212 



TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



(6) The Question of Size-Limits. 



These plaice measurements provide, for the first time 

 since the Committee began to make scientific investiga- 

 tions, satisfactory data for the discussion of possible size- 

 limits. By interpolating on carefully drawn curves 

 constructed from the integrated frequencies, the percentages 

 of fish present on the grounds above or below any specified 

 length can be found. Thus if we wish to consider what 

 would be the effect of a size-limit of 20'5 cms. — just over 

 8 inches — we shall find that the following proportion of 

 all the plaice caught by means of a 6-inch trawl mesh 

 fall below this limit. 





Nelson 



Buoy 



grounds. 



Horse 

 Channel 

 grounds. 



Beaumaris 

 and Red 



Wharf Bay 

 grounds. 



Luce 

 Bay. 



January 



67% 

 58% 

 50% 

 39% 

 45% 

 43% 



54% 

 54% 

 69% 

 51% 



28% 

 28% 

 28% 



23% 



42% 

 37% 

 38% 

 36% 

 59% 

 27% 

 20% 









March 



_ 



April 



. 



May 





June 







July 







August 







September 









) 



November 



22% 



December 







By similar means we can, of course, find the corre- 

 sponding figures for any other proposed size-limits. 



It will be seen also that the adoption of any such size 

 limit would differentiate in favour of one class of fishermen 

 and against others. A 20*5 cm. size-limit would obviously 

 prevent about one-half of all the fish caught on the Nelson 

 Buoy grounds from being landed. Presumably such 

 legislation would have for its object the prevention of 

 trawling on such a ground as this, the argument being that 



