— 4 - 



otter-trawl was employed, except at some of the English stations where a 

 beam-trawl of about the same dimensions was used instead. The work was 

 carried out in the interval between October 1902 and October 1906, and 

 altogether the two vessels trawled during 3000 hours, — disregarding of course 

 the occasions when the trawl broke or got out of order. Practically all the 

 cod caught were measured (in centimeters); and the same was the case with 

 most of the haddock, though from a good many stations the haddock- returns 

 received were too incomplete for us to include them. At other stations only part 

 of the haddocks caught were measured: and in this case, provided returns are to 

 hand for the total quantity caught and the quantity measured, we have reduced 

 the number of hours proportionately. We have in this way managed to deal 

 with returns relating to about 70000 haddocks distributed over almost 1400 

 hours'' and about iiooo cod over more than 2300 hours!) 



Owing to the comparatively large haddock-material in our possession we have 

 been enabled to investigate this species much more elaborately than the cod, both 

 in regard to particular results and to method of study. 



By way of simplifying matters we have divided the whole North Sea into 

 areas and have adopted as the basis of our arrangement the chief localities where 

 haddock-fishing is prosecuted and the different depths. In the chart of the bottom 

 Fig. I the different areas are indicated and letters have been assigned to them, to 

 which we shall constantly refer in the text. The curves of depth are given in 

 fathoms and have been made use of as boundaries for the areas. All boundaries 

 that fall between the curves are indicated by a line of dashes 2. 



The following is the arrangement of areas according to depth: 



Over 50 Fathoms 



A. The Norse Rent 



B. The northerly portion of the North Sea. 



C. The Gut. 



Between 30 and 50 Fathoms 



D. The area round the Great Fisher Bank. 



E. The area lying off the East Coast of Scotland and North England. 



Between 20 and 30 Fathoms 

 G. Between Flamborough Head and the Dogger Bank. 

 I. The Uttle Fisher Bank. 



K. The Southerly and the Northerly Schlickbank. 

 O. The slope north of the Dogger Bank. 



Under 20 Fathoms 

 H. The Dogger Bank. 

 M. The banks off North Holland, Germany and Denmark. 



1 This includes trawls -with negative results. 



2 Roman Figures have also been introduced to denote Fulton's arrangement of areas for the 

 Scottish Fishery Statistics which is also made use of by D'Arcy Thompson, 



