SEA-FISHERIES LABORATORY. 243 



this class of fish — otherwise the half-decked trawling 

 vessels would hardly catch and land them. If we prevent 

 the landing of plaice of less than eight inches from this 

 area, we ought to expect that the fish will migrate, or will 

 hibernate, until another season, when their average length 

 will be some two inches more, and when they will almost 

 have doubled in weight. Then they ought to be caught on 

 either the same or some other ground as larger and more 

 valuable fish. It is not at all likely that these small 

 plaice will be caught next season on the same ground as 

 larger plaice — it seems to us to be far more likely that the 

 adoption of such a size-limit would, in the case of the 

 Nelson Buoy grounds tend to reduce the average size; 

 provided that our assumption that the fish remain there, 

 or closer inshore, during the winter months is true. But 

 the small fish may grow and migrate from these grounds 

 if they are not caught: let it be supposed that they will 

 grow and migrate on to the winter fishing grounds off the 

 coasts of Anglesey and Carnarvon. Then we shall have 

 saved plaice of, say, three ounces in average weight from 

 being caught by the second-class sailing trawlers in order 

 that they may be caught by first-class sailing trawlers as 

 fish of, say, eight to ten ounces in average weight. But this 

 argument assumes that all, or a great proportion, of the 

 small plaice on the Nelson Buoy grounds do grow and 

 migrate, and this is obviously a hypothesis with regard to 

 which we require proof. 



It is, then, considerations of such a kind as we have 

 mentioned above that have, to some extent, influenced us 

 in devising and carrying out these marked fish experi- 

 ments. The results so far attained, and likely to be 

 attained, in the continuance of the experiments, will go 

 far to provide data for a rational discussion of the probable 

 effects of the restrictions contemplated, and may prevent 



