A Tale of the Wabash River Flathead Catfish: Sampling Inefficiencies and Demographics

Flathead catfish, Pylodictus olivarious, are a popular game fish in the Midwestern United States. In the lower 322 km of the Wabash River, flathead catfish are commercially harvested by Illinois and Indiana fishers. Current management regulations are different between the two states. Illinois and Indiana have minimum size limits of 381 and 254 mm respectively. Indiana is in the process of changing their minimum size limit to 381 mm and allowing only one fish over 889 mm to be harvested. Our project will assess the current status of flathead catfish in the Wabash River to inform potential management options for the state of Illinois. We sampled flathead catfish using AC and DC electrofishing during the summer of 2010 and 2011. In 2011, we also set hoopnets and trotlines. To estimate age, we removed pectoral spines from all fish greater than 200 mm. Catch per unit effort (CPUE) was higher for DC electrofishing (32.7 fish/hr) compared to AC electrofishing (2.8 fish/hr). Hoopnetting had a CPUE of 1.1 fish/net night and trotline proved ineffective for flathead sampling. Hoopnetting captured larger fish than either gear type. We aged 68 flathead catfish from 2010. Mean age and length of the flathead catfish was 2.9 years and 363.49 mm.  DC electrofishing seems to be a more effective way to sample flathead catfish than AC electrofishing. However, in order to capture larger fish sampling must include hoopnetting.