APPARATUS AND METHODS EMPLOYED AT THE MARINE FISH 

 HATCHERY AT FLODEVIG. NORWAY. 



By G. M. DANNEVIG, 

 Director Flodevig Hatchery. 



The main point in artificial propagation of marine fishes is to hatch the 

 greatest possible number of fry at the least expense. To attain this end the 

 spawning fish must be treated so that they can yield the greatest number of 

 well-developed eggs; the fertilization must be perfect; the incubators must 

 be able to hatch the greatest number of fry in the smallest space, must be 

 easy of access, and easily cleaned. The following description of the Flodevig 

 hatchery for salt-water fish will show how far the above-stated conditions 

 have been attained. 



Main features of equipment. — The Flodevig hatchery is situated on the 

 seacoast near Arendal, Norway.. The principal parts are a main building, 

 having on the lower floor 42 hatching apparatus, a water wheel, and an 

 aquarium, and on the upper floor, an office, laboratory, egg collector, etc. ; an 

 engine house with boiler and pump capable of delivering about 100,000 liters 

 of sea water per hour; a spawning pond, dimensions 19 by 6 by 3 meters; 

 and a larger pond 34 by 22 by 5 meters, used as a reservoir for sea water. 

 (Fig. I.) These several parts will be more fully described later on. 



Beginning the season's work. — When the spawning season commences, 

 early in February, the pump is set going and the ponds filled with sea water. 

 To insure as far as possible a high and uniform salinity, the water is pumped 

 up from the bottom of the bay, a depth of about 8 fathoms. If the weather 

 has been cold, the concrete walls of the ponds will have a temperature below 

 freezing point; and if so, the pumping must go on for several days until they 

 have the same temperature as the water pumped in. 



The spawning pond must be covered to keep out snow, rain, and to some 

 extent, light. Direct sunlight is apt to blind the fish. 



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