Assessment of beach litter abundance, composition and trends in the OSPAR Maritime Area - 2018 - 2023

Beach litter is defined by OSPAR as any persistent, manufactured or processed, solid material discarded, disposed of or abandoned in the marine and coastal environment, and encountered on beaches. A part of this litter originates from the sea, through deliberate or accidental losses from vessels (including cargos and waste), and transported to and deposited on the coast from the sea by winds and water currents. Another part is directly deposited on the coast by humans, e.g. tourists, fishers or the results of fly-tipping. Litter is also deposited further inland on riverbanks, directly into rivers, in urban areas and in the countryside and is subsequently transported by rivers, rain and wind into the marine environment and onto beaches. In addition, sewage infrastructures discharge litter items directly or indirectly, via rivers and sewage outlets into the sea and these items can be washed ashore. 

The present report aims at assessing: (i) marine beach litter quality status in OSPAR Maritime Area and regions, (ii) current beach litter trends, (iii) the progress towards the achievement of OSPAR objectives and (iv) effectiveness of OSPAR actions to reduce marine litter.

To do so, it provides an assessment of the abundance, composition, spatial distribution and trends of beach litter in the OSPAR Area. The abundance reflects the magnitude of the pollution in adjacent waters and coastal areas; composition shows how common are the different litter types (string and cords, cotton bud sticks, caps and lids, cigarette filters, etc.) or litter material categories (plastic, wood, etc.). The distribution highlights regional specificities that can relate to regional differences in sources, activities or human habits. Trends in the abundance of total litter, individual litter types or groups of types (i.e. fisheries related items, packaging, material class, etc.) reflect changes in the level of pollution.

The present assessment relies on survey sites distributed in the five OSPAR regions. as presented in Figure a. Survey sites used are selected according to defined criteria, based on data availability, described in the OSPAR Quality Status Report 2023. However, it should be noted that in the present report, efforts were made to allow inclusion of data from Arctic survey sites with lower data availability in order to provide assessment in the Arctic Waters region (Region I). The present assessment also includes data from Madeira archipelago’s survey sites in order to allow a more reliable assessment of the Wider Atlantic region (Region V). For the beach litter status assessment from 2021 to 2023, 1 550 surveys collected on 157 survey sites are considered. For the trends assessment from 2018 to 2023, 2 251 surveys collected on 116 sites are considered. For the OSPAR objectives assessment, 468 surveys collected on 77 sites are considered from 2022 to 2023. These data represent the most extensive set of fit-for-purpose beach litter monitoring data in the North-East Atlantic. 

The assessment follows OSPAR beach litter monitoring and assessment methodology (which are described in OSPAR Beach litter CEMP guidelines, 2020). This methodology advises surveying four times a year on fixed 100 m beach sections, on which all beach litter items (> 5 mm), which are visible on the sand surface, are collected, identified and counted using the OSPAR survey list. It is important to note that selection of survey sites is not made randomly, and results can only be regarded as representative for the group of beaches monitored. 

The assessment of beach litter pollution is based on a time-series of abundance of litter categories, individual litter types, groups of litter types and total count of litter items recorded on the OSPAR beach litter survey sites. Non-identifiable meso-plastic fragments (5 mm – 2.5 cm) are not included in the assessment because, due to their small size and the occurrence of very high numbers on some beaches, they are monitored less comparably within the OSPAR Maritime Area (Hanke et al., 2019). Only identifiable litter types and macro-litter fragments (> 2.5 cm) are considered in the present assessment.

It is important to understand the dynamics of beached litter to understand what assessments of beach litter data can tell us. In between any two beach litter surveys, litter items that have been washed ashore by tides or deposited directly on to the beach can be buried, washed or blown away again by subsequent tides and winds. Also, during strong wave action buried litter items can resurface (Williams and Tudor, 2001) and litter can be blown onto a site from adjacent land or streets. Therefore, the amount of litter items recorded during one survey will generally constitute a steady state value of deposition and resuspension. However, on beaches in small bays, enclosed for example by rocky promontories, the dynamics of litter is different. Such sites can trap litter, which is subsequently only redistributed within the bay by waves and wind action. Therefore, the amount of litter items recorded during a survey could potentially represent litter accumulation over time. 

During surveys in some locations, it is common to find litter items from other continents or regions outside the OSPAR Area, due to current and wind patterns. This pollution is referred as “transboundary pollution”. On the other hand, part of litter produced in the OSPAR Maritime Area can be exported outside the area.

