PBDEs in biota - Marine online assessment tool

No assessment against the target set in the UK Marine Strategy Part One (HM Government, 2012) was possible because criteria have not yet been determined for concentrations of polybrominated diphenyl ethers in biota at which adverse effects are likely to occur. However, concentrations in fish and shellfish show a downward trend.

Background

UK target on polybrominated diphenyl ether flame retardants concentrations in biota

This indicator assesses progress against the target set out in the Marine Strategy Part One (HM Government, 2012), which requires that concentrations of substances identified within relevant legislation and international obligations are below levels at which adverse effects are likely to occur. However, no assessment was possible due to a lack of agreed assessment criteria.

Key pressures and impacts

Polybrominated diphenyl ethers, are used mainly as flame retardants in plastics, textiles and electronic equipment, and can enter the environment through emissions from manufacturing processes, evaporation from products that contain them, recycling waste and run-off from waste disposal sites.

Polybrominated diphenyl ether are known to have effects on the nervous, immune and endocrine systems in birds and mammals. They take a long time to break down, have the potential to accumulate in the flesh of fish or shellfish and are toxic.

Measures taken to address the impacts

There is already a robust UK legislative framework in place for controlling pollution from contaminants, including appropriate consenting and monitoring programmes set out in the UK Marine Strategy Part Three (HM Government, 2015). The most frequently used polybrominated diphenyl ether flame retardants (penta-, octa- and deca- bromodiphenyl ethers) have been banned or restricted within the European Union for over a decade: since 2004 for penta- and octa-bromodiphenyl ether (European Commission 2001a; 2003a) and since 2008 for hexabromobiphenyl ether.

Monitoring, assessment and regional co-operation

Areas that have been assessed

Trend assessments were conducted for the UK portion of the Greater North Sea and Celtic Seas Marine Strategy Framework Directive (European Commission, 2008b) sub-regions, and at the smaller scale of some of the UK biogeographic marine regions set out in Charting Progress 2 (UKMMAS, 2010).

Monitoring and assessment methods

Risk-based monitoring and assessment of the status and trends of polybrominated diphenyl ether concentrations in biota was conducted within the annual UK Clean Seas Environmental Monitoring Programme, using methods and principles set out in the OSPAR Co-ordinated Environmental Monitoring Programme (OSPAR Commission, 2008).

Assessment thresholds

OSPAR Environmental Assessment Criteria (OSPAR Commission, 2009), which indicate whether harm is caused to marine life, were not available for this indicator, therefore no assessment was possible.

Although there is an Environmental Quality Standard derived for biota under the Water Framework Directive (European Commission, 2000) for polybrominated diphenyl ethers, this is not directly applicable to the collected monitoring data.

Regional co-operation

The UK had an important role in the development, monitoring and assessment of the OSPAR ‘Polybrominated diphenyl ether in biota’ common indicator (OSPAR Commission, 1996). The UK results have been used in the OSPAR Intermediate Assessment (OSPAR Commission, 2017).

Further information

Polybrominated diphenyl ethers are a group of 209 different compounds (Figure 1), mainly used as flame retardants in different types of materials such as plastics, textiles and electronic products.

Figure 1. Polybrominated diphenyl ether congeners structure. Source: Wikimedia Commons.

Polybrominated diphenyl ethers are flame retardants of the additive type, which means that they are physically combined with the material being treated rather than chemically combined (as in reactive flame retardants) and are more likely to diffuse out of the products (European Commission, 2001b; European Commission, 2003b; Hutzinger and Thoma 1987 in Alaee and others 2003). Leakages of polybrominated diphenyl ether occur during production, use, or disposal of such products, and are mainly spread via diffuse distribution in the atmosphere and via rivers. The presence of polybrominated diphenyl ethers in air samples, for example from Arctic Canada indicates long-range transport in the air (reviewed in de Wit, 2002).

The advantage of these compounds for industry is their high resistance toward acids, bases, heat, light, and reducing and oxidising compounds. However, this becomes a great disadvantage in the environment, where they persist for a long time. Increases of these compounds have been seen in environmental samples since 1970s (reviewed in de Wit 2002). Polybrominated diphenyl ether has been reported as neurotoxic, immunotoxic and to affect thyroid hormone receptors (reviewed in de Wit 2002). Effects on behaviour and learning (Eriksson and others, 2006a, Eriksson and others, 2006b) and hormonal functions (Legler, 2008) have been reported for mammals. Reduced reproductive success in birds has been documented (Fernie and others, 2009).

