Comparison of three sampling methods for small-bodied fish in lentic nearshore and open water habitats

Joseph E. Merz,Steven C. Zeug,Jesse Wiesenfeld,Jesse T. Anderson

doi:10.1007/s10661-021-09027-9

Joseph E. Merz, Steven C. Zeug + Show 2 more

Open Access

https://doi.org/10.1007/s10661-021-09027-9

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Abstract

We performed a preliminary evaluation of a mobile sampling platform with adjustable push net and live box (Platform) against two common methods for sampling small-bodied fish (i.e., 10–100 mm) in two distinct lentic habitats. Nearshore (NS) littoral habitat was sampled by Platform and beach seine, and open water (OW) pelagic habitat by Platform and Kodiak trawl. Our goal was to evaluate the Platform’s ability to describe fish assemblage structure across habitat types in contrast to common techniques restricted to single habitat types that are less comparable due to gear-specific bias. Platform sample speed had a significant positive effect on recapture efficiency of both nearly neutrally buoyant objects and marked fish. Marked fish recapture efficiencies were similar for Platform in NS and OW, indicating similar efficiency across habitat types. Platform capture efficiency was similar to beach seine and greater than Kodiak trawl. With similar sampling time, the Platform collected more individuals and taxa in NS relative to beach seine and in OW relative to Kodiak trawl. Greater taxa detection by the Platform suggests that it may be effective at detecting species that are numerically rare in specific habitats when compared to these methods. Fish CPUE was significantly greater NS regardless of technique. However, by using the Platform, there is greater confidence that this difference was reliable and not a gear selectivity artifact. Overall, this preliminary study demonstrates the Platform’s potential to collect standardized data across NS and OW habitats, track ontogenetic habitat shifts, and detect differences in small-bodied fish taxa richness, relative abundance, and density between NS and OW habitats. Continued experimentation beyond a single reservoir and fish size range is required before consensus can be established regarding the utility of this new push net design.

Highlights

Research on fish-based indices of biological integrity (e.g., Karr, 1981) has greatly improved fish monitoring methods and techniques, broadening our understanding of factors structuring occurrence,1 3 Vol.:(0123456789)255 Page 2 of 20 abundance, and composition of inland fish assemblages (e.g., Angermeier & Smogor, 1995; Aparicio et al, 2011; Deegan et al, 1997; Lyons, 1992)
Platform catch data to those collected by two gear types commonly employed to sample each habitat separately [beach seine (Hahn et al, 2007) in NS, and Kodiak trawl (Damon, 2016) in open water (OW) habitats] to assess the ability of a single technique (Platform) to provide comparable data across habitats. In this preliminary study to assess the practicality of continued development of this novel sampling method, we focused on smallbodied fish and juveniles of select larger fish (i.e., 10–100 mm) that may or may not transition between NS and OW lentic habitats against two common methods used in freshwater and estuarine environments
We evaluated whether the FL distribution of black crappie, the most common species captured among sampling gears and habitat types, differed among gear types within NS and OW habitats during the 14 June 2017 sampling, the day when they were most frequent

Summary

Introduction

Research on fish-based indices of biological integrity (e.g., Karr, 1981) has greatly improved fish monitoring methods and techniques, broadening our understanding of factors structuring occurrence,1 3 Vol.:(0123456789)255 Page 2 of 20 abundance, and composition of inland fish assemblages (e.g., Angermeier & Smogor, 1995; Aparicio et al, 2011; Deegan et al, 1997; Lyons, 1992). Specific sampling gears are often selected based on habitat characteristics, such as depth, sampling area, water temperature, methodology limitations, or target species characteristics (e.g., Pierce et al, 1990; Bonar et al, 2009; Baran et al, 2017). Beach seining is limited by depth and samples relatively small water volumes per haul (LaPointe et al, 2006; Lyons, 1986; Pierce et al, 1990). Composition of captured fish assemblages depends on gear used and Environ Monit Assess (2021) 193: 255 sampling site conditions, limiting our ability to standardize sampling and interpret results across habitat types (Eggleton et al, 2010; Fischer & Quist, 2014a, 2014b)

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