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European Marine Observation and Data Network (EMODnet)

EMODnet Marine litter data used to develop and test the first Marine Litter Assessment Tool

Efforts focused on critically revising methods of marine litter monitoring and data management through reproducible analytical pipelines, assessing their technological readiness and conducting SWOT (Strengths, Weaknesses, Opportunities and Threats) analyses on marine litter monitoring and data management and laboratory intercalibration studies, as well as supporting laboratory capacity building. The results have been actively shared with stakeholders in Europe and beyond and form the basis for setting global cost-effective monitoring standards for marine litter. The project brings together 15 key stakeholders involved in the study and monitoring of plastic pollution in Europe, as well as managers of marine litter data contained in consolidated data infrastructures.

Challenges faced by the user

For Europe, the adoption of the Marine Strategy Framework Directive (MSFD), published in 2008, and the associated two European Commission decisions, published in 2010 and 2017, have been an important pillar in the fight against marine litter. They set out criteria and methodological standards for the monitoring and assessment of good environmental status with regard to marine litter pollution. In 2021, the EU adopted the EU Action Plan ‘Towards Zero Pollution for Air, Water and Soil’, which also set the target of reducing marine plastic litter by 50% and microplastics released into the environment by 30%. In this context, it should be noted that although sufficiently robust tools for assessing eutrophication in the marine environment have been developed and implemented, no efforts have yet been made by the Regional Sea Conventions or at the pan-European level to carry out an integrated assessment of the different types of marine litter under the MSFD. In this project a multi-metric indicator-based assessment tool for mapping and identification of ‘problem areas’ and ‘non-problem areas’ regarding the occurrence of marine litter in Europe's seas, the Marine Litter Assessment Tool (MALT), was developed and should be seen as a first step towards a fully harmonised and coordinated assessment of good environmental status for MSFD descriptor 10 (marine litter). This achievement would not have been possible without the robust and extensive databases developed and maintained by EMODnet Chemistry.

EMODnet services used

EMODnet Chemistry data on marine litter were used to develop and test the prototype Marine Litter Assessment Tool - MALT. The study is based on a Europe-wide dataset consisting of three indicators of marine litter of interest to the MSFD: (1) seabed litter, (2) beach litter and (3) floating micro-litter. They are calculated as Ecological Quality Ratio (EQR) within a Spatial Assessment Unit (SAU) as an aggregated value of the normalised indicator values. These indicators allowed litter status to be determined in 1,957,081 km² (19.1 %) of the total area of Europe's seas (10,243,474 km²). These were divided into the following sea regions: (1) the Baltic Sea (see, (2) the north-east Atlantic (see, (3) the Mediterranean (see and (4) the Black Sea (see

EMODnet beach litter data used for the analysis contained observations from 2010 to 2020 at 1,225 beaches. They were extracted from the EMODnet data collection ‘European beach litter standardised, harmonised and validated datasets 2001/2020 version 2021’. For the seafloor litter indicator, data were extracted from the EMODnet dataset ‘European seafloor litter standardised, harmonised and validated datasets 2006/2021 version 2021’. The dataset used for the analysis covers 20,551 surveys at 20,021 sites in 22 countries, taken in the period 2010–2021. The floating micro-litter data were extracted from the EMODnet dataset ‘European floating micro-litter standardised, harmonised and validated datasets 2011/2020 version 2021’. The extracted dataset used for the analysis covers 839 trawl surveys used on 60 cruises in the period 2011–2020.

Impact of EMODnet

As mentioned above, the EMODnet Chemistry Marine Litter data enabled the development of the multi-metric indicator-based assessment tool MALT  

according to the UNEP criteria (2016). These state that the proposed environmental indicators should be (a) scientifically valid, (b) easy for the public and policy makers to understand, (c) sensitive and responsive to change, (d) cost-effective, and (e) policy relevant. The MALT tool is the first suitable index for the spatial assessment of marine litter in an integrated way. It is a valuable support not only for the implementation of the MSFD, but also for the development and implementation of national or regional marine litter action plans. MALT can be easily expanded as additional types of marine litter data and their thresholds become available.


The tool has led to the data-based conclusion that marine litter is a major problem in European seas. In fact, the "problem areas" account for 74.2% of the Europe’s seas studied area (1,957,081 km² ,19.1 %, of the total area of Europe's seas), while "non-problem areas" were found to cover 505,030 km2 (25.8 %).

Without the data available on a pan-European level it would have not been possible to access the environmental status concerning marine litter in Europe and highlight applications of the MALT tool. I hope that more organisations working with marine monitoring data make this data available through EMODnet to enable the assessment of indicators of marine litter of interest to the Marine Strategy Framework Directive

Bert van Bavel, Chief Scientist Norwegian Institute for Water Research and coordinator of the EUROqCHARM project.


Monitoring beach litter as part of the EUROqCHARM project Credit: EUROqCHARM/NIMRD