Skip to main content

Marine Litter Thematic Assessment

Executive Summary

Under its North-East Atlantic Environment Strategy (NEAES) 2010-2020, OSPAR set an objective “to substantially reduce marine litter in the OSPAR maritime area to levels where properties and quantities of marine litter do not cause harm to the coastal and marine environment”. This thematic assessment describes the marine litter issue and the work of OSPAR to address it. It also looks at the progress made towards achieving the strategic objective that provides the foundation for the next steps.  

Overall, marine litter levels are still high and further efforts are needed. There is a predominance of plastics among marine litter that is reported across all OSPAR Regions. Also, microplastics have been reported in sediments, surface waters, water column and in biota for the OSPAR Maritime Area at different concentrations. Single-use plastics and maritime-related litter are frequently found beach litter items at OSPAR level, with some important regional differences. Nonetheless, there are some positive signs: a decrease in the quantities of litter found on OSPAR beaches between 2015-2020 and in the floating litter in the North Sea between 2009-2018. When considered against the upward trend in plastic production and use in Europe over a similar period, this suggests that progress has been made on preventing plastics from entering the marine environment.

Seal with tangled plastic netting around neck. © Shutterstock

Seal with tangled plastic netting around neck. © Shutterstock

Policy responses to managing marine litter need to continue to reduce inputs, reduce the risks associated with materials and products (e.g., develop alternatives to plastics and design solutions) and facilitate societal change. Because of the links between climate change and marine litter, integrated approaches could benefit both problems.

OSPAR's new Strategy (NEAES 2030) includes a new marine litter strategic objective, supported by eight operational objectives involving new measures for specific sources and pathways and the development of ambitious coordinated strategies, control measures, threshold values and targets. The adoption of a second Regional Action Plan in 2022 is key to its implementation. Regular monitoring and assessment, including developing new common indicators, will continue to play a key role in supporting the measures and evaluating their effectiveness.

Q1. Identify the problems? Are they the same in all OSPAR Regions?

The huge amount of man-made solid waste that ends up in the oceans and becomes marine litter has been identified as one of the pressing challenges of our time. A great number of land-based and sea-based human activities introduce litter into the marine environment. The main direct sea-based sources identified are fishing, aquaculture, shipping, and recreational boating. In addition, marine litter originates from offshore infrastructure (for example in the oil and gas industry). The major direct and indirect land-based sources of marine litter include poor waste management practices, general littering, untreated sewage, run-off and storm water discharges, sewage sludge applied to soils, land-based industry and construction, tourism and recreation, inland shipping, and agriculture. Rivers act as significant pathways of marine litter and therefore measures should be put into place to ensure that litter does not enter them.

Abundance and composition

Beach litter is abundant across the whole OSPAR Maritime Area. The median total count for the OSPAR Maritime Area is 252 items/100 m, varying between 50 (Wider Atlantic (Region V)) and 360 (Bay of Biscay and Iberian Coast (Region IV)). All Regions, except Arctic Waters (Region I), showed a statistically significant decrease between 2015 and 2020 but, in general, marine litter levels remain high. Plastic is predominant (approximately 95% of items found on beaches). Single-use plastics and maritime-related litter are frequently found beach litter items at OSPAR level though some regional specificities in abundance are seen.

Litter is also widespread on the seafloor in a number of OSPAR Regions: Greater North Sea (Region II), Celtic Seas (Region III) and Bay of Biscay and Iberian Coast (Region IV), with fisheries-related and plastic materials predominating. There are no clear trends in Regions III and IV, but it appears to be slightly increasing in Region II.

A high density of floating litter has been identified in Region IV, especially in the south-east corner of the Bay of Biscay. An approximation of the amount of floating litter in Region II is given by monitoring the amounts of plastic particles ingested by the common fulmar seabird. Currently, 51% of beached North Sea fulmars have more than 0,1 g of plastics in their stomachs, exceeding the fulmar threshold value of 10%. However, these amounts decreased significantly in the period 2009-2018. A first assessment also indicates a high incidence of plastic litter ingestion by sea turtles in Region IV, in Region V and Macaronesia.

