438 SOME RESULTS OF THE INTERNATIONAL FISHERY INVESTIGATIONS. 



numerous researches, and the discussion of the results obtained in 

 relation to each other, must be a task of considerable difficulty, and 

 indeed cannot properly be undertaken until the conclusion of the series 

 of investigations. It is most necessary that the reader should bear 

 this in mind in following the present account of the International 

 Fishery Investigations. 



The International Fishery researches fall under three main categories: 



(1) the hydrographic work, which deals with physical investigation on 

 the constitution ami movements of the water in our northern seas ; 



(2) the purely biological work both strictly zoological and bionomical ; 

 and (3) fishery investigations consisting of the fishery experiments 

 involving the use of conmiercial and research fishing gear, and of 

 statistical studies. I will take these main lines of research in the 

 above order. 



The Hydrographical Investigations. 



I think it necessary to give a very short account of the topography 

 of the sea bottom in the area under investigation, though our know- 

 ledge of this was obtained previous to the inception of the International 

 Fisheries work, and has not been materially changed in the course of 

 this. It is well known that the British Isles are situated on a sub- 

 marine plateau which forms part of the European " Continental Shelf." 

 If an imaginary line be drawn in this area so as to connect all points 

 where the sea is 100 fathoms in depth, it will be found that the British 

 Islands are included within it. Such a line will enclose an area which 

 includes a considerable portion of the Atlantic to the west of Ireland 

 and Scotland, the Irish Sea, the English Channel, and the North Sea 

 with the exception of a deep depression which skirts the coasts of 

 Norway and Sweden. Over the greater part of this area the sea is 

 less than 300 feet in depth, and with the exception of two or three 

 isolated " deeps " is everywhere less than 600 feet in depth. 



From the north of Scotland, and extending in a north-westerly 

 direction, is a submarine ridge which connects together the British 

 submarine plateau with the plateaux on which are situated the Faeroe 

 Isles and Iceland. Between Greenland and Iceland, and between 

 Iceland and the Faeroe Isles, are extensive banks over which the 

 sea is from 200 to 300 fathoms in depth. Then joining the Faeroes to 

 the British plateau is a narrow ridge — the Wyville-Thomson Ridge. 

 To the north-east of this ridge the sea bottom rapidly sinks down, 

 forming a channel of over 500 fathoms in depth, deepening to form the 

 Norwegian sea, with a maximum depth of nearly 2000 fathoms. On the 

 south-west side of the ridge the sea bottom as rapidly sinks down into 

 the abysses of the Atlantic Ocean. The Wyville-Thomson Eidge 



