RAPPORTS. XIV: THOMPSON 



— 28 



IV. Seasonal Fluctuations from Month to Month. 



I will close this Report, as in the case of my former one, with a brief account of 

 the monthly fluctuations in the catch of the principal Round Fishes, for which investi- 

 gation our five-years period of statistics now gives us a much improved basis. The re- 



Fig. 58. Monthly Means of North Sea catch (in 

 thousands of cwts.) of Total Demersal fish landed at 

 English East Coats ports by Steam Trawlers 1906 — 10. 



Fig. 59. Monthly Means of North Sea catch (in 



thousands of cwts ) of Haddock landed at English 



East Coast ports by Steam Trawlers 1906 — 10. 



1906 

 J. M. My. Jy. S 



1907 1908 



J. M. My. Jy. S. N. J. M. My. Jy. S. 



1909 

 J. M. My. Jy. S. 



1910 

 J. M. My. Jy. S. N. 



Fig. 60. Total North Sea Catch (in thousands of cwts.) of Demersal Fish landed at English East Coast ports 



by Steam Trawlers, 1906 — 10. 



suits are based entirely on a catch of the steam trawlers, from which alone we can draw 

 ample information throughout the entire year. 



The total catch of all Demersal Fish (fig. 58) shows (as before) a maximum in the 

 month of October and a minimum in the months of spring, but this latter period of mi- 

 nimum is now seen to be interrupted by a small secondary maximum in the month of March. 



The monthly fluctuations in the total catch are, as is now well understood, dominated 

 in the case of our English trawlers by the predominant catch of Haddock. We accord- 



