— a) — 
we notice the interesting fact that these years, 1911 and 1912 (as well as 1913) showed 
an unusually rich yield in the fishery off the coasts of Great Britain. (See Fig. 48, drawn 
from the statements of the English fishery statistics). The supposition that the year 
25 
20 
15 
me CG 0 Wo 07 (th OW WW À À 
Fig. 48. Landings of North Sea herring on the East Coast of England 
for the years 1902—1912. In millions of kg. 
classes 1907, 1908 and 1909, especially that of 1908, should have been particularty 
rich in the case of the Lowestoft material, is thus also confirmed by the results of 
the fishery. 
Occurrence of the rich year classes concurrent with rich yield in the fishe- 
ries (in 1911 and 1912). 
It would appear legitimate, from the foregoing, to draw the following conclusions: 
The Shetland stock contains a large admixture of fat herring, herring with genitals 
maturing, and partly spent fish. 
The fat herrmg immigrate into these waters in the summer, causing an alteration 
in the composition with regard to age. 
Spring samples (May—June) hardly furnish any accurate basis for conclusions as 
to the composition of the stock in summer. 
Future mvestigations should be directed towards a study of the seasonal variations, 
immigration and emigration. 
In spite of the necessity of extensive investigations, the material at hand would 
yet appear to indicate a basis for determination of the composition in point of age for 
the single year. Thus we found that there was a distinct difference in this respect bet- 
ween the years 1910, 1911 and 1912, this being occasioned by a great immigration of 
young fish in 1911 and 1912. This appearance of new year classes on the fishing grounds 
seems to have coincided with the increase noted in the fishery yield. 
A more detailed description of the whole of the available material as to composition 
