74 
being here estimated as actual, outside of levees, and not as in the virgin 
valley—for the purpose of comparison with the 1920 data rather than 
with the fish-yield figures of 1908; and involving as well, the application 
in some cases of both river and lake acre-yield-figures for limited areas 
studied in 1920 to much larger acreages not collected in that year. For 
these reasons, only general results are given here, and tabulation is 
avoided as giving too much of an air of certainty to figures that are at 
the best only approximations. 
In the 60.5 miles between Chillicothe and Havana in July—October, 
1914—15 it appears, then, that there were surplus stocks of both bottom 
and weed animals, after deduction of shell weight, amounting to around 
27,500,000 pounds in a combined open river and lake acreage, including 
Peoria Lake of about 29,000 acres at an approximate gage of ten feet, 
Peoria, or eight feet, Havana. Of this total I have estimated that about 
2,700,000 pounds were in the bottom muds of the river and the wide 
waters of Peoria Lake between Chillicothe and the dam at Copperas 
Creek ; about 3,800,000 pounds in the river muds between Copperas Creek 
dam and Havana; and about 3,000,000 pounds on the lake and other 
backwater floors between Copperas Creek and Havana. Considerably 
more than half of the total, that is, over 18,000,000 pounds (65 per cent.) 
of it, seems to have been made up of the small weed-living species, of 
which Peoria Lake apparently furnished more than 4,000 ,000 pounds a 
few years ago, and the rich lakes between Copperas Creek dam and 
Havana, around 14,000,000 pounds. 
Applying to these same acreages such average weights per acre as 
are suggested by the findings of August—September, 1920, we note first 
an estimated reduction since 1915 in the bottom fauna of Peoria Lake 
and adjacent river between Chillicothe and Copperas Creek that amounts 
roughly to 50 per cent., and that affects about 10,000 acres at the lower 
gages of the ten years preceding 1920. Next are calculated reductions of 
92 to 93 per cent. in the bottom fauna of some 1,400 acres of river and 
some 17,000 acres of lakes between Copperas Creek dam and Havana; 
and, last, reductions to practical nullity in the case of the acre-yield 
figures of small weed-animals both of the weedy acreage of Peoria Lake, 
estimated at 2,000 acres in 1910 i 
10,000 acres of shallow weed-area in the lakes between Copperas Creek 
dam and Havana. The total loss in poundage of surplus stocks between 
Chillicothe and Havana in five years appears indeed to have surpassed 
25,500,000 pounds, or to have amounted on the average for both river 
and lakes, including both bottom and weed populations, to over 93 per 
cent. The extent of the loss is better appreciated when it is known that 
it is usual to figure that the weight of fish living on animal food can be 
increased about one pound for each five pounds of such food eaten. From, 
this view-point the loss in potential fish-yield apparently stands at some- 
thing like 5,000,000 pounds yearly for the section, if also it be true, as is 
