GENERAL CHARACTERISTICS OF THE NORTHERN SEAS 39 



II. GENERAL CHARACTERISTICS OF THE FAUNA OF THE 

 EASTERN SECTOR OF THE ARCTIC BASIN 



Impoverishment of the fauna towards the north and east 



The farther one moves east from the southwestern parts of the Barents Sea, 

 the greater is the distance from the sphere of influence of the warm, saline 

 Atlantic waters and the poorer the quality of the flora and fauna. The flora 

 and fauna of the littoral and of the highest level of the sublittoral are parti- 

 cularly affected by this process of impoverishment. 



In the northern and eastern parts of the Barents Sea the littoral population 

 has almost vanished already. Only three or four of its hardiest representatives 

 (Fucus vesiculosus, Littorina rudis and Ba/anus balanoides) are found on the 

 seashore at low tide, and some species {Mytilus edulus, Fabricia sabella, 

 Balanus balanoides and others) have moved from the littoral into the sub- 

 littoral. These last remains of the littoral fauna are hardly ever found east of 

 Novaya Zemlya. The extreme ice conditions during the eight to nine winter 

 months are particularly destructive of the littoral fauna. 



Although the study of the bottom fauna of the Siberian seas has so far been 

 extremely inadequate, the quantitative and qualitative poverty of both flora 

 and fauna are beyond doubt. The impoverishment of the fauna is particularly 

 clearly marked as one travels eastward, comparing the Barents Sea with the 

 Laptev Sea. A comparison of the number of species of some basic groups is 

 given in Table 10. 



Table 10 



Approximate number of known species of fauna 

 Group groups in 



Barents Sea Kara Sea Laptev Sea 



Total bottom fauna about 1,300 about 1,200 about 500 



A. P. Andriashev (1954) has recorded 204 species and sub-species offish 

 in the northern seas of the u.s.s.r. from the Barents Sea to the Chukotsk Sea. 

 As one moves eastwards, the number of species and their composition for the 

 six families with the greatest number of species undergoes characteristic 

 changes {Table 11). 



Moreover, not only a qualitative impoverishment but also a considerable 

 admixture of brackish relict and fresh-water families, Salmonidae, Gadidae 

 and Cottidae, is characteristic of the Kara Sea and farther east. 



