— 22 — 



but as yet only as regards the north coast. The investigations were made from the 17th 

 to the 22nd of July, beginning at the Horns (the south-eastern part of the coast). No 

 pelagic young of the cod were found along the whole of the east coast; but at the north- 

 eastern promontory of Iceland, Cape Lânganes, we already met the first of them and the 

 numbers steadily increased the further we proceeded along the north coast, so that we 

 already took over 100 in a half-hour's haul ca. 60 miles west of Lânganes. We thus see 

 that, whilst in the beginning of June no pelagic cod young were found oif the north coast, 

 or at least only quite a few at the extreme western part, towards the end of July they 

 were distributed along the whole north coast.^ They had also grown at the same 

 time, the majority being now ca. 2 cm. long. 



The last (4th) voyage round the island for the investigation of these problems was 

 undertaken in the last half of August 1904, beginning at the southern part of the east 

 coast (Chart IX). On this occasion we found that the pelagic cod young were no longer 

 restricted to the north coast, but that they had reached a good distance down along 

 the east coast to almost 60 miles south of Cape Lânganes. At the same time they 

 had grown considerably, most being now from 3 to 5 cm. long.^ It will be seen from the 

 Chart that but few pelagic cod young now occurred off the western part of the north 

 coast, and practically none off the west coast. This arises not only from their being car- 

 ried eastwards to the eastern parts of the east coast, but also from the fact that large 

 quantities of them as they grow up discard the pelagic mode of life and seek the bottom. 



In the two other years (1903 and 1905) the "Thor" was working at Iceland, I found 

 essentially the same conditions as in 1904, the year 1 have specially mentioned here, as 

 the search for the cod young was then specially thorough. There is reason to believe 

 therefore that the results of the "Thor's" investigations really give a correct picture of the 

 normal biology of the cod young at Iceland. 



It will be evident from this how extremely great is the part played by the hydrograph- 

 ical conditions, i. e. temperature and currents, in the distribution of the young cod. In 

 the first place, the low temperatures (ca. 1° — 4°) prevailing on the east and north coasts 

 during the period of reproduction limits the production to the south and west coasts almost 

 exclusively. In the second place, the pelagic cod young hatched there are involved by the 

 currents in a movement round the island. This might almost be called a circulation 

 movement, as it carries the young northwards from the south coast along the west coast 

 in the direction followed by the hands of a watch, then eastwards along the north coast 

 and even from there again southwards along the east coast. On the other hand, on ac- 

 count of the peculiarly sharp, hydrographical boundaries between the Polar Current and 

 the Atlantic Stream at the south-eastern part of the island, it is under ordinary conditions 

 so to speak excluded that floating organisms can be carried directly from the south to the 

 east coast. 



Whilst the great mass of the year's production in March and April is thus found on 



' The (Jhart X shows that the drifting cod young had reached just as far in July 1905 as in .July 

 1904, so that there was very good agreement between the two years in this respect. 



^ From the tables showing the results of the fishing with the young-fish trawl, it will be seen tliat 

 amongst these larger fry there were also a few smaller about 1 cm. long. I imagine that these were 

 hatched in the summer on the north coast, and that they thus have their origin in the weaker "after- 

 spawning" mentioned on p. 19. 



