Currently, 60% of fulmars beached in the UK have more than 0.1g of plastic in their stomachs. This reflects the abundance of floating litter in their environment. There has been no significant change in the amount of plastic found in the stomachs of fulmars over the past ten years.


UK target on litter

There is no specific target related to this indicator, but the UK has adopted a surveillance indicator to monitor the plastic content found in the stomachs of fulmars (in line with the OSPAR Ecological Quality Objective) (Figures 1 and 2). Fulmars forage exclusively at sea, generally at the surface of the water (Figure 3). Monitoring this species, therefore, gives an indication of the abundance of floating litter in their environment and how this is changing.

Figure 1. Fulmars forage exclusively at sea and regularly ingest marine debris, accumulating hard items temporarily in their stomachs. These characteristics make them a useful indicator of densities of marine plastic debris that these birds encounter in their marine foraging areas.


Figure 2. The monitoring system for plastics in stomachs of seabirds uses beached fulmars. The fulmar in this photograph had beached on Texel, the Netherlands, on 8 January 2009.

Figure 3. Plastics from a fulmar stomach with industrial pellets (lower left), thread-like (top left) and a mix of fragmented, sheet-like and foamed (right) consumer plastics. Size indicated by the spherical industrial plastic pellets, which are 4–5mm in diameter. (Fulmar sample NMD-2007-091).

Key pressures and impacts

The key pressure is the input of plastic litter to the marine environment from land-based and sea-based sources originating from both the UK and other countries. There may be an adverse impact on fulmars, but this is still under investigation.

Measures taken to address the likely impacts

The measures taken to reduce the amounts of litter in the marine environment and limit the possible impacts are set out in the UK Marine Strategy Part Three (HM Government, 2015) and include initiatives to address terrestrial and marine sources, removal from waste water, and regional action through the OSPAR Marine Litter Regional Action Plan (OSPAR Commission, 2014).

Monitoring, assessment and regional cooperation

Areas that have been assessed

The beached fulmars were collected on UK coastlines. The foraging ranges of fulmars cover hundreds of miles and the sources of plastic that they ingest are not clearly established.

Monitoring and assessment methods

The OSPAR Coordinated Environmental Monitoring Programme Guidelines for Monitoring and Assessment of plastic particles in stomachs of fulmars in the North Sea area (OSPAR Commission, 2015) were used for this assessment. Beached birds or individuals accidentally killed are used and the number of plastic particles in their stomachs is counted.

Assessment thresholds

No assessment threshold is currently set by the UK but OSPAR has a long-term goal that fewer than 10% of fulmars should have no more than 0.1g of plastic in their stomachs. This assessment looks to see what progress has been made towards this goal.

Regional Cooperation

Results are being used in a similar indicator on litter in fulmar stomachs in the OSPAR Intermediate Assessment 2017 (OSPAR Commission, 2017).

Further information


Many marine organisms, including seabirds, turtles, marine mammals, fish, crustaceans, shellfish and zooplankton ingest human-made debris that they encounter in their environment (Kühn and others, 2015). The quantity of litter ingested and found in marine animal stomachs or intestines, particularly that of persistent materials such as plastics, reflects the abundance of marine litter in the sea.


As a contracting party to OSPAR, the UK has contributed to the OSPAR Common Indicator which monitors plastic abundance in the stomachs of seabirds. This gives an indication of levels and trends in marine litter floating on the surface of the North Sea. The indicator has been implemented through long-term monitoring of plastic abundance in stomach contents of the fulmar (Fulmarus glacialis) which has been developed by OSPAR as an Ecological Quality Objective. This approach has been used as the basis of the OSPAR Common Indicator Assessment for the Intermediate Assessment 2017 (OSPAR Commission, 2017). The Commission Decision on Criteria and Methodological Standards on Good Environmental Status of Marine Waters (European Commission, 2017) refers to indicators related to litter in the water column (including floating at the surface) and to litter ingested by marine animals.


The OSPAR Common Indicator on plastic particles in fulmar stomachs has been presented as a monitoring approach in the Marine Strategy Framework Directive (HM Government, 2012European Commission, 2008, 2010; Galgani and others, 2010), which is suitable for implementation in the Greater North Sea, Arctic Waters and Celtic Seas. The methodology for undertaking assessments of ingested plastic has also been used for other biota indicators for marine litter in other regions where no fulmars occur.

