Eutrophication is the result of excessive enrichment of water with nutrients which may cause an increase in the accelerated growth of algae in the water column and higher forms of plants living on the bottom of the sea. This may result in a range of undesirable disturbances in the marine ecosystem, including a shift in the composition of the flora and fauna which affects habitats and biodiversity, and the depletion of oxygen, causing death of fish and other species. Human activities resulting in anthropogenic nutrient enrichment encompass inputs from point sources (e.g. sewage plants or industry) and from diffuse sources (e.g. agriculture, households not connected to sewerage, overflows, and atmospheric inputs).
The OSPAR Eutrophication Strategy sets the objective to combat eutrophication in the OSPAR maritime area, in order to achieve and maintain by 2010 a healthy marine environment where eutrophication does not occur. The Strategy builds on long-standing commitments of Contracting Parties under OSPAR measures to achieve a substantial reduction at source, in the order of 50% compared to 1985, in inputs of phosphorus and nitrogen into areas where these inputs are likely, directly or indirectly, to cause pollution. Progress in reducing nutrient inputs is regularly assessed by OSPAR based on national implementation reporting by Contracting Parties. The eutrophication related work is implemented by OSPAR’s Eutrophication Committee (EUC).
To assist Contracting Parties in identifying areas in a consistent way where nutrient inputs may cause pollution, and to periodically assess the eutrophication status of the OSPAR maritime area and progress made towards the Strategy’s objective, OSPAR developed a common assessment framework: the Common Procedure for the Identification of the Eutrophication Status of the OSPAR Maritime Area. Five assessment parameters and their assessment levels as defined by the Common Procedure have been developed to form an integrated set of Ecological Quality Objectives (EcoQO) for eutrophication for the North Sea with the overarching objective that all parts of the North Sea should have the status of non-problem areas with regard to eutrophication by 2010, as assessed under the Common Procedure.
OSPAR’s assessment work is supported by monitoring under the Eutrophication Monitoring Programme as part of the OSPAR Co-ordinated Environmental Monitoring Programme (CEMP), and by monitoring to estimate waterborne and atmospheric inputs of nutrients to the OSPAR maritime area under the RID Study and the CAMP monitoring programme. Monitoring is complemented by modeling activities on nutrient reduction scenarios and transboundary nutrient transport to help directing future actions in combating eutrophication.
The implementation of the Eutrophication Strategy takes place within the framework of the obligations and commitments of the various Contracting Parties under other international agreements. This includes the implementation of European Community legislation to reduce nutrient discharges and emissions, including for example the the Nitrates Directive (91/676/EEC), Urban Waste Water Treatment Directive (91/271/EEC), the Water Framework Directive (2000/60/EEC) and the Marine Strategy Framework Directive (2008/56/EC).