RAPPORTS. XIV: THOMPSON 



ÎO — 



the steam trawlers during 1906—07. It was not a little remarkable to find how simply 

 and easily these data fell into place upon a map, and yielded us for each species an in- 

 telligible system of contour lines marking gradations of abundance of the fish. It is also 

 to my mind remarkable that the much better material now to hand scarcely alters or 

 improves upon the maps drawn, three years ago, from the statistics of two years only. 

 I here show the new charts for Cod and for Haddock (fig. 10— ll), which differ a little 

 in detail from those formerly published. In the other cases, namely the charts for Whiting, 



Fig. 1 1 . Mean Catch of Haddock per day's absence by English Fig. 1 2. Total Demersal Catch (in cwts.) per square mile of area 

 Steam Trawlers, 1906 — 10. English Steam Trawlers, 1906 — 10. 



Saithe and Ling it seems unnecessary to publish the charts anew, so similar are the new 

 ones to the old. 



What changes have actually taken place trom year to year in the catches upon the 

 several areas will be dealt with in another part of this report. 



c. The Quantities landed per Square Mile of Area (Table XI a). 



Here again the charts based upon a five year's average differ remarkably little from 

 those which I was able to draw from the work of 1906 — 07, but on the whole I think 

 my new sketches are worth publishing, for they are in some respects both better and 

 clearer than the old. 



We still find that in regard to the total quantity of Demersal fish landed per square 

 mile by English steam trawlers (fig. 12), the Dogger Bank Area (Bi) takes precedence of all 



