[41] POND CULTURE. 



50: 



the fish to enter them, aucl allow the fishermen to approach these de- 

 pressions for catching the fish hiding in them. In ponds containiuo- a 

 great many reeds the side ditches are also to serve as roads by whTch 

 the fish may easily reach their feeding-places near the banks," a'ul as 

 places of refuge in all parts of the pond, where they may find safety 

 from birds of prey and other enemies of fish. Their construction and 

 maintenance should therefore keep all these purposes in view, and they 

 should be kept clean at all times. After the ponds have been laid dry, 

 and the fisheries are over, special attention should be given to the clean- 

 ing out of mud from these ditches. 



4. THE FISH-PIT. 



In order to drain a pond completely and catch all the fish contained 

 in it, the fish must be gathered within a narrow space, where they have 

 water enough to prevent any suffering during the fisheries. For this 

 purpose it is necessary to have a depression near the place where the 

 water flows off into which the fish may gather when the pond is drained, 

 and from which they can easily be taken with nets. This depression is 

 called the fish-pit. When the pond is being drained, the fish, as the 

 water recedes, seek the deep water of the ditches, and through these 

 they enter the fish-pit. The fish-pit will best be formed bv widening 

 the main ditch either on one side of the ditch, as we generally find i't 

 in old ponds, or extending it equally on both sides, which will probably 

 be the more practical way. 



The fish-pit should be kept as clean as possible of mud, and it will 

 therefore be advisable to line it with wood. This should only be omitted 

 in ponds which have a very firm bottom and but little mud. The fish- 

 pit of those ponds, however, which are to serve as spawning ponds 

 should be lined with wood, unless the bottom is very clayey and firm, 

 so that it may be possible to take out all the young fry. The fish-pit 

 should be entirely free from stones, bushes, reeds, &o., so that the fish 

 may not hurt themselves during the fisheries and during wintering, and 

 likewise to prevent any tearing of the nets. After every fishing season 

 the fish-pit should, therefore, be carefully cleaned. If the fish-pit is 

 only to serve for fishing purposes, its depth need not be very great but 

 in order that the water may be let off entirely, and the pond may be 

 cleared of fish, its bottom should be higher than the outlet pipes. If the 

 fish-pit is intended also for wintering fish, its depth should be great 

 enough to prevent the freezing of the pond in winter, and it should be 

 at least 2 meters deeper than the greatest depth of water elsewhere in 

 the pond. 



In order to gain some means of determining the approximate size of 

 the fish-pit, we will state that one generally counts 800 cubic decimeters 

 of water to 100 pounds of carp; but it will in all cases be advisable to 

 count double this quantity, especially when the fish-pit is to serve as a 

 wintering place, or when there is a possible lajck of water during the 



