RAPPORTS. XIV: THOMPSON 



24 



reproduced (fig. 46). Everywhere to the north and east of this line there was an in- 

 creased catch of Haddock in 1907 as compared with 1906; everywhere to the south and 

 westward of it there were indications of decrease. Moreover it was very clear, upon the 

 whole, that the further away from the line in either direction, the greater was the increase 

 or decrease. In like manner, when comparing (as we are now able to do) the succes- 

 sive periods 1907— OÖ, 1908—09, 1909 — 10, we in each case find that the percentage in- 

 creases or decreases for the several areas arrange themselves in an orderly fashion upon 

 the map, and we can say in a word what part of the North Sea was characterised by 



Fig. 46. Percentage Increase or Diminution of Haddock taken per 

 day's fishing by English Steam Trawlers in 1 907 as compared with 1906. 



Fig. 47. Change in Abundance of Haddock 1907 — 08, English 

 Steam Trawlers. 



one tendency or the other. This is made plain on the three following diagrams (fig. 



47-49)- 



In the year 1908, compared with 1907 (fig. 47) there is a tendency to decrease in 

 almost every area, and this is much the greatest in the southern areas, A 1, A3, C3, B 2, 

 B.3. In short the tendency to diminution of Haddock which was manifested in the south- 

 eastern part of the North Sea in 1907 is continued in the same part of the North Sea, 

 and is somewhat extended, during 1908. As we go northward the percentage diminutions 

 are less, and we have slight increases shown for E and D 2, and a slight decrease for F l 

 and B.5. I think it may fairly be represented by drawing the zero line, a line of neither 

 increase nor decrease, across the northern part of the North Sea. A great increase is 



