Assessments of phytoplankton in the Netherlands and neighbouring countries according to OSPAR and WFD

After the implementation of the European Water Framework Directive (EC-WFD, 2000), which was limited to the coastal waters and did not apply to all marine waters, the European Marine Strategy Framework Directive (MSFD) has been adopted in 2008 to protect the marine environment and its ecosystems, and to promote its sustainable use. The MSFD has been anchored into Dutch legislation in 2010. The objective of the MSFD (EC-MSFD, 2008) is to achieve and / or maintain good environmental status in European marine waters. The MSFD requires the Member States to take the necessary measures to achieve this goal in 2020. In the MSFD eleven descriptors have been defined, which are relevant for the implementation of the directive. The descriptor of concern in this report is descriptor 5 for eutrophication, which states: “Human-induced eutrophication is minimised, especially adverse effects thereof, such as losses in biodiversity, ecosystem degradation, harmful algae blooms and oxygen deficiency in bottom waters” (EC-MFSD, 2008). The European Commission is directing the process, but the individual Member States are responsible for the implementation of the MSFD and the cooperation and international coordination within a marine (sub)region. Member states shall, as far as possible, build upon relevant existing programmes and activities developed in the framework of international agreements such as Regional Sea Conventions. In the OSPAR convention eutrophication is one of the points of concern. OSPAR developed the Comprehensive Procedure, which is a harmonized, integral assessment system of the main causes and effects of eutrophication. The OSPAR Common Procedure is ‘fit for the purpose’ of assessing this descriptor and supports the setting of targets and indicators under MSFD (OSPAR, 2012a; OSPAR 2012b). As OSPAR is in force for the whole North-eastern Atlantic, while the WFD is for ecology only valid in marine waters in the zone within one nautical mile from the coast line (Figure 1.1), the comparability between OSPAR COMP and WFD needs attention. There are differences between OSPAR COMP and WFD assessments in the use of chlorophyll-a and Phaeocystis metrics, both in geographical extent and in the aggregation of the metrics into the final assessment. The objective of this report is to make an inventory, for chlorophyll-a and Phaeocystis, of the OSPAR Comprehensive Procedure and of the WFD assessment method and the results of both methods for the Netherlands and the North Sea countries: Belgium, Germany, UK and France. For the WFD Prins & Baretta-Bekker (2010) gave an overview of the scientific background of the Phaeocystis metric, as one of the indicators for eutrophication. It contains the various aspects of the methods from sampling to setting the class boundaries used by the Netherlands and the neighbouring countries. The present report expands on this paper by including the WFD metric for chlorophyll in order to account for the other phytoplankton component.