CONSIDERATION OF INDIVIDUAL FISH ^^ 



migrate to other grounds and grow to a size at which their com- 

 mercial value is much higher. This migration occurs, but it is 

 unlikely that all the fish which would be saved by the size limit 

 would migrate to fresh grounds and grow at the normal rate. In 

 the first place natural causes will be at work diminishing the stock, 

 and secondly the thinning-out of the plaice population on these and 

 similar grounds probably leads to the more rapid growth of the 

 survivors. If these Nelson Buoy fish were protected by a size limit 

 what would happen ? They would migrate offshore and be caught 

 by the first-class sailiag trawlers or the steamers. If then over 

 8 in. they could be marketed, if under they would be uselessly 

 destroyed, since the offshore grounds would yield other classes of 

 fish sufficient to make trawling remunerative, even if a large pro- 

 portion of the plaice were undersized. 



If it could be proved that the destruction of undersized plaice 

 was due mainly to the inshore fisherman, then there would be some 

 justification for putting an additional burden on him. But a study 

 of the statistics shows that it is the exact opposite which is true, 

 i.e. it is the steam trawler which is responsible for the destruction. 

 The three important areas from which small plaice are landed by 

 English and Welsh fishing boats are the North Sea, Irish Sea and 

 English Channel. The following table shows the proportion landed 

 by steam trawlers, first-class sailing trawlers and second and third- 

 class boats respectively. 



Occasionally a small catch of plaice is landed by a steam liner 

 and included in the above totals, but not in the detailed figures. 

 The discrepancy is, it will be seen, very slight and does not affect 

 the argument. 



Alternative methods which have been suggested for the main- 

 tenance of the supply of plaice are artificial hatching and trans- 

 plantation. The hatching of sea fish may well claim a share of our 

 attention, since it is based on the assumption that the fish popula- 

 tion of our seas is falling off owing to over fishing, and that it is 

 possible to remedy this decline by artificial means. In Europe 

 marine hatcheries have been established by the Norwegian Govern- 

 ment at Flodevigen for cod^ and at Drontheim for plaice, by the 

 Scottish Fishery Board at the Bay of Nigg, by the Manx Govern- 

 ment at Port Erin, and by the Lancashire Sea Fisheries Committee 

 at Piel. These institutions are not entirely devoted to the hatching 

 of sea and shellfish, but are also equipped for scientific research, 

 and in the Scottish and Lancashire hatcheries fishermen's classes 



"■ For details of the work done at the Norwegian hatchery see. The Utility of 

 Sea-Fish Hatching, by G. M. Dannevig. Proceedings of the Fourth International 

 Fishery Congress, Washington, U.S.A., Bulletin U.S. Bureau of Fisheries, Vol. 

 XXVIII, 1908. Govt. Printing Office, 1910. 



