River reaches (Figure 3). Far fewer common carp have been taken in the upper 

 river, where CPUEn has been consistantly low during the five years of this project; 

 only 5 common carp per hour or less have been collected from 1994 through 1998. 

 Catches of emerald shiner have typically been less than CPUEn 50 except in the 

 upper river reaches in 1995, when average CPUEn was 165 (Figure 4). Catches of 

 bluegill in all three river sections have shown similar trends over the five years of this 

 study (Figure 5). Bluegill CPUE^ was highest in 1995 (CPUE^ 40-46) and has 

 exhibited an annual cyclical pattern in population size. This pattern appears to be 

 consistant throughout the entire waterway. Catches of freshwater drum have been 

 highest in the middle river reaches (CPUE^ 12-23) (Figure 6). Collections in the 

 lower river have ranged from CPUEn 5-12, and in the upper river have been 

 extremely low by comparison, with CPUE^ <1 during all years of this project. 



D. Catch Rates in Weights (pounds) Collected per Hour by Reach. 



Catch rates in pounds offish collected per hour (CPUEw) were also examined 

 to provide an estimation offish biomass and production of each Illinois River reach. 

 Overall, CPUEw ranged from 48 pounds per hour in 1995 to 74 pounds per hour in 

 1997 (Tables 16-25). La Grange Reach has consistantly provided the highest 

 catches in weight (CPUEw 81-108) except in 1997, when average hourly collections 

 from Peoria Reach were 114 pounds (Table 22). Lowest catches in weight each 

 year have typically come from Starved Rock (CPUEw 1 1-32) and Marseilles (CPUE^ 



32 



