THE SEA OF JAPAN 

 Table 312 



775 



Yoldiella derjugini, Yoldia beringiana, Propeamussium randolphi, Ruccinum 

 bryani; the echinoderms Leptychaster anomalus, Synalactes nozamai and 

 others). In the Sea of Japan the biomass also decreases markedly as depth 

 increases (O. Mokievsky, 1954) {Table 312). 



As can be seen from Table 312 the biomass decreases 1 ,300 times with depth 

 but the range of its fluctuations is considerably curtailed. 



K. Derjugin (1933, 1935, 1939) has observed the following characteristics 

 of the fauna (both plankton and benthos) of the great depths of the Sea of 

 Japan: qualitative and quantitative impoverishment, absence of typically 

 abyssal elements, and the sinking to unusual depths of members of the sub- 

 littoral and bathyal fauna. The plankton of the depths of the Sea of Japan 

 (K. Brodsky, 1941; M. Vinogradov, 1953) includes: Radiolaria of the 

 families Challengeridae and Aulospheridae ; the Siphonophora Dymophies 

 arctica ; the Ctenophora Beroe sp. ; the Copepoda Gaetanus minor, Gaidius bre- 

 vispinus, Eucalanus bungii, Pareuchaeta japonica, Calanus cristatus, C. tonsus 

 (plumchrus), Scolecithricella minor, Microcalanus pigmaeus, Metridia lucens 

 {pacified), Oncaeaborealis, Microsatella rosea; the Ostracoda Conchaecia spp. ; 

 the Amphipoda Primno macropa, Parathemisto japonica ; the Mysidae Metery- 

 throps microphthalma, and the Euphausiidae Euphausia pacifica, Thysanoessa 

 longipes, Th. inermis. A comparison between the zooplankton biomass of the 

 Sea of Japan and of the adjacent regions of the Pacific Ocean shows the con- 

 siderable poverty of the former {Table 313). 



M. Vinogradov had approached this problem differently (1959), following 



Table 313. Plankton biomass {mg/m z ) in the Sea of Japan {K. Brodsky, 1941) and in 

 the Kuril-Kamchatka trench {M. Vinogradov, 1954) 



