FISHERY RESEARCH 339 



In the laboratory also, experiments may be carried out 

 on the rearing of fishes. At Port Erin, for instance, the 

 laboratory possesses a special plaice hatching establishment 

 in which many millions of plaice are reared successfully 

 through the critical period of their lives and then liberated 

 into the sea. Lobsters also are reared at that laboratory 

 in the same way. In Norway it has been for many years 

 the practice to hatch and liberate thousands of young cod 

 in one of the fjords. 



Much work is yet to be done on the artificial culture of 

 such important food shellfish as the oyster and the mussel, 

 and especially is it desirable in the case of the oyster to be 

 able to rear the spat in hatcheries, so that there should 

 always be a supply of tiny oysters to lay on the oyster 

 beds each year and so ensure a provision for future years. 



But the sea is big and the supply of food therefrom would 

 appear to be inexhaustible and it is only natural that 

 fishery investigations should have many critics. It is 

 argued that the expense involved has not been worth the 

 gain and that the sea contains resources that can never 

 be used up by man's puny efforts ; that even if the fisher- 

 men did exhaust one ground they would be forced to move 

 elsewhere for their supply, with the result that the fished- 

 out grounds would have time to recover. Such suggestions 

 appear, perhaps, to be quite sound at the moment, but 

 what of the future ? It is probable that, as world popula- 

 tion increases, man will turn more and more to the sea 

 for his supplies of food. More trawlers will be built, 

 more efiicient means of capture designed. As far as we 

 know at present the trawling areas are undoubtedly confined 

 to the shallow plateaus and as such are limited in extent. 

 Even now the effects of overfishing on such fish as the plaice 

 in the North Sea are apparent, and the time must come 

 when man's efforts will be felt, fifty, a hundred, two 



hundred years ahead ; who knows ? The fishermen of that 



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