Nutrient optima and tolerances of benthic invertebrates, the effects of taxonomic resolution and testing of selected metrics in lakes using an extensive European data base

AbstractThe main objective of the Water Framework Directive (WFD) is to achieve good ecological status for surface waters in Europe by 2015. The ecological status has to be defined based on near-natural reference conditions. Benthic invertebrates and diatoms are among the key biological elements recommended by the Directive to assess ecological quality of water bodies. The purpose of this study is to identify species associations of these biological elements that are characteristic of the different stream types occurring in Luxembourg and that distinguish degraded from reference conditions. In general, the results reveal that diatoms and invertebrates can be considered as complementary indicators with more diatom species being characteristic of small size stream types and more benthic invertebrate species being associated with larger stream types. Among invertebrates, Trichoptera, Hydrachnidia, Ephemeroptera and Diptera show high affinities for most stream types. Plecoptera, Oligochaeta appear as useful indicators for some particular types. If only reference sites are selected (all river types considered), the number of indicator species drops from 55 to 24 for diatoms and from 81 to 48 for benthic invertebrates. Moreover, for the larger stream type, no reference site was found at all. This trend is likely to be a consequence of the multiple anthropogenic pressures that have affected large parts of European lowland rivers for decades. Our results suggest that Trichoptera, Hydrachnidia, Diptera, Ephemeroptera and Oligochaeta could be considered as best candidate groups for a tiered-taxonomic resolution approach where only taxa which have narrow and specific ecological requirements would be identified to finer levels. In Central Europe, however, since taxonomic soundness and easy recognition are required, only Trichoptera and Ephemeroptera are the groups to be recommended at the present time.

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The European Data Base - A new CFD validation tool for the design ofspace vehicles

10.2514/6.1993-3045 ◽

1993 ◽

Cited By ~ 2

Author(s):

REMI ABGRALL ◽

JEAN-ANTOINE DESIDERI ◽

MICHEL MALLET ◽

JACQUES PERIAUX ◽

PIERRE PERRIER ◽

...

Keyword(s):

Data Base ◽

Cfd Validation ◽

European Data ◽

Validation Tool

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Improved freshwater macroinvertebrate detection from environmental DNA through minimized nontarget amplification

ARPHA Conference Abstracts ◽

10.3897/aca.4.e64753 ◽

2021 ◽

Vol 4 ◽

Author(s):

Mandy Sander ◽

Arne Beermann ◽

Dominik Buchner ◽

Vasco Elbrecht ◽

Peter Haase ◽

...

Keyword(s):

Benthic Invertebrates ◽

Environmental Dna ◽

Benthic Invertebrate ◽

Coi Gene ◽

Taxonomic Resolution ◽

Universal Primers ◽

Reference Database ◽

Mountain Range ◽

Degenerate Primers ◽

Universal Primer

Environmental DNA (eDNA) metabarcoding is a new, promising, and non-invasive method to detect biodiversity in aquatic environments. So far, it has mainly been used to screen for fish and amphibian diversity and rarely to detect macroinvertebrates. Typically, DNA metabarcoding relies on PCR amplification of a fragment of the mitochondrial cytochrome c oxidase I (COI) gene with degenerate primers. In comparison to other genes like 16S, COI has a greater taxonomic resolution and availability of an extensive reference database. Benthic stream invertebrates are of critical importance for regulatory biomonitoring, but when using universal primers on eDNA isolated from water, the number of reads and OTUs is “watered down”. This means the target taxa, macroinvertebrates, are underrepresented in comparison to other nontarget taxa, e. g. algae, bacteria, and fungi. The aim of the project was to design an insect-specific primer, which minimizes nontarget amplification. Therefore, data from a time series of 15 months at the Kinzig (Hesse), a silica-rich low-mountain-range stream, which is part of the Rhine‑Main‑Observatory (LTER site) was generated using the universal primers BF2/BR2. With this data we identified the most abundant nontarget taxa and designed a new reverse primer (EPTDr2n) with 3’ ‐ specificity toward benthic invertebrate taxa. Primer specificity was validated in silico together with universal forward primer fwhF2 using available data from GenBank and BOLD. 20 eDNA samples from the Kinzig River and its tributaries were then used to test the new primer in situ together with primer fwhF2. The new primer combination showed a much higher amplification of benthic invertebrates, insects in particular, than two other universal primer pairs for both, number of target reads (fwhF2/EPTDr2n: 99.6% versus BF2/BR2: 25.89% and fwhF2/fwhR2n: 39.04%; Fig. 1) and number of target species (fwhF2/EPTDr2n: 305 versus BF2/BR2: 113 and fwhF2/fwhR2n: 185). Additionally, the number of benthic invertebrate species exceeded even the number of 153 species identified by expert taxonomists at nearby sites across two decades of sampling. While several taxa reported, like a few trichopteran genera, flatworms, and some crustaceans, were not found, the primer shows greatly improved results for eDNA metabarcoding of benthic invertebrates(Leese et al. 2021).

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