106 BIOLOGY OF THE SEAS OF THE U.S.S.R. 



fish consume another like amount, the total annual requirement in plankton 

 would be, probably, of the order of some thousands of millions of tons. 

 Hence the amount of animal plankton in the Barents Sea cannot be con- 

 sidered inexhaustible. On the contrary, Calanus and Euphausiacea in parti- 

 cular might greatly decrease in numbers over large areas of the sea, being 

 eaten by fish, Coelenterata and others. 



Benthos 



Qualitative composition of phytobenthos, The bottom macrophytes (phyto- 

 benthos) form a wide belt round the southern shores of the Barents Sea. 

 The qualitative composition of the macrophytes has been established mainly 

 by the survey of Kjellman (1877), E. S. Sinova (1914, 1923), B. Flerov and 

 Karsakova (1932) and at present it seems to be as given in Table 39. 



* According to A. D. Zinova (1950) 177 species of brown and red algae inhabit the 

 Barents Sea. 



The vertical quantitative distribution of algae off the Murman coast was 

 carefully investigated by M. Kireeva and T. Shchapova (1932) (Fig. 41). Of 

 the 172 forms not more than 20 have the significance of mass forms, the 

 others play a secondary role as regards numbers. 



The littoral zone of the Barents Sea, owing to the predominance of craggy 

 steep shores, is usually narrow. Only in the depths of the gubas are there 

 some more or less considerable areas which dry out with a slight slope to the 

 bottom and are covered with silty sand. On the west of the Murman coast the 

 difference between high and low water is about 4T7 m. The tidal range de- 

 creases as one moves east and north. On the western side of Novaya Zemlya 

 and in the northern parts of the Barents Sea it is no more than 2 to 3 ft. On 

 the other hand, in the Voronka region and especially near the Gorlo of the 

 White Sea, the tidal range increases sharply: at Iokanga up to 6 m, at the 

 Gorlo to 8-5 m. 



The zonal distribution of the littoral algae is given also in the tables below. 

 Among the macrophytes the most important, quantitatively, are Pelvetia, 

 three species of fuci (F. vesiculosus, F. inflatus, F. serratus), Ascophyllum, 

 Chorda ; two species of Laminaria (L. saccharina, L. digitata), Dictyosiphon, 

 Desmarestia and Pylaiella among the brown ones ; two species of Cladophora, 

 two species of Enterimorpha and two species of Monostroma among the 