Polybrominated diphenyl ethers with smaller molecules are more toxic and bioaccumulative than larger ones. The biotic and abiotic debromination of highly-brominated brominated diphenyl ethers (such as decabromodiphenyl ether) to these smaller forms is a possibility and justifies that monitoring is based on a broad set of congeners. All polybrominated diphenyl ethers are hydrophobic or very hydrophobic substances that are very likely to adsorb on particulate matter and not likely to volatilise from the water phase. The higher the degree of bromination, the lower the water solubility. Therefore, decabromodiphenyl ether is found only in low concentrations in fish, in contrast to lower-brominated brominated diphenyl ethers which are more commonly found in marine organisms. Polybrominated diphenyl ethers have the potential to photodegrade in the environment (Nyberg and others, 2013).

Polybrominated diphenyl ethers include the commercial versions of pentabromodiphenyl ether, octabromodiphenyl ether and decabromodiphenyl ether. Because of their persistency, ability to bioaccumulate and toxicity, the polybrominated diphenyl ether substances included in the commercial penta- and octa-bromodiphenyl ether mixtures were banned in the EU in 2004 (European Commission, 2009) and since 2009 have been included in the Stockholm Convention, Annex A, while decabromodiphenyl ether is currently restricted in electrical and electronical products (European Commission, 2008a). However, the European industry has taken voluntary action to reduce releases of decabromodiphenyl ether through the Voluntary Emissions Control Action Programme. Commercial penta- and octa- bromodiphenyl ether products are no longer produced within the EU (United Nations Environment Programme, 2006; 2007), which means that there are no industrial point sources. However, stocks of products containing polybrominated diphenyl ether may still act as a diffuse source.

The Committee for Socio-economic Analysis adopted its final opinion on the proposal (European Chemicals Agency, 2014) from the European Chemicals Agency to restrict the use of decabromodiphenyl ether as a flame retardant in plastics and textiles. The Committee for Socio-economic Analysis confirmed in its draft opinion of June 2015 that the proposed restriction is the most appropriate EU-wide measure (European Chemicals Agency 2015), in terms of the proportionality of its socio-economic benefits to its socio-economic costs. Having considered the 14 comments received during the public consultation on the draft opinion agreed in June 2015, additional derogations for military aircraft, road vehicles, and spare parts for machinery, and agricultural and forestry vehicles was supported.

The European Food Safety Authority recommended 8 substances to monitor, based on the analytical feasibility to measure the chemical compounds, the production volumes as registered in 2006, the occurrence of the chemical compounds in food and feed, their persistence in the environment and their toxicity. These substances are: triBDE 28, tetraBDE 47, pentaBDE 99 and 100, hexaBDE 153 and 154, heptaBDE 183, and decaBDE 209 (European Food Safety Authority 2006; 2011). For environmental monitoring within the EU, Environmental Quality Standards have been derived for these compounds excluding BDE-183 and BDE-209 (Working Group E of the Common Implementation Strategy for the WFD, 2011). OSPAR’s Co-ordinated Environmental Monitoring Programme requires BDE 28, 47, 66, 85, 99, 100, 153, 154 and 183 to be monitored in biota and sediment, and BDE-209 in sediment.

Assessment method

The UK target for contaminants states that “Concentrations of substances identified within relevant legislation and international obligations are below the concentrations at which adverse effects are likely to occur (e.g. are less than Environmental Quality Standards applied within the Water Framework Directive (European Commission, 2008 b) and Environmental Assessment Criteria (OSPAR Commission, 2009) applied within OSPAR)” (HM Government, 2012).

This 2016 assessment of data from the Clean Seas Environmental Monitoring Programme describes the trends and status of contaminant concentrations in biota at monitoring stations around the UK. Assessments are made for a large number of time series, each of a single contaminant in a single species at a single monitoring station. This document is one of a series that synthesises the results of the individual time series to assess status and trends at the biogeographic regional level. In particular, it considers concentrations in sediment of the following congeners (Chemical Abstracts Service numbers given in brackets): BDE-28 (CAS Nr. 41318-75-6), BDE-47 (CAS Nr. 5436-43-1), BDE-99 (CAS Nr. 60348-60-9), BDE-100 (CAS Nr. 60348-60-9), BDE-153 (CAS Nr. 68631-49-2), BDE-154 (CAS Nr. 207122-15-4), and BDE-209 (CAS Nr. 1163-19-5).

