l895 ^^O. 9- HVDR.-BIOL. STUDIES OF THE NORW. FISHERIES. 29 



salLneness of the surface was thus, near land, 11;^ 33.01 per 1000, on 

 the 28th Februar}- at IIu^ 33 92 per 1000, the 9th March at II4I, 

 33.63 per 1000. It can easily be imagined that these changes were due 

 to the Bank Water being set in motion by the hea\y gales in the 

 Spring Herring District. Previous to the 28th Februar}*, when the 

 salineness on the surface near the land was nearly 34 per 1000, thus 

 North Sea Water, unusually heavy \\"esterly Gales prevailed. For the 

 rest, the results of the combined investigations made during these months 

 (see Tables, Stations 140 to 170^ clearly indicate the large amount of 

 saline matter which was met with the whole time in the Spring Herring 

 District. The temperature was, likewise, \er}- high during the whole 

 period, variing, on the surface, from 4.30 to 5.2 0. The Winter was 

 unusually mild and the weather warm throughout. 



In the latter half of the month of March a great change took place 

 in the weather. From tliat time calm, fine weather prevailed daily for 

 several months, and in the month of April we find that a great change 

 occurred in the hydrographical conditions. 



By comparing the month of March with that of April, one will, 

 first and foremost, find that the saUneness of the sifrface sank from 

 about 34 per 1000, to 27 per 1000. thus a difference of no less than 7 

 per icxx). (See for instance PI. I, and Figs. 9 and io\ This difference 

 is not only observable on the surface but also in the depths. 

 From PI. I, Fig. 2; PI. I, Fig. 10, and PI. II, Fig. 3, it will be seen 

 that the paucit}- of the saline contents Jess than 32 per 1000' in April 

 extended to a depth of upwards of 50 mètres. The Baltic Current had, 

 therefore, then reached the Spring Herring District, and in the course 

 of 3 to 4 weeks had succeeded in forcing the Bank Water and that of 

 the North Sea 50 to 70 mètres down in the deep (and away from the 

 coast). The Bank Water at the same time became reduced to a thin 

 layer (or distributed in some other manner? even were it not of so little 

 a thickness as in the Summer PI. I, Fig. i . The month of April thus 

 forms a transition period from Spring to Summer, which is also indi- 

 cated by the close approach of the Atlantic Water to land in the Spring 

 Herring District. One finds 11^, the salineness, at a depth 0/260 mètres, 

 to be 3S--^ P^^ 1000, whilst in December, at about the same spot, it zvas 

 found to be but j4jo per 1000. 



The Temperature Conditions are of great importance The Baltic 

 Current conveyed, during April 1894, comparatively warm water. As 



» See Chart of Depths, II. 



