214 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Sound and the next year in the Grreat Belt.'^ A sknilar alternation, 

 although, of course, on a much larger scale, might well be supposed to 

 take place between the eastern and western shore of the North Sea.'^ 



62. At the first Scandinavian Fishery-Exposition held at Aalesund in 

 1864, Axel Boeck is said to liave advanced the opinion that the end of 

 the last Bohusliin fishery-period was contemporaneous with the recom- 

 mencement of the Norwegian spring-herring fisheries, because the Bo- 

 husliin herrings had transferred their spawning-places to those banks in 

 the North Sea which the spring-herrings had been accustomed to visit 

 during those years when the spring-herring fisheries had ceased. The 

 spring-herrings, therefore, on finding their spawning-places taken up had 

 returned to the west coast of Norway. Afterward Boecl; it seems with 

 good reason, abandoned this opinion, but the attempt to connect the 

 migrations of two great races of herrings with each other nevertheless 

 deserves attention. The same opinion has been entertained by otlier 

 writers both before and after Boeclc. When during the last winter 

 a race of herrings, similar to the " new herrings," visited the coast 

 of Bohusliin, I expressed the opinion that these herrings had been 

 forced to give way to the Norwegian spring-herrings, which about ten 

 years ago had begun to leave their old spawning-places on the west 

 coast of Norway. However this may be, it cannot be doubted that the 

 movement of one race of herrings has an influence on that of other 

 herrings, although this influence may by no means be instantaneous.'^" 

 It is clear that the coming in of larger masses of herrings in one and the 

 same place, though at different seasons of the year, will essentially 

 increase the influence of the disproportionately large races of herrings 

 on a limited extent of coast-waters. It may also be possible for a race 

 of herrings to be driven from its territory by a larger and stronger race, 

 especially if the latter finds its territory too limited in proportion to its 

 size. 



This explanation has also opened out new views by api)lying it to the 

 distinction made between the "■ new-herring fisheries" and the '' spawn- 

 ing-herring fisheries " properly so called, for to some extent, at least, it 

 may explain the fact that '^ new-herring fisheries " both precede and close 

 a large fishery-period. It also facditates the explanation of the regular 

 changes of time and place in the visits of the herrings during a fishery- 



'8 Although it has not heeu fully proved that such a mutual periodicity exists between 

 the herring-fisheries in the Sound and the Great Belt, this whole matter deserves atten- 

 tion and ought to be investigated. 



'3 A fact which may well be connected with the migrations of the herrings from the 

 western to the eastern part of the North Sea, is the cessation of the otherwise regular 

 whale-fisheries near the Faroe Islands from 1754-1776. But this fact, like the great 

 migrations of the herrings in the North Sea, may bo explained by supposing that the 

 fish moved in a northern and southern instead of an eastern and western direction. 



80 Even herrings of different age, though belonging to one and the same race, may 

 thus have to give way to each other, aud the proposed method of explanation maybe 

 applied to the different theories regarding the relationship and maturity of the " new 

 herrings " advanced by H. Strom, G. 0. Sars, and myself. 



i 