The regional assessment only considers coastal and offshore stations and excludes estuarine stations. The results are therefore based on the monitoring data collected within the waters assessed under the Marine Strategy Framework Directive (European Commission, 2008b) and are used as part of the UK’s assessment of these contaminants.

There are currently no assessment criteria developed by OSPAR to assess concentrations of polybrominated diphenyl ethers in sediment.

More details on the assessment methodology applied are available from ICES and BODC.

Results

Findings in the 2012 UK Initial Assessment.

No specific assessment of polybrominated diphenyl ethers was provided (HM Government, 2012).

Latest findings

Status assessment

Due to the lack of assessment criteria, a status assessment was not possible. However, where polybrominated diphenyl ethers have been measured, concentrations are relatively low and frequently below detection limits.

Trend assessment

Downwards trends for averaged polybrominated diphenyl ether concentrations were observed for all three sub-regions (Northern North Sea, Southern North Sea and Irish Sea) where data were available. Similarly, all individual congeners showed significant downwards trend in these sub-regions.

Further information

Concentrations of polybrominated diphenyl ethers are measured in fish liver tissues (Limanda limanda (dab), Pleuronectes platessa (plaice) and Platichthys flesus (European flounder)) and mussel (Mytilus edulis) samples collected from monitoring stations around the UK as part of the Clean Seas Environment Monitoring Programme (Figure 2). Sampling frequency is annual or every few years. Only sub-regions containing at least 3 stations with a reasonable geographic spread were included in the regional assessment of trends (Table 1). Sub-regions with too few stations were excluded from the assessment. The data was used to investigate trends in polybrominated diphenyl ether concentrations and to compare levels and patterns between sub-regions.

Figure 2. Monitoring stations used to assess polybrominated diphenyl ether concentrations in biota. The purple circles are stations where there is a trend assessment for at least one brominated diphenyl ether, and the blue circles are stations used for estimating concentration profiles. The areas delineated by the thinner black lines are the biogeographic regions; those delineated by the thicker black lines are the Marine Strategy Framework Directive sub-regions.

Table 1. Number of stations within each sub-region used in the assessment. Only sub-regions with at least 3 stations with a reasonable geographic spread were included in the regional assessment of trends.

Region	Sub-region (Charting Progress 2 Region)	Trends
Greater North Sea	Northern North Sea	7
	Southern North Sea	7
	East Channel	2
Celtic Seas	Scottish Continental Shelf	0
	Minches and West Scotland	1
	Irish Sea	14
	West Channel and Celtic Sea	2

No status assessment was made for polybrominated diphenyl ethers in biota. There are no OSPAR Background Assessment Concentrations or Environmental Assessment Criteria (OSPAR Commission, 2009) developed to assess the status of polybrominated diphenyl ethers, although Background Concentrations are zero. There is an Environmental Quality Standard (European Commission, 2008c) derived within EU statute to protect marine and freshwater ecosystems as well as humans from adverse effects of chemicals in the aquatic environments. However, the Environmental Quality Standard is not directly applicable to OSPAR monitoring data as set for fish at a trophic level of 4 and the normalisation process required for OSPAR contaminant data to trophic level 4 has not yet been agreed.

The polybrominated diphenyl ether concentration profile can sometimes be useful for examining sources, and for comparing concentrations across regions where assessment criteria are not available. Figure 3 shows the estimated average concentration for each individual congener and for each sub-region in the last year reported at these sites (variable within the assessment period). Sufficient data were only available for three sub-regions. The congener profile pattern was similar between sub-regions, with BDE-47, a tetra brominated compound that is one of the two main components in the pentabromodiphenyl ether commercial mixture, systematically dominating.

Figure 3. Estimated mean brominated diphenyl ether concentration profile (µg/kg wet weight) in final year (with 95% confidence limits).

Trends in polybrominated diphenyl ether concentrations were assessed in sub-regions where there was at least 5 years of data, each containing at least one measurement above the detection limit (Figure 2). Significant downwards trends averaged across all congeners were observed in all three sub-regions. Northern North Sea (-12.3 % trend), Southern North Sea (-16.3 % trend) and Irish Sea (-13.9 % trend) where data was available (Figure 4).

Figure 4. Average trend in polybrominated diphenyl ether congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153 and BDE-154) concentration per sub-region where the downward triangle signifies a significant downward trend (p<0.05).

