THE WHITE SEA 



187 



On the other hand the lowered salinity of the White Sea hinders the pene- 

 tration of many forms, both Arctic and boreal, which are common in the 

 Barents Sea, and even in those parts of it immediately adjacent to the Gorlo of 

 the White Sea. 



In spring and at the beginning of summer the surface water is less saline in 



Fig. 81. Seasonal fluctuations of mean monthly surface salinity (3) and 



temperature (1), and of the bottom salinity (4) and temperature (2) in 



the open parts of the Kandalaksha Guba of the White Sea (Voronkov, 



Uralov and Chernovskaya). 



consequence of the melting of ice and of the inflow off the land of water from 

 melted ice. In winter it becomes more saline in consequence of the lessened 

 inflow off the land and of the formation of sea-ice, and the difference in 

 salinity at that season between the surface and the deep layers is only 2% . 

 In places where there is formation of ice on a large scale the water may be- 

 come still more saline and may slide down submerged slopes into the depths. 

 It is most probable that this is the way that partial aeration of the deep layer 

 takes place in winter. 



Щ In consequence of the big inflow of river water into the White Sea, and of 

 the difficulty of exchange of water with the Barents Sea, the salinity of the 



