INVESTIGATIONS ON PLANKTON PRODUCTION IN FISH 
PONDS 1 
By A. H. WIEBE, Ph. D., Temporary Assistant 
J* 
CONTENTS 
Page 
Introduction 137 
Purpose of this investigation 137 
Literature 140 
Methods of analysis and expression 
of results 141 
Acknowledgments 142 
C pond experiments 142 
Description of ponds 142 
Purpose of this experiment 142 
Limnological data 144 
Organic matter 151 
Plankton 153 
Summary 157 
D pond experiments 158 
Description of ponds 158 
Purpose of this experiment 158 
D pond experiments — Continued. 
Pond D 4 
Notes on vegetation 
Limnological data 
Plankton 
Pond D 5 
Notes on vegetation 
Limnological data 
Plankton 
Pond D 9 
Notes on vegetation 
Limnological data 
Plankton 
Summary of D ponds 
General summary and conclusions 
Literature cited 
INTRODUCTION 
PURPOSE OF THIS INVESTIGATION 
Page 
158 
158 
159 
159 
161 
161 
161 
163 
163 
164 
164 
166 
168 
168 
175 
While the pond culture of fresh-water fishes is an art of many years’ standing in 
certain European countries, notably Germany, in this country pond-fish culture is a 
relatively recent development. Hence, very little accurate knowledge applying to 
pond-fish culture in this country is at present available. With the depletion of the 
native fish stock in our natural waters and with the growing demand for game fish to 
stock inland waters, the need for more exact knowledge as to how to rear fish in ponds 
has become apparent. During the last few years the Bureau of Fisheries, through its 
division of scientific inquiry, has attempted to solve some of the problems pertaining 
to the rearing of game fish in ponds to the fingerling stage rather than to distribute 
them as fry. One of the chief problems has been that of increasing the food supply 
for the fish. 
The amount of available fish food may be increased either directly or indirectly : 
Directly through artificial feeding, indirectly through increasing the natural food 
supply. It is the policy of the bureau in its pond-culture work with warm-water 
fishes to increase fish production by the indirect method of using fertilizers to increase 
the natural food supply rather than to resort to artificial feeding. 
1 This report is based on a doctor’s thesis submitted before the graduate faculty of the University of Wisconsin. It was sub- 
mitted to the Bureau of Fisheries for publication Mar. 13, 1930. 
137 
