Descriptor 9 (contaminants in food) is one of eleven Marine Strategy Framework Directive ( MSFD) qualitative Descriptors to be used in determining whether Good Environmental Status ( GES) has been achieved for European regional seas (Directive EC/2008/56). For monitoring of compliance with GES for Descriptor 9, contaminant concentrations in fish and seafood should be compared against the EC regulatory levels. The fish and shellfish contaminant monitoring currently undertaken in Scotland was reviewed. Monitoring programmes include the UK Clean Seas Environment Monitoring Programme ( CSEMP) undertaken by Marine Scotland Science ( MSS) and Scottish Environment Protection Agency ( SEPA), and the annual surveys of contaminants in shellfish from commercial harvesting areas undertaken by Food Standards Agency for Scotland ( FSAS). The suitability of these activities in addressing the requirements of Descriptor 9 was assessed.
CSEMP is the main UK monitoring programme for contaminants in fish and, in Scotland, is undertaken by MSS. However, as most fish data are for liver tissue of small flatfish they are of limited use for assessing progress towards GES under Descriptor 9, as in the UK fish liver is not generally consumed. For CSEMP, trace metals are determined in fish muscle and liver, and PCBs in fish liver only. Regulatory levels are available for metals, dioxins and PCBs in fish muscle. However, only metals are analysed in fish muscle as part of UK CSEMP. PCBs and dioxins are not measured in fish muscle as this is not a requirement of the OSPAR Coordinated Environmental Monitoring Programme ( CEMP) for the NE Atlantic. Monitoring of shellfish in Scotland is mainly undertaken by FSAS and SEPA. Mussel samples are collected by SEPA to assess compliance with the Water Framework Directive ( WFD; 2000/60/ EC) and its daughter Directive on Environmental Quality Standards ( EQSD; 2008/105/ EC) following the repeal of the Dangerous Substances Directive ( DSD; 2006/11/ EC) in December 2013; samples are analysed for PCBs, PAHs and trace metals, but not dioxins. FSAS undertake contaminant (includes trace metals, PAHs, PCBs and dioxins) monitoring in shellfish for the Shellfish Hygiene Directive (79/923/ EEC). Both SEPA and FSAS shellfish contaminant data could be used for Descriptor 9 assessments, although currently FSAS data is not submitted to the UK Marine Environment Monitoring and Assessment National database ( MERMAN).
The available data from the above shellfish and fish monitoring programmes were obtained from the MERMAN database and from FSAS. Concentrations were mostly below the current available regulatory levels in both fish and shellfish. Although all contaminant groups with regulatory levels were analysed in mussels, dioxins are not routinely measured in fish muscle. However, it is possible to estimate dioxin toxic equivalent concentrations from PCB concentrations, using published models, for comparison with regulatory levels.
Due to the deficiencies of existing environmental monitoring programmes to address the requirements of MSFD Descriptor 9, particularly for fish, a sampling programme targeting appropriate fish species was designed. The designs were based around existing fish stock assessment research vessel surveys, with fish sampled from each trawling location with a probability proportional to the landings by the Scottish fishing fleet. Haddock, monk, and herring were selected based on their importance to the human diet (based on fish landings) and to represent different groups of fish ( e.g. high trophic level, high fat content). The designs were implemented for each species for those parts of the North Sea and the Celtic Seas relevant to the Scottish fleet.