SEA-FISHERIES LABORATORY. 



211 



These results represent the biggest plaice caught anywhere 

 in the Irish Sea area. Here we are concerned only with the 

 Luce Bay figures. The graph shows a fairly well-marked 

 difference between 1920 and 1921 for this region, the plaice 

 taken in 1921 being considerably smaller, on the whole, than 

 those taken in 1920. Now a somewhat similar decrease in 

 size in North Sea plaice, in 1919 and 1920, was held, by the 



Fia. 19. Graphs of the length -frequencies of plaice caught in a 6 -inch 

 mesh trawl-net on the northern grounds in February-April, 1921, and in 

 Luce Bay in September, 1920 and 1921. Summational curves from Table 17. 



English workers, to point to the first results of the renewed 

 intense fishing of the North Sea. That explanation is difficult 

 to extend to the Irish Sea area, for there is comparatively little 

 fishing in these northern grounds, and Luce Bay is, of course, 



