Scottish Marine and Freshwater Science Volume 4 Number 4: Measurement of Contaminants and their Effects in Environmental Samples - Proposal for the Revision of the Sampling Programme
Review of contaminant monitoring currently undertaken in Scotland's seas
Proposed MSFD Descriptor 8 Monitoring for Scotland
MSFD will require the monitoring of contaminants and effects in coastal (≤12 nm) and offshore (>12 nm) waters. Table 3 summarises the gaps identified above in the monitoring programme on a Scottish sea area basis. Monitoring programmes ( UK CSEMP) are already in place in coastal and offshore waters for OSPAR CEMP determinands ( PAHs, PCBs, PBDEs, Hg, Cd, Pb and imposex) in sediment and/or biota. Selected WFD priority substances are also monitored by SEPA in WFD water bodies, which include transitional and coastal waters. SEPA reviewed results for contaminants in water samples collected from transitional and coastal waters and stopped monitoring where all results were below the limit of detection of the analysis and there was no risk of failing the EQS. However, SEPA continues to monitor CEMP contaminants in biota and sediments to assess trends in contaminants and their status with respect to WFD EQS in biota and OSPAR assessment criteria. Most of the WFD priority substances enter the marine environment from land-based sources and therefore if concentrations are low and below EQSs in coastal and transitional waters, it is very unlikely that there will be an issue for offshore waters unless there are recognised offshore sources e.g. PAHs from flaring and exhausts from ships. Therefore, monitoring of WFD priority substances (that are not on the OSPAR CEMP) should not be required in offshore waters, unless a specific offshore input is identified (from oil and gas installations for example).
Table 3: Summary of gaps in the current monitoring of Scottish sea areas, compared to MSFD and OSPAR requirements.
Sea Area |
Gap |
Response |
---|---|---|
Solway and North Channel |
None |
Monitor as per Table 4 |
Clyde |
None |
Monitor as per Table 4 |
Minches and Malin Sea |
None |
Monitor as per Table 4 |
Hebrides |
Contaminants in sediment |
Investigate if suitable sediment can be found |
Effects in fish |
Availability of suitable species to be investigated |
|
Effects in mussels |
Aim to include Loch Roag in 2014 survey |
|
Rockall |
Contaminants in sediment |
Investigate ability to obtain a suitable sample |
Effects in fish |
Availability of suitable species to be investigated |
|
Bailey |
Contaminants in sediment |
Investigate ability to obtain a suitable sample |
Effects in fish |
Availability of suitable species to be investigated |
|
North Scotland Coast |
Contaminants in fish |
Seek a new fishing area |
Effects in fish |
||
Effects in mussels |
Aim to include 1 Orkney site in 2014 survey |
|
Faroe-Shetland |
Contaminants in sediment |
Investigate ability to obtain a suitable sample |
Contaminants in fish |
Aim to find a suitable fishing site |
|
Effects in fish |
Availability of suitable species to be investigated |
|
West Shetland |
Contaminants in fish |
Aim to find a suitable fishing site |
Effects in fish |
||
Effects in mussels |
Aim to include Clift or Vaila Sound in 2014 survey |
|
East Shetland |
Contaminants in sediment |
Extend area of Stratified Random sampling |
Effects in mussels |
Aim to include Ness of Sound Shore in 2014 survey |
|
Forties |
Contaminants in sediment |
Begin Stratified Random sampling |
Contaminants in fish |
Aim to establish a suitable fishing site |
|
Effects in fish |
||
Fladen |
None |
Monitor as per Table 4 |
Moray Firth |
None |
Monitor as per Table 4 |
East Scotland Coast |
None |
Monitor as per Table 4 |
Forth |
Contaminants in fish |
Establish a fishing site in MSFD waters |
Effects in fish |
The frequency of monitoring for MSFD Descriptor 8 should be based on whether concentrations in sediment and biota exceed the relevant assessment criteria, and if there are trends or concentrations are stable.
- Where concentrations are below the BACs ( OSPAR CEMP determinands only) and are stable or declining, monitoring will be required less frequently, and only to confirm there has been no change. Monitoring should be undertaken once per MSFD reporting cycle (every 6 years).
