140 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



The enormous masses in which the herrings appear must doubtless r 

 if they select a narrow bay as their spawning-place, produce quite a 

 change in the nature of the coast, both by their becoming with their 

 roe and young ones the food of numerous marine animals, and by the 

 food which they and their young ones eat, which change may finally 

 assume such dimensions that the coast becomes unsuitable as a spawn- 

 ing-place. On the coast of Bohus-lan unfavorable weather has contrib- 

 uted not a little toward bringing about such a change. Because a tem- 

 perature of + 3° C. has no destructive effect, it cannot be maintained 

 that a still lower temperature, with its consequent formation of bottom- 

 ice, will not prove injurious. 1 Not sufficient attention seems to have 

 been paid to the very destructive effect which several severe winters, 

 .'ollowing close one upon the other, must have had on the spawning- 

 places of the herring, especially on the outer coast. 



Another question which is closely related to that of the disappear- 

 ance of the " old" herring is, why, during the fishing-period, the herrings 

 came to the coast at different seasons of the year. Already during the 

 first half of the last fishing-period, it was observed in Bohus-lan that 

 the herrings commenced to come later, and people began to fear " that 

 the herrings, as had happened repeatedly in former times, to the irrep- 

 arable injury of the province and the whole kingdom, would leave the 

 coasts of Sweden." 2 People began to inquire into the possible causes 

 of such an event, and attempts were made through various laws and 

 regulations to prevent so dire a calamity. 3 After the herring-fisheries 

 had ceased in the year 1808, people thought that in this circumstance 

 they had a proof that the herring had been driven away by the coast- 

 population, and the same causes were given for it as were supposed to 

 have brought about the stoppage of the fisheries. By Axel BoecWs in- 

 vestigations this whole question entered upon a new phase. He showed 

 that there always had existed, in this respect, a very remarkable simi- 

 larity between the great Bohus-liiu fisheries and the Norwegian spring- 

 herring-fisheries, 4 a circumstance which gives increased weight to the 

 point in question, and possibly contains the key to the question of the 

 periodicity of the great Scandinavian herring-fisheries. Bocclc has not, 

 however, attempted to assign any cause for the later arrival of the herring 

 during the fishing-period, but this has recently been done by G. 0. Sars. 6 

 Regarding the appearance of the herring on different places of the 

 coast during the fishing-period, Boeck seems to have pointed out the 



l Boeck, A., Om Silden og Sildefiskerierne, p. 119.— Widegren, Nya Handl. ror Sillf„ 

 p. 38. — Cederstrom, Fiskodling och Sveriges Fiskerier, p. 216.— Edlund, Ofvers. .if kgl. 

 Vet. Akad:s Forhandl. f. 1883, p. 372 ; f. 1865, p. 209. 



2 R. St. Fiskeri-Deputations beriittelse orn fiskeriornas tillstand i Rikct afgifvcn vid 

 Riksdagen d. 18 Maj. 1772.— Enl. Cederstrom, Fiskodling ock Sveriges Fiskerier, p. 192. 



3 Trangrumsacten, pp. 151-154, 158, 1G6. 

 4 Om Silden og Sildefiskerierne, pp. 102-110. 

 6 Indberetning for Aaret 1S73, pp. 55-5G. 



