Chapter VIII 



CAi""-: OF PDl'il& 



A. Ob.jects and Methods of Pond Care . 



Aside from the rationally planned stock regulation and the artificial feeding, the 

 care of ponds is the most important means for the intensification of the pond industry, 

 and is indeed predominantly for the increasing of natural growth in natural carp and 

 trout ponds. In the main, the care of ponds has three tasks: 



(1) Proper raaintenance and improvement of the pond with regard to construction 

 and spaciousness, that is, maintenance of dams, elimination and prevention 

 of shallows, etc. 



(2) Creation of non-objectionable environments from the viewpoint of hyginene, 

 that is, improvement of the oxygen content, propl^rlactic and destructive 

 measures against disease and disease carriers in the pond. 



(3) Increasing of productivity by definitely aimed control in the metabolic 

 cycle in the pond to gain more favorable conditions for the strongest 

 possible development and utilization of fish food animals. 



These three main objects are always closely interwoven and often react up>on one 

 another. A technical mode of action is often successful in two, three, or more directions. 

 Liming, for instance, will not only destroy disease germs and food con5)etitors, but will 

 also bring about a most favorable alkaline reaction, which is important from the viewpoints 

 of hygiene and production. Liming also introduces into the ponds certain necessary aliments, 

 to wit: calcium and carbonic acid, which in turn stimulate the aquatic life of the ponds. 

 A separation of the various methods of pond care, in the sense of their action, is not 

 practical. Therefore in the following, the various methods of pond care are arranged in 

 groups and discussed in succession and at the same time the varied activities of these 

 methods, which are at once obvious on the basis of already discussed production-biological 

 fundamentals, are pointed out. 



The most important tasks in the proper care of ponds arei 



Improvements in construction. 

 Improveiaent of the soil. 



Clearing of the ponds from rushes and weeds. 

 Clearing of the banks, 

 In^Drovement of the oxygen content. 

 Liming and fertilizing, 



B, Maintenance of Pond Arrangements. 



It really remains to be^ pointed out, that pond arrangements must be continually kept 

 in order. Immediately after the fishing out, the fish trenches in the pond are to be 

 cleaned out, newly formed cavities are to be drained off or eliminated, floating islands 

 are to be anchored down by pouring on sand, loan or similar material. For ditch clean- 

 ing, simple ditch scrapers (firm wooden boxes having one front wall removed) are often 

 used. They are drawn through the slimy ditches by draught animals. Also the dams must 

 be continually controlled and kept in order. Wherever the crown of the dam is too close 

 to the water surface, the dam is to be subsequently raised. With too low a dam crown, 

 leaping trout too easily land upon the crown and cannot get back in the pond. The same 

 happens when plants on the dam crown are not mowed off regularly. Paths made by animals 

 must at once be dug up and obliterated as they can easily cause dam breaks. Smaller 

 fissures in dams may be plugged with sand bags and temporarily repaired. In case of 

 water seepage on account of the presence of alluvial sand, etc., it may be attempted to 

 tighten the dam by coating the inside with a sawdust sludge or worked up clay. Seepage 

 at the sluice box must be eliminated with particular care. 



The sluices themselves must be continually repaired. With slxiices made of masonry 

 or of concrete, any fissures occurring after draining must at once be carefully plastered 



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