13 



LATHI! SI VCIvS OF CADOIDS 



actually and relatively, the central fishing grounds of the Dogger continue to be, in spite 

 of the general belief that its supplies are far less than they were of old. 



d. The Catch in the various Zones of Depth (Table I, IV). 



The following diagram (fig. 18) illustrates the amount of employment in the several 

 zones of depth, that is to say the number of voyages from the large areas A.B. C, etc., 



Fig. 17. Catch of Whiting (in cwts.) per square mile of area; 

 English Steam Trawlers, 1906 — 10. 



Fig. 18. Percentage of Landings by the various 

 Classes of English North Sea fishing vessels, 1906 — 10. 



20 40 60 SO 100 Cm., 



100 



Fig. 19. Percentage Number of Landings at the 

 various depths by the several Classes of English 

 North Sea Fishing Vessels; 1906 — 10. (Summa- 

 tion curves.) 



for the several classes of fishing vessels. It will be seen that the sailing trawlers and 

 sailing liners both do by much the largest part of their fishing in area B., that is to say 

 between 20 and 40 metres depth; but while the sailing trawlers cease to work below 60 

 metres, some 16 % of the work of the sailing liners is done below that depth. The re- 

 gions of depth in which the steam liners and steam trawlers work were also represented 

 in my former report, and there is no change to be discerned in the present curve. 



If we draw the same curves in another form (fig. 19), by summing the percentage 

 of fishing done in the successive areas, then each point of the new curve will show the 

 percentage of fishing that is done below or above the corresponding depth. By this 



