470 SOME RESULTS OF THE INTERNATIONAL FISHERY INVESTIGATIONS. 



we are still far from knowing enough to enable us to follow out the 

 habits and wanderings of this important food fish. One may con- 

 fidently expect, however, that the result of the International Investiga- 

 tions will be to make clear the principal features in the life liistory 

 of this fish. The following account is based on the work so far 

 published : — 



The cod has not the same importance for the fisheries of Britain as 

 for those of Norway. Over the whole North Sea the fish occurs and 

 is caught, but it only forms a part of the general catches of the fisliery 

 fleets. In Norway, however, it is the fishery, and the cod has for the 

 fisheries naturalists of that country a degree of importance which has 

 justified considerable research. The great cod fishery in Norway is that 

 which is followed in the spring of the year on the coastal banks from 

 Lofoten to Tromso. The line-fishery there for spawning cod, the 

 " Skrei " fishery, sometimes obtains great dimensions. In the spring 

 of the year the adult fish frequent the coastal banks in great shoals. 

 They are found almost exclusively on these grounds. At this time they 

 are spawning, and it is when the fish are most numerous that the 

 pelagic eggs at the surface of the sea are also present in greatest 

 abundance. Tiie Norwegian research vessel, for instance, took as many 

 as 5800 cod on 17,800 hooks in one day, and during the entire spawning 

 season of the same year about one and a half million of cod were 

 caught by the entire fishing lleet. Experimental fishing operations 

 were carried on over a wide area, but the fish were restricted to a 

 comparatively small ground. On the Lofoten fishing grounds the 

 Norwegian naturalists found that the characteristic spawning size 

 of the fish was about 28 inches. In the North Sea the cod spawns 

 when about the same size. On the other hand, very different conditions 

 obtain in the Cattegat. Petersen found considerable numbers of cod 

 spawning there when no larger than about 12 inches. 



On most cod grounds investigated the early part of the year to the 

 spring is the period when spawning takes place. In the Lofoten fisheries 

 the spring is the spawning season, and the same is the case in the North 

 Sea. In the Cattegat, spawning takes place earlier in the year. In the 

 Irish Sea cod spawn in the spring. But a remarkable exception to this 

 general behaviour of the cod was first demonstrated by Fulton,* who 

 found when fishing from the Scottish International research steamer 

 GoldsecJcer that cod might spawn in the North Sea in the autumn. In 

 August of 1903 both fertilized and developing cod eggs were found in 

 the townets, and ripe and mature cod were taken in the trawl. The 

 discovery was quite novel. Hitherto an autumn spawning was only 

 known in the case of herring, and the well-known spring and autumn 

 * Publications de Circonstance, No. 8, 1904. 



