Management of 
Small Artificial Lakes 
A Summary of Fisheries 
Investigations, 1938-1942 
GEORGE W. BENNETT 
HE management of lakes for fish- 
ing should not be confused with fish 
culture as generally practiced in the 
United States. Lake management may re- 
quire the products of fish culture, but its 
concept is much broader in that it attempts 
to discover and apply fundamental biologi- 
cal principles and relationships associated 
with fishes in natural or artificial waters, 
with the practical object of increasing fish 
yields and maintaining them. While cur- 
rent literature dealing with the physical, 
chemical and biological aspects of fish en- 
vironment is voluminous, little is known 
concerning the ecological interrelationships 
of the fishes themselves, and this field offers 
a great deal of promise to those investi- 
gators who are called upon to find a solu- 
tion to the ever increasing fishing pressure 
of a recreation-minded public. 
Artificial lakes, although often lacking 
some of the scenic beauty of natural 
waters, can be made attractive as centers 
of recreation throughout much of our 
country. From the standpoint of fish man- 
agement, they have an advantage over 
natural waters in that they are usually 
smaller, and often can be drained or other- 
wise rid of undesirable fish. However, 
large natural lakes as well as large arti- 
ficial lakes are practically beyond the scope 
of the fish manager, once they become 
filled with undesirable fish. Large-scale 
netting operations on such waters may 
reduce the numbers of these undesirable 
species, but offer little assurance of perma- 
nent improvement. 
The material in this paper includes 
information from several sources. That 
gathered by Dr. David H. Thompson, IIli- 
nois Natural History Survey Zoologist, 
and the author, from censusing the fish of 
22 small artificial lakes in Illinois has been 
of great value in determining the kinds of 
fish suited to this type of habitat. It has 
also revealed some of the causes for poor 
fish yields, as well as information on the 
compatibility of various species. Angling 
records supplemented by hoopnet samples 
from several lakes provide a means of 
measuring the eftects of underfishing and 
overfishing on fish populations. The case 
histories of many experimental lakes in 
which various combinations of fishes have 
been stocked suggest the degree of useful- 
ness of the different combinations in fish 
management. 
Objectives of Fish Management 
‘The primary objective of fish manage- 
ment is to produce and maintain “good 
fishing.” A definition of “good fishing”’ 
should include the element of numbers of 
fish caught per unit of time or effort, as 
well as that of size of individual fish. 
Numbers and sizes can hardly be defined 
satisfactorily for all cases, because of vari- 
ation in the kinds of fish involved as well 
as in desires of the fishermen. However, 
the fish manager has need of some criterion 
useful (although not entirely satisfactory ) 
in comparing the “goodness” of fishing 
waters. There is some agreement on the 
criterion of numbers placed at one fish per 
man-hour. In Illinois, where nearly all 
catches are bass, crappies, sunfish (cen- 
trarchids) or catfish, we have defined “‘de- 
sirable size” for several common species 
(Bennett, Thompson & Parr 1940, p. ee 
ese 7s] 
