Background and project

To meet the obligations of the Water Framework Directive and its daughter directives, member states are required to assess the chemical status of surface water bodies. Within this framework, certain environmental quality standards (EQS) have been set for biota (fish, invertebrates), and the revision of the EQS Directive has led to an increase in the number of these biota EQS (Directive 2013/39/EU). Given the uncertainties associated with the use of these organisms in monitoring (variations linked to age, species, sex, residence time in the water body, metabolism, absence of biota in certain water bodies, etc.), some member states are advocating the use of passive samplers whose deployment is better controlled (exposure time, fixed location, exposed surface, etc.). They enable low-cost sampling, the detection and quantification of compounds at ultra-thin concentrations, and the comparison of data from different stations. In fact, the new EQS directive encourages their continued development.
The Moerman “Biotes” project began in 2013 with the main aim of developing the monitoring of surface water bodies on the “biotes” matrix and to develop, evaluate and if necessary validate the use of passive samplers as a possible alternative to the “biotes” matrix. The project also includes the development of invertebrate caging techniques. Caging could be an alternative method for sampling organisms, particularly at sites where the species of interest are absent.


During the first year of the project, the most relevant biota species were selected and a sampling strategy developed. Four species of fish and aquatic invertebrates (crustaceans and molluscs) were selected for micropollutant analysis. The contaminants targeted are mercury, hexachlorobenzene and hexachlorobutadiene, as well as polycyclic aromatic hydrocarbons (benzo-a-pyrene and fluoranthene), substances for which an EQS is available in the “biota” matrix.
Analyses in this particular matrix are currently being fine-tuned. During 2013, samples were taken at several stations, mainly selected from the WFD monitoring network in the Walloon Region, in order to obtain sufficient sampling to enable these fine-tunings. Sampling is carried out in collaboration with DEMNA during annual census fishing and with the University of Liège. An agreement with the Walloon region, drawn up in the form of a Service Level Agreement (SLA), sets out the terms of collaboration between ISSeP, DGO3 and DEMNA, and the results obtained. In addition, a partnership agreement has been signed with ULg to carry out complementary research.

On the other hand, the experimental phase of active biomonitoring is currently being fine-tuned before the start of field experiments. These concern the choice of organism to be caged (initially, the caging of Gammarus pulex will be considered), the choice of cage type, the sites to be caged (reference site(s) and polluted sites to carry out trials), the system for acclimatizing organisms in the laboratory, as well as a number of additional details such as the size of the organisms, the quantity of organisms per cage, the number of cages per site, the food to be supplied, the optimum physico-chemical parameters, etc. The finalization of the caging methods is scheduled for 2014.
In this context, a European drafting group was organized, in which ISSeP took part, with the aim of implementing monitoring programs in biota. The processing and expression of the resulting data to assess their compliance with environmental quality standards in biota are also discussed. Publication of the final version of this “Supplementary guidance for the implementation of EQSbiota” is scheduled for September 2014. An initial meeting was held in September 2013 in London to organize the writing. Two additional meetings will be held in January 2014 in Paris and in May 2014 in Amsterdam to follow up on the drafting process. A contribution will be made by drafting the chapter on good practices for caging aquatic organisms.
Finally, a literature review is currently underway to determine which types of passive samplers could be used in this project.