[73] POND CULTURE. .OoO 



licnce will show after years which are the ligures that are most likely 

 to insure success. 



As r(';iarcls the spawning- ])on(ls. there is— if the relative size of these 

 l)on(ls should not be quite uj) to the standard — less danger that they 

 could not produce the number of fish necessary for the stock ponds, be- 

 cause too small an area can, in case of necessity, sui>[)ort two and three 

 times the standard number of spawners. 



The proportion of the area of the winter jjonds to the entire i)()nd 

 area is not so important as the proper proportion between the raising 

 ponds and the stock i)onds, for if necessary raising ponds can easily be 

 transformed into winter i)onds, and if these ponds are i)roi)erly ar- 

 ranged, double the number of fish per hectare can be wintered in them. 

 The case may frequently occur that the given pond area is such as to 

 make it impossible to maintain the standard relation of size of the ditter- 

 ent classes of ponds. In whatever way we may make our calculation, we 

 shall in that case always arrive at the result that it will be im]K)ssible 

 to stock sufficiently one or the other of our ponds, and that conse- 

 quently we must suffer more or less loss, wliich but rarely will be pre- 

 vented by accidental circumstances. 



The greatest possible profit which can be derived from an entire pond 

 area will l)e diminished in i)roportiou as one is compelled to make 

 changes in the standard relative size of the different classes of ponds. 



The correctness of this assertion will at once become apparent if we, 

 for instance, compare the management of a pond farm having an entire 

 pond area of 100 hectares divided among 4 ponds of 25, or 5 ponds of 20 

 hectares, with that required by a pond farm likewise embracing a pond 

 area of 100 hectares but divided among 5 ponds of 4, 12, 15, 00, and 

 liectares. After the various ponds have been assigned, some for spawn- 

 ing, others for raising, and others for stock ponds, it must be ascer- 

 tained whether the individual jionds of one and the same class differ 

 very considerably from each other in regard to their nature, whether 

 they resemble each other or have the same character in all resjiects. 

 In the last-mentioned case it will be best to place an equal number of 

 fish per hectare in each of these ponds. If, however, one has a number of 

 ponds whose soil and other qualities differ very considerably from each 

 other they shonid be subdivided into different categories according to 

 tlieir quality, and the same number of fish per hectare should be i)laced 

 in all the ponds of one and the same category. 



The result of the first year during which this method of stocking has 

 been employed — making the number of fish rather too low than too 

 high — will enable the i)ond culturist to form a tolerably correct idea of 

 the quality of each individual pond, if compared with the other ponds 

 and the entire pond area. In this way the overstocking of the entire 

 pond area will be avoided. The possible overstocking of one or the 

 <^»ther of the ponds will only aid in arriving at some definite opinion as 

 regards their relative productivity; and if the pro])er ratio of stocking 



