Demographics of a Recreationally Important Population of Spotted Bass in the Wabash River, Illinois

Although Spotted Bass are one of the most sought after game species in the Wabash River, little information is available regarding their demographics. We sought to assess the population of spotted bass in the Wabash River using both three-phase AC electrofishing and pulsed DC electrofishing. Average density as measured by CPUE was significantly higher with DC electrofishing compared to AC electrofishing. Whereas the average minimum length sampled by both gears was similar, the length frequency distributions were significantly different between gears. The proportional size distribution was different between gears with AC electrofishing sampling a greater proportion of quality sized fish. The proportion of preferred fish was low and no fish were of memorable size. Although fish were in good condition they were short lived with no individuals greater than age five. We necropsied frozen 46 specimens to assess the parasite loads in the liver, kidney, and heart. Approximately 76% of individuals had substantial parasite loads in at least one organ, 60% had parasites in at least two, and 43% were parasitized in all three. Although recreationally used, the population of Spotted Bass in the Wabash River is comprised of a low density of small, short lived individuals in good condition.