Indicator Assessment

Hazardous substances in marine organisms

Indicator Assessment

Prod-ID: IND-165-en

Also known as: CSI 049 , MAR 001

Published 21 Oct 2019 Last modified 18 Nov 2021

20 min read

Topics: Water and marine environment Biodiversity — Ecosystems

This page was archived on 18 Nov 2021 with reason: No more updates will be done

Concentrations of eight hazardous substances in European seas were generally 'low' or 'moderate' in line with the results of the previous assessment (2015). In some cases, however, the way we have traditionally defined 'moderate' levels meant that EU environmental quality standards (EQS) were exceeded. Any concentrations of hazardous substances exceeding EQS are unacceptable for marine organisms.
In general, concentrations in European Seas were 'moderate' for cadmium, mercury, lead, hexachlorobenzene, DDT (dichlorodiphenyltrichloroethane), polychlorinated biphenyls and benzo[a]pyrene. Both 'moderate' and 'high' concentrations of mercury exceeded the EQS and were found in a significant proportion of all seas. 'High' concentrations for hexachlorobenzene and benzo[a]pyrene, exceeding the EQS particularly in the case of the latter, were also found across all seas. Concentrations of lindane (gamma-hexachlorocyclohexane) were 'high' in the Mediterranean sea and generally low elsewhere.
Polychlorinated biphenyl levels appear to be decreasing in the North-East Atlantic Ocean. This suggests that policy measures and initiatives to decrease inputs of these substances in the region have had some success. For the remaining seven hazardous substances, it appears that the impact of abatement policies in this region might have stabilised.
Abatement policies for all eight hazardous substances have been in effect for the Baltic Sea, but no downward trends could be identified in the current assessment, indicating that the impact of such policies might have stabilised.
Because of insufficient data coverage, a comprehensive assessment all eight hazardous substances for the Mediterranean Sea could not be conducted. Available data for this region indicates that policies to reduce pollution have had an impact 'though.
The Black Sea is not included in this assessment due to lack of data.

Hazardous substances in marine organisms in European seas

Note: The maps show eight contaminants distributed in four regional seas (no data available for the Black Sea). In each map the locations where the contaminant was measured are coloured to indicate which class was registered; green (low concentration), yellow (moderate concentration) or red (high concentration). The pie charts cover the North Atlantic Sea, the Baltic Sea and the Mediterranean Sea, showing the percentage of each class of the regional seas. Any regional trend for a particular class is indicated by black arrows.

Data source:

Downloads and more info

The findings of the station-by-station overview of 2008-2017 concentrations of hazardous substances in mussels and fish are summarised below. Note that, in some cases, the way we have traditionally defined 'moderate' levels meant that EU environmental quality standards (EQS) were exceeded. Any concentrations of hazardous substances exceeding EQS are unacceptable for marine organisms.

Cadmium: an EQS for cadmium in biota has yet to be developed; however, risk-based limits from the OSPAR Commission and the limits set for the EU Regulation on limits of hazardous substances in foodstuffs (1881/2006/EC) were used to define the lower and upper limits for the 'moderate' class, respectively. Concentrations of cadmium in recent years have generally been classified as 'moderate' or, to a lesser degree, 'low' in mussels and fish from the North-East Atlantic Ocean and Baltic Sea, and mussels from the Mediterranean Sea (Fig. 1). 'High' concentrations, which were those that exceeded the limits set in the Foodstuffs Regulation and likely to pose a risk for marine organisms, were found in the North-East Atlantic Ocean and Baltic Sea.

Mercury: there is an EQS for mercury in biota, which defines the lower limit of the 'moderate' class for this substance. Concentrations of mercury in recent years have generally been classified as 'moderate' or, to a lesser degree, 'low' in mussels and fish from the North-East Atlantic Ocean and Baltic Sea, and mussels from the Mediterranean Sea. These 'moderate' concentrations exceeded the EQS but were lower than the limits set in the EU Foodstuffs Regulation. Nevertheless, 'moderate' and 'high' values together are dominant in the European seas assessed and not acceptable for marine organisms.

Lead: an EQS for lead in biota has yet to be developed; however, background-based limits from the OSPAR Commission and the limits set for foodstuffs in the EU have been used to define the lower and upper limits for the 'moderate' class, respectively. Concentrations of lead in recent years have generally been classified as 'moderate' or, to a lesser degree, 'low' in mussels and fish from the North-East Atlantic Ocean and Baltic Sea, and mussels from the Mediterranean Sea (Fig. 1). 'High' concentrations, which were those that exceeded the limits set in the EU Foodstuffs Regulation and likely to pose risk for marine organisms, were found, but in a small proportion, across all the seas assessed.

