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



of the inlet are only slightly warmed. The floor of the fjord is covered by a 

 homogeneous bed — a very soft green-grey silt, with a few boulders. There 

 is no submarine barrier at the outlet of the gulf and the whole column of water 

 is very well aerated. Owing to the homegeneity of its bed and to the hydro- 

 logical conditions, the Sturfjord bottom fauna likewise is very varied. The 

 dominant forms are Astarte borealis, A. montagui, Macoma calcarea, Nucula 

 tenuis, Maldane sarsi, Ophioeten sericeum and Strongylocentrotus droebachien- 

 sis. Among the characteristic forms the following must be noted : Leda pernula, 

 Axinus fexuosus, Turitella reticulata, Amphiura sundevalli, Nephthys malm- 

 greni and Chaetozone setosa. 



Off the shore of the inlet lives the mollusc Portlandia arctica, probably in 

 large numbers, as if emphasizing the high Arctic character of the fjord. The 

 high Arctic Stegophiura nodosa is also found there. The number of bivalves 

 and the general biomass increase considerably as one moves deeper into the 

 fjord, the latter increasing from 126 g/m 2 (average for the outer part of the 

 fjord) to 468 g/m 2 (in its inner part) ; epifauna is markedly preponderant. 



At some individual stations a considerably higher biomass was encountered. 

 The presence of the community Onuphis conchylega, Pecten groenlandicus 

 and Area glacialis common in other parts of the Barents Sea is to be expected 

 here. It is difficult to say what factors condition the high benthos biomass in 

 Sturfjord and what are its main sources of nourishment under such severe 

 climatic conditions. 



For the sake of comparison one might mention the exceptionally high bio- 

 mass recorded in 1926 in the Mashigina Guba in Novaya Zemlya. Its climatic 

 conditions are also very severe and glaciers come right down to the waters 

 of the guba. The benthos biomass on the soft silt bottom was found to be 

 3,394 g/m 2 , consisting mostly of infauna. This is, probably, the highest infauna 

 biomass ever registered in the sea. It consists mainly of Saxicava arctica, 

 which here is one of the infauna components, Mya truncata and Cardium 

 cilia turn. 



Comparison of the Barents Sea bottom communities and those of other regions 

 of the North Atlantic. The Barents Sea biocoenoses are very similar in their 

 composition to those of Greenland waters. Almost identical groupings are 

 observed there. 



The bottom biocoenoses of Icelandic waters, while retaining a great simi- 

 larity with those of the Barents Sea, present a transition from Arctic groupings 

 to north-boreal ones. 



Although the bottom biocoenoses of the Faroe Islands produce a series 

 of typical forms like those of the Barents Sea, their general aspects are 

 different : Faroe waters are a place where the north-boreal species preponder- 

 ate markedly. Only littoral fauna retain their qualitative uniformity over all 

 the huge distance from the North Sea to the White Sea. 



A comparison of a number of forms of the highest biomass of the Barents 

 Sea and of that of other bodies of water of the northern Atlantic (Greenland, 

 Iceland, Faroe Islands) is of interest. 



As shown in this comparison (Table 66), the biomass indices of the Barents 