The differences (expressed as percentage yearly change) in the regional trends for each individual congener are shown in Figure 5. All congeners show significant downwards trend in all three sub-regions, with BDE-99 (the other main component in the pentabromodiphenyl ether commercial mixture) showing the largest annual decrease where measured. This downwards trend could reflect management measures implemented either through regulatory tools or on an industry voluntary basis.

Figure 5. Differences in the regional trends between brominated diphenyl ether congeners where a downward triangle signifies mean concentration is significantly decreasing (p<0.05).

Conclusions

Polybrominated diphenyl ether concentrations in biota were only measured at a limited number of sampling stations and were found to be decreasing at these sites. Lack of assessment criteria means it was not possible to assess whether the UK target had been met.

Knowledge gaps

There are currently no OSPAR Background Assessment Concentrations or Environmental Assessment Criteria (OSPAR Commission, 2009) available for polybrominated diphenyl ether concentrations in biota, and existing Environmental Quality Standards for polybrominated diphenyl ethers in biota cannot be applied. There is a clear need for assessment criteria to be developed for polybrominated diphenyl ethers in biota.

References

Alaee, M, Arias P, Sjödin A, Bergman, Å (2003) ‘An overview of commercially used brominated flame-retardants, their applications, their use patterns in different countries/regions and possible modes of release’ Environment International, 29(6): 683–689 (viewed on 6 November 2018)

de Wilt CA (2002) ‘An overview of brominated flame retardants in the environment’ Chemosphere 4(5): 583-624 (viewed on 06 November 2018)

European Food Safety Authority (2006) ‘EFSA/WHO International Conference with support of ILSI Europe on Risk Assessment of Compounds that are both Genotoxic and Carcinogenic’ Meeting Summary Report, 16-18 November 2005, Brussels, Belgium (viewed on 8 November 2018)

European Food Safety Authority (2011) ‘Scientific Opinion on Polybrominated Diphenyl Ethers (PBDEs) in Food’ Panel on Contaminants in the Food Chain (CONTAM), EFSA Journal 9(5):2156 (viewed on 6 November 2018)

Eriksson P, Fischer C, Fredriksson A (2006a) ‘Polybrominated diphenyl ethers, a group of brominated flame-retardants, can interact with polychlorinated biphenyls in enhancing developmental neurobehavioral defects’ Toxicological Sciences 94: 302-309 (viewed on 6 November 2018)

Eriksson P, Fischer C, Wallin M, Jakobsson E, Fredriksson A (2006b) ‘Impaired behaviour, learning and memory, in adult mice neonatally exposed to hexabromocyclododecane (HBCDD)’ Environmental Toxicology and Pharmacology, 21: 317-322 (viewed on 6 November 2018)

European Chemicals Agency (2014) ‘Annex XV Restriction Report, Proposal for a Restriction, Substance Name: Bis(pentabromophenyl) ether’ Helsinki, Finland. Prepared in collaboration with the Norweigian Environment Agency, Version Number 1.0, 1 August 2014 (viewed on 8 December 2018)

European Chemicals Agency (2015) ‘Opinion on an Annex XV dossier proposing restrictions on Bis(pentabromophenyl ether (DecaBDE)’ Committee for Risk Assessment (RAC); Committee for Socio-economic Analysis (SEAC), ECHA/RAC/RES-O-0000006155-77-01/D, ECHA/SEAC/RES-O-0000006155-77-03/F, (viewed on 8 December 2018)

European Commission (2000) ‘Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy’ Official Journal of the European Union L 327, 22.12.2000, pages 1–73 (viewed on 16 November 2018)

European Commission (2001a) ‘Opinion of the Economic and Social Committee on the "Proposal for a Directive of the European Parliament and of the Council amending for the 24th time Council Directive 76/769/EEC relating to restrictions on the marketing and use of certain dangerous substances and preparations (pentabromodiphenyl ether)"’Official Journal of the European Union C 193, 10.7.2001, pages 27–28 (viewed on 8 December 2018)

European Commission (2001b) ‘European Union Risk Assessment Report for diphenyl ether, pentabromo derivative (CAS-No.:32534-81-9; EINECS-No.: 251-084-2)’ (Final approved version).

