THE STOCK OF PLAICE 43 



the same percentage (10 to 40 per cent.) of all the plaice m 

 the area are captured. But there are so many hundreds of 

 millions of plaice in the sea that inferences dra^\n from experi- 

 ments with a few hundreds of fish must obviously be received 

 with extreme caution. They are in fact subject to a very 

 heav}^ ' margin of statistical error ', more especially as the 

 plaice population has never been satisfactorily computed. 

 Will any one ever be able to prove that there are so many 

 milhons of plaice in the sea ? It is hardly probable. For fish, 

 unlike men or cattle, do not receive an approximately even 

 accretion to their population every year. On the contrary, 

 it will almost certainly be found that in most years a huge but 

 very variable proportion of infants is destroyed. It has been 

 computed from experiments that 20 to 40 per cent, of all 

 the plaice on the grounds are captured every year. But 

 such computations will not perhaps convince a really sceptical 

 mind. 



The Causes of Diminution oj Large Plaice Landings 



Ever since they began to be conscious that plaice were being 

 ' j&shed out ' — which was at least thirty years before naturalists 

 were in a position to confirm their belief — trawlermen have 

 ascribed the trouble to the operations of the trawl. At the 

 outset the fishermen were told that the supplies of fish were 

 ' inexhaustible ', and that the destruction wrought by man 

 could never spoil the supply. The fishermen ' knew better '. 



Trawling on Small Plaice Grounds 



Skippers and owners up to the outbreak of war were agreed 

 that the exact process was just this. The trawlers found that 

 from the middle of April to the middle of August profitable 

 catches could be made on the nursery grounds between the 

 Horn Beefs and the Heligoland Bight. Competition drove 

 them against their better judgment to catch these fish. As 

 Skipper B. Douglas, of Grimsby, put it to Mr. Tennant's 

 Committee in 1908 : ' While one can do it, another thinks he 

 ought to do it, though he knows it is not right. Three captains 

 that I have spoken to this week have said the same thing — 

 that it will ruin the grounds if something is not done.' That 

 was the view of the trawler owners and fishermen in the plaice 

 ports in 1908 — and long before it. Too many immature fish 

 were caught on the nurseries before they could get into deep 

 water to grow and spawn. It would be ' better business ' 

 for the catcher and for the nation to allow these small fish to 



