467 
FisH CatcH, ILLInoris River anp LAKES, 1908 
(Inn, Fish Comm.) 
La Salle to Copperas Creek dam 
La Salle to Hennepin 520,000 lbs. 
Henry to Lacon 852,000 “ 
Chillicothe 350,000 “ 
Peoria 2,800,000 “ 
*Pekin (one half) 1,700,000 “ 
ANON ¢ SET be Tae aa eden ection ceoametiorstes 6,222,000 lbs. 
Copperas Cr. dam to Lagrange dam 
*Pekin (one half) 1,700,000 Ibs. | 
Havana 3,800,000 “| 
Bath 1,900,000 “ | 
Browning 1,700,000 ‘“ 
Beardstown 1,950,000 “ ; 
Fit te ee te ts I EE SAI eS SP caso rate: cere 11,050,000 Ibs. 
Lagrange dam to Grafton 
Meredosia 684,000 Ibs. 
Naples to Pearl 409,000 “ 
Kampsville to Grafton 905,000 “ 
RUCAIRM ETRE LAT, 3 Dal tet Sg teary stemttcterans ote 1,998,000 Ibs. 
Gra EEO len ws | 1, PaO Wily paabecetareletticrerstere oie 19,270,000 Ibs. 
«Pekin catch divided between adjacent reaches because of heavy fishing by 
Pekin crews in Spring Lake. 
? 
BotTToM- AND SHORE-FAUNA VALUATIONS, 1915, IN TERMS OF MontTHS 
SuppLy FoR ANNUAL INCREMENT IN FISH-WEIGHT 
oF 150 Pounps PER ACRE 
How close to a critical minimum, from the point of view of the fish- 
ery, the stocks of bottom invertebrates in the lower Illinois River had 
dropped in July—October, 1915, after 5 to 8 months’ feeding, is most 
clearly seen after we have changed the bottom-fauna valuations into 
terms of months’ supply of food for an annual yield of fish somewhat 
nearly equal to the average for the year 1908 on the acreage estimated 
to prevail during half of the year. In the tables next following, these 
calculations are shown as they come out for an annual weight increment 
of 150 lbs. per acre, the year’s feeding being completed in 9 months 
(March—November), animal food only being used, and an averagé 
consumption of five pounds of bottom and shore invertebrates (shells 
of mollusks deducted) for one pound increase in fish weight being as- 
sumed. The feeding ratio (5:1) adopted is the estimate of Walter* for 
carp and carp-like fishes, living on wild animal food, and is close to the 
* Die Fischerei als Nebenbetrieb des Landwirtes u. Forstmannes. 1903. 
