Some practical Fisheries Questions in the Light 

 of the Results obtained 



Just as we have endeavoured in the foregoing to give a summary of those results 

 which appear to issue from the investigations, we shall in the following discuss some 

 practical fisheries questions in the light of the results obtained. We shall deal first of 

 all with the old question: 



1. How far do the fish migrate? It must be pointed out firstly, that the areas 

 of distribution are very different according to the different ages or stages. The question 

 of the migrations of a certain species is therefore quite different at the separate stages. 

 It is of great importance for the whole migration question, that it has been possible to 

 determine the distribution of the youngest plankton stages with such accuracy. In this 

 way not only was knowledge gained of the places where the spawning fish and the eggs 

 themselves occurred, but a firm basis was also obtained for judging of the passive and 

 active wanderings of several species. If we compare, for example, the boundaries of the 

 distribution of the larvae or young fishes with the known spawning places, the smallest 

 distances between the areas of occurrence of the different stages must at all events corre- 

 spond to the smallest movements which the individuals undertake during their develop- 

 ment. If, likewise, we find spent fish outside the spawning place after the spawning is 

 over, we seem justified in drawing the conclusion that these fish have migrated away 

 from the spawning places after completing spawning. 



The present report presents numerous examples to show that this comparative 

 method may yield very important results. We have seen that the eggs are carried during 

 their development to larvae and young fish away from the spawning places, that the young 

 pelagic stages are found far from these places and that the young bottom stages in 

 several gadoids grow up many miles distant from the places where they were spawned. 

 Reference may be specially made to the following examples. 



We have seen that the young of the cod grow up in great quantities on the north- 

 ernmost coasts of Norway, though they are only spawned much further to the south. At 

 Iceland the eggs were only found on the south and west coasts, whereas the young fish 

 grow up chiefly on the north and east coasts. 