The purpose of monitoring plastic abundance in the stomachs of fulmars is to:

  • obtain a quantitative measure for spatial and temporal patterns in the abundance and composition of marine litter, in particular plastics, mainly floating at the surface
  • provide an indication of ecological harm caused by such litter

In 2015, OSPAR adopted Guidelines for Monitoring and Assessment of Plastic Particles in Stomachs of Fulmars in the North Sea Area (OSPAR Commission, 2015) to guarantee consistent monitoring methods and uniform submission of data by the relevant OSPAR contracting parties.

While plastic ingested by the fulmar was selected as an ‘ecological indicator’ for trends in marine litter by OSPAR (OSPAR Commission, 2009) and as an indicator for ‘impact on biota’ in the Marine Strategy Framework Directive (MSFD Indicator 10.2.1 in European Commission, 2010), the results of fulmar monitoring have a broader additional significance:

  • both size range and location of debris monitored by fulmars is complementary to macro-debris monitored on beaches
  • fulmar ingestion has a focus on floating marine debris and addresses the Marine Strategy Framework DirectiveIndicator on trends in litter in the water column
  • the size range of plastics ingested by fulmars could be used as a functional instrument for monitoring microplastics at the upper end of their size scale and contribute to the Indicator on trends in micro-particles

Suitability of fulmars for monitoring marine litter

Fulmars are pelagic (open sea) seabirds that belong to the large group of the tubenoses (Procellariiformes) of which the albatrosses are the best-known representatives. These birds forage exclusively at sea and never on land, and rarely forage close to shore. The fulmar is a poor diver, and thus feeds on what is available at or within a few metres of the water surface. Like most tubenosed seabirds, fulmars regularly ingest a variety of marine debris, taken directly and intentionally as it may resemble prey, or unintentionally when mixed with attractive food wastes. Indirect ingestion, for example, through preying on fish with ingested plastics or scavenging on guts of other dead animals, can also occur. A preliminary survey suggests that approximately 90% of ingested plastic items found in the first glandular stomach of fulmars are 10mm or less in diameter, and over 50% are 5mm or less (Bravo Rebolledo, 2011). Thus, litter ingested by fulmars is mostly in the micro (<5mm) and meso (5–25mm) size range. Unlike most gulls, fulmars do not normally regurgitate indigestible components of their diet but gradually grind these in their muscular stomach (gizzard) until the particles are worn or broken into sizes small enough to pass into the intestines and be excreted (which appears to happen at particle sizes of approximately 2–3mm (Bravo Rebolledo, 2011). Fulmar stomach contents can therefore integrate litter encountered during feeding over periods of days to weeks (Van Franeker and Law, 2015).

Assessment method

Full details of methods are provided in the OSPAR Guidelines for Monitoring and Assessment of Plastic Particles in Stomachs of Fulmars in the North Sea Area (OSPAR Commission, 2015).

Corpses of dead beached birds are collected by volunteer networks, but processed at experienced laboratories. At dissection, in addition to the date, the discovery location is specified by a system of area codes and geographical coordinates for the area. Based on several internal and external anatomical characteristics, birds are classified as either adults or non-adults. The pilot study for fulmar monitoring (Van Franeker and Meijboom, 2002) showed that age is a relevant variable because younger birds generally have more plastic in the stomach than adults.

Stomach contents are carefully rinsed in a sieve with a 1mm mesh and then transferred to a petri dish for sorting under a binocular microscope. This size of mesh is used because smaller meshes become easily clogged with mucus from the stomach wall and with other stomach contents. Analyses using smaller meshes were found to be extremely time consuming and particles smaller than 1mm are very rare in the stomachs (Bravo Rebolledo, 2011) and contribute very little to the numerical abundance of particles and plastic mass.

Two types of plastic categories are distinguished in the OSPAR Common Indicator. Industrial plastic pellets are separated from consumer debris such as sheets, foams, threadlike materials and hard fragments. For each of these categories the number of particles and mass (in grams and to the fourth decimal place) is recorded. The final assessment is based only on the total weight of plastics in stomachs, but industrial and consumer waste plastics have different sources and as such provide very useful information for interpreting the monitoring data.