The composition of litter recorded on beaches also reflects its ability to reach the shore. The litter washed ashore is biased towards litter items that float and those that do not disintegrate, dissolve or decay quickly in the marine environment. The main category of litter found on beaches is plastic, which often floats and does not disintegrate rapidly in water (OSPAR Quality Status Report 2023; Addamo et al., 2017). The main components of the other common categories all float and/or decay slowly (wood, bottles, jars, light bulbs, tins and cans). Metal and glass from seaborne sources are therefore probably underrepresented because they are more likely to sink than items made of plastic, rubber and wood. Paper is probably also underrepresented because it will generally disintegrate more rapidly in water than other materials. On beaches intensively used for recreation, the greater part of beach litter is often composed of items abandoned by beach visitors (e.g. fast-food packaging and cigarette butts) rather than litter washed ashore.

The survey sites of the OSPAR Beach Litter Monitoring Programme are located on the North-East Atlantic coasts of Denmark (including beaches in East Greenland and Faeroe islands), France, Germany, Iceland, Ireland, the Netherlands, Norway, Portugal, Spain, Sweden and the United Kingdom (Figure a). The present assessment also includes data from Madeira archipelago’s survey sites in order to allow a more reliable assessment of the Wider Atlantic region.

In the present assessment, only survey sites with sufficient data availability were included to ensure a robust assessment, except for the Arctic Waters region where difficult monitoring conditions can hinder from conducting surveys. For the Arctic Water region, all monitoring sites and associated surveys are included. In total, 193 out of the 257 monitoring sites registered in the OSPAR Beach Litter Database have data (at least one survey) over the six-year period from 2018 to 2023. Survey sites were selected according to decision criteria presented in the OSPAR Quality Status Report 2023 (except for Arctic Waters). For the beach litter status assessment from 2021 to 2023, only sites with at least three surveys per year over two years are selected (157 sites with 1 550 surveys). For the trends assessment from 2018 to 2023, only survey sites with at least two surveys per year over five years are included (116 sites 2 251 surveys). The list of sites and surveys included in the assessment are presented in Table a.

The surveys are carried out according to the OSPAR Coordinated Environmental Monitoring Programme (CEMP) guidelines for marine monitoring and assessment of beach litter (2020) and reported in the OSPAR Beach Litter Database.

The beaches, on which the survey sites are situated, mainly consist of sand or gravel and are exposed to the open sea. They are in most cases accessible to surveyors all year round for surveying and litter removal. However, some sites, such as in the north of the OSPAR Maritime Area (Arctic Waters), are not accessible or not possible to survey during the winter survey period. In the present assessment, all surveys and sites available in the Arctic Waters region have been selected. 

The beaches have a length of 100 m, are generally free of buildings all year round, and are (in most cases) not subject to litter collection activities (beach cleaning). National coordinators of the surveys have used expert judgement and local knowledge of coastal areas when selecting the survey sites. For example, in some countries local conditions do not allow for selection of beaches mainly consisting of sand, and in some locations, it is not possible to select beaches of 100 m in length. The start and end points of the survey sites are marked clearly and registered into the OSPAR Beach Litter Database, to ensure that exactly the same site is monitored for all surveys.

According to the OSPAR beach litter CEMP guidelines (2020), at each survey site, all litter items should be recorded four times a year using the OSPAR beach litter monitoring protocol. The survey periods are described as follows in the OSPAR beach litter CEMP guidelines: winter (January), spring (April), summer (July), and autumn (October). However, due to limitations dictated by weather conditions, availability of manpower etc. not all survey sites included in this analysis have been surveyed as regularly as this for the whole period (see Table a). Some survey sites have only recently been added to the network of survey sites and surveys on other sites have been discontinued. 

Data on the amount of litter on a survey site is recorded at the litter-type level. In total, 112 predefined litter types are considered in the present assessment. Each item found on the survey site is allocated to one of the 112 litter types. Items comprise identifiable pieces of litter, including items such as plastic bottles, tetra-pack containers, metal drinks cans, and rubber gloves as well as unidentifiable fragments of litter objects. The litter types are assigned to following categories according to the material from which they are made: Artificial polymer materials/Plastic (63 litter types), Rubber (4 litter types), Cloth (5 litter types), Paper / cardboard (8 litter types), Processed / worked wood (9 litter types), Metal (15 litter types), Glass and ceramics (6 litter types), Undefined (2 litter types). The list of litter types with their unique OSPAR identification number and their allocation to material types, additional relevant categories along with its ability to be identified (fragments being generally too degraded to be identifiable) and if the litter type is targeted by measures, is presented in Table b. Additional relevant categories are:

• Category of single-use plastics (SUP), single-use plastic litter types that are targeted by the European Union (EU) Directive 2019/904, this category is harmonised with the one used at EU level.
• Extended category of Single-use plastics (SUP+), extended SUP category that includes all single-use plastics identified in the OSPAR survey list (not only the ones targeted by the EU Directive 2019/904).
• Category of maritime-related plastic items (SEA_plastic), category that includes all maritime-related plastic items (not only the ones targeted by the EU Directive 2019/904).
• Category of maritime-related items (SEA_all), extended SEA category that includes all maritime-related items (plastic and non-plastic).

