classes obtained during different years, all year classes of which provided the fishing industry 

 with similar indices of catches that amounted to 4.2-5.2 billion specimens, we obtJiin the figures 

 presented in Table 8 . 



The 1904 year class yielded considerable catches for 10 years. Fishing the 1918 year class 

 continued over approximately the same period of time; however, the amount of herring caught 

 during the first five years of commercial exploitation was considerably greater than during the 

 subsequent period. The 1930 year class was fished heavily for 7 years; a particularly great number 

 of herring of that year class were caught at the age of 6-8 years . The above data show that the 

 rate of exploitation of individual year classes increased during recent years and year classes of 

 approximately equal abimdance are now thoroughly exploited by fishing within shorter periods of 

 time. In view of the aforesaid, the number of the oldest specimens in a stock has decreased. In 

 our opinion, herring of the 1904 year class prevailed in catches over such a protracted period of 

 time not only because of its great abundance, but also because of the low fishing intensity during 

 that period . 



The slight drop in the number of the oldest specimens in the spawning population of 

 Norwegian herring observed after the thirties is quite normal, since at the beginning of our cen- 

 tury the stock of Atlantic-Scandinavian herring were actually still Intact. We may state that the 

 effect of fishing conducted over the course of several decades produced no drastic changes in the 

 structure of the spawning population of the Norwegian stock. At the beginning of our century, as 

 well as now, the spawning population is represented by a great number of different age groups, 

 which contribute to the preservation of a high and stable reproductive ability of the race. 



In our opinion, the development of fishing on adult herring cannot seriously affect as yet 

 the stock of Atlantic-Scandinavian herring, since to catch an additional million of centners of large 

 herring we need eliminate only 300-350 million specimens. 



However, we think that the fishing of young herring conducted by Norway affects the stocks 

 of herring In an altogether different manner. The main bulk of young Atlantic-Scandinavian herring 



of the Norwegian school populate coastal waters, directly offshore, where they are easily accessi- 

 ble to fishermen. 



In the past, when the fishing of Atlantic -Scandinavian herring was still little developed, 

 elimination of several hundreds of thousands of centners of young herring a year was fundamentally 

 unimportant. In that respect, we fully share the viewpoint of Lea (40). At the present time, how- 

 ever, the fishing intensity has greatly Increased, and the fishing industry aims at obtaining maxi- 

 mum catches of Atlantic-Scandinavian herring. Under such conditions, the elimination of a great 

 nimiber of young fish will affect In one way or another the overall potential herring catch. There- 

 fore, the problem of fishing young herring must be subjected to very serious investigations . 



Only a few years ago, it seemed that Norway decided to stop fishing for small herring, 

 while intensively developing the fishing of large herring. The catches of young herring obtained 

 during five years, i.e. from 1946 to 1950, amounted to 4 million centners, i.e. constituted 0.7-0.8 

 million centner a year . These figures amounted to approximately half the annual young herring 

 catches recorded in the thirties . This undertaking appeared quite rational, since Norway itself, 

 more than any other country, should be concerned about rational exploitation of the stock of Atlantic- 

 Scandinavian herring. However, in 1951, the catches of young herring increased again and were 

 over 2 million centners in 1951; in 1952, about 3.0 million centners; in 1953, to 1.5 million centners, 

 and, in 1954, over 2 million centners. The overall catches for the 4 years were equal to approx- 

 imately 8.5 million centners, i.e. twice the amount caught in the course of the preceding five years. 



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