European Commission (2003a) ‘Directive 2003/11/EC of the European Parliament and of the Council of 6 February 2003 amending for the 24th time Council Directive 76/769/EEC relating to restrictions on the marketing and use of certain dangerous substances and preparations (pentabromodiphenyl ether, octabromodiphenyl ether)’ Official Journal of the European Union L 42, 15.2.2003, pages 45–46 (viewed on 8 December 2018)

European Commission (2003b) ‘European Union Risk Assessment Report for diphenyl ether, octabromo derivative (CAS-No.:32536-52-0, EINECS-No.: 251-087-9)’ (Final approved version). Institute for Health and Consumer Protection- European Chemicals Bureau 2003 (viewed on 6 November 2018)

European Commission (2008a) ‘Designation of the Chamber responsible for cases of the kind referred to in Article 104b of the rules of procedure of the Court of Justice’ Official Journal of the European Union C116, 09.5.2008, Pages 2-2 (viewed on 6 November 2018)

European Commission (2008b) ‘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, 25.6.2008, pages 19-40 (viewed on 16 November 2018)

European Commission (2008c) ‘Directive 2008/105/EC of the European Parliament and of the Council of 16 December 2008 on environmental quality standards in the field of water policy, amending and subsequently repealing Council Directives 82/176/EEC, 83/513/EEC, 84/156/EEC, 84/491/EEC, 86/280/EEC and amending Directive 2000/60/EC of the European Parliament and of the Council’ (viewed on 29 November 2018)

European Commission (2009) ‘Commission Regulation (EC) No 552/2009 of 22 June 2009 amending Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) as regards Annex XVII (Text with EEA relevance)’ Official Journal of the European Union L164, 26.2.2019, Pages 7-31 (viewed on 6 November 2018)

Fernie KJ, Shutt JL, Letcher RJ, Ritchie IJ, Bird DM (2009) ‘Environmentally relevant concentrations of DE-71 and HBCD alter eggshell thickness and reproductive success of American kestrels’ Environmental Science and Technology 43: 2124-30 (viewed on 6 November 2018)

Hutzinger O, Thoma H (1987) ‘Polybrominated dibenzo-p-dioxins and dibenzofurans: the flame-retardant issue’ Chemosphere 16: 1877–1880 (viewed on 6 November 2018)

HM Government (2012) ‘

Institute for Health and Consumer Protection- European Chemicals Bureau. August 2000 (viewed on 6 November 2018)

Legler J (2008) ‘New insights into the endocrine disrupting effects of brominated flame-retardants. Chemosphere’ 73: 216-222 (viewed on 6 November 2018)

Nyberg E, Birgnert A, Danielsson S, Mannio J, and HELCOM CORESET expert group for hazardous substances (2013) ‘HELCOM Core Indicator of Hazardous Substances Polybrominated Diphenyl Ethers (PBDE)’ (viewed on 22 November 2016)

OSPAR Commission (1996) ‘Pentabromodiphenyl Ether, Polybrominated biphenyl’ OSPAR Publication 51/2009 ISBN 0 946955 58 1 (viewed on 6 November 2018)

OSPAR Commission (2008) ‘CEMP Assessment Manual. Co-ordinated Environmental Monitoring Programme Assessment Manual for contaminants in sediment and biota’ OSPAR Publication 379/2008 ISBN 978-1-906840-20-4 (viewed on 3 December 2018)

OSPAR Commission (2009) ‘Background Document on CEMP Assessment Criteria for QSR 2010’ OSPAR Publication 461/2009. ISBN 978-1-907390-08-1 (viewed on 8 December 2018)

OSPAR Commission (2017) ‘Intermediate Assessment 2017’ (viewed on 16 November 2018)

UKMMAS (2010) 'Charting Progress 2: An assessment of the state of the UK seas' Published by Defra on behalf of the UK Marine Monitoring and Assessment Strategy community (viewed on 4 January 2019)

United Nations Environment Program (2006) ‘Risk profile on commercial Penta bromophenyl ether’ UNEP/POPS/POPRC.2/17/Add.1, 21 Stockholm Convention on Persistent Organic Pollutants Persistent Organic Pollutants Review Committee, Second meeting, Geneva, 6–10 November 2006 (viewed on 8 December 2018)

United Nations Environment Program (2007) ‘Risk profile on commercial octabromodiphenyl ether’ UNEP/POPS/POPRC.3/14. Stockholm Convention on Persistent Organic Pollutants Persistent Organic Pollutants Review Committee, third meeting, Geneva, 19–23 November 2007 (viewed on 8 December 2018)

