316 KNUT DAHL. 



interests of trout and salmon-fisheries were quite separable. 

 This is, however, not the case in salmon-rivers, and the 

 introduction of full liberty as to mesh would inconvenience the 

 fishing of both species. 



As regards those salmon-rivers which wholly or nearly 

 wholly are let for sporting-purposes, and as regards the smaller 

 trout-rivers, where net gear can not easily be employed, the 

 question of mesh is of very small importance. 



Respecting those rivers, the lower parts of which are fished 

 by numerous seines, while the upper reaches are hired by 

 sportsmen, e. g. most northern rivers, a reduction of the mesh 

 will to some extent cause fewer grilse than usual to reach the 

 upper reaches. 



The present mesh certainly retains grilse, down to the smal- 

 lest sizes occurring in our enclosed waters. Nevertheless a few 

 grilse break through, either bursting the mesh or being so slender 

 that they are able to wriggle through the mesh, even though being 

 of the same length or weight as many of the smallest caught. 



This fact is shown by a few of the grilse, caught in the 

 upper parts of the rivers, being marked by the meshes. 



Attention is very often drawn to this fact by sportsmen, 

 and I have also myself observed it in the rivers. Thus in the 

 upper parts of the Orkla I once examined the catch made in a 

 day by British anglers. About 25 ^/o of the grilse were marked. 



Clearly this marking of fishes will to some extent occur, 

 no matter what size our mesh is; but I deem it also probable 

 that this phenomenon at the present time must be mainly 

 attributed to the use of seines in the lower parts of the rivers. 

 In these limited stretches of water, where the fishes are hunted 

 with net after net, as they ascend the river, obviously the 

 chances of a majority of the ascending fishes coming in contact 

 with net gear are greater than in the sea, where the fish move 

 in a considerably wider area and the room for escape is far 

 greater. 



