— 21 — APPENDIX F: HENKING 



The haddock (Gadus aeglefinus L.) is a summer-species. It is tal<en in greater 

 numbers in summer than in winter over the whole southern and northern North Sea, in 

 the Skager Rak and in the Kattegat. Why does it occur in increased quantities almost 

 everywhere within this large region at the same time? Once upon a time the probable 

 explanation would have been, that it sought the bottom-layers more in summer than in 

 winter. 



The case is quite different with the hake (Merluccius). It is known as an inhabitant 

 of both sides of the Atlantic and as a swift predatory fish. In the most southern parts 

 of the North Sea it is only a somewhat rare visitor. It is probable therefore, that it 

 comes from the north, where it is more frequently caught. 



Whether the hake, so far as large quantities are concerned, is a stationary inhabitant 

 (stand-fish) of the North Sea, may be doubted. The notion of an emigration on a large 

 scale has greater probability. In the first three to four months of the year it is hardly 

 taken at all (see Fig. l — 6). Then it appears in ever-increasing numbers, perhaps with 

 the inflow of Atlantic water (see annexed Chart for 1903, May-curve). We may picture 

 how the first shoals quickly spread over the plateau of the northern North Sea and 

 appear in dense masses in the Skager Rak (Fig. 5 — 6) and Kattegat already in June ; in 

 August they also cover the southern North Sea in considerable numbers (Fig. 3—4), 

 whilst the shoals following lead to the maximum-stock in the northern North Sea about 

 September. They thus undoubtedly enter into more weakly saline and warmer waters. 



Pettersson states, that the hake spawns on a bank off the Swedish coast north 

 from Marstrand in August of each year, and disappears completely in September. It is 

 possible that it wanders back generally to the Atlantic Ocean at this period. After Sep- 

 tember it quickly becomes rarer everywhere (Fig 3 — 6). Late in the year, a second 

 increase in the catch occurs only in the northern North Sea — as if the fish were on 

 the return journey. 



The possibility of extensive migrations arises also from the circumstance, that the 

 hake occurs in the catches of the trawlers only as large fish seemingly, more rarely as 

 medium-sized specimens. The measurements made by us, show the foUoving: 



Place of capture Date of capture Total length 



cm 



Mouth of the Skager Rak 18. June 1904 58— 84 



Hanstholm end of June 1904 70 — 93 



„ end of July 1904 43— 82 



20. October 1903 39—44, 54—100 



Hirshals 15. July 1904 65— 95 



Maseskär 6. July 1904 65-5— 103 



Horns Reef 13. December 1903 76— 81 (only 2specim.) 



Heligoland 25. June 1904 50, 72 — 105 



The correctness of the picture sketched in the foregoing will have to be ascertained 

 by further investigations'. 



I) The picture agrees in general with the data given by Fulton for the catches of trawlers in the northern 

 North Sea for the year 1901. Two maxima also occur here, often quite uninistakeably, but somewhat later in 

 the year. See Fulton, North Sea Investigations, II. (20. Ann. Report. Fishery Board of Scotland. Pt. Ill, 

 Table III. 1902). 