Hexachlorobenzene (HCB): there is an EQS for HCB in biota, which defines the upper limit of the 'moderate' class for this substance. Concentrations of HCB in recent years have generally been classified as 'moderate' or, to a lesser degree, 'low' in mussels and fish from the North-East Atlantic Ocean and Baltic Sea, and mussels from the Mediterranean Sea (Fig. 1). 'High' concentrations, which are not as common as 'moderate' concentrations in the European seas assessed, exceeded the EQS and are not acceptable for marine organisms.

Lindane (HCHG): an EQS for lindane in biota has yet to be developed; however, background- and risk-based limits from the OSPAR Commission were used to define the lower and upper limits of the 'moderate' class, respectively. Concentrations of Lindane in recent years have generally been classified as 'low' or, to a lesser degree, 'high' in mussels and fish from the North-East Atlantic Ocean and Baltic Sea, whereas concentrations in mussels from the Mediterranean Sea were classified as 'high' at all stations (Fig. 1). 'High' concentrations exceeded the OSPAR Commission risk-based environmental assessment criteria and likely to pose a risk for marine organisms.

DDT: an EQS for DDT (dichlorodiphenyltrichloroethane) in biota has yet to be developed; however, background limits from the OSPAR Commission and risk-based limits from the Norwegian EQS were used to define the lower and upper limits for the 'moderate' class, respectively. Concentrations of DDT in recent years have generally been classified as 'moderate' in mussels and fish from the North-East Atlantic Ocean and Baltic Sea, and in mussels from the Mediterranean Sea (Fig. 1). 'High' concentrations , which were found, but in a small proportion, in the North-East Atlantic Ocean are likely to pose a risk for marine organisms.

Polychlorobiphenyls (PCBs): EQSs for PCBs in biota have yet to be developed; however, background- and risk-based limits from Norway and the OSPAR Commission were used to define the lower and upper limits for the moderate class, respectively. Concentrations of PCBs in recent years have generally been classified as 'moderate' or, to a lesser degree, 'high' in mussels and fish from the North-East Atlantic Ocean and Baltic Sea, and mussels from the Mediterranean Sea (Fig. 1). 'Moderate' and 'high' concentrations were those that exceeded the OSPAR Commission environmental assessment criteria and likely to pose a risk for marine organisms.

Benzo[a]pyrene (BaP): this occurs naturally in the sea but concentrations can be excessive as a result of anthropogenic activities. There is an EQS for BaP in biota, which defines the upper limit of the 'moderate' class for this substance. Concentrations of BaP in recent years have generally been classified as 'moderate' or, to a lesser degree, 'high' in mussels from the North-East Atlantic Ocean and Baltic Sea, and mussels from the Mediterranean Sea (Fig. 1). 'High' values, which reflect considerable proportions of the European seas assessed, exceeded the EQS and are not acceptable for marine organisms.

Changes in trends in the concentrations of hazardous substances in European seas since the last assessment (2003-2012) are summarised below.

Cadmium: this assessment, based on results for 2008-2017, shows improvements from the last assessment, based on the results for 2003-2012, which detected a general downward trend for North East Atlantic Ocean. Improvements could have been caused by a decrease in cadmium inputs for this region.

Mercury: the current assessment (2008-2017) detects a general upward trend for the North-East Atlantic Ocean, as seen in the previous assessment (2003-2012).

Lead: a downward trend was detected for stations with 'low' concentrations in the North-East Atlantic, whereas a general upward trend was detected for stations with 'moderate' concentrations in the same region. These findings for 2008-2017 only partly support the findings from the last assessment (2003-2012) and, hence, only partly reflect the decrease in inputs for this region.

HCB: in the previous assessment (2003-2014), a general downward trend was found for the North-East Atlantic. However, no general trends were detected in the latest assessment (2008-2017), which indicates that the impact of abatement policies, as a whole, might have stabilised.

Lindane: in the previous assessment (2003-2014), a general downward trend was found for the North-East Atlantic Ocean as well as for the Baltic Sea. However, no general trends were detected in the latest assessment (2008-2017), which indicates that the impact of abatement policies, as a whole, might have has stabilised.

DDT: in the previous assessment (2003-2014), a general downward trend was found for the North-East Atlantic Ocean. However, no general trends were detected in the current assessment (2008-2017), which indicates that the impact of abatement policies, as a whole, might have stabilised.