It should be noted that over the period considered in the present assessment (2018-2023), the OSPAR survey list in use did not allow to assess the FISH category (that includes plastic fishing gear, including aquaculture gear, litter types that are targeted by the EU Directive 2019/904) adopted at EU level for reporting (European Commission et al., 2024). This category will be considered in the future with the implementation of the updated OSPAR survey list in 2025.

Paraffin and other chemicals, which although included in the beach litter database are recorded using a different method than for litter items, and are not analysed here.
During each survey for a given survey site, the number of individual pieces of litter is recorded for each litter type. The survey forms allow for the registration of identifiable items, unknown items and litter fragments in different size categories. Litter items which do not fit into a definite litter type category, are registered under the litter types ‘other’ for the given material or use category (e.g. litter type “other plastic/polystyrene items”, OSPAR ID 48). A short description of the litter types is included on the survey form. Multilingual photo guides are available to assist surveyors with the identification and categorisation of litter items. All litter items are normally removed from the beach during the survey.

The location and physical characteristics of survey sites are influent parameters in terms of litter deposition/retention patterns as well as potential sources; for this reason, the characteristics of beaches are recorded in detail. This information includes the proximity of possible sources of marine litter to the beach, as well as other factors that could help explain the amount, type, and composition of marine litter found. This information is stored in the OSPAR Beach Litter Database.

The assessment method used in the present report is described in the OSPAR Beach litter CEMP guidelines and is also detailed below. Non-identifiable meso-plastic fragments (5 mm - 2.5 cm) are excluded from the analysis.

Excel and the software package litteR (Walvoort et al., 2021) are used to analyse abundance, top items and trends in the results of the OSPAR beach litter surveys. litteR calculates total count, abundances of litter types and groups and trends at the individual survey site level using robust statistical methods which are appropriate for the skewed litter data distributions (Schulz et al., 2017, 2019), and then aggregates the beach results to higher spatial levels (blocking method, Van Belle and Hughes, 1984).

The litter types and groups analysed include:

• material categories (artificial polymer material, rubber, cloth/textile, paper/cardboard, metal, glass/ceramics and undefined),
• the four categories SUP/SUP+ and SEA_plastic/SEA_all, that traduce different litter sources,
• five litter types which were directly targeted by the OSPAR Marine Litter Regional Action Plan (RAP ML 2014-2021) (plastic bags, cigarette filters, cotton bud sticks, hunting cartridges and balloons). More litter types, relevant for the RAP ML, will be considered in the future with the implementation of the updated OSPAR survey list in 2025.

Indicators are calculated for four nested spatial scales: survey sites, OSPAR/MSFD-country-subregion, OSPAR Region and OSPAR Maritime Area. The present report focuses on results obtained at the OSPAR Maritime Area and regions levels. 

Abundances and litter composition are evaluated for a three-year period from 2021 to 2023, using median-based robust calculation methods. The associated percentages are also calculated in a robust way based on the medians.

Trends in total count, litter categories and individual litter types are evaluated over the last six years (from 2018 to 2023).

Progresses towards the achievement of targets under the operational objectives S4.O3 and S4.O4 at the end of 2023 are assessed by calculating reduction percentages between time periods from 2022 to 2023 and the reference years from 2015 to 2016, as described in the reports for the monitoring of progress against the objectives (André et al., 2024a, 2024b  and MSFD report on trends (European Commission et al., 2024). Please note that the baseline for the Wider Atlantic only covers 2016 as no survey were available in 2015. In addition, Madeira archipelago’s survey sites, included in the present assessment, were not taken into account in the baseline calculations from 2015 to 2016 as monitoring started in 2020.

In order to assess abundances, litter composition and trends at OSPAR region and OSPAR Maritime Area scales, monitoring data are aggregated in a stepwise process at survey site level and then at OSPAR/MSFD-country-subregion. In the present assessment, it is considered that at least three sites are needed to make calculations at an aggregated scale. If less than three sites are available in the OSPAR/MSFD-country-subregion, results should be considered with care and are considered to be indicative (with lower information).

