— 191 — 
in the following years being noted on the same ordinates. A certain parallel may, it 
is true, be drawn, the rise in temperature in 1910—1912 being succeeded by a decrease 
in the quantity of liver m 1911— 
1913; on the other hand, the quantity 
of liver m 1911 and 1912 is seen to 
be relatively high, despite the fact 
that the temperature here, instead 
of being low, is high, (cf. 1903 and 
1904). No direct relation can there- 
fore be proved. 
»Fig. 120 shows the variations in 
extent of the coastal water area 
and in the yield of the sprat fishery 
. indifferent years. HELLAND-HANSEN 
and Nansen have suggested the 
existence of arelation between these 
two factors, on the basis of the 
curves for 1901—1905 (on the left 
of the figure). The conditions pre- 
Fig. 119. Mean temperature of Atlantic water. wailing in 1910—1912 cannot, how- 
---- Amount of liver in skrei (hl. pr. 1,000 fish). ever, in any way be made to fit 
(Drawn by LEA). in with this theory. Even dis- 
regarding the great increase in the 
yield of the fishery (here indicated by the height of the curve in 1910—1912 as compared 
with 1901—1905), the general direction of the two curves exhibits so little similarity 
that we find the “relation” between 
the yield of the fishery and the 
extent of the coastal water area 
1910—1912 exactly the reverse of 
that indicated for 1901—1905. 
Conclusions. 
»l) The hydrographical con- 
ditions at any one place can in the 
course of a very short time undergo 
great alteration. 
«2) Owing to these rapid 
changes, the details of any survey 
of hydrographical conditions as ex- 
pressed in a section can only be 190 002 105 10% 1 ie TI 
regarded as expressive of these rapid Fig. 120. Extent af coastal water area. 
Re - - - - Yield of sprat. 
variations. (Drawn by Lea). 
»3) Since however, the direction 
of the rapid changes referred to varies for the different points of observation, such a 
section will yet suffice to give a fairly representative view of the hydrographical con- 
ditions at the time of observation. 
