252 



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



than 1 to 3 g/m 2 . The biomass increases at lesser depths, and on the shallows 

 off the Yamal shores to 100 or 200 and at times even to 300 g/m 2 . 



The quantitative characteristics of the main biocoenoses is given in Fig. 

 108. 



Thus it is evident that the Kara Sea is really bioanisotropic. The almost 



Fig. 109. Distribution of benthos biomass in Kara Sea (g/m 3 ) (Filatova 

 and Zenkevitch). 



complete absence of fish within the area of brown muds (which might 

 justifiably be called the Ashless sea) is explained by the general lower productive 

 properties of this body of water and by the brown mud possessing conditions 

 unfavourable to fish-life. 



The benthos biomass of the Kara Sea brown mud is twenty times lower than 

 the average Barents Sea biomass ; the productivity difference, however, is still 

 more marked, since the processes of biological plankton production are almost 

 suspended for 8 to 9 months and as a consequence all the links of the food 

 chain are slackened. The lowering of productive properties of the Kara Sea 



