158 



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



within the whole habitat. Some forms are adapted to low temperatures, others 

 to higher ones; some live in shallow waters and others in the deep. 



Biomass, productivity, PI В coefficient. Quantitative study of the Barents Sea 

 fauna has made it possible to give an outline of the relationship between bio- 

 mass, productivity and PI В ratio for the main groups of organisms (Table 68). 



Table 68 



Group of 

 Organisms 



Biomass 

 tons 



Annual productivity, 

 tons 



Mean PI В 

 ratio 



Bacteria in water 



column 

 Bacteria in sea-bed 

 Phytoplankton 

 Phytobenthos 

 Zooplankton 

 Zoobenthos 

 Fish 



Sea animals 



1 million 



10 millions 



Some millions 



Some tens of millions 



140-150 millions 

 Some hundreds of 



millions 

 300-400 thousand 



Hundreds of millions 



? 



100-200 millions 

 Some tens of millions 



25-30 millions 

 Some millions 



Above 100 

 ? 



About 50 

 About 1 



J to* 



The biomass of the total area of the Barents Sea must be about 250 million 

 tons, or on average about 1 80 g per square metre of sea surface. 



Sea birds, which are of importance in the life of the sea in general and of 

 the Barents Sea in particular, should be included in Table 68. Unfortunately, 

 even rough data for the whole Barents Sea are not available at present. There 

 are only some data of G. Gorbunov (1925) and L. Portenko (1931) for the 

 western coasts of Novaya Zemlya, where there are large gatherings of birds. 



Guillemot (Uria lomvia lomvia) is the basic predominant species numbering 

 about 4 million in Novaya Zemlya. There are at least 600,000 on Pukhovy 

 Island alone, according to L. Portenko's calculations. 



The teeming waters of the Barents Sea off Novaya Zemlya offer abundant 

 food for all these birds, which consume small fish (caplin, pollack and others) 

 and large pelagic crustaceans (Euphausiacea and others) in amounts of over 

 a hundred thousand tons. These small fish and crustaceans likewise require 

 millions of tons of animal plankton, principally Euphausiacea, Calanus fin- 

 marchicus and its other planktons. 



Fish 



General composition. A. Andriashev (1954) distinguishes 144 species offish, of 

 52 families, in the Barents Sea. As one moves eastwards through the Barents 

 Sea the variety of fish species decreases rapidly and in the eastern part of the 

 Sea barely half this number is present. Some families of the Barents Sea fish 

 are represented by a variety of species such as the following: Gadidae (19 

 species), Pleuronectidae (9 species), Zoarcidae (14 species), Cottidae (12 

 species), Rajidae (7 species) and Salmonidae (7 species). Most families, how- 

 ever, are represented by one or two species. Herring and bass, so important 

 in fisheries, are among these latter. 



