A STUDY ON TROUT AND YOUNG SALMON. 305 



regulations relating to the different fisheries may without much 

 difficulty be formed. 



c. The protection of young trout. 



As shown above, it is the interests of the trout and not 

 those of the salmon, which must be the object of regulations 

 aiming at the protection of young fish under the forms men- 

 tioned on page 299. In the framing of such regulations a 

 special value is attached to the fixing of a size limit at which 

 the protection of the young fish is to commence. 



I admit that a correct estimate of this size limit with due 

 regard to the demands of the fishing industry and the economy 

 of the fish in question, presents a problem not easily solved. 

 Especially difficult is the solution when, as in the present case, 

 the question refers to a species of fish, which practically speak- 

 ing is only caught "on the sly", and to a fishery, the value of 

 which is an unknown figure, and the development of which 

 belongs to the future. 



As starting points I here recommend an endeavour to rea- 

 lize what sizes in the present species, represent the fry or young 

 fish. At the same time we must endeavour to sift the distinc- 

 tion fry = non edible, non-marketable fish. 



In connection with these investigations, we must next attempt 

 to make clear how high the size limit may be fixed without 

 injury to future fishing industry and local fishing-interests. 



For illustration of these points I have gathered some material. 



If we e. g. look up table V and observe the groups of 

 fishes contained in the different columns, it is clear that the 

 members of the upper groups from 10 — 20 cm. must be regarded 

 as the „fry", representing the individuals emigrating for the first 

 time into the sea. 



If we now consider the size (about 20 cm.) at which trout 

 become marketable we find, that the non-edible, non-marketable 

 fish, are represented by the fry. 



Nyt Mag. f. Natur v. XXXXIL IV. 20 



