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jthat is, leave the bottom exposed for a time to the action of the sun and 
frost. This destroys excessive plant growth and kills out destructive water 
beetles and ther enemies of young fishes and is approved by most profes- 
jsional fish culturists. With a series of ponds constructed at different levels, 
jthe overflow of the upper ponds will serve to feed those below. The more 
fall there is to the water the better will be its aeration—a matter of sreat 
jimportance to small ponds. It is desirable that surface water caused by 
jrainstorms be kept out of small ponds by banking up or ditching. 
| The following instances, among many which came under the writer’s 
|/personal observation, will serve to show some of the difficulties in the way 
jof successful management,. where ponds are constructed without provision 
jhaving been made for drawing down or seining. 
| A certain deep lake of about two acres in Connecticult, formed at great 
jexpense by damming a brook, is without any provision for drawing down. 
|The conditions prevailing in it are unknown, and nothing but hook and line 
or some form of trap net are available for ascertaining its contents, since 
its borders will not permit the use of a drag net. In the meantime, snap- 
ping turtles kill the young ducks on it each summer, and there is no way of 
getting rid of them. 
Another pond, which could not be lowered, was believed to be without 
fishes, until the use of a seine in one corner showed that the yellow perch 
fry introduced two years before ‘had already attained good size. The pres- 
ence of snags elsewhere in this lake prevented the use of the net. The 
management of this pond will always be difficult and unsatisfactory. 
A lake in Zodlogical Park stocked with yellow perch fry in 1903, was 
represented to be without fishes, until the use of a seine sent from a Aqua- 
rium a year later, showed it to be well supplied. The full’utilization of this 
lake is, however, impossible since its bottom has many scattered rocks which 
prevent effective seining. If the rocks had been removed originally, a good 
sized seine would sweep it from end to end. 
Water Supply.—The water supply of the fish pond is the most important 
thing to be considered. It must in fact be taken into consideration before 
the artificial pond is made. The flow of water should be abundant. About 
twice as much will usually be required as the beginner thinks is necessary. 
Ponds fed by strong springs are excellent and are not subject to the dangers 
of which stream-fed ponds are exposed. Their temperature is naturally 
more equable throughout the year and they are less liable to neavy freez- 
ing in winter. In warm weather and in the winter time, pond fishes avoid 
extreme tempeature by frequenting the vicinity of bottom springs. Spring 
water, however, contains less life available as fish food, and less air than 
that from brooks. Its value for pond supply will be improved, if it can be 
led some distance as a rivulet. Fish-life in small ponds with limited water 
supply will suffer from heavy ice in winter. The ice should be broken 
daily, and masses of brush and branches placed partly in the water will aid 
in keeping air holes open, especially if they are moved by the wind. 
Extent and Depth of Ponds.—The extent and depth of ponds made by 
damming streams, will be governed somewhat by the nature of the situation 
available. A pond of an acre or more in extent, and with eight or ten feet 
of water in the deepest part, will, if properly managed, give excellent results. 
It may be necessary to make it less than one-quarter of an acre in extent, but 
a small pond should have an extreme depth of not less than six feet, al-~ 
though it is quite possible with a strong water supply to raise fishes in very 
small and shallow ponds. This, however, means active cultivation, with daily 
feeding of the fishes, numerous ponds to permit of sorting and all the details 
of a fish cultural establishment. As a matter of fact, nearly all of the 
extensive fish-breeding carried on by the national and State fish commis- 
Sions have been done in ponds of ‘rectangular shape, averaging perhaps less 
than 100 feet in length and 25 feet in width, having depths of only three or 
four feet. Such ponds are worked in series, as nursery and rearing ponds, 
and there are generally two or more ponds of larger size in which fishes of 
