_ 33 — JOH. H.TORT AND C. G. JOH. PETEESEN 



70 cm. It may be taken that fish of this size represent the first spawning year. The size 

 may vary in the different years and within the different shoals which arrive, just as the 

 maximum may be different on neighbouring banks. Almost all the fish of the shoals spawn, 

 though some are sterile. The smallest size at which the spawning cod of the coastal banks 

 are sexually ripe, lies between 50 and 60 cm. as a rule, yet very little under 60 cm. 



At Iceland the spawning cod are larger than at Norway. The maximum of the curve 

 showing the ripe cod lies about 90 cm. in July (see Table PI. IV), and the smallest sexually 

 ripe have a size of 66 cm. All smaller cod were immature, according to the comprehensive 

 investigations of Schmidt. 



Holt has investigated the maturity of the cod in the North Sea. According to his in- 

 vestigations, some mature males and females occurred already at 55 cm., but the majority of 

 the cod were first mature at 70 — Ö0 cm. Fulton has found mature cod of only 52 cm. on the 

 east coast of the Shetlands, but only exceptionally. From the numerous measurements made 

 for Committee A, a large "Skrei"-group can be distinctly detected in the North Sea. Whilst 

 the hauls of the investigation-steamers in summer gave sizes of 30 — 60 cm. principally and in 

 considerable numbers, cod of 65 to 100 cm. appeared in winter. 



Whilst an approximate agreement, with certain fluctuations, seems to rule from the northern 

 Norwegian Sea to the North Sea with regard to the size at which maturity is attained by the 

 spawning cod, different relations appear in certain Danish and Norwegian fjords. 



G. 0. Sars long ago found and studied ripe cod of both sexes of ca. 30 cm. in length in 

 the Christiania Fjord. This has been more exactly confirmed in recent years and in several of 

 the fjords of the Norwegian east coast, where spawning cod of only 27 cm. in size have 

 been found. 



In the comprehensive number of measurements transmitted to Committee A by C. G-. Job. 

 Petersen, quantities of ripe cod of both sexes occur at 30 cm. in length, some even less 

 than this. 



In this connection, it is of great interest that the sizes, which are characteristic of spawn- 

 ing cod in the North Sea and Norwegian Sea, are quite absent from the Kattegat and Danish 

 Belts. The question then arises, whether the smaller size at which these fjord cod attain maturity 

 means, that they belong to a special race. We can only discuss this after we have treated 

 of the natural history of the various age-groups. 



2. The natural history of the cod in its first year 

 In previous pages, we have seen that the cod-eggs spawned in spring, are found exclus- 

 ively • on the coastal banks. During the months of April and May these eggs develop 

 to larvae and later to young fish. We shall now consider their fate in the difi'erent regions 

 during development, more closely. 



In the years 1900 and 1901, the distribution of the eggs and young fish in the seas of 

 northern Norway has been investigated at various times, the upper layers being fished with 

 large nets at a large number of observation-stations. 



The drawing on the Chart (Fig. 6) has been based on the results of these investigations. 

 The curve Nr. 1 shows the distribution of the floating cod-eggs, and this corresponds to the extent 

 of the coastal banks shown by the dotted lines of depths. The other cui'ves (II and III) show 



Appendix G 5 



