78 American Fisheries Society 



Apparently as a consequence, the product of black 

 bass, according to the United States census of this year, has 

 risen from $11,000 for the Illinois River in 1899 to $58,000 

 in 1908, when the census statistics were obtained. 



That perhaps is enough for that branch of the subject. 



1 made last year a statement with regard to the plankton 

 production of the Illinois River under existing conditions 

 as compared with those that obtained before the opening of 

 the Chicago Drainage Canal. I simply said to you at the 

 Xew York meeting, I remember, that the plankton product 

 was larger now than it used to be before the Chicago canal 

 was opened, bringing in an enormous amount of lake water 

 and sewage. We now have our data in more definite form, 

 and can compare the plankton product per cubic meter of 

 the water of the river before and after the opening of the 

 drainage canal. We found that the product was between 

 l wo and three times as great per cubic meter of the water of 

 the Illinois River in 1909 as it was before that canal was 

 opened; and the bass fishery and the carp fishery, and the 

 product of the whole river system, have risen in something 

 like a corresponding ratio. I have some statistics here which 

 1 will not trouble you to read, but will pass that point with 

 the general statement just made. 



Xow it might seem that we could rest content with the 

 present condition of things, so far as Chicago sewage and 

 (he drainage canal are concerned; it might seem that it was 

 like looking a gift horse in the mouth to go further. Never- 

 theless, I thought it my duty to look into the horse's mouth — 

 to see, that is, what the conditions are where the drainage 

 canal empties into the Illinois system ; and the greater part 

 of our work this season has been directed to that point. 

 R. E. Richardson, biologist of my staff, and C. II. Spauld- 

 ing, chemist, worked during midsummer from station to 

 station on the upper 93 miles of the Illinois, from its origin 

 at the junction of the Kankakee and the Des Plaines to the 

 upper end of Peoria Lake. 



