DEMNA-DNE : Occurrences of Diatoms (Bacillariophyceae) in running waters of Wallonia, Belgium

Study Extent

The current monitoring network is composed of more than 440 sampling stations distributed among the Wallonia. The concerned habitats include lentic and lotic brooks, streams, largest rivers and canals from the hydrographic districts of the Meuse, the Scheldt, the Rhine and the Seine.

Sampling

The sampling methodology is derived from the french standard (NF T90-354). Sampling is generally carried out on well-lit sections, preferably on submerged stones, pebbles or boulders, so as to present a diatomic population representative of environmental conditions. Biofilm is collected by scraping the substrate surface with a toothbrush or scraper over a total area of at least 100 cm².

Quality Control

The Department is ISO9001 certified. Some sampling was performed by external contractors, also certified. Data are submitted to a procedural validation by experts during samling, sorting, identification and encoding of records within the AQUABIO database.

Method steps

1. Choice of surfaces to be sampled
2. Diatom film sampling according to NF T90-354 standard
3. Recovery of the biofilm in a pillbox with alcohol
4. Mounting on microscope coverslips
5. Identification and counting
6. Import of the samling results into the AQUABIO Database
7. Control and validation of content
8. Cleaning and DarwinCore transformation of validated data and publication to GBIF

Diatoms

1. Chromista
   common name: Kelp, Diatoms, And Allies rank: kingdom
2. Bacillariophyceae Dangeard, 1933[1]
   common name: diatoms rank: class

The sampling network is composed of about 440 sites in Wallonia