GENERAL CHARACTERISTICS OF FAR EASTERN SEAS 



697 



there is ice in the northern part of the Tartary Strait. The ice is carried out 

 into the Ocean through the Kuril Straits and along the Kamchatka coast. 

 Large areas of the Okhotsk and Bering Seas are covered with ice for almost 

 eight months. As for the other seas of the u.s.s.R., this phenomenon is found 

 only in those off the Siberian coast. 



The salinity of the Far Eastern Seas (apart from on their littoral and in the 

 mouths of the rivers) does not exhibit pronounced fluctuations (P. Ushakov, 

 1953), but varies merely within the limits 31 to 33-5% (Fig. 331). The surface 

 waters of the northwestern part of the Sea of Okhotsk (the influence of the 



Fig. 335. Mean limit of floe-ice from March to June: 1 March; 2 April; 3 May; 



4 June (Ushakov, 1953). 



Amur) and of the Bay of Anadyr (the Anadyr River) have lost some of their 

 salinity. At a depth of 50 m their salinity varies within the limits 32-5 to 33% 

 and at a depth of 200 m within those of 33-25 to 33-50% (P. Ushakov, 1953). 



The salinity of the Sea of Japan is somewhat higher ; along the western 

 coast the salinity of the surface waters is below 34% , along the eastern coast 

 it is above 34% . With depth this difference disappears and the salinity rises to 

 34-5% . 



Vertical changes of temperature, salinity, and the contents of oxygen, 

 phosphorus and silicon over the 'shallows' of the Kuril-Kamchatka trench 

 are shown in Figs. 332 and 333. 



The oxygen conditions of the Okhotsk and Bering Seas are practically the 

 same as those of the adjacent parts of the Pacific. This is one of their most 

 characteristic peculiarities as 'inlets' of the Pacific. Their oxygen content 

 decreases gradually with depth, reaching only 10 per cent of saturation in the 



