APPENDIX B: HEINCKE _ 34 _ 



already, namely firstly, that the young haddock of the 0-group grow very quickly in the 

 months of the summer and autumn, and may be about 14 to 17 cm. long at the end of 

 their first year, and secondly, that the rate of growth must be much slower in the 

 winter and spring, perhaps only half as great or even less. 



Our investigations of the age of the haddock, from the otoliths and bones, are as yet, 

 too defective to permit of certain results. Nevertheless, we have found, that haddock, 

 taken in March of about 25 cm. in length, were at least 2 full years, perhaps already 

 3 years old, according to the rings on the bones; those of about 30cm. in March, were at 

 least 3 years old, perhaps already quite or nearly 4 full years old. 



Concerning the occurrence and distribution of the youngest stages 

 of the haddock, our investigations give a most important result. These 

 small Jiaddock of 14 to 20 cm. in length and mostly of the I-group, have been taken in 

 the northern North Sea at many places, even in the Skager Rak. On the other hand, 

 they were found only in quite insignificant quantities in the southern North Sea, and 

 none at all under 18 cm. in length, even though we fished at the same places with various 

 nets, quite small-neshed nets also. Further, we have always found the fish of 20 to 25 

 cm. in length, to be in very small quantities in the southern North Sea, and only those 

 of 25 to 30 cm. and over, occurred more frequently. The great majority of all the had- 

 dock, taken by us in the southern North Sea, consisted of larger and older fish of 35 cm. 

 onwards to 60 and 70 cm. and more. The catches of the trawl and line-fisheries show 

 the same thing. From our investigations on the age we believe, that the larger haddock 

 of about 45 cm. onwards to 70 cm. and more must be considered 5 to 10 years old. 



We cannot as yet determine from our investigations, the size and age at which the 

 haddock spawns for the first time, with certainty, but can conjecture it with some 

 amount of probability. In March, 1904, we captured altogether about 1500 haddock from 

 16 to 66 cm. in length at six different places of the North Sea from the Barren Ground 

 in the south to the Great Fisher Bank and the Skager Kak in the north. These were 

 measured and examined as to their sex and degree of ripeness of the sexual products. The 

 great majority of these haddock were found at the spawning time, i. e., they were almost 

 ripe, had running spawn or were even spent. The smallest female distinctly ripe, measured 

 28 cm., the smallest ripe male 26 cm. The great majority of all the ripe fish measured, 

 however, 32 to 36 cm. It may be considered certain, that the majority of these were 

 going to spawn for the first time in their life. They were thus about 33 to 34 cm. long 

 on an average, at first-maturity, and the majority were probably just four years old, in any 

 case three. 



It is only the hauls just mentioned, made in March, which have given some conclu- 

 sions regarding the places, within the region under our survey, where large 

 quantities of spawning haddock occur. With exception of the haul on the Barren 

 Ground, these were all made in the northern North Sea. Otherwise, with quite 

 insignificant exceptions, we have never found spawning haddock in the 

 southern North Sea. Numerous large haddock (to over 90 cm. in length) used, in 

 earlier years, to be taken in quantities with long-lines by the Heligoland fishermen and by 

 ourselves on the fishing-grounds in the neighbourhood of Heligoland, in autumn to De- 

 cember, and in spring from the end of March onwards, but only extremely seldom were 



