1 895- ^'û. O. HVDR.-BIOL. STUDIES OF THE XORW. FISHERIES. 7 



engaged in it, but, since 1870, it has gone greatly backwards, and this 

 vear it has even been asked, whether, on the whole, there has been anv 

 Spring Herring Fisher}-. 



It was but natural that scientific investigations should be first directed 

 to these great essential circumstances. 



The first great advance towards comprehending the approach of fish, 

 was die fundamental discover}- that both the influx of the Spring Cod, 

 the Spring Herrings, as well as that of the Mackerel, consists of such mi- 

 grations as are undertaken b}- many species of fish, even by fresh water 

 fishes, in order to spawn in shallow water. 



In the year 1864, G. 0. Sars, during the months of Februar}- and 

 March, found the glassy roe of the cod drifting in the sea ofi" the Lofotens, 

 and b}- close observations during several }-ears, he next succeeded in 

 studying the development of the fn,- and its habits, until it, as a large 

 fish, left the coast in order to emigrate to the resorts of the adult fishes 

 in the ocean. Sars^ has, besides, described the influx: how it takes 

 place during the ripening of the sexual organs of the Cod, and how it 

 concludes on spawning, during which the great shoals often approach as 

 far as the regions of sea weed. 



In the Spring Herring Fisher}- District, the spawning migration of the 

 Herring was obscr\-ed in the decade i860 to 1870, b}- A. Boeck 2, who 

 described the spawning places of the Herring, the process of spawning, 

 the influx &c., &c., and gathered together a large store of matter for 

 throwing light on the Herring Fisheries and their histor}-. 



The propagation of the Mackerel was studied b}- Sars^, who, in 

 1875, found its eggs drifting a few feet below the sea surface near the 

 coast during the summer. 



The »Summer Herring« we, however, encounter under other con- 

 ditions. The Summer Herrings, wliich, in small shoals, wander over great 

 expanses of ocean, collect during die Summer and Autiunn, and come in 

 towards the land to seek their nourishment in the great masses of food, 

 plankton (small marine animals and algae , which can appear in vast quan- 

 tities in the coastal waters at those periods. Whilst, the Spring Herrings, 

 during their influx, are thin, famisliing, and have ripe sexual organs, the 

 Summer Herrings are fat, search diligenü}- for food, and have but re- 



^ Report to the Home Department. Christiania 1S79. See Report for the year 1S64. 



- The Herring and the Herring Fisheries, especially the Nor\vegian Spring Herring Fishery-. 

 Christiania 1S71. 



3 Report for 1S75. 



