Key messages: Hazardous substances, in particular ‘legacy substances’, pollute European seas. In general, concentrations of hazardous substances in marine organisms were low or moderate between 2010 and 2021. However, all hazardous substances exceeded safe limits in some areas. Exceedances were seen most frequently for benzo[α]pyrene, lindane (HCHG) and polychlorinated biphenyl (PCB). The range of substances monitored is relatively limited.  

 Hazardous substances in marine organisms in European seas, 2010-2021  

To build this indicator, levels of nine hazardous substances monitored in mussels and oysters from European seas were compared to environmental quality standardsand thresholds as set under the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR). All hazardous substances monitored between 2010 and 2021 exceeded safe limits in some areas. In general, concentrations were low or moderate, with exceedances most frequently seen for benzo[α]pyrene, HCHG and the PCB compound CB118. HCHG and PCB are examples of ‘legacy substances’ that are no longer intentionally used in production or specific settings (e.g electrical equipment, pesticides) as their uses have been or are being phased out/banned. The indicator thus shows that although these substances are ‘legacy’, they still pose a significant threat to marine ecosystems, biota and human health throughout the food chain.

Sufficient data to identify trends were available for only the North-East Atlantic Ocean and the Baltic Sea. Depending on the hazardous substances monitored, a stable or decreasing trend was observed in the North-East Atlantic Ocean. Despite time trends could be determined for the Baltic Sea, they were not significant. Abatement policies may explain these trends.

Curbing pollution at its source is vital for reaching the Marine Strategy Framework Directive (MSFD) objectives for good environmental status. The MSFD programme of measures is designed to address the sources of chemical pollution, including industrial discharges, agricultural runoff and shipping activities. Regional sea conventions (RSC) also help curb pollution via action plans focusing on key sources of pollution, such as agricultural and industrial activities.

The number of hazardous substances monitored is relatively limited, thus further chemicals monitoring would allow better assessment of the levels of a larger range of hazardous substances in marine organisms. This would enable more understanding and prevention of chemical-related risks.

Please consult the relevant indicators and signals below for a more comprehensive overview on the topic.

The data presented in the indicator come from both the European Marine Observation and Data Network (EMODnet), and the International Council for the Exploration of the Sea (ICES). They cover three European seas: the Baltic and Mediterranean seas, and the North-East Atlantic Ocean. No data are presented for the Black Sea, for which data coverage is low.

The monitored hazardous substances include cadmium, copper, lead, mercury, the polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BAP), and the compounds hexachlorobenzene (HCB), lindane, dichlorodiphenyldichloroethylene (DDE) and polychlorinated biphenyl (PCB) CB118, which are banned in the EU. In organisms, dichlorodiphenyltrichloroethane (DDT) is quite rapidly metabolised to DDE, which is also toxic. Consequently, almost all monitoring programs measure DDE as a proxy for DDT.

Concentrations were classified by environmental quality standards in biota where available. Background assessment concentrations criteria and maximum permissible concentrations for humans as established under the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) were used to set the upper limit for the 'low' and 'moderate' classes, respectively.

More information is available at the EEA’s indicator page and the EEA’s water and marine environment page.

Relevant objectives under the Chemicals Strategy for Sustainability

    • Restore human health and environment to a good quality status

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Other relevant indicators and signals

References and footnotes

  1. EU, 2013, 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 (Text with EEA relevance) (OJ L 226, 24.8.2013, p. 1–17).
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  2. Dietz, R., et al., 2021, ‘A risk assessment of the effects of mercury on Baltic Sea, Greater North Sea and North Atlantic wildlife, fish and bivalves’, Environment International 146, p. 106178 (DOI: 10.1016/j.envint.2020.106178).
    a b
  3. EU, 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) (Text with EEA relevance) (OJ L 164, 25.6.2008, p. 19-40).