- Where concentrations are acceptable (less than relevant assessment criteria, EQS, ERL or EAC) but greater than the BAC, and concentrations are stable or declining, it may be appropriate to reduce the frequency of monitoring to one in every three years. If concentrations are below BACs, but if there is an upward trend monitoring should also be done every 3 years.
- Annual monitoring will continue at sites where contaminant concentrations are elevated (greater than relevant assessment criteria, EQS, ERL or EAC). Annual monitoring should also be undertaken if concentrations are above BACs, but below EACs/ EQS, but there is an upward trend.
This is similar to the approach adopted in England and Wales. SEPA have already reduced their sediment monitoring (contaminants and benthic invertebrates) to one-year-in-three at some locations, although annual monitoring continues at locations where concentrations are elevated (Clyde and Forth). This above approach should be taken for sediment and biota in all Scottish sea areas. Proposed monitoring frequency for each contaminant groups is shown in Table 4. Concentrations of PAHs, PCBs, PBDEs and trace metals in a number of Scottish sea areas are low, however, no area is below BACs for all contaminant groups. PAHs and most PCBs are less than BACs in sediment from east Shetland, west Shetland and Fladen. Some metals (Pb in Fladen) and CB118 exceed BACs, however, concentrations are below EACs for all contaminant groups in sediment from these areas, and are stable or showing downwards trends. Therefore, monitoring should be undertaken every 6 years for PAHs (Fladen and east Shetland [5] ) and trace metals (east Shetland) and every 3 years for PCBs (Fladen and east Shetland) and for trace metals (Fladen). Sediment from Moray Firth, Solway Firth and North Channel, Minches and Malin Sea and east Scotland coast are below ERLs for PAHs, but exceed EACs/ ERLs for some metals and CB118. Concentrations are either stable or declining and therefore monitoring should be every 3 years for PAHs and annually for PCBs and trace metals. Fish data ( PCBs and trace metals) is also available for these areas, and concentrations are below assessment criteria ( EACs or EC food safety levels) and are not increasing for all contaminant groups, except for trace metals (Cd) in the east Scotland coast. Therefore, fish monitoring should be every 3 years, except for trace metals in east Scotland coast where annual monitoring should continue. PBDE concentrations in sediment from Scottish sea areas are generally below LoDs (except in Clyde and Forth). There are currently no OSPAR assessment criteria ( BACs or EAC). There is an EQS proposed, but this is below detection limits using the best available techniques. However, if concentrations are close to zero and at least below the limits of detection of the most advanced analytical techniques in general use then monitoring can be reduced 5. Monitoring for PBDEs in sediment should therefore be reduced to once per reporting cycle (6 years) in all areas except the Clyde and Forth, where annual monitoring should continue. In the Clyde assessment criteria ( EACs/ ERLs/ EC values) are generally exceeded for all contaminant groups in fish and sediment therefore annual monitoring of sediment and biota should continue.
Table 4 Frequency contaminant groups should be monitored in sediment and fish from Scottish sea areas. A number of areas are not currently monitored routinely (*). These areas should be sampled on a 6 yearly rolling programme for all contaminant groups and biological effects (if possible though sampling in some areas may be difficult). North Scotland coast and west Shetland does not have suitable sediment type for sediment monitoring and therefore, should only be sampled for fish (if possible)
Scottish Sea Area |
PCBs ( ICES 7) |
PAHs ( OSPAR Set) |
PBDEs ( OSPAR Set) |
Trace Metals |
Biological effects ( OSPAR MIME common and candidate indicators) |
---|---|---|---|---|---|
Solway and North Channel |
Sediment: annual Fish: 3 years |
3 years |
Sediment: 6 years Fish: 3 years |
Sediment: annual Fish: 3 years |
Fish: 3 years Mussels: 3-4 years |
Clyde |
annual |
annual |
annual |
annual |
Fish: annual Mussels: 3-4 years Gastropods: 2014 |
Minches and Malin Sea |
Sediment: annual Fish: 3 years |
3 years |
Sediment: 6 years Fish: 3 years |
Sediment: annual Fish: 3 years |
Fish: 6 years Mussels: 6 years Gastropods: 2014 |
Hebrides* |
6 years |
6 years |
6 years |
6 years |
Fish: 6 years Mussels: 6 years |
Rockall* |
6 years |
6 years |
6 years |
6 years |
N/A |
