were years when also a regular or uniform plankton production could be observed in the Barents 

 Sea as well as in the Greenland Sea (1951). 



^MW "^g/m^ 



%!"'' 



Figure 7 . Biomass of plankton in the 0-50 meter layer in the Spitsbergen (A) and the North 

 Cape (B) currents in various years . 



K. M. Deryugin (10) was the first to take notice of the asynchronism of the change in inten- 

 sity of the influx of Atlantic waters --with respect to the Barents Sea --along the separate streams 

 of the current . The asynchronism in the change of the intensity of the North Cape current and of 

 the eastern branch of the Norwegian current is also confirmed by hydrological observations made 

 in recent years. In this connection, the change in the intensity of the inflow of warm waters is 

 characteristic not only of the currents as a whole but also of separate branches of the afore- 

 mentioned currents . 



Some years, more warm water enters the westerii regions of th; Norwegian Sea and In 

 other years enters the eastern regions . 



It seems that the years when there is an abundant production of zooplankton in the Bear 

 Island-Spitsbergen region are distinguished by fevorable conditions for the feeding of herring in the 

 northern latitudes of the Greenland Sea. In connection with this, herring can penetrate far into the 

 north (e.g. in 1949) or enter the polar waters of the East Greenland current. This was observed in 

 1954. The regions where herring feed and fatten do not remain unchanged from year to year; for 

 they can shift to the north and to the south, so that the time arid the regions where fish feed are 

 closely related with the time of the plankton development. On the other hand, the development of 



121 



