DEMNA : Diatoms samples from an ongoing monitoring network on surface waterbodies of Wallonia (since 2005)
Citation
Msaaf M, Darchambeau F, Cherot F, Coupremanne M (2017). DEMNA : Diatoms samples from an ongoing monitoring network on surface waterbodies of Wallonia (since 2005). Version 1.1. Service Public de Wallonie – Département d’Etude du Milieu Naturel et Agricole (SPW – DEMNA). Metadata dataset https://doi.org/10.15468/vvkk9a accessed via GBIF.org on 2024-04-30.Description
WARNING: SOME ERRORS WHERE SPOTED WITHIN THE DATASET. USE IS NOT RECOMMENDED BEFORE 2018 UPDATE. This dataset refers to diatoms samplings performed in the frame of the Eu water framework directive. The microscope slides collection is created, implemented and maintened by the Hydrobiology unit at the Department for the Study of the Natural and Agricultural Environment (DEMNA - Public Service of Wallonia). Phytoplankton samplings are based on an ongoing monitoring network comprising more than 440 surveyed stations distributed among the Wallonia (Southern Belgium), and which started in 2005. Diatoms, with macrophytes ( doi:10.15468/cumtkq ), fishes ( doi:10.15468/jgddny ) and macroinvertebrates ( doi:10.15468/ew00u8 ), is one of the 4 biological indicator groups used to assess the biological quality of surface water masses. In the case of this collection, the monitoring and sampling designs are adapted to the calculation of the IPS (Index of Specific Pollusensibility) that is reported to Europe every year. The dataset will be updated yearly, after the reporting to Europe and its underlying validation work. We invite you to consult cigale ( geoapps.wallonie.be/CigaleInter/) to access the assessment results, or to adress specific requests to the DEMNA. please notice that this dataset does not replace any official convention on the provision of biological data delivered by the department.Purpose
Diatoms sampling are performed in the frame of the Eu water framework directive. Diatoms, with macrophytes, fishes and macroinvertebrates is one of the biological indicator groups used to assess the biological quality of surface water masses. The index determined is the Index of Specific Pollusensibility (IPS), which is reported to europe every year.Sampling Description
Study Extent
The monitoring network is composed of more than 440 control stations, distributed among the hydrographic districts of the Meuse, the Scheldt, the Rhine and the Seine (Wallonia areas). As far as possible, two annual campaigns, one between May and June (early summer) and one between September and October (late summer) are carried out.The early summer period provides, in principle, the most favorable estimation (dilution of pollutants, reduced microbiological activities). The late-summer period often corresponds to the most unfavorable conditions (the pollutants are less diluted, the activity of biodegradation is maximum). The samples are adapted to the reconstitution of a community sufficiently diversified and in equilibrium with the physicochemical conditions: carried out 15 days after floods of low intensity or 4 weeks after floods which resulted in a rearrangement of the supports.Sampling
The sampling is preferably done on lotic facies, even if it is not the dominant facies. The lentic environments will be prospected only by default. Only the epilithic algae will be used, ie the living species on hard and inert substrates. The choice of the type of support to prospect can be hierarchized as follows: 1: Hard natural support as stable as possible, in order of preference; Stones, pebbles, pebbles. 2: Missing this: artificial hard support (platforms, bridge pillars, canalized river wall) .3: In the absence of any support or in the case of a particular study, artificial substrates (tile Faience, stone blocks). The sampling takes place on a surface of minimum 100 cc, square meters on the upper face of the support. Ideally, 5 stable natural supports are chosen randomly so as to have a sample of diatomic flora representative of the sampling station. The algae are harvested by scraping with a blade or a knife or by brushing and diluted with a little water and labeled. , Fix with a volume of 4% formalin which represents about 10% of the sample volume. Upon returning to the laboratory, samples are stored in a dark, cool place awaiting treatment and where they stay for at least 24 hours for decanting suspended solids.Quality Control
A set of constraints of the database ensure a first standardization of content (predefined taxa lists, habitat typology, etc.). OMNIDIA: a computer program with a large taxonomic database and allowing the calculation of several diatomic indexes whose IPS is used. The encoded data and computed indices are also subject to validation work before their transfer to Europe.Method steps
- Site selection
- Choice of facies and substrate to be sampled
- Diatoms sampling
- Labeling of the samples
- Pre-treatment (fix samples)
- Decantation in the laboratory
- Preparation and mounting of the microscope slides : Removal of organic matter (hydrogen peroxide 35%), Elimination of calcium carbonates (37% hydrochloric acid), rinsing, dilution and assembly of the microscope slides
- Identification and counting
- Storage of the microscope slides into the collection
- Importing the results into the unit'database : AQUABIO
Taxonomic Coverages
Freshwater diatoms. The dataset includes more than 1240 taxa, belonging to 40 different families. The lowest taxanomic resolution is the genus, with only about 50 taxa concerned. The major part of the occurrences are species (more than 980 species) or infraspecific (more than 200 subspecies, forms, varieties).
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Chromistacommon name: Brown algae lineage rank: kingdom
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Ochrophytacommon name: Ochrophytes rank: phylum
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Bacillariophyceae Dangeard, 1933common name: Diatoms rank: class
Geographic Coverages
Wallonia, southern Belgium
Bibliographic Citations
Contacts
Maryse Msaaforiginator
position: Principal adjoint
Department d'étude du milieu naturel et agricole
Avenue Maréchal Juin 23
Gembloux
5030
Namur
BE
email: maryse.msaaf@spw.wallonie.be
François Darchambeau
originator
position: Attached
Department d'étude du milieu naturel et agricole
Avenue Maréchal Juin 23
Gembloux
5030
Namur
BE
email: francois.darchambeau@spw.wallonie.be
Maryse Msaaf
metadata author
position: Principal adjoint
Department d'étude du milieu naturel et agricole
Avenue Maréchal Juin 23
Gembloux
5030
Namur
BE
email: maryse.msaaf@spw.wallonie.be
Frédéric Cherot
metadata author
position: Qualified attached
Department d'étude du milieu naturel et agricole
Avenue Maréchal Juin 23
Gembloux
5030
Namur
BE
email: frederic.cherot@spw.wallonie.be
Maxime Coupremanne
metadata author
Belgian Biodiversity Platform
22 Avenue de la faculté
Gembloux
5030
Namur
BE
email: mcouprem@gmail.com
François Darchambeau
principal investigator
position: Attached
Department d'étude du milieu naturel et agricole
Avenue Maréchal Juin 23
Gembloux
5030
Namur
BE
email: francois.darchambeau@spw.wallonie.be
Maxime Coupremanne
administrative point of contact
Belgian Biodiversity Platform
22 Avenue de la faculté
Gembloux
5030
Namur
BE
email: mcouprem@gmail.com
Maryse Msaaf
administrative point of contact
position: principal adjoint
Department d'étude du milieu naturel et agricole
Avenue Maréchal Juin 23
Gembloux
5030
Namur
BE
email: maryse.msaaf@spw.wallonie.be