214 



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



communities of the Bab'e Sea, which is separated from the rest of the Sea by 

 the western side of Velikiye Islands (Gulf of Kandalaksha). The fairly large 

 (9x13 km) and comparatively shallow (down to 39 m) Bab'e Sea is connected 

 with the White Sea by two narrow and very shallow passes (Fig. 90). Below 

 15 m the circulation is slack, the oxygen content is low (about 50 per cent), 

 low temperature is permanent (below 20 m it is below zero), while its salinity 

 is comparatively high (close to 27% ). 



The whole of the shallow part of the Bab'e Sea down to 4 to 6 m is covered 

 with Zostera fields. Macoma baltica, Mya arenaria, Arenicola marina, Littorina 

 littorea, L. rudis and other typical inhabitants of the littoral come down here 

 from it. Asterias rubens grows here in huge numbers. Sublittoral forms like 



Fig. 91. Bottom biocoenoses of Rugozerskaya Inlet and their dominant 

 forms (Brotzky and Zhdanova and Semenova): 1 Leda permtla, Yoldia 

 hyperborea, Astarte montagui; 2 Portlandia arctica, Leda permda, Asterias 

 lincki; 3 Astarte montagui, Leda permda, Ophiocantha bidentata; 4 Astarte 

 borealis, Yoldia hyperborea, Leda permda; 5 Portlandia arctica, Yoldia 

 hyperborea, Pectinaria hyperborea; 6 Mesidothea en to топ, Macoma 



baltica. 



Macoma calcarea, Ophiura robusta etc. become predominant in the lower 

 parts of this level. 



From 7 m downwards Zostera is replaced by red algae, mainly Phyllo- 

 phora, with a small admixture of Laminaria. Like the Zostera, Phyllophora 

 encircles the whole of the Bab'e Sea, extending to a depth of 1 5 m. Ophiura 

 robusta is a dominant animal form in this Sea, among the rest the following 

 should be noted : the ascidian Boltenia echinata ; the molluscs : Astarte ellip- 

 tica, Saxicava arctica, Macoma calcarea ; the echinoderms : Ophiura nodosa, 

 Ophiopholis aculeata, Asterias rubens, Cribrella sanguinolenta etc. ; the 

 polychaetes : Harmothoe imbricata and H. nodosa ; and the crustaceans. 



This zone is the feeding ground of large numbers of cod. 



Below 1 5 m the growth of red algae is cut off abruptly and the algae are 

 replaced by a Portlandia arctica community; a definite impoverishment in 

 forms takes place. The population consists of the following forms : the mol- 

 luscs Macoma calcarea, Astarte elliptica, Saxicava arctica Pandora glacialis, 



