SEA-FISHERIES LABORATOE-T. '271 



EXPERIMENTS IX MARKING PLAICE. 

 By Jas. Johnstone. 



During the autumn of 190-1 tlie Scientific Sub- 

 committee of the Lancashire and Western Sea Fisheries 

 Joint Committee considered a suggestion made to them 

 with regard to the marking of living sea fishes, and 

 authorised the expenditure of i' : 30 on experiments in this 

 direction, with special reference to plaice and soles. The 

 marking and liberation of living fishes is, of course, an 

 old idea, but until a few years ago it has not been carried 

 out on a really large scale. Many experiments have been 

 made on salmon, but with somewhat ambiguous results. 

 About ten years ago Dr. Pulton made some experiments 

 of this kind on the East Coast of Scotland with regard to 

 plaice and obtained valuable results.* TV hen the Inter- 

 national Scheme of Fishery Investigations was adopted in 

 1902 by the Xorth European countries, it became possible 

 to carry out such experiments on a scale commensurate 

 with the importance of the object, and various methods of 

 marking fishes were elaborated. England, Holland, 

 Germany, Denmark and Belgium have all taken part in 

 these investigations, and up to the end of 1903. 6,239 

 living plaice were marked and liberated in various parts 

 of the Xorth Sea. Of these, S69 were recovered up to the 

 end of June, 1904. t 



Various " marks " — vulcanite studs with indiarubber 

 collars, aluminium rings, &c. — have been employed in 



* Report Fishery Board for Scotland for 1892. Pt. 3. pp. 176-196. 1892 

 f These experiments are still in progress, and the full results are 

 not yet published. See, however, the Publication of the Council 

 Permanent pour l'exploration de la Mer, Rapports et Prcces-verbaux 

 Copenhague, Vol. 2, 1901. p. xxviii. ; also Mr. Garstang's evidence 

 Select Co m mittee Sea Fisheries Bill (H. L.), 1901. 



