158 THE GAME BREEDER 



entailed in their use, as large and con- roily and demanding less attention to 

 tinuous deposits of mud in breeding screens owing to absence of currents, 

 ponds will ruin any eggs present, and in- Uncontaminated open waters have 

 variably kill recently hatched fry. Fur- many advantages. Their temperatures 

 thermore, protracted roily water will re- are seasonal; usually there are no ab- 

 tard and sometimes prevent growth of normal gaseous constituents to be cor- 

 the aquatic vegetation so essential to rected; the plankton or pelagic animal 

 pond fish-cultural operations. It is also and plant life contained therein forms a 

 imperative that undesirable and predace- valuable addition to the natural food 

 ous fishes be rigorously excluded from supply in the pond, and were it riot for 

 the ponds, and it will be impossible to the difficulty of control and occasional 

 accomplish this if the water supply is roilyness, such waters would be prefer- 

 beyond control during certain periods, able to springs and wells as a source of 



From the foregoing it can readily be supply to fish ponds, 

 seen that if a stream is subject to ap- Wells, both flowing and power lifted, 

 preciable changes, as a result of storms are successfully used in some sections 

 or drainage from local watersheds, it for the cultivation of fish. Before in- 

 will be unwise to establish a pond therein curring the expense of constructing 

 by the construction of dams, as is often ponds to be supplied from such a source, 

 contemplated. It will be entirely feas- however, it will be advisable to thor- 

 ible, however, to conduct water from oughly test the water in order to dem- 

 such a stream to ponds adjacently lo- onstrate its fitness for fish culture. This 

 cated, provided the intake is adequately can best be done by fitting up a running- 

 screened, the supply arranged so that it water supply in a retaining reservoir, and 

 can be cut off during times of excessive holding therein, for an extended period, 

 turbidity, and measures are taken to pre- a number of specimens of the species of 

 vent the inundation of the pond site in fish it is desired to propagate. If they 

 high-water periods. thrive, it may be assumed that the water 



It may be necessary to erect a dam is free from injurious gases or mineral 

 in the channel of the stream, to provide substances and is adapted to the work 

 the required head of water for a gravity it is proposed to undertake. 

 flow to the pond, in which case it may Rain Water (Surface Drainage). 

 be of a simple type, designed merely to Another class of ponds available for 

 accomplish the end in view. The intake the propagation of fish, known as "sky 

 from the stream should be wide and ponds," embraces those wholly or partly 

 deep, thus presenting a large screen sur- dependent upon local precipitation for 

 face to obviate the complete stoppage of their supply of water. Such ponds are 

 the water supply in the absence of the invariably profuse in the production of 

 caretaker. It should be covered by a fish food, and for this reason would be 

 series of screens^ graduated in size, the ideal were there an auxiliary water sup- 

 first to consist of coarse hog wire, or ply adequate to maintain constant sur- 

 wooden racks with Hke openings, to catch face levels during the critical nesting 

 the largest objects. The intermediate season, and a fair depth throughout the 

 screen. (of 2-inch mesh) will intercept remainder of the year. In the absence 

 vegetation, while the inner one must be of this reserve many such ponds become 

 fine enough to exclude smaller debris and practically dry during periods of drought 

 the fry of undesirable fishes. Immedi- or freeze to the bottom in the winter 

 ately below, the screens, gates should be months. Where ponds are subjected to 

 provided so that the water may be shut such conditions fish cultural operations 

 off at will and diverted into a storm chan- are impracticable, 

 nel when it becomes too^ roily for use. Ponds dependent entirely upon preci- 



Where the source of supply is a lake pitation and surface drainage for their 



the difficulties referred to above are not water supply must necessarily be located 



encountered, lake water seldom being at a low elevation, in order that the sur- 



