33 



B. HELLAND-HANvSEN 



Fig. 24. Average catches of haddock per trawl-hour in the 



Great Fisher Bank area. The position of the base Unes of the 



curves denotes the period of capture. The numbers of the 



groups denote the year of spawning 



per hour within each area 

 at the various seasons, and 

 arrange them chronologically 

 month by month. From these 

 figures one can get a good 

 idea of the development of the 

 haddock-supply within the area 

 during the course of years. With 

 each curve we have shown the 

 years of spawning that are 

 probably respective represented 

 by the length-groups. These 

 birth-figures are not entirely to 

 be depended upon — as has been 

 previously shown — either for 

 group III or to some extent for 

 group II. The four areas chosen 

 are the Northern Area, (B), 

 together with the Gut (C), where 

 the depth is over 50 fathoms: 

 the area round the Great Fisher 

 Bank (D) where we have 30 — 50 

 fathoms: the area (G) between 

 Flamborough Head and the 

 Dogger Bank, where the depth 

 is 20 — 30 fathoms: and finally 

 the Dogger Bank itself (H) 

 where the depth is under 20 

 fathoms. 



As the vertical measure- 

 ments of the curves are of the 

 same standard for all and give 

 the number per hour of the 

 various sizes, we can get an 

 impression from the figures of 

 the varying distribution of 

 numbers. It is clear that among 

 the areas selected the catch 

 per hour has all through been 

 greatest in the Great Fisher 

 Bank area, and least on the 

 Dogger Bank and off Flam- 

 borough Head. So that we get 

 again the picture previously 

 shown (pages 12 — 13) by an 

 5 



