[Reprinted by permission of the New York Zodlogical Society.] 
THE CULTIVATION OF FISHES IN SMALL PONDS. 
—_— 
BY CHARLES H. TOWNSEND. 
Aquarium Battery Park, New York City. 
In presenting this paper to the Fisheries Society, I do so less in the hope 
of affording instruction to professional fish culturists like yourself, than of 
creating some discussion of the subject and profiting thereby myself. For 
several years I have been experimenting with small natural and artificial 
ponds on private estates in the vicinity of New York, with a view to ascer- 
taining their possibilities for producing the commoner fishes. Requests for 
information on the subject of home fish ponds are being made constantly by 
the public. I have arranged the matter under the general headings of “‘Nat- 
ural Ponds” and ‘Artificial Ponds” and have attempted to present brief and 
general instructions for their management. The raising of trout is not con- 
sidered in this connection. Trout require special conditions of water supply 
and temperature, seldom found on the farm. For the ordinary run of ponds, 
it is necessary to restrict the list of available fishes to perches, basses and 
sunfishes to which they are adapted. 
Natural Ponds or Lakes.—It is assumed that the position of the natural 
pond is such that no arrangement can be made for drawing off the water. Its 
possibilities will, therefore, have to be considered separately. Its fish life, 
moreover, can never be brought under complete control. If the character and 
abundance of the fish life in the pond are not known it is desirable that it be 
ascertained as far as possible by fishing or netting. If the pond is without 
any fishes it should, of course, be stocked at once, and the selection of fishes 
made with due regard to its natural conditions. The extreme depth, mid- 
summer temperature, plant life and character of the bottom of the pond 
should all be ascertained. The summer bottom temperature of deep ponds 
should be known. ° It can be taken by lowering the thermometer in a pail and 
allowing it to remain some time. If pulled up rapidly the temperature will 
not have time to rise materially. A series of bottom temperatures will 
serve to indicate the presence of bottom springs. 
A wide area of shallow water in a pond not well supplied by springs or 
rivulets usually means great warmth in summer. If such a pond can be 
temporarily lowered and deepened in places, its conditions for fish life 
would be greatly improved as there is a decided difference in temperature 
between surface and bottom waters. Below six or eight feet the tempera- 
ture decreases at the rate of about two degrees for each foot of depth. In- 
creased depth would also give fishes an additional chance for life in winter 
when heavy ice diminishes their supply of air. A small pond supplied 
chiefly by rainfall, may be increased somewhat in water supply by leading 
to it ditches from adjacent fields; while its depth may admit of some in- 
crease by enbankments. If water can be had by boring an artestian well — 
may make just the difference between a poor pond and a good one. Fish 
ponds should have water plants to afford shelter for young fishes and har- 
