Overview of EMODnet Chemistry eutrophication data: Informing a strategy for monitoring under the EU Marine Strategy Framework Directive

We aimed to assess eutrophication in situ data coverage in the EU marine regions to inform a data acquisition strategy for the eutrophication assessments under the Marine Strategy Framework Directive (MSFD). We analysed eutrophication datasets provided by the European Marine Observation and Data Network (EMODnet) Chemistry covering the Atlantic, Baltic, Black, Mediterranean and North Seas, between 2012 and 2021. For each marine region, we assessed spatial temporal coverage of nutrients, including Dissolved Inorganic Nitrogen, Total Nitrogen, Dissolved Inorganic Phosphorus, and Total Phosphate, as well as surface concentrations of Chlorophyll a and bottom concentrations of Dissolved Oxygen. We identified >3M valid data entries with heterogeneous spatial-temporal coverage across EU marine regions and subregions. The gaps identified will be used to 1) identify opportunities to consolidate monitoring approaches in terms of scale, methodologies, and parameters coverage 2) improve MSFD reporting 3) further promote sharing of eutrophication data into EMODnet Chemistry. Overall, this work will contribute to ensure wider, more comparable and higher-quality eutrophication datasets, hence strengthening the eutrophication assessments under the MSFD.