There is a common consensus that microplastics are widely present in the marine environment. They have been reported in sediments (beach, estuarine, subtidal and seafloor), surface waters, water columns and biota for the OSPAR Maritime Area at different concentrations. The main reported types of microplastics were fibres and fragments/particles. Tyre wear and (macro) litter (breaking down into smaller pieces) were identified as the largest land-based sources. Sea-based activities also contribute to the global burden of microplastics, including fishing, aquaculture, shipping, and other marine activities.

One of the major pathways for litter to enter the marine environment is via rivers and other tributaries. A rudimentary estimate of the total macro litter exported by six rivers (the Seine, Rhine, Meuse, Ems, Weser and Thames) to the Greater North Sea area (Region II) is 10,5 – 220,6 tonnes per year, mostly plastics.

Overall, some indicators show downward trends in some Regions; however, general levels of marine litter remain high.

Impact

Marine litter (including microplastics) is known to have severe ecological impacts. The known adverse effects on marine animals comprise ingestion of plastic particles via filter feeding, suspension feeding, and consumption of prey exposed to microplastics, or direct ingestion in mistake for food, causing blockages and damage to the digestive tract; entanglement, especially with filamentous litter items (such as loops, packaging bands or net-like structures, e.g., from derelict fishing gear); as well as smothering of benthic habitats and generation of artificial hard substrate. Furthermore, floating litter may act as a vector for the transport of contaminants and biota, including microbes which change or modify species assemblages. As a next step, dose-response relationships have to be established in order to develop additional threshold values and targeted measures.

Marine litter is also a pressure on ecosystem services, as its associated ecological consequences may compromise the provision of ecosystem services underpinned by the affected ecological components. Impacts on ecosystem services can have important implications for both the economic and social aspects of human welfare. There can be negative impacts on economic sectors such as tourism, fisheries, aquaculture, navigation, and energy and on the social aspects in terms of the attractiveness, enjoyment and interest from having clean beaches / marine areas and marine fauna in good condition, which in turn also affects people's psychological wellbeing.

Q2. What has been done?

The OSPAR North-East Atlantic Environment Strategy 2010-2020 (NEAES 2010-2020) aimed to “develop appropriate programmes and measures to reduce amounts of litter in the marine environment and to stop litter entering the marine environment, both from sea-based and land-based sources”. The primary instrument for achieving this was the OSPAR Regional Action Plan for Marine Litter (RAP ML). When adopted in 2014, it was at the forefront of international collaborative efforts to tackle the issues associated with marine litter. The RAP ML set the policy context for OSPAR’s work on marine litter, but also contained prevention and mitigation actions that OSPAR committed to work on between 2014 and 2020. These consisted of 32 collective actions and 23 national actions which aimed to address both land-based and sea-based sources and pathways of marine litter, as well as education, outreach and removal activities. Together, the actions formed a comprehensive strategy / approach to tackle marine litter, with the national actions designed to support implementation of the collective actions.

OSPAR has also adopted specific Recommendations partly resulting from RAP ML collective actions. Recommendation 2016/01 promotes the establishment of fishing for litter (FFL) initiatives in fishing harbours of Contracting Parties, supported by an associated target to “increase the total number of vessels participating in FFL schemes in the OSPAR Maritime Area by 100% by 2021, compared to the baseline situation in 2017” . Recommendation 2019/01 aims at reducing marine litter by promoting the implementation of training programmes for fishers which address the social, economic and ecological impacts of marine litter. OSPAR Recommendation 2021/06 aims at reducing plastic pellet loss by promoting the timely development and implementation of effective and consistent pellet loss prevention standards and certification schemes for the entire supply chain.

