11 



I.ATKI! STACKS OF GADOIDS 





others; but it does not do so to the same degree as formerly. In 1906 we had ex- 

 tremely large catches upon this area, so large that for the two years 1906 — 07 we were 

 able to lay down a zone of over 100 cwts. per sq. m. in this region. The mean for 

 1906 — 10 gives only 74 cwts. for the Dogger Bank Area, and 62 for the adjacent area to the 

 eastward C2; our zone of 100 cwts. has accordingly disappeared from the map. With 

 the Dogger Bank as a focus our chart now assumes the form of a simple series of con- 

 centric circles, or rather ovals, indicating a rapid gradation from the central zone of 50 



Fig. 13. Catch of Haddock (in cwts.) per square mile of area; 

 English Steam Trawlers, 1906 — 10. 



Fig. 14. Catch of Cod (in cwts.) per square mile of area; English 

 Steam Trawlers, 1906 — 10. 



cwts. per. sq. m. to a small region in the extreme south-west, and the great region in 

 the north (Fi, D3, etc.), in both of which regions English trawlers take less than 10 cwt, 

 or half a ton, from each sq. m. 



So greatly does the amount of fishing of English trawlers concentrate upon the 

 Dogger Bank and other central regions of the North Sea, that it will be found that for 

 every single fish the chart of quantities taken per sq. m. more or less resembles that for 

 the total catch, or in other words consists of a series of contours surrounding a focus 

 on or near the Dogger. In short the amount of fishing upon this central region is so 

 great as to override the great differences in the relative abundance of the different fish, 

 and to produce a series of more or less uniform charts instead of the very different ones 

 illustrated in the last Section. 



Thus, in the case of both Haddock and Cod (fig. 13, 14) we have, for the quantities caught 



