380 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 3 



of 0.678 fish per man-hour was due to 

 abnormal success in angling for bluegills. 

 The average catch for the period covered 

 by the census was 0.531 fish per man-hour. 

 Throughout the creel census period 

 there was a gradual reduction in the aver- 

 age weight of fish caught ; average weights 

 were 0.92 pound in 1938; 0.32 in 1939; 

 0.24 in 1940 and 0.22 in 1941. Abnor- 

 mally high average weights may be 

 observed for September and October of 

 1938, August and September of 1939, and 

 October of 1940. These were due to the 



influence of proportionally larger catches 

 of largemouth bass, a fish that averaged 

 heavier than other species. 



As a brief summary of fishing at Onized 

 Lake it may be stated that, during the 

 period of study, this 2-acre lake produced 

 a hook-and-line yield of 3,997 fish, weigh- 

 ing 1,152.43 pounds, requiring fishermen 

 to expend 7,526.9 man-hours in return for 

 an average catch of 0.531 fish per man- 

 hour, table 3. 



Statistics on fishing intensity and yield 

 from widely scattered investigations are 



Table 5. — Analysis of the hook-and-line catch by species, Onized Lake, 1938,* 1939, 1940 and 

 1941.t 



Year 



Statistics 



ffi 



H 

 O 



S 

 w 



O M 



b! en 



< < 



1-1 m 



Cl. 

 0. 

 < 



u 



o 



.J 



I— ( 



o 

 a 



pa 



j Number 13 3 3 3 2 4 



I Total weight, 



1938* N pounds 19.25 0.75 1,00 0.75 0.50 3.50 



i Average weight, 



\ pounds 1.48 0.25 0.33 0.25 0.25 0.88 



/Number 62 502 1,393 14 137 4 48 



1 Total weight, 



1939 (^ pounds 106.31 181.19 347.21 5.05 24.90 2.75 32.50 



i Average weight, 



f pounds 1.71 0.36 0.25 0.36 0.18 0.69 0.68 



J Number 29 56 639 54 358 3 23 13 



I Total weight, 



1940 <' pounds 39.78 22.45 131.85 15.81 55.07 2.50 15.12 2.45 



j Average weight, 



( pounds 1.37 0.40 0.21 0.29 0.15 0.83 0.66 0.19 



^Number 8 31 398 34 122 14 27 



1 Total weight, 



1941 1 <■ pounds 13.74 10.25 73.75 11.75 14.75 12.25 5.25 



J Average weight, 



( pounds 1.72 0.33 0.18 0.34 0.12 0.88 0.19 



^Totalnumber 112 592 2,433 105 619 7 89 40 3,997 



All 1 Total weight, 



Y x pounds 179.08 214.64 553.81 33.36 95.22 5.25 63.37 7.70 1,152.43 



j Average weight, 



( pounds 1.60 0.36 0.23 0.32 0.15 0.75 0.71 0.19 



Per Cent of 



Total Number 2.8 14.8 60.9 2.6 15.5 0.2 2.2 1.0 100. ( 



Per Cent of 



Total Weight 15.5 18.6 48.1 2.9 8.3 0.5 "5.5 0.6 100. 



*Only September and October in this year. 

 tOnly April, May and June in this year. 