Assessment of abundance between 2021 and 2023

The median beach litter total counts of the OSPAR Maritime Area and the different OSPAR regions over the period from 2021 to 2023 are presented in Figure b. The median total count of the OSPAR Maritime Area over a three-year period between 2021 and 2023, is 135 litter items per 100 m of coastline (against 252 litter items/100 m from 2018 to 2020). It appears that the pollution level varies between OSPAR regions, from 71 litter items/100 m for the OSPAR region Arctic Waters to 247 litter items/100m for the OSPAR region Greater North Sea. Abundance in the Wider Atlantic and Arctic Waters regions appear to be lower than in the three other regions.
 

The median beach litter total counts of the OSPAR Maritime Area and the different OSPAR regions over the period from 2021 to 2023 are presented in Figure b. The median total count of the OSPAR Maritime Area over a three-year period between 2021 and 2023, is 135 litter items per 100 m of coastline (against 252 litter items/100 m from 2018 to 2020). It appears that the pollution level varies between OSPAR regions, from 71 litter items/100 m for the OSPAR region Arctic Waters to 247 litter items/100m for the OSPAR region Greater North Sea. Abundance in the Wider Atlantic and Arctic Waters regions appear to be lower than in the three other regions.

At the beach scale, pollution levels range from 1 to 2 588 litter items/100 m (see Figure c).

It must be noted that several phenomena can influence beach litter abundance. Regular beach clean-up can decrease the pollution level whereas transboundary transport of pollution due to wind and currents can exacerbate it in some areas (e.g. on the Sweden coast). Though these phenomena are known to occur, their extent and effect on beach litter monitoring is currently not well quantified in the OSPAR Maritime Area.

Assessment of OSPAR threshold value between 2021 and 2023

At the OSPAR region scales, which is the scale agreed to assess the OSPAR threshold value, the TV assessments values range between 98 and 206 litter items/100 m, which is much higher than the threshold value of 20 litter items/100 m adopted at OSPAR and European levels (Van Loon et al., 2020), as presented in Figure d. To reach this threshold value, a reduction ranging between 80% and 90% is required.

Material composition of beach litter between 2021 and 2023

The composition of beach litter pollution in the OSPAR Maritime Area and regions is presented in Figure e. A major part of litter found on OSPAR beaches are made of plastic with a median of 115 litter items/100 m recorded at the OSPAR Maritime Area level. All other material categories have medians equal or inferior to 8 litter items/100 m. Similar results are observed in OSPAR regions as plastic remains the most important material, from 50 litter items/100 m for the OSPAR region Wider Atlantic (71% of the beach litter pollution of the region) to 224 litter items/100 m for the OSPAR regions Bay of Biscay and Iberian Coast (95% of the beach litter pollution of the region). This confirms that plastic still represents the most important part of the pollution regardless of the geographical scale, indicating measures targeting this material should be continued and prioritized to substantially reduce beach litter pollution.

Status of categories and litter types of interest between 2021 and 2023

The litter categories “Single-use plastics” (SUP) and “Maritime-related plastic items” (SEA_plastic) are of great interest in the OSPAR Maritime Area since they are targeted by measures. In addition, the two groups represent a non-negligible part of beach litter pollution in the OSPAR Area. The details of their median counts are presented for the OSPAR Maritime Area and regions in Figure f. Percentages are shown in Figure g.

It should be noted that over the period 2018-2023, considered in the present assessment, the OSPAR survey list in use did not allow to assess the FISH category (that includes plastic fishing gear, including aquaculture gear, litter types that are targeted by the EU Directive 2019/904) adopted at EU level for reporting (European Commission et al., 2024). This category will be considered in the future with the implementation of the updated OSPAR survey list in 2025.

At the OSPAR level, SUP items show a median total count of 23 litter items/100 m representing 20% of the pollution (against 42 litter items/100 m in the previous assessment). When looking at the regional distribution of this category, the OSPAR region Bay of Biscay and Iberian Coast remains the most affected by the presence of SUP, with a median value of 39 litter items/100 m (against 90 litter items/100 m in the previous assessment). On their side, the three regions Wider Atlantic, Greater North Sea and Celtic Seas present median values ranging from 23 to 34 litter items/100 m, whereas the OSPAR region Arctic Waters presents the lowest median values in SUP items with 8 litter items/100 m. The extended SUP+ category (including also single-use plastics not targeted by the EU Directive 2019/904) shows a similar pattern as the SUP category but with higher median abundances at both, the OSPAR Maritime Area and region scales (Figure f).