Besides the RAP ML, other measures have been taken to combat marine litter, such as national actions resulting from implementing the EU Marine Strategy Framework Directive (MSFD), other EU initiatives such as the Single-Use Plastics Directive, Plastic Bag Directive, Port Reception Facilities Directive, work on microplastics, and several EU-funded projects. 

In order to support these measures and determine their effectiveness, further monitoring and assessment work has been carried out including the development of common indicators on seafloor litter and on "ingestion of plastic in turtles".

Q3. Did it work?

A review of the RAP ML reported that, as of June 2021, of the 32 collective actions, 78% (25) were considered complete or fully implemented, 9% (3) were still in progress, and 13% (4) were limited in progress and no further action was foreseen under this RAP ML. Regarding the national actions under the RAP ML, for almost all Contracting Parties over 75% of actions were fully implemented or in progress. The FFL target in Recommendation 2016/01 had already been reached by 2020!

The review of the RAP ML concluded that the work completed under the RAP ML had been extensive but was not always easy to quantify or to illustrate through concrete outputs. The RAP ML was ambitious and had inspired action and progress in OSPAR Contracting Parties and other international organisations (e.g., Arctic Council, G7, UN). Furthermore, OSPAR had contributed to the evidence base for and benefited from the adoption of recent EU initiatives, such as the Single-Use Plastics Directive, the Port Reception Facilities Directive, work on microplastics and several EU-funded projects.

In terms of evidence of change in the quantities of marine litter in the North-East Atlantic, criteria like threshold values only exist so far for beach litter (EU only) and plastic litter in fulmar stomachs when it comes to determining the effectiveness of measures, but additional ones for other marine compartments and impacts are currently being developed.

At present, an important reduction in the abundance of beach litter (currently 252 items/100 m) would be required at the OSPAR level to reach the threshold value of 20 litter items/100 m adopted at the EU level, which is an indicative value of beach litter status in the OSPAR Area. Furthermore, currently 51% of beached North Sea fulmars have more than 0,1 g of plastics in their stomachs, exceeding the fulmar threshold value of 10%.

Nonetheless, there are positive signs of a decrease in quantities of litter found on OSPAR beaches and of floating litter in Region II - the Greater North Sea - over the last 10 years (as identified through the OSPAR Indicator Assessments). When this is considered against the upward trend in plastics production and consumption in Europe over a similar period, as well as the predictions for plastic consumption and waste issues to intensify in the future, it suggests that progress has been made on preventing plastics from entering the marine environment. Under the new RAP ML currently being developed, more specific measures will be taken in order to achieve and quantify further overall reductions of marine litter levels and specific litter items.

Q4. How does this field affect the overall quality status?

The marine litter objective in the NEAES 2010-2020 was defined as “to substantially reduce marine litter in the OSPAR Maritime Area to levels where properties and quantities of marine litter do not cause harm to the coastal and marine environment”. Based on the current assessment it could be concluded that although there are indications that the pressures from marine litter are reducing, marine litter levels are still high. Some seafloor litter even seems to be increasing, not unexpectedly, as the seafloor is a sink for marine litter. Further efforts are needed.

At present, an important reduction in total count would be required at the OSPAR level to reach, for example, the threshold value of 20 beach litter items/100 m adopted at the EU level. Overall, and in view of the observed trends, results show that current measures should be continued and strengthened with additional measures in order to increase the reduction in beach litter in the OSPAR Maritime Area and achieve OSPAR’s objectives. This concerns especially NEAES 2030 Operational Objective S4.O3, which aims at a reduction of 50% of single-use plastic and maritime-related items in 2025 and 75% in 2030. Threshold values need to be developed for other indicators in order to better understand the extent of harm caused by litter to the marine environment.

Since 2010, fisheries and shipping intensity levels have remained relatively stable; future developments are uncertain, but shipping might increase in Region I - Arctic Waters. Aquaculture, tourism, and marine infrastructure developments (renewable energy) have been expanding sectors and will probably further expand until 2030, thus potentially increasing marine litter pressure from these sectors.