Data collected in this way make it possible to determine:

  • frequency of occurrence (’incidence’, the proportion of birds having plastic in the stomach)
  • arithmetic average and standard error of the mean for number or mass of plastic
  • geometric means (from transformed data to reduce impacts of data outliers)
  • the indicator performance (i.e. the percentage of birds exceeding the threshold level of 0.1g of ingested plastic as defined in the OSPAR long term goal)

The reference level for the presence of plastics in stomachs of northern fulmars (or any marine organism) is zero, because synthetic materials are solely man-made, and were only introduced into the marine environment in about the mid-1900s.

However, accepting that incidental losses are unavoidable, (OSPAR Commission, 2008, 2009) has defined an (undated) long-term goal for the fulmar indicator in the North Sea as:

“There should be less than 10% of northern fulmars (Fulmarus glacialis) having more than 0.1g plastic particles in the stomach in samples of 50 to 100 beach-washed fulmars from each of 4 to 5 areas of the North Sea over a period of at least five years”.

Therefore, the basic monitoring information required is the total mass of plastic in individual stomachs, and the percentage of stomachs exceeding the 0.1g threshold level (referred to as ‘Indicator performance’).

The OSPAR Assessment for abundance of plastics in stomachs of northern fulmars is therefore calculated as the percentage of investigated birds exceeding the 0.1g threshold level of plastics in the stomach over the most recent five-year period of available data.

In this assessment, the most recent five-year period is 2010–2014. It is important to emphasise that all data concerning average ingested debris or indicator performance are so called ‘population averages’, meaning that clean birds without any plastic in the stomachs are included in all calculations. Analyses in the pilot study by Van Franeker and Meijboom (2002) suggest that about 40 stomachs is the minimum sample size to obtain a reliable figure for plastic ingestion representative of a selected area and period of time. This recommendation should be taken into account when spatial aggregations of data are being made.


Findings in the UK Initial Assessment in 2012

The UK Marine Strategy Part One (HM Government, 2012) did not provide an assessment of this indicator.

Latest findings

Status Assessment

Plastic contents of 365 fulmar stomachs from the UK originating mainly from the Shetland and Orkney Islands and the east coast of England were analysed. The material contained only three birds from the Scottish east- coast and only one from the English Channel.

The data has been combined into a single overall UK evaluation, combining the UK sub-regions. Fulmars forage over a wide range so the location the bird is found may not reflect where they fed. The early data from years 2002 and 2003 had to be excluded because in those years the English coast did not participate in the survey, and a regionally unbalanced sample could potentially bias the averaged overall data. The results, therefore, cover 11 years, 2004 to 2014, and 323 fulmar stomachs. As specified in the guidelines for this indicator, data are viewed in running 5-year periods, in which the ‘current period’ concerns the most recent 5 years of data (2010 to 2014), and trends are tested over the most recent 10 years of data (2005 to 2014).

Assessment 2010 to 2014

Over the 5-year period 2010 to 2014, 88 fulmar stomachs from the United Kingdom were analysed, mainly from the Scottish Islands and the English North Sea coast. This is a relatively low number of birds in comparison to earlier 5-year periods (Table 1), but it seems beached fulmars were relatively scarce in all North Sea sub-regions in this period. The recommended sample size for a reliable average for a specific period and area is 40 birds or more, so the 2010 to 2014 samples are considered more than adequate.

Of the 88 birds analysed for the 2010 to 2014 period, 94 % had some ingested plastic, with average values (± standard error) per individual of 39 ± 12 particles and 0.32 ± 0.05 g per bird (Table 1). In this period, 63 % of stomachs contained more than 0.1 g of plastic. OSPAR has formulated a long-term goal to reduce that proportion to less than 10 %. No short-term goal has been specified for the Marine Strategy Framework Directive.

The 2005 to 2014 trend

Data for other 5-year periods specified in Table 1 shows that the current 5-year averages for total plastic do not differ strongly from those in earlier periods of the monitoring programme. Statistical analysis over the last ten years (2005 to 2014) shows no significant change in ingested plastic mass in 253 fulmars sampled in the United Kingdom over this period. This was the same for industrial and user plastic categories.

Table 1.   Abundance of total plastics in fulmar stomachs in running 5-year periods since 2004.

