— 183 — 
Later observations as to the theories of Helland-Hansen and Nansen. 
Theories and conclusions such as these very naturally aroused the greatest atten- 
tion and interest. 
such to all appearence complicated biological 
and human phenomena as the fluctuations in 
the yield of the fishery should have their origin 
in the simplest physical causes. On the other 
hand, it was by no means easy to refute the 
theories in question, since the task of showing 
them false was apparently no less difficult than 
that of proving them true. Despite the fact 
that many points long since acknowledged in the 
fishing industry were in direct opposition to the 
theories now put forward, I endeavoured, for 
my own part, during the following years, to 
continue and extend the investigations before 
coming to any conclusion as to the hypotheses 
which HELLAND-HANSEN and NANSEN had built 
upon the material collected by the Norwegian 
fishery investigations. 
On the one hand, it would seem nothing short of marvellous that 
Z /90! /302 1903 1909 1905 
Z-IE /902 1903 1904 1905 1906 
Fig. 114. I. The mean temperature of the 
intermediate Atlantic water in the Sogne- 
fjord Section, in May. 
Il. The mean air-temperature at noon, ob- 
served at Svolver, in Lofoten, during the 
fishing season. 
Ill. The number of Cod (in millions) 
caught before March, 15. 
IV. The percentage of Cod caught before 
March 15, in proportion to the total 
In the following pages, I will endeavour to 
quantity of the whole season. 
make clear my own opinion on the matter; it 
may, however, be as well to glance for a moment 
at the fluctuations in the fishery itself, first as regards the quantity, and secondly the 
quality of the fish. 
Varying yield of the cod fishery; quantity, 
The first supposition or basis of HELLAND-HaNsEN and NanseEn’s theory was, that 
a rich yield of roe in the Lofoten fishery was followed by a good yield of fish in Lofoten 
seven years later, and in Finmarken five. We have now, in the previous chapters, seen 
how the fluctuations in the yield of the cod and herring fishery exactly coincide with 
those in the numerical value of the year classes, some of these being richer than others, 
and thus occasioning an augmented yield in the years in which they are chiefly taken. 
It would therefore be natural to glance at the conditions prevailing in Lofoten as regards 
the quantity of roe during the years in which the richest year classes were spawned; 
in the case of the cod, especially the years 1903 and 1904. 
The fishery statistics give the following statements. 
Quantity of roe No. of hectolitres of roe 
Year (in 1,000 hectolitres) per 1,000 fish 
On 16.6 1.41 
TODE 13.7 1.12 
II een es 10.5 0.85 
NO OAS ee 8.1 0.79 
HOOD Serpette: 15,7 1.16 
