ir 
134 or 2 years of age are generally known as “bladsild’”, and have, as long as they bear 
this name, a length of 12—15 or 16cm. The largest of the “bladsild”, or those in the 
transition stage between these and the fat herrings, fish of 16—19cm. in length, are 
often used as “skjæresild” and form, as it were, a separate group, consisting partly of 
the larger 134 or two year fish, and partly of the smaller 234 or three year olds. 
We have seen, in Fig. 5, the sizes for the two groups of “kril”, and “bladsild” as 
taken in the seine hauls at Lofoten in March 1913. The former consisted for the most 
part of fish 8 or 9 cm. long; the latter being principally 13—14 em. in length. 
As noticed above, the growth of a new year does not commence until the end of 
April or beginning of May, and the whole growth for the year is completed in the course 
of some few months. During May or June, therefore, a great number of the then 14 
year old fish become “bladsild”, whereas others, of more retarded growth, are still to 
be reckoned as “kril”. In the course of the autumn, however, by far the greater part 
of the “kril” from the spring pass into the “bladsild” stage, while of the 2?/, year fish, 
a great number have gone over to the “fat herring”’ class, the lower size limit of which 
may be taken as about 19 cm. 
Thus the small herring consist of fish between 8 and 19cm. in length; a size cor- 
responding, for the most part, to the first two years of life. 
These two year classes, “kril’’ and “bladsild”, often move in separate shoals, each 
class keeping to itself, and often in shoals consisting only of these two classes together; 
now and again, however, either or both may be found together with the fat herring. 
Only exceptionally do they occur in shoals of full grown fish. As to the reason why 
these youngest year classes should thus move sometimes separately and at other times 
together, nothing is known. An elucidation of this problem in the natural history of 
the herring would be of value, also from a ‘practical point of view. 
The yield of the small herring fishery varies greatly. It amounted in 1904 to 107,000, 
in 1911 to 701,000 hectolitres. It is also generally observed that the size of the small 
herring varies from year to year, the yield one year consisting chiefly of “kril”, and the 
next mainly of “bladsild”. We shall return to this point later on. 
The fat herring and fishery for same. 
When the herring reach a size of 19 or 20 cm., large deposits of fat begin to form 
in the muscles and round the intestines. This is especially noticeable in summer and 
autumn, and the fish remain in this condition until the genital organs begin to develope, 
and the fish are nearing maturity. This adipose deposit is mostly observed in fish of 
19 to 26 or 27 cm., and fish of these sizes are therefore known as “fat herring’”. 
These fish vary greatly in size from year to year. This is very distinctly evident 
in three samples from Nordland, all taken with the seine in August, one in 1907, 
another in 1908, and the third in 1909. The following table shows the percentage in each 
sample of the different sizes, at centimetre intervals. 
wa a a Ba BA 2 20 ay 2a OS À) 
ln 10 MS RO MAA fe an al 
IOS 06 10e 8 9 9, 2% 2 8 6 2 1 il ins 
WO ee ae eo) on kL BO SOLO. OL) aI) ze ale Le) 
