THE WHITE SEA 



211 



Here there are many different representatives of the poriferae, bryozoans, poly- 

 chaetes, crustaceans, echinoderms, ascidians and molluscs, some living on the 

 sea-weeds themselves, some on the rocks, some on the sea-bed which here is 

 usually mud. ' 



In the inner parts of the Inlet the red algae Phyllophora flourishes luxu- 

 riantly, at a depth of 6 to 22 m on the muddy sea-bed, and is accompanied 

 by its community of animal forms with average biomass of 29 g/m 2 . The pre- 

 dominant form is Ophiura robusta. Of the polychaetes Scoloplos armiger, 

 Nephthys minuta and Myriochele oculata predominate; sometimes ascidians 



Fig. 90. Chart of Gulf of Kandalaksha 



including Rugozerskaya Inlet. 1 Bab'e More; 



2 Site of White Sea Biological Station of 



Moscow University; 3 Velikiye Is. 



are found in great numbers; most characteristic among the molluscs are 

 Astarte elliptica, Cardium ciliatum and Axinus flexuosus. Rather deeper (20 

 to 30 m) colonies of Portlandia arctica are encountered in combination with 

 Leda pernula, Myriochele oculata, Yoldia hyperborea, Pectinaria hyperborea 

 and Maldanidae. This community, which has a biomass of 25 g/m 2 , is in 

 composition very like the communities on mud bottoms of the lower level of 

 the sublittoral, but it is characteristic of it that Portlandia exists here for a 

 considerable period of the year at a temperature above zero, and is separated 

 from the population which inhabits the deep part of the White Sea. 



The lower division of the sublittoral (45 to 150 m) is characterized by the 

 great predominance of spacious areas of mud bottom, with only an occasional 

 rock, which are inhabited by red algae of various forms (Ptilota, Odonthalia, 

 Delesseria, Ahnfeltia, Polysiphonia and others). On these last there develops 



