— 158 — 
1896. “This winter also, the skrei were small, very different, however, from last 
year’. 
1897. “Skrei larger and fatter than last year”. 
1898. “This winter, the skrei were everywhere large and fat. The richer the fishery 
the more even are the fish in size”. 
1899. “Roe about the same as last winter, liver larger, and general condition much 
better”. 
The curve for the years 1894—1899 should be compared with these statements. 
From 1881 to 1883, the reports are so vague that it is difficult to obtain definite 
information from them. In 1883, we find the complaint that the fish “often vary greatly 
from one day to another, even fish taken on the same day frequently showing very dif- 
ferent results. It is difficult to say what is the cause of this irregularity; the popular 
opinion however, that it is due to the arrival of different shoals on the ground, may be 
not far wrong. Thus at the commencement of the season, one day’s catch was reckoned 
at 900—1000 fish to the barrel’? —1. e. of liver — “while on the following day, only 6— 
700 fish were required to make up the same quantity. Some connection doubtless exists — 
between the smaller amount of liver and the smaller size of the fish. As to the reason 
of the irregular net fishery, it is possible that the mesh used is too large, so that not 
all the fish are held”, — etc. ete. 
In 1886, however, we find the following definite statement: “This year, the skrei, 
especially those taken m January and early February, were large, fat and in good con- 
dition; the generally expressed opinion was that such thoroughly fine fish had not been 
seen in Lofoten for many a year. After the middle of February, the fish were somewhat 
smaller, but still fine and fat’’. 
Thus we find, in these reports, a great deal of information as to the fluctuations 
of the fishery from year to year, or even within one and the same season. It will, however, 
here suffice to point out that the reports indicate, for the earlier years, a similar wave- 
movement to that which has been shown in the foregoing for the period 1903—1913. 
The periodical fluctuations, renewal and mortality of the skrei. 
Consideration of these movements at once suggests two questions: 
Firstly as to the cause or causes of the great difference in the numerical values of 
different year classes, in which each new wave originates. 
Secondly, as to the conditions which determine the length or duration of such in- 
crease. 
The first question cannot be dealt with until I have been able, in subsequent chap- 
ters, to set forth the whole of the material now at my disposal. The second, however, 
belongs naturally to the sphere of the present chapter. 
Longevity of the skrei. Mortality among the stock. 
If the increase in the weight of the skrei is due exclusively to the growth ‘of a single 
year class, and this class could be imagined to be isolated from the others, then it is 
evident that the increase in weight would depend upon the longevity of this one year 
class. Should there, on the other hand, be many year classes to be considered, no single 
