SEA- FISHERIES LABORATORY. 199 



the quantity landed in 1907. Not only so, but very consider- 

 able measurements of the plaice caught aboard trawlers showed 

 that the size of the fish had also increased in a notable manner. 

 So much for the results obtained by the English investigators 

 in the North Sea : similar conclusions were made both by the 

 Danish and German workers. 



Fig. 15b represents the total landings on the West Coast, 

 while Fig. 15c is a graph of the same data for the English 

 Channel. Even when we take the quantity of plaice landed 

 per day's fishing the same general result is obtained. There 

 is a marked drop in the catches from the year 1911, in the West 

 Coast and English Channel data, to about 1914-5, and then 

 there is an equally marked rise to about 1918-20. In so far 

 the experience of the southern and western fisheries is similar 

 to that on the East Coast, but there are other features of the 

 graphs representing the latter regions that call for comment. 

 In the case of both the West Coast and Channel there is a 

 rise in the quantities landed from 1906 till 1911, and then 

 follows the falling-off. The latter, it has been noted, com- 

 menced, in the North Sea, in 1907, but we must remember 

 that we do not know as accurately what were the landings 

 in the years immediately preceding 1907 : it may be that they 

 had gradually been rising, just as were those from the West 

 Coast and Channel. Further, the still more important informa- 

 tion as to the quantities landed per day's fishing, per vessel, 

 are not known. 



So long, then, as we do not know what was the statistical 

 history of the North Sea plaice fisheries prior to 1907, it is 

 not quite certain whether the changes noted were of the 

 nature of those due to a reduction of the stock by over-fishing, 

 or to a natural fluctuation that might have occurred no matter 

 how the intensity of fishing varied (within reasonable limits, 

 of course). 



In 1918 everything pointed to the conclusion that greatly 



