Effect of Block Net Use and Time of Sampling on Backpack Electrofishing Catches in Three Kansas Reservoirs

Abstract

Using backpack electrofishing in three Kansas reservoirs, we investigated the need for block nets when estimating density (fish/ha) and species diversity and determined whether time of sampling affected catch rates (fish/h) of age-0 largemouth bass Micropterus salmoides and age-0 Lepomis spp. and species diversity. Block nets were used to enclose or buoys were used to mark the boundaries of 149 m 2 of reservoir surface area. Species richness, diversity, and density of age-0 largemouth bass and Lepomis spp. did not differ significantly between areas enclosed with block nets and areas marked with buoys, but species richness, diversity, and catch rates differed significantly between day and night sampling. Age-0 largemouth bass and Lepomis spp. catch rates, species richness, and species diversity were all significantly higher during night sampling. Our results indicate that use of block nets may not be necessary to estimate age-0 largemouth bass and Lepomis spp. densities, species richness, or diversity in reservoir littoral areas. We recommend night sampling because of significantly higher catch rates and better representation of the littoral fish assemblage.

An evaluation of multiple-pass seining to monitor blackstripe topminnow Fundulus notatus (Rafinesque, 1820) in the Sydenham River (Ontario, Canada)

“…A number of studies have found electrofishing‐based estimates of stream and reservoir fish species diversity and richness to be unaffected by block‐net use (Vadas and Orth, ; Simonson and Lyons, ; Schoenebeck et al., ). Conversely, Steele et al.…”

“…A number of studies have found electrofishing-based estimates of stream and reservoir fish species diversity and richness to be unaffected by block-net use (Vadas and Orth, 1993;Simonson and Lyons, 1995;Schoenebeck et al, 2005). Conversely, Steele et al (2006) reported that seining without block-nets underestimated estuarine fish species richness by two-fold and density by four-fold.…”

Accurate Estimation of Salmonid Abundance in Small Streams using Nighttime Removal Electrofishing: an Evaluation using Marked Fish

“…Nighttime electrofishing proved highly effective for sampling salmonid populations in wadeable streams, and the resulting three-pass removal estimates were both accurate and precise. Likewise, others have reported increased sampling efficiency at night, probably because fish are more available for capture owing to diel microhabitat selection, activity, or less fright response (Sanders 1992;Schoenebeck et al 2005;Hardie et al 2006). Three-pass capture probabilities for salmonids were higher than in two recent evaluations of daytime electrofishing (Peterson et al 2004;Rosenberger and Dunham 2005) but similar to other studies during the day (Riley and Fausch 1992;Sweka et al 2006).…”

“…Nighttime electrofishing is one potential means to address the first problem and achieve high capture probability for salmonids. It has proven effective for sampling lentic habitats (Dumont and Dennis 1997;Pierce et al 2001;Schoenebeck et al 2005) and large rivers (Sanders 1992). Many salmonids seek cover during daylight but are more active at night (Young 1999;Jakober et al 2000;Diana et al 2004), which may lead to increased capture efficiency at night, as has been reported for snorkeling (Dumont and Dennis 1997;Thurow et al 2006).…”

Spatial and Temporal Variability in a Large‐Reservoir Fish Assessment and Application of a Stratified Random Sampling Approach

“…), season of sampling (Pope and Willis ; Schoenebeck and Hansen ), time of sampling within a day (McInerny and Cross ; Schoenebeck et al. ), spawning movements (Colvin ; Palmer et al. ), sampling gear used (Colvin ), depth of gear deployment (Blackwell and Brown ; Rhea et al.…”