. Annual report - New York Zoological Society. Zoology. 100 NEW YORK ZOOLOGICAL WHITE PERCH. exposed for a time to the action of the sun and frost. It destroys excessive plant growth and kills out destructive water beetles and other enemies of young fishes and is approved by most profes- sional fish culturists. With a series of ponds constructed at different levels, the 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 great importance to small ponds. It is desirable that surface water caused by
. Annual report - New York Zoological Society. Zoology. 100 NEW YORK ZOOLOGICAL WHITE PERCH. exposed for a time to the action of the sun and frost. It destroys excessive plant growth and kills out destructive water beetles and other enemies of young fishes and is approved by most profes- sional fish culturists. With a series of ponds constructed at different levels, the 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 great importance to small ponds. It is desirable that surface water caused by rainstorms 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 diffi- culties in the way of successful management, where ponds are constructed without provision having been made for drawing down or seining: A certain deep lake of about two acres in Connecticut, formed at great expense 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 of the use of a drag net. In the meantime, snapping turtles kill the voung 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. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original New York Zoological Society. New York, The Society
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1906
