GENERAL CHARACTERISTICS OF THE NORTHERN SEAS 



65 



The sublittoral fauna of the Arctic region, which differs fairly sharply from 

 the abyssal, may in its turn be divided into two sub-regions — the shallow, 

 lower Arctic one, including the Barents and White Seas (the White Sea- 

 Spitsbergen province of the Arctic region, according to Gurjanova), and the 

 shallow, high Arctic sub-region, including all the other seas of the Soviet 

 and American sectors (the Siberian province and the North American- 

 Greenland province of the Arctic region, according to E. Gurjanova). Again, 



Fig. 16. Zoogeographical zonation of the Arctic region (according to various investi- 

 gators). / Abyssal Arctic sub-region ; // Lower-Arctic, shallow sub-region ; HI High 

 Arctic, shallow sub-region ; Ilia Shallow marine province ; Illb Shallow brackish- 

 water province ; Ilia 1 Suberian region, Ilia 2 North American Greenland region. The 

 propagation of the boreal littoral fauna northwards and eastwards is marked by a 

 dotted line (Zenkevitch, 1947). 



as has been stated above, the littoral fauna and to a certain extent the fauna 

 of the upper level of the Murman sublittoral and that of the western part of 

 the White Sea has a distinctly boreal character. E. F. Gurjanova, I. Zachs and 

 P. Ushakov (1925) attributed a sub- Arctic nature to it; however, this littoral 

 fauna, changing but little, reaches the shores of Brittany. On the other hand 

 it is evident that in the Ice Age and the Yoldian stage the Murman and White 

 Sea littoral was in the same state as it is at present in the high Arctic regions, 

 i.e. it was practically absent and only later, with the rise of temperature, could 

 the littoral fauna move northward and eastward. The absence of littoral fauna 

 is, in fact, characteristic of the high Arctic. 



Movement far to the north and to the east is made possible for the boreal 



