— 156 — 
between the Finmark fish and the skrei appears to support the hypothesis stated above. 
Moreover, both measurements and age determinations are fortunately available for the 
skrei in the years 1906 and 1907. These figures, which form the most important part 
of the material at our disposal here, are given below. 
Composition in point of size, for skrei 1906 and 1907. 
50-54 55-59 60-64 65-69 70-74 75-79 80-84 85-89 90-94 95-99 
OO GR EEE a i Bee AE) Sano) Pel ABB) Be Bal 
OUT a. OS OO OF) ME 10,8 2b a Ie Gh 227 
Composition in point of age for skrei 1906 and 1907. 
1902 1901 1900 1899 1898 1897 1896 1895 1894 1893 
dcs 50 je 05 CO BL SL LOD 
1907. OO Of Is 195 450 220 Ge LA 
It is immediately noticeable that m both of these years, there are scarcely any fish 
under 65 cm. (1/, % for the two years in average) or even under 70 cm. (2.8 % for both 
years in average). In contrast to this, the skrei sample from Svendsgrunden in 1903 
showed 46.8 % under 65cm. In like manner, the figures for 1906 show none under 7 years 
old, for 1907, only 2.8 % under 8 years. This proves that only a very slight immigration 
of young skrei took place in these years, and it is easy then to understand that the 
size must have increased, the same fish of the same year classes constantly growing older. 
The two most numerously represented year classes, both in 1906 and 1907 are those 
of 1898 and 1897; these fish were 
m NEM 22000 3 and 4 years old 
D END aa A OY, » 
) IND er OD & @ » 
and must, with the 1896 year class, have furnished the greater part of the additions 
to the skrei stock during the period under discussion. 
Periodical variations in the average size of the skrei. 
It must thus be certain that the stock of cod has certain periods of renewal, and other 
periods with but slight addition of young fish. As the loddefisk are recruited from 
the small fish, so the former in turn send batches to join the skrei, as soon as a new and 
rich year class has reached the age at which the fish can pass from one group to the other. 
The periods of renewal of the shoals are distinguished by a decrease in the average size. 
When the immigration of young fish is slight, the average size increases with the growth of 
the individuals. There will thus arise a fluctuation im size of the the stock, with periods 
of increase and of decrease. 
The fishery authorities endeavour each year to calculate the average weight of the 
Lofoten skrei, and it is interesting, in this connection, to examine these averages for 
a considerable period of years. 
Fig. 99 shows these averages furnished by the fishery authorities (average gutted 
weight) for the years 1882— 1912. It will be noticed that the line joining the different 
