l89^. Xo. 9. HYDR.-BIOL. STUDIES OF THE NORW. FISHERIES. II 



By such results, Sars was even more strengthened in the theory-, 

 already advanced by him (1873) \ on similar grounds. According to Sar^ 

 opinion the Herrings, which during the winter come in such vast shoals, 

 wander about singly, or in small shoals in the uppermost layers of the 

 open sea during the rest of the year. The Herring chases the small or- 

 o-anisms wliich exist in the ocean in countless numbers, and which form 

 both the nourishment of the Herring and the great Whale-bone \\'hales. 

 »Onlv during the height of Summer 1, and when the sea is like glass, does 

 one find the prey up to the very surface, wliilst on the least ripple it 

 sinks at once, some feet below it, in which case the extended shoals, 

 which chase it, escape notice.» 



When the prey, during the Autumn, accumulates in by the coast, and 

 when the sexual organs ripen durmg the Winter, the various shoals unite 

 and commence to wander in towards land. 



During this migration landwards, the shoals have been often observed 

 at sea. Boeck- states that, in 1861, the master of a vessel arrived at 

 Haugesund reported that he, some 48 to 60 miles North West of Utsire 

 (see Chart of Depths II), had sailed through dense shoals of Herrings, and 

 observed the sea to be quite green, as it appears to be when the masses 

 of Herrings are near the surface, and, about twelve days after that, the fishing 

 commenced at Utsire and Rj&vaer.« Stirs'^ gives an excessively interesting 

 observation. »Some while« he says »previous to the great approach of 

 Herrings at Espevær, the mackerel fishermen often caught in their drift 

 nets, at a distance of 24 to 32 miles from land, considerably quantities of 

 large and fat Summer Herrings, whilst shoals of both large and small Her- 

 rings were constantly observed from the mackerel boats during their 

 homeward vovages. Shordy afterwards, on account of a sudden change 

 of weather, the current ran in towards the islands by Espevær (see Chart 

 of Depths 11), and carried with it vast quantities of food which became 

 packed in all the surroimding bays and sounds, and was at once followed 

 by the stream of Herrings from the ocean.« 



According to Sars' theory the migration of the Herrings is thus de- 

 pendent on the presence of the food, and this, in its turn is dependent 

 on the currents of the ocean. »We thus come,« says Sars^*, «to the re- 

 sult, that the variations in the Spring Herring Fishery on our West^Coast 

 must, in the last instance, be presumed to be dependent on the meteoro- 



1 Report to the Home Department for the year 1S73. 



2 Page 123. 



3 Loc. cit p. 47. 

 Page 131. 