The ecological quality objective percentage gives the proportion of birds having more than 0.1 g of plastic in the stomach, as defined in the OSPAR long-term target for ecological quality (OSPAR Commission, 2009). Incidence reflects the proportion of birds having any plastic in the stomach. Geometric mean mass is an added metric to reduce potential influence of extreme outliers on data points. Standard errors (SE) are provided.

5-year period


EcoQO (% over 0.1 g)

Incidence (%)

Average No. ± SE

Average mass (g) ± SE

Geometric mean mass





30.4 ± 3.1

0.30 ± 0.04






31.3 ± 3.2

0.36 ± 0.05






30.0 ± 3.1

0.35 ± 0.05






29.6 ± 3.0

0.35 ± 0.05






30.1 ± 2.9

0.38 ± 0.05






37.6 ± 9.4

0.34 ± 0.05






39.1 ± 12.0

0.32 ± 0.05



The UK data since 2004 shows approximately 60% of surveyed fulmars exceed the 0.1g threshold level used in the OSPAR target definition. This matches the long-term pattern observed in the Netherlands and other North Sea locations. Long-term data from the Netherlands showed an increase in plastic pollution from the 1980s to 1990s, followed by a decrease back to 1980s levels, but since the early 2000s quantities of plastics found in stomachs have been fairly constant (Van Franeker, 2015).

Further information

Harm to biota

The 0.1g threshold in combination with a percentage of fulmars not allowed to exceed the threshold is not based on a quantitative assessment of harm to fulmars. Individual fulmars and other wildlife can suffer and die from the ingestion of plastic, but such effects are hard to quantify in terms of reductions in populations or species. Sub-lethal effects on many individuals may have population effects, even if they are difficult to quantify. Further research to document such sub-lethal effects is therefore warranted.

Although firm evidence for the cause(s) of decline is impossible to obtain, ingestion of plastic debris is considered an ongoing threat to the fulmar population that needs to be addressed. In this respect, it is important to consider that the fulmar is a single indicator species and that to fully understand the impacts of plastic debris on the marine ecosystem further development of other indicator species is recommended.

Knowledge gaps

There is a lack of data from the UK west coast. The fulmar dataset holds only a very few birds for the western shores. A recent paper on fulmars beached in Ireland showed surprisingly high levels of plastic ingestion, although the sample size was low. Attempts to set up more beached bird surveys on western shores continue. Larger sample sizes and better coverage of the Celtic Seas are required to improve the assessment. The surveillance indicators for sea floor litter and floating litter have been developed, tested and both indicate that litter is present in significant amounts, but we will need to refine these indicators to give us more accuracy. 

Further information

The Indicator on Plastic Particles in Fulmars Stomachs aims to reflect litter floating at the surface, and potential harm from marine litter in the environment to pelagic (open sea) marine organisms. However, the fulmar monitoring effort does not give direct information on ‘harm’ or ‘damage’ but simply quantifies spatial and temporal patterns in abundance of plastics in fulmar stomachs as an indirect measure of harm. Dedicated experimental laboratory-based research into evidence of harm to fulmars from specified levels and types of plastics, as a specific example of harm, would help to strengthen the role of the indicator.


Bravo Rebolledo E (2011) ‘Threshold levels and size dependent passage of plastic litter in stomachs of Fulmars’ MSc Thesis. Wageningen University, Aquatic Ecology and Water Quality Management Group Report no. 008/2011. 32pp.

European Commission (2008) ‘Directive 2008/56/EC of the European Parliament and of the Council of 17 June 2008 establishing a framework for community action in the field of marine environmental policy (Marine Strategy Framework Directive)’ Official Journal of the European Union L 164: 19-40 (viewed on 21 September 2018)

European Commission (2010) ‘Commission Decision of 1 September 2010 on criteria and methodological standards on Good Environmental Status of marine waters’ (notified under document C(2010) 5956) (Text with EEA Relevance) (2010/477/EU), Official Journal of the European Union L232:14-24 (viewed on 5 July 2018)

European Commission (2017) ‘Commission Decision (EU) 2017/848 of 17 May 2017 laying down criteria and methodological standards on good environmental status of marine waters and specifications and standardised methods for monitoring and assessment, and repealing Decision 2010/477/EU (Text with EEA relevance)’ C/2017/2901, Official Journal of the European Union L 125, 18.5.2017, pages 43–74. (viewed on 10 October 2018)

