TABLE 1. A DESCRIPTION OF THE MASSES OF WATER 

 OF VARIOUS ORIGINS OUNE OF 1954). 



•On the surface because of thawing ice, the salinity is 34.27^/oo 



3. Because the time of the development of plankton shifts vrtien moving from the shores of 

 Norway in a northern and north-westerly direction, the herring, when making feeding migrations, 

 have the opportunity, apparently, to be always approximately, under the same conditions that pre- 

 vail at tile beginning of the biological spring. 



By keeping somewhat ahead of tiie mass -development of phytoplankton (the "blooming"), the 

 herring have a chance, over the entire distance of the migration route, to feed on accumulations of 

 crustaceans that are preparing for reproduction. It must be said that in early spring the mature 

 Calanus is the largest and most nutritious food for herrings . 



Feeding upon comparatively large and fet crustaceans, the herring fatten quickly after win- 

 ter starvation. 



4. Young, immature herring and also those that spawned for the first time (21-28 cm.) in 

 the Norwegian Sea, as weU as the herring fry in the Barents Sea, feed upon the fat, pink, young 

 Calanus . Later they feed upon the red yoimg of Calaniis (Calanus flnmarchicus of the I-FV cope pod 

 stages). 



5. In June-July, the herring of tiie older age groups reach the boxmdaries of the polar waters 

 where they again meet the conditions of the beginning biological spring (spawning concentrations of 

 Calanus hyperboreus and the beginning of the development of jiiytoplankton) . 



6. In August - October, the feeding of the herring comes to an end. During this period, the 

 plankton is very pwor and consists of tiny Copepoda, v^ch are unfit as food for large herring. For 

 this reason, the composition and amount of plankton have no influence upon the distribution of the 



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