BULLETIN OP THE UNITED STATES FISH COMMISSION. 249 



33.— DIRECTIONS CONCERNING THE CONSTRUCTION OF CARP 



PONDS. 



[Condensed from the report of the Maryland Fish Commission for 1880.] 



The cultivation of carp is of sufficient importance to fully warrant 

 the construction of ponds for the purpose. Bat there already exist in 

 many places ponds used for the collection of ice, or for supplying water 

 to live stock , which could be converted into carp ponds at a compara- 

 tively small cost. There are also many depressions of surface < in the 

 lands which could be .filled with water with but little labor, and made 

 to answer the purpose admirably. 



It is very desirable, on several accounts, that the ponds should be so 

 constructed as to permit the water to be drawn off. The fish can then be 

 captured and assorted, when those intended for breeding can be returned 

 to the pond and the remainder placed in tanks from which to be taken, 

 by the aid of dip-nets, as required for market or for food. Drawing off 

 the water is also desirable for destroying such enemies of the fish as 

 may be therein. 



In the case of ponds supplied by the inflow of tide-water, eggs of 

 other fishes are often wafted in, and the fish thus produced may con- 

 sume the food, eggs, and young of the carp. By draining the ponds 

 once or twice a year these intruders can be readily removed. 



To utilize an ice pond for carp is very simple. It is not necessary 

 that the drainage from the surrounding fields should be diverted, except 

 when excessive in quantity or liable to become so after a heavy fall of 

 rain. A certain amount of such drainage often proves beneficial, as 

 considerable quantities of food are thus conveyed into the ponds. If 

 admitted, an "overflow" must be provided, which should be well pro- 

 tected by wire-cloth screens to prevent the escape of the fish. This 

 overflow constitutes the most important feature in the construction of a 

 pond. 



For illustration, Fig. 1 is a pond located in a meadow, through which 

 flows a small stream. The pond is formed upon two sides by embank- 

 ments of earth obtained by the removal of a portion of the soil from the 

 inclosed space. The water may be supplied either by introducing it from 

 the rivulet itself at some higher point, or, as in this illustration, from a 

 spring in the adjacent meadow, supplemented by the surface drainage 

 from the surroundiug high land. A small tributary of the rivulet is 

 utilized in this instance to carry off the surplus water, which is allowed 

 to escape from the pond through the overflow O. A is the apparatus 

 for emptying the pond. B is a frame inclosing the end of the discharge 

 pipe leadiug from the pond, and provided with the screens s s s. C is 



