APPENDIX E: HEINOKE 



18 



that many more of the smaller plaice are only retained by the narrow-meshed young-fish 

 trawl. Just as remarkable is the fact, that a haul with this latter net, on the same spot 

 and immediately after haul I with the large trawl, brought in only 5 plaice, of which none 

 were under 24 cm, in length. From this we may conclude that smaller plaice, than those 

 shown by curve I, did not really occur there in any quantity worth mentioning. 



I. 40 m. 70sm.fr.Land, 133 plaice 90 f.Trl. 



II. 37 m. 50 sm. - 



III. 30 m. 30 sm. - 



IV. 25 m. 16 sm. - 



V \ 



,, /15m. 12 sm. ■ 

 Va.' 



VI. 7m. 2sm. - 



- 116 - 



- 121 - 



- 767 - 

 /3351 — 

 V 366 — 



- 1561 - 



HeUg. Tr. 



i,^ä^ 



16 18 £0 22 ?<! 26 28 30 32 Ih 36 38 52 65 



Eig. 2. Analysis of 7 hauls of plaice with the 90 foot trawl (I — V) and the Heligoland young-fish trawl 

 (Va & VI), arranged according to size. The numbers are the percentages of the total caught each 

 haul. The 7 hauls were made on the 23rd and 24th of July 1903, on a line north-west from the island 



of Juist as far as to the 40 m. line. 



The results of the 7 hauls just mentioned, are again represented graphically in the 

 accompanying table (Fig. 3) in somewhat different form, in order to show the relation 

 between the size of the plaice and the depths and distance from land more clearly. 



With regard to the distribution of the various size-groups of the plaice in the 

 winter months, we still lack sufficiently numerous observations. It is probable, that 

 the relations are somewhat different from what they are in the summer. Many places of 

 the coastal waters within the 20 m. line, where small and medium plaice, to 30 cm. in 

 length, are caught in quantities in the summer, are fished in winter without result, at 

 least from November to February, as e. g. in the neighbourhood of Heligoland. On the 

 other hand, it has repeatedly been shown by positive results, that relatively more large 

 plaice of 40 to 60 cm. occur even on these grounds in winter, from January to March, 

 than in summer. 



