56 JOHAN HJORT. M.-N. Kl. 



migrations Whilst it, therefore, at the outset, appears to us cer- 

 tain that the Ocean, in the greatest and most important features, 

 exerts an influence on the lives of the fish, a new question arises, viz. 

 Does the Ocean, too, also exercise any influence on the — apparently so 

 capricious — alterations and changes to which the influxions ert)- 

 pirically are subjected, or must these be presumed to occur without any 

 conformity to law? Why, for instance, does the Herring, one year 

 come into the land to spawn, whilst in other years it proceeds far out 

 to sea and spawns there? 



It is clear that these questions can only be solved by long experience, 

 that one, above all, will only after a long period of contemporary investiga- 

 tions of the sea and the fisheries, first be able to make it clear to zvhat 

 an extent the influence of the Ocean on the movements of fish is per- 

 ceptible. In the following pages I shall endeavour to shew the experi- 

 ences derived through the investigations of others and myself which are 

 now available, and I shall confine myself to the Norwegian Fisheries, 

 which in many respects occupy a unique position. For several reasons 

 I considered it best to treat each fishery separately. 



The Norwegian Spring Herring Fishery is due, as previously men- 

 tioned to the spawning migration of the Herring. »The Herring,« says 

 Boeck ^, »proceeds, guided by its instinct, to the coast, in order to find 

 suitable localities in which to spawn its roe and shed its milt, and where 

 its fry can subsequently become developed, find food and be in safety, 

 from its enemies. For this purpose a coast, which, seawards, is pro- 

 tected by many islands and rocks, between which lies a bottom covered 

 with stones and sand, having, besides, an abundancy of seaweed, is espe- 

 cially suitable. On the other hand, an open coast, exposed to the power 

 of the sea, cannot offer a sufficiently calm bottom, or protection to the 

 young during development. Therefore one sees that no fishing took 

 place, or takes place along the shores of Jæderen or Lister, or other 

 parts which are wanting in an island belt, and these places appear, 

 like projecting headlands, to be the boundary marks of the fisheries.« 



The Spring Herring Fishery in former times took place along a 

 great part of our shores, Boeck says from Lindesnæs til Christianssund. 



1 Loe cit. 



