Development of a Predictive Model of Fauna and Flora to Evaluate the Ecological State of Luxembourg's Rivers - MODELECOTOX

Coordinating Institution: CRP Gabriel Lippmann
From: 01/04/2002
To: 31/03/2005
Budget: 748,188.00€
Contact(s): Dohet Alain

Summary

The main goal of the MODELECOTOX project was to develop a Water-Framework-Directive-compliant predictive model which, on the basis of physical and chemical key variables of the habitat, enables us to predict the aquatic fauna (benthic macro-invertebrates) and flora (benthic diatoms) expected in non-disturbed running water sites (reference sites). In addition, according to the WFD, toxic compounds poured by industries and agriculture into rivers are to be controlled. A second objective of the project was therefore to estimate the influence of some priority toxic substances on target organisms, by the means of microcosm experiments. A third objective was to study, by means of molecular and morphological techniques, the taxonomy of benthic algae, which are important for bio-indication but present difficulties of identification.

In 2005, research activities focused on the implementation of our model, the development of a graphical user interface based on the results obtained by the predictive model and the completion of the revision of the taxonomy of epilithic diatoms from Luxembourg rivers.

The principle of the model consists in estimating the probabilities of occurrence of taxa at a given site in theabsence of significant anthropogenic stress. The deviation between the observed and expected (near reference) conditions enables to calibrate an index value to estimate the quality of the river studied. Various combinations (seasons, taxonomic level) of the model were tested. The results obtained consolidate the relevance of the model as a tool for the assessment of the quality of the rivers. At a family level, the model logically has fewer taxonomic units, which accordingly reduces the uncertainty of the model. In collaboration with the CREDI research unit of the Public Research Centre Gabriel Lippmann, a graphical user interface was designed on the basis of the results obtained by the predictive model. The development of this tool aimed to provide to the water managers a convivial interface allowing an optimal assessment of the ecological status of the rivers, which fulfils the principal recommendations of the WFD.

The revision of the taxonomy of the epilithic diatoms from Luxembourg rivers has been completed, as well at the writing of the monograph “Diatoms of the Grand-Duchy of Luxembourg. The benthic flora of watercourses”, which is about to be submitted for publication in the book series “Iconographia Diatomologica”. Most diatoms of Luxembourg are described and 150 taxa are illustrated in optical microscopy and scanning electronic microscopy. This taxonomic work opens important perspectives in the field of biogeography and ecology of the algae.

Figure 1: Diatomée (Staurosira venter) au microscope électronique à balayage

Figure 2: Site de référence sur le Consdorferbaach