SEA-FISHERIES LABORATORY. 209 



II. — Investigations concerning the effects of liberating 



artificially hatched Cod Larvae in the Fiords 



of Southern Norway. 



By Knut Dahl. 



At the request of Professor Herdman I intend, in 

 the following pages, to give a short account of the 

 special investigations undertaken in this country in order 

 to understand the conditions under which we are adding 

 hatched pelagic cod larvae to Norwegian fiords. A more 

 detailed account has been published in Norwegian, and 

 will probably appear later in English or German. I 

 will here only state a few main results. 



The investigations were carried out in some of the 

 small fiords of the Skagerrak, and also on the coast and 

 in the " Skiaergaard " outside the fiords. Captain 

 Dannevig and I undertook, upon a plan made by him, a 

 series of investigations in the fiords: Sondeledfiord, near 

 Kisor, and Hellefiord, near Kragero (see Chart, fig. 3). 



In these fiords the occurrence of cod fry (of the year) 

 in the bottom stage (littoral fry) was investigated by 

 means of a large series of hauls with a small seine (101- 

 10G hauls in the Sondeledfiord, and 21-27 hauls in the 

 Hellefiord). These hauls were made, as far as possible, 

 in the same places and in the same manner. Tbey were 

 first made in September-October, 1908, and repeated in 

 July-August, 1904, September-October, 1904, July- 

 August, 1905, and September-October, 1905. The seine 

 was 22 fathoms long, 4*20 metres deep in the middle. 

 The mesh was about 18 meshes per foot (Norw.) on the 

 wings of the seine. In the middle part of the seine 

 p 



