Comparing passive sampling, mussel caging and biomarkers for the evaluation of water quality for European Directives in Normandy coastal waters (France)

In the scope of the Water Framework Directive (WFD, 2000/60/EC) implementation, the aim of this work was to compare the response of different emerging tools to evaluate the chemical status of water bodies in Normandy coastal waters (France). These tools included passive samplers foreseen in future evaluation campaigns in France as a replacement for bulk seawater sampling (i.e. Diffusive Gradient in Thin films (DGT), and Polar Organic Chemical Integrative Sampler (POCIS)). They were deployed at three contrasted sites in terms of pollution level along the Normandy coast, simultaneously to mussel caging, in which three common biomarkers were analysed at the end of the experiment. This work highlighted the operational challenge of deploying passive samplers and caging in open coastal waters of the Channel. The only POCIS that could be analysed from the bay of Veys revealed the presence of metabolites of forbidden pesticides, and of several pharmaceutical substances. Results given by DGTs confirmed a gradient in metal concentrations between the three sites with a maximum at the Seine estuary, confirmed with organic and metal analyses in mussels, and with the lysosomal membrane stability biomarker which gives an indication of organisms’ health status relative to their environment