approaches the coast 

 almost everywhere, moving away from it only in the western, northeastern 

 and mainly in the northwestern part of the Sea. The angle of the floor dip is 

 usually 4° to 6°, but it often reaches 12° and even 14°. 



