Physico-chemical supporting elements in coastal waters, WFD-MSFD-RSC Links: a review of standards to support good ecological status under the Water Framework Directive, Marine Strategy Framework Directive and Regional Sea Conventions

This report highlights the common trends and disagreements identified between the information reported by Member States (MSs) to Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD) reportings on the standards for general physico-chemical elements, including nutrients, and the methodological standards agreed and used for the assessment of Eutrophication criteria elements at regional sea level by the Regional Sea Conventions (RSC). For the criteria under Descriptor 5, "Eutrophication", and the physico-chemical indicators of eutrophication, the MSFD Decision ((EU) 2017/848) established that criteria elements, threshold values and methodological standards, within coastal waters, should be used, as under the Water Framework Directive 2000/60/EC. On the other hand, Coperation between the Member States of one marine region and with neighbouring countries which share the same marine waters, should take place through these Regional Sea Conventions (Article 6 of the MSFD). However, a firts outcome (Salas Herrero et al., 2020), showed some gaps in the harmonization of the criteria and parameters used by MSs. The main aim of the current report is to continue with this comparison and analyse and compare the boundaries values of the physicochemical parameters, for the assessment of Good Status in coastal waters under the WFD, MSFD and those included in Regional Sea Conventions (RSC) reports, f highlighting the reasons (i.e local-specific, technical) for the lack of harmonization, and to provide recommendations for further work. The first results is that the discrepancy between the monitoring plans provided by MSs and the reporting of threshold values does not allow a comprehensive comparison between WFD and MSFD threshold values. Many countries have reported different parameters for both Directives, not being possible the comparison. Dissoved Inorganic Nitrogen (DIN) and Total Phosphorus (TP) are the parameters with higher number countries (10) reporting threshold values for both Directives. In general, when the comparison has been possible between WFD and MSFD reporting, the same threshold values have been observed in both reporting. Some exceptions could be related to different metrics used, or different areas considered, and this should be explained by the experts. Our recommendation is to consider the same assessment season, the same metric and the same areas (or national types) to be reported. Countries like Poland and Sweden are good exa