Evaluation of freshwater invertebrate sampling methods in a shallow aridland river (Rio Grande, New Mexico)

Abstract

Aridland rivers can present several logistical challenges for invertebrate sampling due to shifting substrate and low invertebrate densities. We compared 4 sampling methods for collecting both meiofauna and macroinvertebrates in an aridland river (Rio Grande, New Mexico): a water column sampling method, an epibenthic core, a throwtrap, and a stovepipe sampling method. The objective of this study was to find the most efficient combination of sampling methods with which to collect the entire assemblage. Differences were tested among sampling methods in terms of abundance, taxonomic richness, assemblage composition, and invertebrate body size. No single sampling method was able to provide accurate estimates of both abundance and taxonomic richness across the range of body sizes of taxa collected in this study. Invertebrates were concentrated in the epibenthos, and thus using the water column sampling method was not necessary. Samples from the epibenthic core and stovepipe sampling methods contained relatively high densities of small-bodied meiofauna, while throwtrap samples included both meiofauna and macroinvertebrates. Throwtrap and epibenthic core sampling methods together provided the most accurate estimates of taxonomic richness, density, abundance, and invertebrate assemblage composition, and were processed relatively efficiently in the laboratory. Sampling methods that performed well in the Rio Grande are likely to work well in other higher-order (> 4) rivers with shifting substrates.

Macroinvertebrate Community Composition in Wetlands of the Desert Southwest is Driven by wastewater-associated Nutrient Loading Despite Differences in Salinity

“…The increase in predators in the absence of wastewater was also found by other studies relating declines in predators as a result of increased nutrients and anthropogenic disturbances (Fu et al 2016 ; Zhang et al 2019 ). Corixidae, in particular, have been commonly observed in other studies in Rio Grande habitats (Bain et al 2011, Burdett et al 2015 ), which we found were generally lower in nutrients than wastewater fed sites.…”

Are nutrients or salinity the drivers of macroinvertebrate community composition in wetlands of the desert Southwest?

“…The percent Odonata, EOT and Predators also increased signi cantly within non-wastewater sites, likely due to their sensitivity to anthropogenic impacts (Kutcher and Bried 2014). The increase in Predators may also be explained by increased presense of macroinvertebrates such as corixidae within the Rio Grade water column (Burdett et al 2015). Since there were multiple sites ooed with river water and two sites at the river itself, this may have led to an increase in Predators sampled from these sites.…”

Assessment of Aquatic Macroinvertebrate Sampling Methods for Nonregulatory Water Quality Programs

“…The effectiveness and efficiency of macroinvertebrate sampling protocols have been assessed for both regulatory and research purposes (Burdett et al, 2015; Buss et al, 2015; Ghani et al, 2016; Lenat, 1988; Stein et al, 2008), typically comparing individual sampling methods with each other (e.g., kicknet, Dnets, and serber samples), rather than combinations of different sampling methods (Burdett et al, 2015; Ghani et al, 2016; Stein et al, 2008; Tronstad and Hotaling, 2017; Tubić et al, 2017). Dnets and strainers were assessed for similarity between the sampling methods gauged by Sørensen similarity index for the purpose of water quality assessments (Stein et al, 2008).…”

“…Dnets and strainers were assessed for similarity between the sampling methods gauged by Sørensen similarity index for the purpose of water quality assessments (Stein et al, 2008). Serber nets were recommended for both regulatory and aquatic ecosystem productivity studies (Burdett et al, 2015), whereas kicknet sampling features prominently in aquatic method studies for the collection of samples with high abundance and richness (Everall et al, 2017; Ghani et al, 2016). A combination of standardized qualitative methods (two kicknet samples, three Dnet samples, one leaf pack sample, three aufwuchs samples, one sand sample, and visual collections) were compared with semiquantitative kicknet sampling by the North Carolina Division of Environmental Management (now the North Carolina Department of Environmental Quality) (Lenat, 1988).…”