Results of the analysis of median abundances of plastic bags, cigarette filters, cotton bud sticks, hunting cartridges and balloons, that were targeted by the RAP ML 1, are shown in Table c. At both, the OSPAR Maritime Area and regions scales, these litter types appear to have low median abundances ranging between 0 and 2 litter items/100 m. It should be noted that none of these litter types are found in the Top10 litter types observed at the OSPAR Maritime Area scale (Figure h). It should be noted that more litter types, relevant for the RAP ML, will be considered in the future with the implementation of the updated OSPAR survey list in 2025.

Trends of beach litter over the last six years between 2018 and 2023

Significant decreases in litter abundance are observed over the last six years as detailed in Table d, which confirmed the lower litter abundance observed at the OSPAR Maritime Area scale and in most regions. Significant decreases in both, total counts and plastic items, are observed at the OSPAR Maritime Area scale and in all regions though limited for the Arctic Waters and Wider Atlantic regions (less than 4 litter items/100 m per year). For other regions, decreases in total counts range from 14 to 30 litter items/100 m per year whereas decreases in plastic counts range from 10 to 23 litter items/100 m per year.

Table d: Median total and plastic counts (from 2021 to 2023) and associated slopes (from 2018 to 2023) in the OSPAR Maritime Area and the five OSPAR regions. Arrows indicate significant trends

	Median (litter items/100 m) and associated slopes (litter items/100 m/year)
Geographical scale	Total count		Plastic
OSPAR Maritime Area	15	↓ -19	0	↓ -12
Arctic Waters	71	↓ -4	66	↓ -3
Greater North Sea	247	↓ -19	224	↓ -20
Celtic Seas	135	↓ -14	115	↓ -10
Bay of Biscay and Iberian Coast	204	↓ -30	187	↓ -23
Wider Atlantic	94	↓ -2	50	↓ -1

Decreasing trends are also observed for SUP and SUP+ categories at the OSPAR Maritime Area scale and in four regions: Greater North Sea, Celtic Seas, Bay of Biscay and Iberian Coast and Arctic Waters with slopes ranging from -2 to -8 litter items/100 m per year (Table e). However, for the Wider Atlantic, significant increasing trends are observed for both SUP and SUP+ (+1 litter item/100 m per year).

Decreasing trends are also observed for SEA_plastic and SEA_all categories at OSPAR Maritime Area scale and in three regions: Greater North Sea, Celtic Seas and Bay of Biscay and Iberian Coast with slopes ranging from -3 to -4 litter items/100 m per year (Table e). For the two other regions (Arctic Waters and Wider Atlantic), trends were not significant indicating that abundances remain stable for these categories.

*Note that slopes cannot be calculated if number of surveys for a site is lower than 3. Following survey sites have been excluded from trend assessment: GRL004, GRL005, GRL019, GRL021, GRL022

Progress towards the achievement of beach litter targets under operational objectives S4.O3 and S4.O4 between 2022 and 2023

Progresses towards the achievement of beach litter targets under operational objectives S4.O3 and S4.O4 at the end of 2023 are presented in Table f and Table g. These tables also include results of the assessment at the end of 2021, for comparison.

Regarding the objective of 50% reduction in the category SUP+SEA_plastic by 2025 under objective S4.O3, progress towards the target is observed at the OSPAR Maritime Area scale at the end of 2023, with a reduction of 23.2% in SUP+SEA_plastic counts. At region scale, one region (Arctic Waters) has already achieved the objective (-75.8%) and three regions are progressing toward the target (Greater North Sea, Celtic Seas, Bay of Biscay and Iberian Coast) with reduction percentages ranging from 14.6% to 32.5%). However, it should be noted that Wider Atlantic is exhibiting a 36.1% increase, that could be explained by the recent inclusion of Madeira archipelago’s survey sites.

Regarding the objective of 70% reduction in beach litter total count by 2030 under objective S4.O4, progress towards the target is observed at the OSPAR Maritime Area scale at the end of 2023, with a reduction of 18.2% in beach litter total count. At region scale, four regions are progressing towards the target (Arctic Waters, Greater North Sea, Bay of Biscay and Iberian Coast, Wider Atlantic) with reduction percentages ranging from 10.2% and 57.6%, whereas the Celtic Sea is exhibiting a 5.8% increase.

Top litter types of OSPAR Maritime Area from 2021 to 2023

The top litter types of the OSPAR Maritime Area are presented in Figure h. Among the 10 litter types presented, all of them are classified as plastic. The top-one litter type is non-identifiable plastic fragments (“plastic/polystyrene pieces 2.5-50 cm”; median abundance: 18.3 litter items/100 m). This confirms the important fragmentation of plastic in the environment, increasing the number of items, making recovery more difficult and raising concern in terms of environmental impact with an increasing risk of ingestion.

