THE CASPIAN SEA 645 



The limit of saturation is reached at this last salinity. 

 If we take 26-24 per cent by weight as its present mean salinity, its com- 

 position will be the following : 



SO 2- ions represent 6-24 per cent by weight 

 Cl~ ions represent 11-89 per cent by weight 

 Mg 2+ ions represent 2-76 per cent by weight 

 Na + ions represent 5-35 per cent by weight 



The ratio Cl-/Mg 2+ is 4-31. 



The waters of the inlet contain about 17-88 milliard tons of salts, among 

 them 9-3 milliard tons of sodium chloride, 5-33 of magnesium sulphate and 

 2-8 of magnesium chloride. More than 8 milliard tons of mirabilite and other 

 salts were precipitated on the bottom of the Gulf of Karabugas in the winter 

 of 1949-50. 



In winter, when the temperature of the waters of the Gulf of Karabugas falls, 

 mirabilite (Glauber salt) is precipitated. The salinity of the Gulf of Karabugas 

 is now twenty times higher than that of the Caspian Sea. 



In 1897 the A. Spindler and N. Andrussov expedition discovered a mass of 

 Artemia salina in the inlet ; now owing to the rise of salinity this crustacean 

 has disappeared from the inlet ; only its eggs are found in large numbers on 

 the shores. Animal organisms are absent from the inlet; its waters, however, 

 are teeming with various representatives of microflora — algae and micro- 

 organisms. The alga Aphanothece salina, forming huge, slimy colonies off the 

 shores, and the Flagellates Dunaliella viridis and D. salina, with their profuse 

 flowering during the precipitation of Glauber salt, are the two mass forms. 

 There are, according to A. Pel'sh (1936), about 530,000 cells of Dunaliella 

 to a gramme of solid salt mass, and on the average 2 1 ,000,000 micro-organisms 

 to 1 cm 3 of the water of the Gulf of Karabugas. 



V. CONCLUSIONS 

 S. P. Brujevitch tries to draw a comparison of total biomass and production 

 of the whole body of water from the data on the numbers of the main com- 

 ponents of the fauna and flora of the Caspian Sea. This table cannot be 

 considered as very accurate, but the orders of quantities given for most of the 

 groups can be taken as more or less valid {Table 276). 