PCBs: in the previous assessment (2003-2014), a general downward trend was found for the North-East Atlantic Ocean as well as for the Baltic Sea. In the latest assessment (2008-2017), a general downward trend was found for the North-East Atlantic Ocean.

BaP: in the previous assessment (2003-2014), a general downward trend was found for the North-East Atlantic Ocean. However, for the current assessment, based on results for 2008-2017, no general trends were detected, which indicates that the impact of abatement policies, as a whole, has stabilised.

Supporting information

Indicator definition

This indicator describes the levels of and trends in the levels of eight hazardous substances in marine biota in European seas, based on individual assessments of monitoring data for the following substances:

mercury (Hg) and its compounds;

cadmium (Cd) and its compounds;
lead (Pb) and its compounds;

HCB;

PCBs, using chlorinated biphenyls CB28, CB52, CB101, CB118, CB138, CB153 and CB180 as representatives;
the pesticide DDT (using pp’DDE as a representative);
the pesticide Lindane (1,2,3,4,5,6-hexachlorocyclohexane);
the polyaromatic hydrocarbon BaP.

The indicator is based on data on the levels of these substances measured in organisms from the regional seas as follows:

Baltic Sea — Atlantic herring (Clupea harengus);

North-East Atlantic Ocean — blue mussel (Mytilus app), Atlantic cod (Gadus morhua), flounder (Platichtys flesus);

Mediterranean Sea — Mediterranean mussel (Mytilus galloprovinicialis);

Black Sea — Mediterranean mussel (Mytilus galloprovinicialis).

Units

The classification in the maps is based on concentrations in µg/kg, which are then classified into one of three classes: green (low concentration), yellow (moderate concentration) or red (high concentration). In addition, a pie chart shows the percentage accounted for by each class within each of the four regional seas.

Rationale

Justification for indicator selection

Hazardous substances are widespread in the marine environment. Many can be found at low concentrations in the Earth's crust and occur naturally in seawater. Synthetic hazardous substances such as PCBs, DDT, polybrominated diphenyl ethers (PBDEs) and perfluorocarbons (PFCs) are not found naturally in the environment. The main sources are generally waste/disposal, the burning of fossil fuels and industrial activities, including mining and production. Human activities have caused a general mobilisation of these hazardous substances in the marine environment. The pathway of contamination is not always obvious, but it is primarily through riverine discharge and atmospheric deposition. Hence, although hot spots tend to be directly linked to particular human activities, the substances are also found in organisms that are collected far from point sources.

The effects that some hazardous substances have on the environment and their potential risk to human health because of their toxic, bioaccumulative and persistent characteristics have led to considerable efforts (at the political, management and scientific levels) to address them. Specific policies and conventions aim to minimise the direct and indirect effects of these contaminants, generally by reducing emissions and discharges to the marine environment.

There is a large number of potentially hazardous substances, but, to date, data with sufficient geographical and temporal coverage are available for only a few, which is insufficient to warrant a pan-European assessment of hazardous substances in marine organisms. Therefore, this indicator is based on the assessment of eight substances: the metals cadmium, lead and mercury; the pesticides DDT and lindane; two other types of synthetic substance, HCB and PCBs; and as of the 2014 assessment the polycyclic aromatic hydrocarbon BaP. All eight contaminants are included in the lists of the Environmental Quality Standards Directive (EQSD), a 'daughter' directive of the Water Framework Directive (WFD). However, although their use has been severely restricted or banned, observations show that these substances are still present or accumulating in all of Europe’s seas, thus meriting continued monitoring.

Scientific references

Directive 2013/39/EU of the European Parliament and of the Council of 12 August 2013 amending Directives 2000/60/EC and 2008/105/EC as regards priority substances in the field of water policy
EEA, 2011 Hazardous Substances Europe’s fresh and marine waters An overview, Robert Collins (ed.). European Environmental Agency Technical report, no. 8/2011. ISBN 978-92-9212-213-9, 61 pp
EEA, 2018. Mercury in Europe’s environment A priority for European and global action. European Environmental Agency Report, no. 11/2018. ISBN 978-92-9213-984-1, 72 pp
OSPAR, 2017, Intermediate Assessment Pressures from Human Activities: Contaminants

Policy context and targets

Context description

A range of EU, regional and national legislation has been implemented in Europe to address the use of chemicals and their emission to the environment, including to fresh and marine waters:

The regulation of chemical pollutants in water began with the Dangerous Substances Directive (76/464/EEC), which has been integrated into the WFD (2000/60/EC). It requires the establishment of a list of priority substances by 2021 and of EQSs for newly identified priority substances by the end of 2027
The chemical status of Europe's surface waters is currently addressed in accordance with the EQSD (2013/39/EU), a 'daughter' directive of the WFD, whose Annex II replaced the first list of priority substances set out in Decision No 2455/2001/EC. The EQSD defines EQSs for fresh and coastal waters for pollutants of EU-wide relevance, known as priority substances. Member States are required to take action with the view to meeting the quality standards set out in the objectives of the EQSD.
More recently, combating this type of pollution in the open sea has been address by the Marine Strategy Framework Directive (2008/56/EC), which requires the achievement or maintenance of GES in European seas by the year 2020 at the latest, through the adoption of national marine strategies based on 11 qualitative descriptors. Descriptor 8 ('Concentrations of contaminants are at levels not giving rise to pollution effects') and Descriptor 9 ('Contaminants in fish and other seafood for human consumption do not exceed levels established by Community legislation or other relevant standards') refer specifically to contaminants.

Complementing these efforts are the Basel, Rotterdam and Stockholm Conventions, which are multilateral environmental agreements that have the common objective of protecting human health and the environment from hazardous chemicals and wastes.

Targets

The aim of the WFD was to achieve zero, near-zero or background contaminant concentrations (more specifically defined in a daughter directive on environmental quality standards, i.e. the EQSD, 2008/105/EC), depending on the contaminant. This was to be achieved through abatement actions in relation to emmissions, with the objective of reaching good ecological and chemical status by 2015 for fresh, transitional and coastal waters. Goals similar to those of the WFD have also been outlined by OSPAR and the Baltic Marine Environment Protection Commission (Helcom). For the Mediterranean Sea, similar targets have been adopted. The reduction and phasing-out targets were formulated in accordance with related regional and international conventions and programmes, such as EU directives, policies and strategies, and the Stockholm and Basel Conventions. However, similar targets have yet to be formulated for the Black Sea, although discussions are under way.

Within the scope of the Marine Strategy Framework Directive, hazardous substances are the relevant criteria and indicators in marine waters under Descriptor 8 ('Concentrations of contaminants are at levels not giving rise to pollution effects') and Descriptor 9 ('Contaminants in fish and other seafood for human consumption do not exceed levels established by Community legislation or other relevant standards'). In this regard, Member States are required to take into account relevant existing environmental targets, including the EQSs set out in the EQSD. Therefore, this directive applies to waters covered by both the WFD and the Marine Strategy Framework Directive, i.e. the seaward side of the baseline to the extent of territorial waters. A process is under way to define standards for the hazardous substances listed in biota, with a view to applying these to the marine and coastal environments.

Methodology

Methodology for indicator calculation

The two main sources of data for this indicator are ICES and EMODNet datasets. ICES data come from OSPAR and HELCOM contracting parties, and are therefore sub-samples of national data assembled for the purpose of providing comparable indicators of state and impact of transitional, coastal and marine waters (TCM-data) on a Europe-wide scale. In addition, data supplied by EMODnet were combined with the ICES data.

Geographical coverage

There is generally good data coverage for concentrations in the North-East Atlantic and in the Baltic; however, the Mediterranean Sea was represented only by data from France and Italy. An improvement in data reporting is needed to provide a better estimate of levels and trends for the Mediterranean Sea. For the Black Sea, the only available data were Romanian mussel data, and because of the requirement for conversion to preferred assessment basis (see more details in methodology link below), too few data were available for assessment. In general, the data for this sea region were not sufficient for analysis.

Temporal coverage

Concentrations in biota were measured during the period from 1978 to 2017. However, the assessment only includes time series from 2008 onward and that cover at least 2 years, not necessarily contiguous. Trends were calculated for only time series with at least 5 years of data with at least one non-censored measurement (see more details in methodology link below); many of these series have gaps, with intervals of 2 or more years between observations.

Tissues

For fish, only concentrations from the following tissues were used:

for mercury, muscle was used;
for the other metals, liver was used;
for organic compounds, liver was used in all fish except herring (Clupea harengus), for which muscle was used.

Other samples were discarded. This is the same procedure as that followed by OSPAR.

More details on the methodology and limit concentrations used for classification can be found here.

Methodology for gap filling

The assessment method does not require that time series be complete, so no actions are taken to fill such gaps. Instead, the method adapts to gaps in the time series.