There are a number of ways in which climate change could affect the quantities of marine litter entering the marine environment, especially from rivers, and its subsequent distribution and deposition. While there may be a need to adapt to some of these changes, it is not currently a major factor influencing OSPAR’s marine litter objectives or the selection of actions for the RAP ML. More work is needed on risk assessment related to extreme weather events. In this connection, the driving factor will be the need to protect vulnerable communities from the devastating effects of flooding; these measures should in turn help to reduce inputs of marine litter.

Q5. What do we do next?

The presence (and associated impacts) of marine litter is driving society to call for action to change producer and consumer habits, reduce inputs and facilitate its removal. Actions are needed that address every stage of the plastic life cycle, with a special emphasis on reducing plastics production. Policy responses to managing marine litter need to consider all these driving forces in order to reduce inputs, reduce the risks associated with materials (e.g., alternatives to plastic) and facilitate societal change. Because of the links between climate change and marine plastic pollution, integrated approaches could benefit both problems.

The NEAES 2030 includes a new marine litter strategic objective (S4): “Prevent inputs of and significantly reduce marine litter, including microplastics, in the marine environment to reach levels that do not cause adverse impacts to the marine and coastal environment with the ultimate aim of eliminating inputs of litter.” S4 is supported by eight operational objectives on new measures for specific sources and pathways and on the development of ambitious coordinated strategies, control measures, threshold values and targets. The adoption of a new Regional Action Plan in 2022 is key to its implementation. Regular monitoring and assessment, including developing new common indicators, will continue to play a major role in supporting the measures and evaluating their effectiveness.

  • OSPAR will use the QSR findings and continued monitoring and assessment to guide the definition of specific actions under the new RAP and evaluate existing and new measures;
  • OSPAR will introduce a microplastics indicator;
  • OSPAR will use the new RAP to develop new measures that add value to national and other international actions;
  • OSPAR will continue to consider new indicators such as those relating to ingestion / harm to gather evidence to better understand the impact of marine litter;
  • OSPAR will further develop its knowledge base on a better understanding of sources, transport, pathways, and fate of marine litter including on seafloor and floating litter and hotspot accumulations;
  • OSPAR will continue to monitor, assess, and provide evidence of harm to inform and direct efforts and maximise the impact that they have on protecting the marine environment;
  • OSPAR will develop approaches to prevent and reduce riverine input.

Very few knowledge gaps have been highlighted in the thematic assessment on Marine Litter. However, a number of knowledge gaps were identified in the marine litter common indicator assessments, the supporting technical supplements and other assessments. These will all be considered for inclusion in OSPAR’s Science Agenda.

Footnotes

1OSPAR Contracting Party reporting on this target will be available in 2022

Marine Litter Assessments


Contributors

Lead Authors: Lex Oosterbaan, Stefanie Werner, Jesus Gago, Youna Lyons

Supporting authors: Camille Lacroix, Willem van Loon, Josie Russell, Jon Barry, Francois Galgani, Adil Bakir, Paul Vriend, Eric Copius Peereboom, Patricia Pérez, Federico Cornacchia, Jennifer Godwin, Emily Corcoran, Robert Ewing, Mareike Erfeling, Adrian Judd, Jemma Lonsdale, Barbara Berx

Supported by: Intersessional Correspondence Group on Marine Litter (ICG ML) and its Monitoring Expert groups, Intersessional Correspondence Group on managing the delivery of the Quality Status Report (ICG-QSR), Intersessional Correspondence Group on Ecosystem assessment outlook – Cumulative effects (ICG-EcoC), Intersessional Correspondence Group on Economic and Social Analysis (ICG-ESA), Climate Change Expert Group (CCEG), OSPAR Commission Secretariat

Citation

OSPAR, 2023. Marine Litter Thematic Assessment. In: OSPAR, 2023: Quality Status Report 2023. OSPAR Commission, London. Available at: https://oap.ospar.org/en/ospar-assessments/quality-status-reports/qsr-2023/thematic-assessments/marine-litter

Printable PDF