41 



B. HELLAND-HANSEN 



catches. It is quite in accordance with other British and German investigations 

 to assume that, taking the whole aggregate of haddocks in the North Sea, there 

 are in the northerly half more of the smaller sizes than are to be found in the 

 southerly half. 



D'AucY Thomi'.son does not give the average weight of the Medium. The weight 

 of this group ought to be 13-4, if we may judge from the other figures. We get 

 then the remarkable circumstance that there are apparently fewer Medium than 

 either Smalls on the one side or Large on the other. This is hardly to be 

 explained by the mere assertion that a shorter range of lengths has been allotted 

 to Medium than to the two other sizes. There is for instance no doubt that a 

 large amount of the fish we have classified in our preceding remarks as Extra 

 Smalls are designated Smalls by the fishermen. The chief reason is obviously that 

 the Medium are in actual fact not a sharply defined market-group; so that there 

 is most likely included in this group in our material part of the fish classified 

 by the fishermen as Smalls and some of the Large as well. 



This would also explain why in D'Arcy Thompson's statistics Large constitute 

 a good three-sevenths of the total weight of the catch, while in our material 

 they do not reach more than two-ninths: though the circumstance must not of 

 course be forgotten that a large quantity of the smaller sizes are thrown over- 

 board and accordingly the weight of Large becomes comparatively greater, and 

 we must always remember that the fishermen first and foremost search out the 

 haunts of the larger fish. 



While the weights of the market-groups here mentioned are much less in 

 the average North Sea catch as shown by the research steamers than what they 

 are as shown by the reports of the Scotch trawlers, the total weights of Extra 

 Large per trawl-hour is roughly about the same. With us the weights given 

 make not the slightest claim to be regarded as exact, chiefly because the total 

 amount of Extra Large in the whole quantity examined was small. 



Consequent on the previous analysis of the average total number per hour 

 for each year we can get a quantitative expression of the average total weight 

 per hour in each of the years 1903 — 6. Here again we are indebted to Fulton 

 for his statement giving the average weight of the different centimeter-sizes. 

 However seeing that his statements were based on material which contained very 

 few individuals over 50 cm., and that large individuals were very scantily re- 

 presented in our catches too, we shall disregard the Extra Large group 

 altogether. 



The figures that we get are then as follows: — 



Average per trawl-hour 



Total Weight in Kilos 

 15-9 



8-6 



8-6 



1 1-6 