Among the top 10 litter types, four belong to the SUP category (“caps/lids”, “crisp/sweet packets and lolly sticks”, “drinks (bottle, containers and drums)” and “food containers incl. fast food containers”) and three belong to the SEA_plastic category (“strings and cords (diameter less than 1 cm)”, “ropes (diameter more than 1 cm)” and “net and pieces of net <50 cm”). These results show that these litter categories, though targeted by measures, remain an issue on the OSPAR beaches.

Types of surveyed items

The analysis of identified litter types, non-identified litter types and non-identifiable plastic fragments (Figure i) shows that the majority of litter observed on OSPAR beaches is identified, 74% of litter being identified litter types in the OSPAR list (against 79% in the previous assessment). However, 15% of the beach litter pollution appears to be non-identifiable as it is composed of non-identifiable plastic fragments (against 13% found in the previous assessment). These litter items could result from various sources or activities that cannot be identified, which prevent the implementation of dedicated measures to combat them. In addition, 11% of the beach litter pollution is made of non-identified litter items (against 8% in the previous assessment). This value reflects the limited capacity of the OSPAR litter survey list to cover all the items collected. To improve the coverage of the OSPAR list, the addition of new litter types could be considered.

Measures coverage

The good adequacy of the OSPAR Regional Action Plans 1 & 2 for Marine Litter (RAP ML 2014-2021 and RAP ML 2022-2030), SUP and fishing gear EU Directive 2019/904 is estimated by assessing the total amount of litter items directly targeted by these measures (Figure j). At OSPAR level, 55% of the litter items recorded are directly targeted either by the directive or the RAP ML 1 & 2 and 16% are partially targeted. This traduces an improvement of better coverage with the adoption of the new RAP ML, as 54% and 1% of items were found to be directly and partially targeted, respectively, in the previous assessment. This also shows that the directive and the RAP ML measures cover a good proportion of beach litter pollution, but there is still room for improvement.

Over the period from 2021 to 2023, beach litter remains abundant in the OSPAR Maritime Area and in OSPAR regions, though less than observed over the period from 2018 to 2020 with a median total abundance of 135 litter items/100 m from 2021 to 2023 compared to 252 litter items/100 m from 2018 to 2020. The Greater North Sea is now the region presenting the highest level of pollution as the Bay of Biscay and Iberian Coast exhibit a lower level of pollution than in the previous assessment. The regions with the lowest level of pollution are Arctic Waters and the Wider Atlantic.

At the end of 2023, the OSPAR threshold value of 20 litter items/100 m, that traduces good beach litter status in the OSPAR Maritime Area, is not achieved and reduction between 80% (Wider Atlantic) and 90% (Bay of Biscay and Iberian Coast) is required at the level of OSPAR regions to reach the TV. 

Plastic remains predominant in all OSPAR regions, reaching a median value of 115 litter items/100 m at the OSPAR Maritime Area level and representing 93% of the pollution (against 194 litter items/100 m, representing 94% of the pollution over the period from 2018 to 2021). 

Single-use plastics and maritime-related plastic items, which are targeted by different measures and targeted by the operational objective S4.O3, present median values of 23 litter items/100 m and 19 litter items/100 m respectively in the OSPAR Maritime Area (20% and 17% of the pollution respectively). However, regional specificities are observed in terms of litter composition in the different OSPAR regions, single-use plastics being predominant in the Bay of Biscay and Iberian Coast (median value of 39 litter items/100 m) and maritime-related plastic items being predominant in the Greater North Sea (median value of 42 litter items/100 m). 

An extended single-use plastic category was also studied to assess the coverage of the EU Directive 2019/904. Results show that some single-use plastic items found on OSPAR beaches are not targeted by the Directive which emphasizes the need to address these items via the RAP-ML 2 action A.4.1. 

The analysis of the extended maritime-related items category that includes both, plastic and non-plastic items, shows similar results as the plastic category constitutes the large majority of maritime-related items found on OSPAR beaches.

Significant decreasing trends in litter abundance are observed in the OSPAR Maritime Area and in four of the five OSPAR regions over the last six years, which is confirmed by the lower median total counts in the OSPAR Maritime Area and in all regions observed from 2021 to 2023 compared to the time period from 2018 to 2020, except for the Wider Atlantic region that exhibits a higher median total count. This could be explained by Madeira archipelago’s survey sites which have been included recently in the status assessments for this region.

