i 
THE INVESTIGATION OF A RIVER SYSTEM IN THE IN¬ 
TEREST OF ITS FISHERIES.* 
We have in Illinois a river of the same name as the state, which 
is in many ways one of the most remarkable streams in the country, 
and in no respect is it more remarkable than in its natural adapta¬ 
tion to the breeding and maintenance of a large and varied popula¬ 
tion of fishes and other useful aquatic animals; in none has it made 
a more remarkable record than in the supply of fish food which it 
has produced and is now producing—not for Illinois only, but 
for the country at large, sending out of the state, as it does, and 
mainly into eastern cities, much the largest part of its catch. The 
annual yield of the Illinois river in fishes only is over twenty-four 
million pounds, worth at wholesale about $738,000. If this annual 
output were turned into silver dollars, and these were placed in a 
row, equidistant from each other, along one of the banks of the 
stream, there would be a dollar every year for every two feet of the 
river’s course from its origin to its mouth. 
Furthermore, we have no reason to suppose that this stream and 
its adjacent waters have yet reached their limit of economic yield. 
The effect produced on them by the opening of the drainage canal 
from Chicago, and the still greater effect due to the introduction of 
the European carp, are examples of the fact that the original con¬ 
dition of the stream may be largely changed for the better, and give 
us reason to believe that it may be made a still more important as¬ 
set than now, both for the people of the state and for the general 
public who are the chief consumers of its product. Evidently this 
is one of the natural resources of the state and country which should 
be carefully safeguarded. A thoroughgoing, practical investigation 
of this stream is now especially imperative because of the great 
changes in progress at the present time in its environment and the 
still greater changes contemplated or impending, which have affected, 
or must certainly affect, greatly and permanently, its value for the 
purposes which it now serves. Reclamation projects, for the pro¬ 
tection, drainage, and cultivation of its bottom-lands; manufactur¬ 
ing projects, threatening a various contamination of its waters; ca¬ 
nalization projects and projects for the control and equalization of 
its flow, in the interests of transportation,—all are being earnestly 
agitated, and several of them are in process of active execution. 
*Read before the American Fisheries Society, New York City, September 
28, 1910. 
