Comparison of Three Methods for Sampling Panfish in Iowa Impoundments

Abstract

Science-based decision making in fisheries management requires the collection of sampling data with the acknowledgment that all gears have inherent sampling biases. Fyke nets are a common tool for sampling panfish. However, recent evaluations suggest hoop nets are more effective for evaluating these populations. We compared panfish relative abundance, size structure, condition, sampling effort to capture 100 individuals, and sampling precision for small (61 × 122-cm frames) and large (91 × 183-cm frames) fyke nets soaked for 24 h and tandem hoop nets soaked for 72 h during spring and fall. Hoop nets and large fyke nets captured more Bluegills Lepomis macrochirus, Black Crappies Pomoxis nigromaculatus, and White Crappies P. annularis than did small fyke nets, but catch rates for Redear Sunfish L. microlophus were similar among gear types. Bluegills captured in hoop nets were generally longer than those captured in small or large fyke nets, but the length of other panfish was similar among gears. Bluegill size structure was generally largest and Black Crappie size structure was generally smallest in hoop nets compared with that in fyke nets. Relative weight was greater for Bluegills captured in small fyke nets and was higher in the spring than fall. Hoop nets generally captured more panfish with fewer net sets and with greater precision than did small or large fyke nets, providing an additional tool for fisheries biologists for population assessments.

Received March 4, 2016; accepted July 13, 2016 Published online October 28, 2016

ACKNOWLEDGMENTS

We thank C. Dolan, B. Ellison, B. Hayes, T. Shay, P. Sleeper, C. Mack, M. Boucher, V. Poulton, and G. Scholten for assistance with study design and fish sampling. We additionally thank R. Krogman, J. Koch, and anonymous reviewers for comments that improved this manuscript. Funding for this project was provided by the Iowa Department of Natural Resources through Iowa fishing license sales.