The assessment of progress toward targets achievement under operational objectives S4.O3 and S4.O4 shows that most regions are progressing towards the achievement of targets. For S4.O3 that aims at a 50% reduction in single-use plastics and maritime-related plastic items on OSPAR beaches by 2025, results show that at the end of 2023, progress towards the objective is observed in the OSPAR Maritime Area as well as in four out of the five OSPAR regions, including Arctic Waters for which the objective is already achieved if results remain stable. However, there is an alert for the Wider Atlantic region that exhibits an increase in percentage, that could be explained by the recent inclusion of Madeira archipelago’s survey sites. For S4.O4 that aims at a 70% reduction in beach litter total count in the OSPAR Maritime Area by 2030, results show that at the end of 2023, reductions in beach litter total count are observed at the OSPAR Maritime Area level and in four OSPAR regions (Arctic Waters, Greater North Sea, Bay of Biscay and Iberian Coast and Wider Atlantic). However, the region Wider Atlantic that achieved the objective in 2021, does not achieve it anymore and the region Celtic Seas stopped its progress and exhibits an increase in percentage.

The identification of the beach litter pollution by the OSPAR survey list seems adequate since 74% of litter collected are identified by the OSPAR list and only 11% are not identified. Results confirm the presence of numerous non-identifiable fragments representing 15% of litter found on OSPAR beaches, which cannot be used to identify pollution sources. 

Regarding existing measures, they present a good coverage with 55% of litter found on OSPAR beaches, which are directly targeted by either OSPAR Marine Litter Regional Action Plan 1 & 2 actions or the EU Directive 2019/904.

Overall, and in view of observed trends, results suggest that actions should be continued to pursue the reduction of marine litter in the OSPAR Maritime Area to achieve the OSPAR strategic objective and associated operational objectives S4.O3 and S4.O4, adopted in the North-East Atlantic Environment Strategy 2020-2030 and reach good environmental status in the OSPAR Maritime Area.

The present assessment allows identifying existing knowledge gaps hindering a precise assessment of beach litter pollution. These gaps are:

• 15% of marine litter observed in OSPAR Maritime Area are non-identifiable fragments. This large quantity of fragments appears to be problematic as they could not be linked to specific objectives and activities. It therefore hinders the implementation of dedicated measures. More research is needed to improve the knowledge on fragments composition and sources;
• The non-identified litter items represent 10%, of which the litter type “other plastic/polystyrene items” is present in the top litter types with a median value of 4.3 items/100 m, indicating that they do not have a proper category to be classified in and cannot be counted individually. Further investigations should be made to improve knowledge on these items and assess if they require to be targeted by action and as a consequence, if they need to be individually monitored;
• Some litter types are known to be abundant on the European coastline (e.g. expanded polystyrenes). As a consequence, these groups of items are already targeted by measures (OSPAR Marine Litter Regional Action Plan). However, in some cases, they are not individually monitored in the OSPAR beach litter surveys. It is recommended to adapt the monitoring litter list to existing measures in order to ensure a better knowledge of their abundance and a proper assessment of the efficiency of measures;
• Sources of beach litter have not been identified in the present study because of a lack of methodology to properly identify these sources. Beyond the identification of sources of the different litter types, this methodology could allow an estimation of transboundary pollution, i.e. to determine the part of litter items that does not originate from the country, region or area where they have been collected. In that sense, the Marine Strategy Framework Directive Technical Group on Marine Litter (MSFD TG ML) has planned to develop a suitable model to estimate transboundary pollution in the mid-term future (Van Loon et al., 2020). This method could lead to estimate the part of litter items of the present study that comes from outside the OSPAR Maritime Area or that is transferred between OSPAR regions.
• The survey sites which supplied the data used in the analysis of beach litter for the OSPAR regions are situated on beaches, which are very variable in their topography, hydrography, geography, proximity to point sources and human use, all of which can influence the amount of litter deposited on the beach. Differences in the topography, geography of the beaches and hydrodynamic conditions (tides, waves, currents, etc.) were succinctly considered in the applied aggregation method but need to be more considered in future assessments.
• Weather phenomena can also influence litter deposition. In the future, the effects of weather phenomena, such as the North Atlantic Oscillation (NAO), should be analysed to assess their influence on abundance and trends in the beach litter dataset.

Addamo, A. M., Laroche, P., Hanke, G. (2017) Top Marine Beach Litter Items in Europe, EUR 29249 EN, Publications Office of the European Union, Luxembourg, ISBN 978-92-79-87711-7, doi:10.2760/496717, JRC108181. https://publications.jrc.ec.europa.eu/repository/bitstream/JRC108181/technical_report_top_marine_litter_it ems_eur_29249_en_pdf.pdf

André, S., Schulz, M., Strand, J., van Loon, W., Walvoort, D., Barry, J., Lacroix, C. (2023) Methodology for assessing the OSPAR threshold value for beach litter. ICG-ML (2) Meeting of the Intersessional Correspondence Group on Marine Litter, Scheveningen, the Netherlands and Webex, 13-16 June 2023.

