— io8 — 



As the cod occurs more than the haddock on rough grounds where the research- 

 steamers cannot fish, the representative value of the trawl hauls is naturally not so 

 great as for the haddock. 



As these 11,440 cod were taken in 2387 fishing hours, we find that, no regard being 

 taken for the time of year or fishing ground, only 4.S specimens were caught per 

 hour of fishing. According to the average weight this represents 6.1 kg. Since, as 

 shown above, 49.4 haddock were taken on an average per hour of fishing, the number 

 of cod is only about a tenth part of the haddock. Quite a different result is obtained 

 however from a comparison of the average weight of the cod and haddock. Here the 

 cod is represented by 6.i kg., the haddock by H.g kg. The weight of the cod thus 

 exceeds the half of the weight of haddock found, or in other words, each cod weighs 

 on an average more than five times as much as the haddock. As the hauls on which 

 this comparison is based are not equally distributed over the North Sea or the different 

 seasons, however, these averages cannot make any claim on being very representative. 

 In the case of the cod, however, there is but a small variation between the different years 

 (only 20°/o), whereas the variations of the haddock are large (about 50%). 



With regard to the different areas, we find a somewhat higher number in the northern 

 and central parts of the North Sea (over 7 specimens) than in the shallowest southern 

 part (about 2^/2 specimens). 



Fig. 42 shows the average distribution of the number of specimens and of the 

 weight per fishing hour over the various sizes (in centimeters). 



The curve for the number (the broken line) shows, just like the corresponding curve 

 for the haddock, a rise up to 24—25 cm. (resulting from the size of mesh); fewer small 

 cod than small haddock were apparently taken at these sizes. The curve sinks quickly 

 from its maximum to 55 cm., then more slowly. Of cod more than 110 cm. in length 

 only 9 specimens were taken in the 2387 hours. For each specimen of 100 cm. in length 

 there occur 20 at 25 cm., about 10 at 40 and 3—4 at 60 cm. A comparison with the 

 haddock shows, that the large specimens of the cod are much more numerous in 

 proportion to the total than the corresponding specimens of the haddock, 

 or conversely, that the small cod are scarcer in proportion to the total 

 than the young haddock. 



The weight curve (the continuous line) is essentially different. It reaches its maximum 

 at sizes where the number curve has already greatly declined. The younger stages 

 only constitute quite a small part of the total quantity by weight. 



As with the haddock we can distinguish between different commercial classes of 

 the cod: 



1. "Unmarketable" under 29 cm, in length. 



2. The small cod, "codling", of 29—60 cm.' 



3. The large "cod" over 60 cm. 



Examining the number and weight of each class, as represented on fig. 42, by the 

 light of these divisions, we obtain the following averages: 



I With Helland-Hansen we follow here the divisions employed by Fulton and D'Arcy Thompson. 