Working Group E of the Common Implementation Strategy for the WFD (2011) ‘Polybrominated diphenyl ethers (BDES)’ EQS dossier, prepared by the Sub-Group on Review of the Priority Substances List under Working Group E of the Common Implementation Strategy for the Water Framework Directive, reviewed by the Scientific Committee on Health and Environmental Risks (viewed on 8 December 2018)

Acknowledgements

Assessment metadata

Assessment Type	UK Marine Strategy Framework Directive Indicator Assessment
	D8
	D8.1 Concentration of Contaminants
	Marine Strategy Part One
Point of contact email	marinestrategy@defra.gov.uk
Metadata date	Monday, October 1, 2018
Title	Contaminant and biological effect data to support MSFD Descriptor 8 1999-2015 by CSEMP Region
Resource abstract	The results of the individual time series at coastal and offshore stations were synthesised to assess status and trends at the biogeographic regional level and formed the basis of eleven of the indicator assessments that comprised the UK's 2018 MSFD assessment of Descriptor 8.
Linkage	In addition to links provided in ‘References’ section above: OSPAR Commission (2005) ‘2005 Assessment of data collected under the Co-ordinated Environmental Monitoring Programme (CEMP)’ Publication Number 235 (viewed on 10 January 2019) OSPAR Commission (2006) ‘2005/2006 CEMP Assessment: Trends and concentrations of selected hazardous substances in the marine environment’ Publication Number 288 (viewed on 10 January 2019) OSPAR Commission (2007) ‘2006/2007 CEMP Assessment: Trends and concentrations of selected hazardous substances in the marine environment’ Publication Number 330 (viewed on 10 January 2019) OSPAR Commission (2008) ‘CEMP Assessment Manual: Co-ordinated Environmental Monitoring Programme Assessment Manual for contaminants in sediment and biota’ Publication Number 379 (viewed on 10 January 2019) OSPAR Commission (2009) ‘CEMP assessment report: 2008/2009 Assessment of trends and concentrations of selected hazardous substances in sediments and biota’ Publication Number 390 (viewed on 10 January 2019) OSPAR Commission (2009) ‘Agreement on CEMP Assessment Criteria for the QSR 2010' Agreement 2009-2 (viewed on 10 January 2019) OSPAR Commission (2016) 'OSPAR Coordinated Environmental Monitoring Programme’ Agreement 2016-1 (viewed on 10 January 2019)
Conditions applying to access and use	© Crown copyright, licenced under the Open Government Licence (OGL).
Assessment Lineage	The 2016 assessment of the UK's Clean Seas Environment Monitoring Programme described the status and trends of contaminant concentrations and biological effects measurements in biota and sediment at monitoring stations in waters around the UK. Assessments were made for a large number of time series, typically each of a single contaminant in a single species (for biota) at a single monitoring station. The results of the individual time series at coastal and offshore stations were synthesised to assess status and trends at the biogeographic regional level and formed the basis of this indicator. Data were submitted to the MERMAN database from relevant Competent Monitoring Authorities. A series of templates were populated by submitting officers and submitted to the database which has in-built data restrictions and a data filter to ensure high quality, accurate data are submitted. The data filter has formulae in-built which use Accredited Quality Control information from known standards, limits, standard deviations and/or inter laboratory calibration exercises to calculate a score. Only data that passed a threshold agreed with the national advisory bodies were used for assessments. The data for 1999 - 2015 were extracted from MERMAN. Further data checks were made and records with obvious errors were deleted or corrected. The data were standardised to agreed units and bases. The data were grouped into time series of a single contaminant in a single species at a single monitoring station. Time series with no data for the period 2010 - 2015 were excluded. The individual time series were assessed for both trends and status. The methods behind the assessments and the individual time series results are available from the British Oceanographic Data Centre. The results of the individual time series at coastal and offshore stations were then synthesised to assess status and trends at the biogeographic regional level. The methods and results are available from the British Oceanographic Data Centre.
Dataset metadata	https://portal.medin.org.uk/portal/start.php#details?tpc=012_Marine_Scotland_FishDAC_12111
Dataset DOI	http://dx.doi.org/10.7489/12111-1

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

Philippe Bersuder¹, Lynda Webster² and Rob Fryer² 2018. Status and trends of polybrominated diphenyl ether (PBDE) flame-retardants concentrations in UK biota. UK Marine Online Assessment Tool, available at: https://moat.cefas.co.uk/pressures-from-human-activities/contaminants/pbdes-in-biota/

¹Centre for Environment, Fisheries and Aquaculture Science

²Marine Scotland