A Comparison of Two Methods for Sampling Bluegill and Redear Sunfish in Small Impoundments

Abstract

AbstractBluegill Lepomis macrochirus and Redear Sunfish L. microlophus are highly regarded recreational species throughout North America. Management of these species relies on sampling methods that accurately and efficiently describe population characteristics of the target population. Largemouth Bass Micropterus salmoides and crappies Pomoxis spp. are commonly sampled with spring electrofishing and fall fyke netting, respectively. If lepomids can be effectively sampled concurrently with Largemouth Bass or crappies with one of these sampling methods, it would improve sampling efficiency in small impoundments. Our objective was to compare two sampling methods (North American standard fyke netting and electrofishing) for sampling Bluegill and Redear Sunfish populations in small impoundments by comparing size structure, sampling precision (relative standard error), and sampling efficiency (effort needed to collect 125 stock‐length fish). Typically, spring electrofishing caught a wider size range of Bluegill and Redear Sunfish than fyke nets, but proportional size distribution was similar between gears. However, length frequencies differed between gears in all impoundments for Bluegill and in three of five impoundments for Redear Sunfish. Electrofishing typically caught a greater proportion of large lepomids than fyke nets in those cases, though the differences were subtle and management decisions would likely be similar using data from either gear. With the exception of Pawhuska Lake (which had low catch rates leading to poor precision for both species and both gears), catch rates were typically high enough to collect sufficient numbers (125 stock‐length fish) of Bluegill to adequately describe size structure with 5–20 net‐nights for fyke nets or 4–28 transects for electrofishing, but Redear Sunfish sampling would require considerably more sampling effort to produce sufficient amounts of fish in most cases (24–79 net‐nights for fyke nets or 12–57 transects for electrofishing). Spring electrofishing is the more precise (lower relative standard error) of the two sampling methods for collecting lepomids.