Evaluation of Hoop-Net Size and Bait Selection for Sampling Channel Catfish in Iowa Impoundments

Abstract

We compared seasonal catches of channel catfish Ictalurus punctatus between large (76-cm-diameter frames; 25-mm bar measure mesh) and small (61-cm-diameter frames; 19-mm bar measure mesh) tandem hoop-net series and between two different bait types (soybean cake and waste cheese) during 2004. Size structure data collected by both gears provided similar estimates of proportional stock density (PSD) for the gear and bait types within impoundments. Catch across seasons was similar within impoundments; however, estimates of PSD varied by season. Large hoop nets captured substantially more fish than the small hoop nets. Bait type did not significantly affect catch per unit effort (CPUE) of hoop nets except in summer, when nets baited with soybean cake captured significantly more (>1.5 times) channel catfish than nets baited with waste cheese. The CPUE precision was greatest for large hoop nets baited with soybean cake during summer or fall. We suggest use of large hoop nets and soybean cake as a standard summer sampling regime. Large hoop nets baited with soybean cake caught more fish, provided the most precise estimates of CPUE, had low levels of fish mortality, and were convenient for use during the summer, when management biologists have time to devote to channel catfish sampling. In addition, soybean cake is preferred over waste cheese because it produces less odor, has fewer storage problems, and can be obtained easily from local suppliers.