counter the simultaneous production of phytoplankton and zooplankton. In these regions, which 

 have sharp temperature gradients, solid herring concentrations are quite often encountered, re- 

 gardless of the abundance of phytoplankton. 



There the herring usually stay at a depth of 20-40 m. The captains of fishing boats fish 

 these schools successfully by using nets with long lines. But also here the herring do not enter far 

 into the region engulfed by the "green blooming", since there is almost always less plankton in the 

 center of the "blooming". 



The formation of herring concentrations in the region of the polar front is usually facilitated 

 by a good herring food yield there (up to 9000 mg/j„3). This production is a result of the simulta- 

 neous development of several populations of mass species of planktonic organisms that usually 

 characterize the various biological seasons such as: spawning Calanus finmarchlcus of the VI 

 copepod stage, young Calanus finmarchicus of the I-II-III-IV stages, mature spiecimens and young 

 of Calanus hyperboreus , young of Themisto abyssorum and Themlsto libellula , Pseudocalanus elon- 

 gatus, the young of Euphausiacea, and others. This varied plankton is encountered at various 

 levels in the water in the Faroes and Jan Mayen regions . During the entire month of June, the sur- 

 face layers are replenished by crustaceans that rise to the surface for spawning and also by those 

 that were carried there from more southern regions. Here phytoplankton often develops on the 

 surface and the herring feed at a depth of 20-40 m. upon the concentrations of Calanus hyperboreus 

 and Calanus finmarchicus of the IV-V stages . 



The vernal biological processes spread gradually also to the polar waters . The herring 

 also leave for the polar waters . Towards the beginning of the abundant production of phytoplankton 

 in the waters of the East Greenland current (latter part of July-August) the herring finish their 

 feeding, turn south and enter the Atlantic waters, where the production of diatoms is almost finish- 

 ed. Only in patches do peridineans appear. 



Thus our observations indicate that the relation of herring to the "blooming" must be stud- 

 ied, bearing in mind the season, and, of necessity, link it with the peculiarities of the hydrological 

 conditions of the region that is being studied. 



Herring of the older age groups usually begin their feeding migrations prior to the mass 

 production of phytoplankton, i.e. at the very beginning of the biological spring, and move northward 

 while feeding upon the spawning accumulations of Calanus along the route . The herring, so it 

 seems, move away from the "green blooming" ( Phaeocystis ). 



Young herring, those spawning for the first time or still immature, begin feeding somewhat 

 later and move along the migration routes after the "blooming" while feeding upon the fry of Calan- 

 us . 



Their relation to the "blooming" is the same as that of Murmansk herring: they do not form 

 concentrations in the "blooming" but they can feed at some depths below the "blooming" (Manteyfel', 

 1941). 



Thus, on the basis of the observations of the production of phytoplankton and the distribution 

 of herring, which were conducted by us in 1953, the following can be stated: 



1 . Concentrations of large herring, as a rule, are not observed in the eastern and central 

 regions of the Norwegian Sea during the mass production of Phaeocystis (of the "green blooming") 

 since the herring of older age groups finish their spawning prior to the start of phytoplankton devel- 

 opment. From the spawning grounds, the herring go northward. They start to feed or fatten upon 



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