served in 1953-54. The individual indices for the different stages of maturity show considerable 

 fluctuations . 



TABLE 9. NUTRITIONAL CONDITION FACTOR FOR HERRINGS IN DIFFERENT 

 MONTHS (OBSERVATIONS MADE IN 1954 AND 1955). 



Development of the herring gonads is the final stage in the feeding period. 



From a comparison of the individual factors - feeding rate, fatness, weight and maturity 

 of the gonads, shown in Figure 6, we conclude that they are all closely interrelated and that they 

 determine the physiological condition of the herring. 



Conclusions 



1. The physiological condition of the herring is determined to a large extent by its season- 

 al distribution. During the winter, pre -spawning schools of herring concentrate in the south- 

 western part of the Norwegian Sea, near the spawning grounds. The majority of Atlantic -Scandin- 

 avian herring spawn during February and March. 



During the spring, in an exhausted condition after spawning, the herring begins to feed 

 actively, and its distribution also depends on the accumulation of plankton. In the summer, the 

 herring continues its migration in search of food, travelling to northern latitudes with the warm 

 Norwegian current. During the summer-autumn period, after it has finished feeding, the herring 

 forms into groups and begins to leave the northern feeding grounds for its winter quarters and 

 spawning grounds . 



2. The food of the Atlantic -Scandinavian herring consists of 39 species of plankton organ- 

 isms belonging to the following orders: Cop)epoda, Cladocera, Cirripiedia, Amphipoda ( Themisto ), 

 Euphausiacea, MoUusca, Vermes, Apjjendicularia and young fish, but the principal of these are 

 Euphausiacea ( Meganyctiphanes norvegica and the genus Thysanoessa ), Coj)eiX)da ( Calanus ) and 



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