The regional assessments are based on tallies of results for a single time series within each region, without further consideration of geographical distribution within the region. Any gaps in the geographical coverage will mean that the regional assessment may not be representative of the region as a whole. No attempts are made to extrapolate results from available data to estimate conditions in geographical areas without data.

Methodology references

1881/2006/EC Commission regulation Commission regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs.
E.C. 2003, technical document Technical guidance document in support of Commission Directive 93/67/EEC on risk assessment for new notified substances and Commission Regulation (EC) No 1488/94 on risk assessment for existing substances and Commission Directive (EC) 98/8 on biocides. European Commission
ICES, 2000. Report Of The Working Group on Statistical Aspects of Environmental Monitoring Nantes, France, 27- 31 March 2000 91 pp. ICES, 2000.
OSPAR 2008 Co-ordinated Environmental Monitoring Programme - Assessment manual for contaminants in sediment and biota. OSPAR Commission, 2008, publication no. 379/2008. ISBN 978-1-906840-20-4. 39 pp.
OSPAR 2009a Trends in waterborne inputs Assessment of riverine inputs and direct discharges of nutrents and selected hazardous substances to OSAPR maritime area in 1990-2006, OSPAR Commission, publication number 448/2009, 113 pp.. ISBN 978-1-906840-88-4
OSPAR 2009b CEMP: 2008/2009 Assessment of trends and concentrations of selected hazardous substances in sediments and biota. OSPAR Publication Number: 390/2009. ISBN 978-1-906840-30-3.

Uncertainties

Methodology uncertainty

Aggregated data do not necessarily convey the uncertainty problems. In addition, the time coverage is very variable between series and some of the trends shown may be based mainly on older data. The statistical significance of trends is based on a two-sided test with a nominal 5 % significance level, performed separately for each time series, without regard to serial correlation. A finding of 'No trend' (i.e. no statistically significant trend) may be due either to a lack of any real trend or to insufficient data (too few years in the data series or values in general being below the reporting limit).

Data sets uncertainty

This assessment is based on data reported to the EEA by EEA member countries. These data have significant gaps in terms of coverage (geographical and temporal) and consistency, especially for the Mediterranean and Black Seas. These data uncertainties, therefore, hinder a more comprehensive assessment of concentrations of and trends in hazardous substances in European marine waters. The assessment therefore does not necessarily convey the uncertainty these problems cause. It should also be noted that the three-class system used to classify the concentrations of hazardous substances (as green, yellow or red) does not necessarily highlight risks to human consumption.

Rationale uncertainty

The classification system reflects both observed levels of contaminants and the uncertainty in relation to the trends or levels indicated by the available data. Thus, a red classification does not necessarily mean that estimated levels are above the limit; it may merely indicate that the uncertainty is so large (because of lack of data and/or high variability in data) that it cannot be concluded with reasonable confidence that the true level is below the highest limit. It should also be noted that this three-class system for classifying concentrations of hazardous substances in fish does not highlight cases in which there is a risk to human consumption.

More generally, it should also be noted that considerable efforts have been made (i.e. at the policy, management and research levels) to establish and maintain monitoring programmes to assess the level and effect of and trends in hazardous substances in biota, and to select the most appropriate indicator tissues for particular species. However, there is a lack of reliable and consistent data for many hazardous substances and for several regions. Although basic legislation is in place to combat excessive exposure, specific assessment criteria with respect to levels, trends and effects need to be further developed for the indicator matrices. Furthermore, the measurement of concentrations in biota is not coordinated with measurements of inputs, which enhances the uncertainty in the correlation between the two.

It should also be noted that this indicator should not be used as an assessment of compliance monitoring in relation to the WFD, mainly because the monitoring strategy and assessment criteria used in this indicator measure the status of hazardous substances in biota, whereas the WFD EQSs concern concentrations in water for the most part. The exceptions include mercury and HCB in 'prey tissue', i.e. the whole individual, which would only apply to mussels in this indicator. There is a provision under the EQSD that allows Member States to establish other EQSs for biota (and sediment) for other substances as long as they provide the same level of protection. The ongoing development of technical guidance for deriving EQSs for the WFD should help Member States if they choose this solution. In addition to this, Member States will also have to take account of new legislation, for example technical specifications for chemical analysis (Directive 2009/90/EC) and updates to the EQSD, for example the Priority Substances Directive 2013/39/EU.

Data sources

Europe Seas
provided by European Environment Agency (EEA)
Chemistry data - Data & products on marine water quality
provided by European Marine Observation and Data Network (EMODnet)
Oceanographic database
provided by International Council for the Exploration of the Sea (ICES)