Galgani F, Fleet D, van Franeker J, Katsanevakis S, Mouat J, Oosterbaan L, Poitou I, Hanke G, Thompson R, Amato E, Birkun A, Janssen C (2010) ‘Properties and quantities of marine litter do not cause harm to the coastal and marine environment’ Report on the identification of descriptors for the Good Environmental Status of European Seas regarding marine litter under the Marine Strategy Framework Directive. MSFD GES Task Group 10, final report 19/04/2010, 50 pages.

HM Government (2015) ‘Marine Strategy Part Three: UK Programme of Measures’ (viewed on 5 July 2018)

Kühn S, Bravo Rebolledo EL, Van Franeker JA (2015) ‘Deleterious effects of litter on marine life’ in: Bergmann, M., Gutow, L., and Klages, M. (editors) Marine Anthropogenic Litter. Springer, Berlin, pages 75-116.

OSPAR Commission (2008) ‘Background Document for the EcoQO on plastic particles in stomachs of seabirds’ OSPAR Commission, Biodiversity Series Publication Number: 355/2008. OSPAR, London, 18 pages (viewed on 10 October 2018)

OSPAR Commission (2009) ‘EcoQO Handbook - Handbook for the application of Ecological Quality Objectives in the North Sea’ Second Edition – 2009, OSPAR Biodiversity Series Publication 307/2009. OSPAR Commission London, 65 pages (viewed on 10 October 2018)

OSPAR Commission (2014) ‘Marine Litter Regional Action Plan’ ISBN: 978-1-906840-86-0 (viewed on 21 September 2018)

OSPAR Commission (2015) ‘Coordinated Environmental Monitoring Programme (CEMP) Guidelines for Monitoring and Assessment of plastic particles in stomachs of fulmars in the North Sea area’ Agreement 2015-03 (viewed on 10 October 2018)

OSPAR Commission (2017) ‘Intermediate Assessment 2017’ (viewed 21 September 2018)

Van Franeker JA, Law KL (2015) ‘Seabirds, gyres and global trends in plastic pollution’ Environmental Pollution 203: 89-96 (viewed on 10 October 2018)

van Franeker JA, Meijboom A (2002) ‘Litter NSV; marine litter monitoring by northern fulmars (a pilot study)’ Number 401, Alterra (viewed on 10 October 2018)

van Franeker JA (2015) ‘Fulmar Litter EcoQO monitoring in the Netherlands - Update 2014’ IMARES Report C123/15, Institute for Marine Resources and Ecosystem Studies, Texel. 55 pages (viewed on 10 October 2018) 


Assessment metadata
Assessment TypeUK MSFD Indicator Assessment

D10 Marine Litter


Floating litter using plastic in fulmar stomachs

Point of contact
Metadata dateThursday, April 1, 2021
TitleFloating litter using plastic in fulmar stomachs
Resource abstract
Conditions applying to access and use

All data sets used in the assessment are not yet publicly available, as it happens with the OSPAR assessment. Major parts of data collection for the assessments were non-funded effort by volunteer groups as well as professionals. They kindly request that within 5 years of the End-date of the assessment, usage of raw data for formal reports and scientific articles is not done without consultation.

Assessment Lineage
Indicator assessment results
Dataset metadata

Please, see summary of data in report van Franeker JA (2015) ‘Fulmar Litter EcoQO monitoring in the Netherlands - Update 2014’, and details in metadata for the OSPAR assessment Plastic Particles in Fulmar Stomachs in the North Sea and further information in supplementary material Van Franeker and others 2021.

Links to datasets identifiers

please, see references above

Dataset DOI

please, see references above

The Metadata are “data about the content, quality, condition, and other characteristics of data” (FGDC Content Standard for Digital Geospatial Metadata Workbook, Ver 2.0, May 1, 2000).

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Recommended reference for this indicator assessment

Tarquin Dorrington1 and Jan Andries van Franeker2 2018. Plastic Particles in the Fulmar Stomachs in the North Sea. UK Marine Online Assessment Tool, available at:

1Department for Environment, Food and Rural Affairs

 2Wageningen Marine Research