The recent MSFD Commission Decision (EU) 2017/848 of 17 May 2017 lays down criteria and methodological standards on good environmental status of marine waters, and specifications and standardised methods for monitoring and assessment.
This Decision repeals former Decision 2010/477/EU applied during the Initial Assessment phase and the new one has to be applied during the next reporting phase in 2018.
This new text categorizes criteria in primary and secondary ones. Member States shall use primary criteria and associated methodological standards, specifications and standardised methods laid down in the Annex to ensure consistency across the Union. Full text
Chlorophyll-a concentration in the water is considered a primary criteria for Descriptor 5 on Eutrophication (D5C2) and the methodologies and thresholds have to be set in accordance with the Water Framework Directive (2000/60/EC)