Apart from migrations of a comparatively small nimiber of individual specimens from one 

 school to another, it is possible that the migration paths of different populations of herring became 

 displaced as a result of varying oceanographic conditions in different regions. The latter assump- 

 tion may be further confirmed by the results of tagging the cod, which complete regular annual 

 migrations between Iceland and Greenland. However, according to Taning, the extent of these 

 migrations fluctuates markedly. During certain years, only a small percentage of fish specimens 

 marked in Greenland were caught in Iceland - 5.9 per cent (1927), whereas during other years more 

 than half of them were recovered (54 per cent in 1931 and 72 per cent in 1933). In 1930-1933, sev- 

 eral specimens of cod marked in the Barents Sea were caught off the south-western coast of Norway 

 (11). E)uring the last few years, despite the large-scale tagging, we observed no migration of cod 

 from the Barents Sea to the southern shores of Norway (16). We attribute the latter circumstance 

 to the considerable warming of the north-eastern peripheries of the Atlantic --the Barents Sea in 

 particular- - during recent years . 



We have grounds to assume that the degree of isolation of different populations of Atlantic- 

 Scandinavian herring is less for abundant year classes, which are always propagated over larger 

 territorie s . 



The theory expressed by the Icelandic scientist Fridriksson (42), maintaining that the 

 spring school of Iceland herring is insignificant in dimensions, is scarcely credible. Fridriksson 

 assumes that, having completed several spawnings, the older herring of the Norwegian schools 

 migrate en masse to the region of Iceland and the Lofoten Islands . 



We think it more probable that herring of older age groups migrate from the region of the 

 Lofoten Islands to the south-western shores of Norway. 



There is no doubt that the migration of herring from Iceland to Norway takes place, but 

 this migration is probably small-scale. 



The insufficient information available on the subject matter prevents our discussing the 

 drift of herring fry hatched in the region of Viking Bank . It is n >t unlikely that the drift of fry from 

 the Viking Bank proceeds at a certain distance from the shores and that their further development 

 occurs in the open zones of the Norwegian Sea. This is the most significant gap in the data on 

 biology of Atlantic-Scandinavian herring and must be filled as soon as possible . 



In Icelandic waters we encounter herring of all stages of development - from early larvae 

 to the oldest age groups . However, the incomplete data on their biology complicate the task of 

 drawing a precise scheme of migrations . 



In the opinion of Fridriksson, the main bulk of large herring caugjit north of Iceland are 

 Norwegian spring herring arriving there for feeding purposes from the south-western shores of 

 Norway. Fridriksson regards the fact that the feeding grounds of large Norwegian herring are un- 

 known, as the most convincing argument in favor of his hypothesis . He wrote on that problem as 

 follows: "Norwegians do not know where their her 'ing spend Che summer, while Icelanders do not 

 know the spawning grounds of their schools . Both problems may be solved if we admit that the two 

 populations belong to the same school and if we assume that the herring from the northern coast 

 (of Iceland) spawn in Norwegian waters; we may thus explain the migrations of both the Icelandic 

 as well as the Norwegian herring" . 



Feeding of Atlantic -Scandinavian herring in the region of the polar front in the northern 

 zone of the Norwegian Sea and eastern half of the Greenland Sea is now beyond doubt. It has been 

 established throu^ investigations, and confirmed by the experience of the intensive Soviet fishing 



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