FISH PONDS ON FARMS. vi 
There are no authentic published records as to the financial returns 
that may be expected from the pursuit of pond fish culture on a 
commercial basis. Many theories have been advanced on this point, 
but, as in other undertakings of importance, the efficiency necessary 
in order to profitably conduct such a business can only be gained by 
repeated efforts and actual experience. Furthermore, in order to 
arrive at an estimate of any value one would have to take into con- 
sideration such important factors as the topographical features of 
the site, the character and quantity of the water supply available, the 
extent of the enterprise, and the location of the plant with reference 
to market and transportation facilities. 
Taking all these facts into consideration, one can readily see the 
futility of attempting to forecast in a general treatise the financial 
returns that may be expected from any given pond area devoted to 
commercial fish culture. 
All this, however, detracts in no way from the argument favoring 
the construction of ponds with the view to providing a food supply 
for private use. The feasibility of pond fish culture on this basis 
has been fully demonstrated, and ample quantities of fish for home 
use are to-day being propagated in established ponds on farms, 
proving the value of such an undertaking for that purpose alone. 
After gaining the required experience and knowledge of the sub- 
ject as a result of conducting work for several years on a limited 
scale, the farmer will be well qualified to judge as to the practicabil- 
ity of extending his operations, and can then, if he so chooses, in- 
crease his facilities with the view of raising fish for the market. 
Frequent inquiries are received by the Bureau of Fisheries re- 
garding the use of natural ponds, lakes, and streams, for the raising 
of fish. With respect to such water areas it may be stated that if 
drainage is provided for, the pond bed cleared of débris, the site 
protected against the inflow of surface water—if, in short, complete 
control is effected, natural water areas will possess many advan- 
tages over artificial constructions. There is objection, however, to 
any body of water not under complete control. 
WATER SUPPLY—VOLUME, QUALITY, AND TEMPERATURE. 
In a brood pond, a constant water level should be maintained at 
all times, especially during the breeding season. The required flow, 
which will vary with the character of the soil, must be sufficient to 
replace loss by evaporation and seepage. An amount just short of 
overflowing the pond is the ideal to be attained, as it is desirable to 
avoid a current. A surplus of water is preferable to a shortage, as 
any excess may be easily diverted through waste channels or held as 
an emergency reserve. 