André, S., Schulz, M., Strand, J., van Loon, W., Walvoort, D., Barry, J., Lacroix, C. (2024a). Report for the monitoring of progress against the NEAES Operational Objective S4.O3. ICG-ML (2) Meeting of the Intersessional Correspondence Group on Marine Litter, Online, 9-11 December 2024.

André, S., Schulz, M., Strand, J., van Loon, W., Walvoort, D., Barry, J., Lacroix, C. (2024a). Report for the monitoring of progress against the beach litter target under the NEAES Operational Objective S4.O4. ICG-ML (2) Meeting of the Intersessional Correspondence Group on Marine Litter, Online, 9-11 December 2024.

Directive (EU) 2019/904 of the European Parliament and of the Council of 5 June 2019 on the reduction of the impact of certain plastic products on the environment. https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32019L0904&from=FR

European Commission: Joint Research Centre, MSFD TECHNICAL GROUP ON MARINE LITTER, …, Hanke, G., Walwoort, D., Ruiz-Orejón, L.F., van Loon, W.M.G.M., Giorgetti, A., Molina-Jack, M.E. and Vinci, M., (2024). European Coastline Macro Litter Trends 2015 - 2021, Publications Office of the European Union, Luxembourg, https://data.europa.eu/doi/10.2760/0752301, JRC138907. https://publications.jrc.ec.europa.eu/repository/handle/JRC138907

Hanke, G., Walvoort, D., van Loon, W., Addamo, A.M., Brosich, A., del Mar Chaves Montero, M., Molina Jack, M.E., Vinci, M., Giorgetti, A. (2019) EU Marine Beach Litter Baselines, EUR 30022 EN, Publications Office of the European Union, Luxemburg, ISBN 978-92-76-14243-0, doi:10.2760/16903, JRC114129. https://publications.jrc.ec.europa.eu/repository/bitstream/JRC114129/eu-marine-litter-baselines.pdf

OSPAR Beach Litter Database: https://beachlitter.ospar.org/

OSPAR Quality Status Report 2023. Lacroix, C., André, S., and van Loon, W. (2022). Abundance, Composition and Trends of Beach Litter. In: OSPAR, 2023: The 2023 Quality Status Report for the North-East Atlantic. OSPAR Commission, London. https://oap.ospar.org/en/ospar-assessments/quality-status-reports/qsr-2023/indicator-assessments/beach-litter/

OSPAR first Regional Action Plan on Marine Litter (RAP ML 1) 2014-2021: https://www.ospar.org/documents?v=34422

OSPAR second Regional Action Plan on Marine Litter (RAP ML 2) 2022-2030: https://www.ospar.org/documents?v=49384

OSPAR CEMP Guidelines for Monitoring and Assessment of beach litter (2020): https://www.ospar.org/work-areas/cross-cutting-issues/cemp

Van Loon, W., Hanke, G., Fleet, D., Werner, S., Barry, J., Strand, J., Eriksson, J., Galgani, F., Gräwe, D., Schulz, M., Vlachogianni, T., Press, M., Blidberg, E., Walvoort, D. (2020) A European Threshold Value and Assessment Method for Macro Litter on Coastlines. EUR 30347 EN, Publications Office of the European Union, Luxembourg, ISBN 978-92-76-21444-1, doi:10.2760/54369, JRC121707. https://ec.europa.eu/jrc/en/publication/european-threshold-value-and-assessment-method-macro-littercoastlines

Schulz, M., van Loon, W., Fleet, D. M., Baggelaar, P., & van der Meulen, E. (2017). OSPAR standard method and software for statistical analysis of beach litter data. Marine pollution bulletin, 122(1-2), 166-175.

Schulz, M., Walvoort, D. J., Barry, J., Fleet, D. M., & van Loon, W. M. (2019). Baseline and power analyses for the assessment of beach litter reductions in the European OSPAR region. Environmental Pollution, 248, 555-564.

Tudor, D. and Williams, A. (2004) Development of a ‘Matrix Scoring Technique’ to determine litter sources at a Bristol Channel beach. Journal of Coastal Conservation, 10(1), pp.119-127.

Van Belle, G., & Hughes, J. P. (1984). Nonparametric tests for trend in water quality. Water resources research, 20(1), 127-136. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/WR020i001p00127

Walvoort, D. and van Loon, W. (2021). litteR software for statistical analysis of litter data. https://cran.r-project.org/web/packages/litteR/index.html