— 102 — 



It is of importance that other investigations also confirm these results obtained 

 from the material of the research steamers. We may mention here that fishing 

 experiments in the Skager Rak gave a similar result. Fig. 33 for example represents the 

 analysis of a catch of haddock. The large number of the II group spawned in the year 

 1904 and the small number of the III and IV groups spawned in 1903 and 1902 will be 

 noticed. From D'Arcy Thompson's account of the fluctuations in the occurrence of the 

 "small haddock" it appears repeatedly, that they showed the same character as that 

 described above during the years investigated. 



If we now consider D'Arcy Thompson's account of the seasonal variations in 

 the occurrence of the small haddock, we see that these are not so considerable but that 

 they might be explained as simply due to migrations or change of habitat by the fishes. 

 There certainly seems everywhere and in all curves a tendency in the catches to increase 

 in autumn, winter and beginning of spring, but this may be explained by the rapid growth 

 of the younger year-groups just during the latter half of the year, which leads to the 

 "unmarketable" becoming "extra small" and these again the "small". Some difficulty in 

 judging of the matter arises however from the fact, that the market group "small" is 

 very often so extensive that it also includes larger, mature fish, which undoubtedly under- 

 take considerable migrations (see later regarding this). 



The fluctuation in the quantities, which is illustrated by the curves showing the com- 

 parison of the different years with one another, possesses however a much more 

 distinct character. Reference may be made here specially to the curve showing the line 

 fishery in the Moray Firth (D'Arcy Thompson's fig. 40 [fig. 34]) and to the percentage 

 curve showing the relation between "small" and "total haddock" for 1901 — 1906 (fig. 35). 

 We see here a distinct minimum in autumn 1904, when the year-group of 1903 should 

 have added new individuals to the class "small", and a strong rise in autumn 1905 due 

 to the numerous year-group of 1904. We also notice the large numbers in 1903, of 

 which there are also indications in the material from the research steamers. 



The English fisheries statistics confirm this. In the statistical report for 1905 Archer 

 gives some curves showing the quantities of haddock in the different commercial classes 

 landed during the years 1903, 1904 and 1905 (see fig. 35). Here also we find a large 

 quantity of "small" haddock in the year 1903, a very small number in 1904 and a sharp 

 rise in the autumn of 1905. 



The German Fisheries statistics show on the other hand different conditions, and 

 no final conclusions can therefore be reached at present. The results obtained are 

 chiefly of value in regard to methods. 



According to Fulton the average size at which the haddock become mature may 

 be placed at about 28 cm. From this Helland-H.'^nsen has calculated that 60 % of all 

 the haddock caught by the research steamers were immature and that about the half of 

 all the "marketable" haddock must have been mature. As appears from what has been 

 shown above, the 28 cm. haddock belong to the commercial class "small" and the 3rd 

 year-group. Since the class "small" is thus composed both of mature and immature 



