SEA-FISHERIES LABORATORY. 221 



movements of the water-masses. The pelagic cod fry may, 

 therefore, not be considered as belonging to a certain small 

 fiord or locality. It forms a moving and changing part 

 of the stock of fry belonging to a far greater area of 

 water. 



As the movements of the water masses differ in 

 different years, they would be expected to produce annual 

 variations in the occurrence of the fry. This has, indeed, 

 proved to be the case. In May, 1904, there was a very 

 weak Baltic current and plenty of western water in the 

 Skagerrak.* All the summer there were large masses of 

 drifting fry to be seen in the sea and especially in the 

 beginning of June they were very numerous. I could 

 nearly everywhere note their presence, by direct observa- 

 tion, under the drifting jellyfish, and easily catch them 

 with a small hand net. I could anchor my boat in the 

 open Skagerrak off Eisor, and observe the pelagic young 

 of cod, haddock, and whiting in great masses drift past 

 under the jelly-fish with a speed of 3-4 knots. The sea 

 was quite full of jelly-fish and under nearly every one oi 

 them swam one or several young fish, which easily were 

 caught for examination. By towing my small tow-net 

 (1 m. diam.) for five minutes, I could catch up to 39 cod, 

 haddock, and whiting of 2 to 3 cm. length. The " Michael 

 Bars " found these young fish distributed in the upper 

 layers over the whole of the deeper Skagerrak, and there 

 can be no doubt as to these young having drifted out 

 from shallow water, because no cod spawn in the deep 

 Skagerrak. 



In 1905 things were entirely different. This year 

 there was a strong Baltic current. t During the early 



* See Bulletin of International Council for the Study of the Sea. 



f See Bulletin of the International Council for the Study of the Sea, 



1904-5. 



