THE BARENTS SEA 111 



fauna of the western Murman Peninsula was made by the author and his 

 collaborators (1945), while the eastern Murman was surveyed in 1939 by 

 N. Sokolova (1940), T. Gurjeva (1948) and T. Matveeva (1948). 



A difference in the length of its drying-out period, its temperature and 

 salinity oscillations, and finally, the variety of the littoral zone soils made it 

 possible for us to divide it fractionally into a system of horizons and zones. 



E. F. Gurjanova et al. (1928) gave a system of subdivisions for the cliffs 

 and the rocks of the littoral of the western Murman coast {Table 43). 



Table 43 

 Horizon Floor Form Depth, ft 



I 1 Lichens 4-1 



2 Pelvetta canaliculata 3-7 



II 1 \ (Littorina rudis \ (Fucus vesiculosus 3-4 



2 \ iBalamts balanoides\ I Ascophyllum nodosum 2-5 



3 J \Mytilus edulis J I Fucus inflatus 20 



\ Cladophora, Spangomor- 

 pha, Monostroma, Rho- 

 \dymenia 1 -3 



HI 1 Halosaccion, Ectocarpus, Pylatella 0-5 



2 Balanus crenatus crust-Lithothamnion 



The littoral and its fauna change considerably with the distance from the 

 open sea and the nature of the connection with it. This enables us to dis- 

 tinguish the following six main bionomic types* for the Murman littoral. 



(/) Open shore, exposed to heavy swell 



(2) Quiet bays situated near the open sea, but protected against the buffeting 

 of the waves 



(3) Narrow straits, protected against the swell, but washed by very strong 

 currents 



(4) Deep-cut gubas at some distance from the open sea, without any swell 

 or currents and with a somewhat lowered salinity 



(5) Gubas of greatly reduced salinity remote from the open sea, without 

 swell or current 



(6) Estuaries of low salinity and an absence of currents. 



Every bionomic type is characterized by its own peculiar composition and its 

 own distribution of organisms. Many littoral biocoenoses are found in all the 

 bionomic types, but they undergo definite changes in their vertical position, 

 in their composition and in the relative significance of their separate compo- 

 nents. 



In the seas of the Arctic basin, where for the greater part of the year float- 

 ing ice is piled up at the shores, life is very scarce in the littoral and the upper 



* A term introduced by de Beauchamp and Zachs in 1913 for a definite combination 

 of conditions of existence, determining the character of the biocoenoses. 



