SOME RESULTS OF THE INTERNATIONAL FISHERY INVESTIGATIONS. 469 



may be positively detrimental to the industry generally. The lesson 

 that such investigations of crowded fishing grounds, with large numbers 

 of small plaice growing slowly, teach is the necessity for trans- 

 plantation. Long ago Petersen pointed this out in the case of the 

 Limfjord plaice fisheries, and the International Investigations point 

 this advice more clearly. Garstang, in a remarkable series of experi- 

 ments carried on on tlie effect of transplanting plaice from overcrowded 

 to less frequented grounds, has shown how useful such measures might 

 conceivably be.* It was observed, as we have seen, that plaice on the 

 " small-fish (irounds " off the coast of Denmark or off the east coast 

 of England grew slowly in comparison with plaice on the more open 

 and less crowded grounds on the Dogger Bank. A number of plaice 

 were therefore captured on these grounds and taken across to the 

 Dogger, where they were marked and liberated. The growth rates of 

 the fishes on the latter locality could then be compared with the same 

 growth rates on the localities from which the fish were originally taken, 

 and which had been determined by other experiments. About 40 per 

 cent of tlie fishes transplanted to the Dogger were subsequently re- 

 captured, and these showed a remarkably higher rate of growth than 

 obtained on their original localities. Whereas on the Horn Eeef 

 grounds — a good example of a crowded plaice ground — the fish increased 

 in length about If inch in the course of a year, tlic same fishes on 

 the Dogger added about 5 inches to their length in the same period. 



Whether such transplantation operations could be carried out on 

 a really large scale, and would be productive of such results as would 

 ijistify the expenditure of public money on this work, is a question 

 which is discussed at some length by Mr. Garstang. The practical 

 difficulties attending such work are of course very great, and one can 

 see that considerable organization of methods would be required. 

 Conspicuous commercial success has attended similar operations carried 

 out by the Lancashire and Western Sea Fisheries Committee ;f but the 

 practical details of the transplanting operations, which in this case 

 concerned mussels, were of course much more easily dealt with. 



The life histori/ of the Cod.'l 



With respect to the natural history of the cod, we find that the 

 investigations are still very incomplete, A very considerable amount 

 of material for the study of the life history of this fish has been 

 collected by the Norwegian, Danish, and English research vessels, but 



* Garstang, Fishery and Hydrographical Invcsticjations in the North Sea, etc. , Southern 

 Area, p. 4.'), 1905. 



t See Scott and Baxter, liejwrt Lancashire Sea Fisheries Laboratory for 1905. 

 X Iljort and Petersen, Rapjds. d Proc.-verb., vol. iii. 1905, app. G. 



NEW SEKIES. VOL. VII, NO, 5. 2 I 



