of the Fishery Board for Scotland. 



235 



Arendal branch of the Society, chiefly I understand at the instigation of 

 Captain G. M. Dannevig, decided to erect a hatchery for the propagation 

 of sea fish, lobsters, &c. The necessary funds having been raised, an 

 experimental station was started at Flodevig, near Arendal. 



Hatching operations were begun in February 1884, and although the 

 work had to be carried on in the face of many disadvantages, Dannevig 

 succeeded in hatching and setting free during March and April over 

 5,000,000 young cod and nearly 2,000,000 young flounders, and later in 

 the season he made a successful experiment in hatching lobsters. Young 

 cod 2J to 4 inches in length were abundant in the vicinity of the 

 hatching station in September — presumably they were some of the survi- 

 vors of the fry turned adrift during March and April. In the autumn of 

 1885 I visited the Flodevig hatching station, and through the kindness of 

 Captain Dannevig had an opportunity of examining the hatching appli- 

 ances and carrying off specimens of artificially-hatched young cod and 

 other fish, and also of young lobsters at various stages of development, 

 which had been bred from ' berries ' placed in special hatching boxes. 



During the spring of 1885, over 27,000,000 of cod fry were turned 

 out from the hatchery, and about 10,000 lobsters were hatched, of which 

 a considerable number were still in the station on my arrival in August. 

 Some of them had assumed the form of the adult lobster, while others 

 had not got beyond the larval stages. During the spring of 1886, still 

 better success was obtained by Dannevig. 



The scale on which the operations are carried on at Flodevig (though 

 still in the nature of experiments), .will be best understood from the 

 following table, which gives the results of the hatching work for 1886. 



From this table it will be observed that, during the months of 

 February, March, and April, 68,880,000 artificially fertilised eggs were 

 placed into the hatching boxes. From these 32,518,000 fry were obtained, 

 and set free soon after they were hatched ; that is, 52*9 per cent, of the 

 eggs were successfully hatched. Whether this is a better result than 

 unaided nature gains, it is impossible to say. The table further shows 

 that the temperature varied from 1*0 R. (1*25 C.) to 4*5 E. (5*62 C), and 

 that the specific gravity of the water was sometimes as low as 1*015 

 - "005 lower than the specific gravity of the eggs, at other times as high 

 as 1-027. 



The large percentage of deaths seems to have resulted partly from the 

 changes in the salinity of the water, and partly from the presence of 

 exceedingly minute particles in the water which, by coating the eggs, 

 prevented sufficient oxygen reaching them during development. Hence 

 one might expect that, with . thoroughly filtered water, having a specific 

 gravity of from D024 to 1*026, better results would be obtained. 



Not only has Dannevig succeeded in hatching millions of sea fish, he 

 has managed to rear a number of cod and herring. Some of the cod 

 fry, hatched on the 27th of April 1885, were introduced into a small pond 

 near the hatchery on the 3rd of May. A number of the cod are now 

 (April 1887) nearly 12 inches in length, while others are only about half 

 this length. We thus learn (I believe for the first time) that a cod may 

 during its first year reach a length of 1 2 inches. If it grows thus rapidly 

 in confinement, it may grow at a still greater rate in the open sea. Some 

 of the old fishermen of the Forth believe that cod reach maturity in 

 about two years ; in this they may be fairly near the truth. 



In the same pond, Dannevig set free a number of young herring, but 

 they nearly all fell victims to the hungry cod. Some of the survivors 

 are now about 4 inches in length. If this is an indication of the rate 

 at which herring grow in the open sea, it is evident they cannot reach 



