NORTH SEA INVESTIGATIONS 389 



They are for turbot and brill 12 inches, for soles and lemon sole 

 {Pleuronectes microcephalus) 10 inches, and for plaice 11 inches. 

 How far they fall short of the biological limits, at least for the 

 North Sea district, can be judged by comparing them with the 

 table of sizes on p. 384 ; and, indeed, I may remark that the prohibi- 

 tion of the sale of turbot and brill under 12 inches in length is 

 rather a work of supererogation, since the number of smaller fish of 

 these species that come to market, at all events at Grimsby, is 

 utterly insignificant. 



The benefit to be expected from any measure of prohibition 

 depends of course on the vitality of the fish, and it is very gener- 

 ally asserted that the bulk of the small fish trawled on these eastern 

 grounds would not survive if returned. My own experience leads 

 me to believe that this view is correct* so long as the present 

 system of long hauls is maintained. Hence we must seek for such 

 a limit as will render the grounds most frequented by these small 

 fish unprofitable to the fisherman (since any less limit would only 

 involve an infinitely greater waste than takes place at present), and 

 in doing so it is necessary to glance at the general conditions of 

 this fishery. 



Exclusive of less important forms, the species chiefly met with 

 are plaice, turbot, and soles. The plaice, on most grounds, do not 

 exceed a length of 15 inches, and are mostly less than 13 inches in 

 length. The turbot are fairly abundant, but, as I have already 

 shown, almost all immature ; soles are scarce. It is only the cer- 

 tainty of being able to fill up with small plaice that induces the 

 fisherman to cross to the easteim side, since the soles and turbot 

 would not nearly pay his expenses by themselves. Now I am confident 

 that if the Conference limit of 11 inches for plaice were enforced, 

 there would still be enough saleable fish left to make the grounds 

 worth visiting, whereas if it were raised to 15 or even 14 inches the 

 grounds would assuredly be left alone ; and although such would be 

 below the biological limit, I believe the practical closing to our 

 huge fleets of such a magnificent nursery for young plaice would be 

 in itself a sufficient protection for the species. Certain rough 

 patches of ground, practically surrounded by areas yielding only 

 small fish, abound with only large fish ; these would still be access- 

 ible to fishermen, whereas in any scheme of geographical restric- 

 tion it would hardly be possible to exempt them. Moreover the 

 restriction of size would probably do away with the destruction of 

 small plaice by shrimp- or sole-trawls, since the fish are not injured 



* Owing to the great mass of fish caught in a single haul, I consider it quite possible to 

 hold this view without throwing any doubt on the value of the results obtained by my 

 friend Dr. Fulton iu his experiments on the vitality of trawled fish (Report S. F. B,, 1891). 



