31 — 



KNUT DAHL 



During the years 1904 and 1905 llie occurrence of littoral cod fry was examined 

 by me in the Sandnes and St0le Fjords, where larvae from the Fiodevigen never were 

 liberated, and also in the Kristiania Fjord, vvliere some fry (2Ü millions) were liberated 

 both years. 



The seine employed was 38 metres long. Depth in the middle 4-5 m., in the points 

 1-75 m. Mesh, 16 meshes per foot (Norw.) un the wing. A piece of net 5 mm. between 

 the knots, lO-ô m. long, was inserted in the middle of the .seine. The smallest littoral 

 cod fry could always be retained by this seine. 



With this seine the Sandnes and the Stole Fjords were examined in July (respectively 

 10 and 7 hauls), and September— October (respectively 21 and 20 hauls). The hauls 

 were first made in 1904 and repeated in 1905. 



In the Kristiania Fjord 28 hauls were made in August, 1904 and 1905. All the hauls 

 were made as far as possible in the same places and in the same manner in both years. 



The cod obtained in every one of these hauls have been all accurately measured 

 and recorded. During the months of July and August it is not very difficult to separate 

 the fry of the year from the smallest of those from the previous season, by means of 

 the graphic method. Certainly a blending of the largest fry of the group and the 

 smallest of the I group occurs even in July. If however the material is classified 

 according to smaller localities essential errors are in the main avoided. 



In September and October a separation by means of the graphic method becomes 

 somewhat more difficult. This is easily seen in the table (see page 28, columns for 

 September — October). 



By arranging this material obtained in the autumn according to smaller localities 

 and by employing the graphic method coupled with age-assessments (by means of scales 

 or otoliths) of representative samples, a fairly reliable classification of the fry has proved 

 possible. Now in those fjords, where the material during autumn has been large, I do 

 not consider the errors incurred as being of essential importance to the result. But 

 where the material has been small and where the range of variation in the size of the 

 fry has been a wide one, no great accuracy can be claimed^. 



'■ A detailed account of this classification of the fry will be found in ''Nytten af Torskeudklaekning" 

 kapitel IV. 



