Figure 4. --Quantity of Calanus cristatus in the 0-200 m. layer 

 in August-October 1954. 1 - 0-0. 25 per m.^; 2 - 0.25-0.5 

 per m.3; 3 - 0.5-1.0 per m.^; 4 - more than 1 per m.'. 



WO 



\ 500 



i 



BDOmUm'' 



Figure 5. --Vertical distribution of the zooplankton 

 biomass at one of the stations in the region of 

 the Kurile-Kamchatka Trench. 



shows the impoverishment of the levels corres- 

 ponding to the cold intermediate layer and the 

 abrupt enrichment of the 180-300 m. layer 

 which lies below it (fig. 5). 



The nnore strongly marked the cold inter- 

 mediate layer is, the poorer it is in plankton. 

 The correlation between the sharpness of the 

 cold intermediate layer and the amount of 



12 



