196 REPOET OF COMMISSIONER OF FISH AND FISHERIES. 



been observed that the young herrings, as they grow up, leave the shal- 

 low waters near the coast and go into deeper waters farther out towards 

 the ocean, whence, after a while, they return to the coast in company 

 with the older herrings. The knowledge of the details of these migra- 

 tions is, like our knowledge of their physical and biological causes, so 

 limited that very little can be said regarding them. 



Regarding the coming of the herrings from the sea to the coast we 

 only know that during the spawning- season they generally approach the 

 spawning-places in dense schools, coming from the north, and that when 

 visiting the coast for other purposes the schools are smaller and more 

 scattered, extending over a larger stretch of coast, and come both from 

 the north and the south. Those herrings which come to seek food gen- 

 erally remain for some time in the outer waters before they come near 

 the coast, and their ^isits are neither as regular nor as long as when 

 they come to spawn. But even the great mass of herrings does, during 

 the spawning-season, not remain near the coast longer than one or two 

 months, exceptions from this rule being very rare indeed. Herrings 

 which have thus remained near the coast over their regular time become 

 almost entirely worthless. During the last great Bohuslan herring-fish- 

 eries this seems to have occurred more frequently. 



In approaching the coast the herrings generaEy begin at a certain 

 point, spreading from it either to the left or right or in both directions, 

 influenced in this by the weather, the currents of the sea, and the nature 

 of the bottom. The herrings do not like to visit the place where they 

 have spawned, a second time. It has also been noticed that the large 

 herrings do not go as high up the fiords as the small ones, and that when 

 the spawning-season comes in winter or spring the large herrings spawn 

 before the small ones, whilst when the spawning-season comes in sum- 

 mer or autumn the small or younger herrings spawn before the larger 

 and older ones. After spawning, the herrings have often been observed 

 to go nearer the coast than before .spawning; fishing with drag-nets may 

 therefore be carried on long after fishing with stationary nets has ceased, 

 as the "= empty "fish (those that have spawned) do not easih' enter a 

 stationary net. 



The going-out of the herrings is generally a much quicker process 

 than their coming-in, and as it is more difficult to catch herrings whilst 

 they are leaving the coast, we know very little about it. After the her- 

 rings have left the coast, they do not stay outside any length of time, 

 but immediately go out to sea to seek food and enjoy the greater pro- 

 tection which the deeper water affords. When the herrings have been 

 to the coast for the piupose of spawning, they genially leave the coast 

 in a northerly direction. 



"With regard to the extent of the annual migration4of the herrings, I 

 have already mentioned the different opinions, and I Ifill only add here 

 that the larger a school of herrings is, the greater will be the extent of 

 territory where they must seek their food, and the farther from the coast 



