EU Standardised methods
Member States should focus their monitoring on nutrients levels and on those direct effects (e.g. Chl-a concentration, phytoplankton abundance and composition, water transparency) and indirect effects (e.g. oxygen concentration, macrophytes) that are closely linked to nutrient enrichment and relevant to their marine region or sub-region.

Nutrient input is a dominant pressure for eutrophication. Nutrient inputs are not included in the list of indicators for D5 in the COM Decision 210/477/EU as such but annex III specifies the importance of locating the sources of the nutrient input determining the level of eutrophication and according to article 11 of the MSFD monitoring should be based on annex III.

In addition to river discharge, atmospheric deposition and nutrient input from diffuse sources are also important. Member States should specify how important such additional sources of nutrients are, and how they obtain sufficient data.
Technical guidance on monitoring for the Marine Strategy Framework Directive:
Regional Sea Conventions
Within HELCOM, the Contracting Parties have the mandate to monitor their marine and coastal waters and to communicate their data to the Convention Secretariat. The programme COMBINE (Cooperative Monitoring in the Baltic Environment) created in 1992, ensure a joint monitoring of the whole basin on a basis of a number of biotic and abiotic indicators.

The HELCOM monitoring and assessment strategy was revised in 2013 to support the implementation of the Baltic Sea Action Plan and the EU MSFD.
The Pilot-project BALSAM (2013-2015) co-funded by DG ENV enabled Baltic member states to optimize and harmonize their monitoring programmes with recommendations toward coordinated use of the oceanographic campaigns and data management system.
OSPAR's Joint Assessment and Monitoring Programme (JAMP) describes the strategy, themes and products that Contracting Parties are committed to deliver, through collaborative efforts, over the period 2014-2021. This programme regroups thematic manuals of which several are linked to eutrophication issues/parameters:
Monitoring of eutrophication within OSPAR Area also benefits from data collection under three other programmes for:
Barcelona Convention
The Mediterranean Action Plan (MAP), established under the auspices of UNEP, includes the MED POL programme responsible for the activities linked to the protection of the Mediterranean Sea against pollution from terrestrial and marine activities.
IN 2008, the Contracting Parties of the Barcelona Convention agreed to integrate an Ecosystem Approach (EcAp) to MAP, evolving toward an integrated and periodical monitoring of the Mediterranean over a 6 years cycle. This new strategy is an adaptation to MSFD requirements with a set of Ecological Objectives (EO), including eutrophication (EO5).
Black Sea Commission
The Strategic Action Plan for the Environmental Protection and Rehabilitation of the Black Sea (BSSAP), reformulated and adopted in 2009 includes an integrated programme of monitoring and assessment BSIMAP.