Bailey* |
6 years |
6 years |
6 years |
6 years |
N/A |
North Scotland Coast* |
6 years |
6 years |
6 years |
6 years |
Fish: 6 years Mussels: 6 years Gastropods: 2014 |
Faroe-Shetland* |
6 years |
6 years |
6 years |
6 years |
N/A |
West Shetland |
6 years |
6 years |
6 years |
6 years |
Fish: 6 years Mussels: 6 years Gastropods: 2 years |
East Shetland |
3 years |
6 years |
6 years |
6 years |
Fish: 6 years Mussels: 6 years Gastropods: 2014 |
Forties* |
6 years |
6 years |
6 years |
6 years |
Fish: 6 years |
Fladen |
3 years |
6 years |
6 years |
3 years |
Fish: 6 years |
Moray Firth |
Sediment: annual Fish: annual |
3 years |
Sediment: 6 years Fish: annual |
Sediment: annual Fish: annual |
Fish: annual Mussels: 6 years Gastropods: 2014 |
East Scotland Coast |
Sediment: annual Fish: annual |
3 years |
Sediment: 6 years Fish: 3 years |
annual |
Fish: annual Mussels: 3 years |
Forth |
annual |
annual |
annual |
annual |
Fish: annual Mussels: 3 years Gastropods: 2014 |
Biological effects are not required for the WFD, although their role in providing information on substances not known a priori to be present in the environment, and on the effects of mixtures of substances has been recognised by the EU commissioning the Chemical Monitoring and Emerging Pollutants expert group of its Working Group E (Chemicals) to produce a technical report on aquatic effect-based monitoring tools. However, some OSPAR pre-CEMP determinands (including the PAH-specific effects measurements of EROD and bile metabolites) are currently monitored in fish in offshore waters as part of CSEMP, or have been measured during research programmes. Some of these were noted by OSPAR MIME as being candidate indicators likely to be used by a number of Member States, allowing regional comparisons.
Scotland will monitor selected biological effects measurements (including the common and candidate indicators) from the ICES integrated scheme on a rolling basis such that we sample from each Scottish sea area at least once per MSFD reporting cycle. The scheme allows for monitoring for mixture effects, which chemical analyses alone cannot do, and provides a view of the health of monitored wildlife, in addition to explicitly informing on contaminants and their direct (and additive) effects.
At locations where pressures are highest (Clyde and Forth), or where there is evidence of several effects currently being above EAC ( e.g. in the Integrated Assessment research project), then sampling should be conducted annually; if several effects are above BAC then monitoring should be every three years; otherwise once per 6-year MSFD cycle.
In fish we would use the ICES integrated approach annually in the Clyde and Forth, with samples analysed for: EROD, bile metabolites, lysosomal stability, micronucleus, liver histopathology, liver neoplasms, and external disease. The east Scotland coast and the Moray Firth should also be sampled annually for biological effects measurements. The Solway and North Channel should be sampled every three years, whereas the Minches and Malin Sea, Fladen and Shetland should be sampled every 6 years. New fish sampling sites should be established in the offshore part of the Forth sea area, the north Scotland coast and in the Forties sea area, with possibly (if a suitable site can be found) additional ones in the oil production areas of the east Shetland and Fladen sea areas, although in the latter two areas the sentinel species would need to be cod, and not dab. The frequency of sampling at the new sites will be established in light of the data generated.
With further regard to the spatial distribution of fishing sites, it is proposed to reduce the number of sites visited annually in the Clyde sea area from 7 to 5, maintaining the Bowling (Clyde estuary), Holy Loch (inner Firth), Garroch Head (middle Firth), Hunterston (Largs Channel) and Pladda (outer Firth) sites; the inner four sites to be sampled annually and the Pladda site every 3 years. In the Forth sea area, the Alloa site will no longer be sampled and will be replaced with a coastal water site in the outer Firth, the frequency of sampling to depend upon the data obtained. In the east Scotland coast sea area, the St Andrews Bay site will be moved, if a suitable site can be found, to the Tay estuary and sampled annually, with annual sampling continuing at the Montrose Bank site. Currently there are two fishing sites in each of the Moray Firth and the Minch/Malin sea areas. The Moray Firth sites should be visited every 3 years. In The Minches and Malin Sea, the current North Minch site will be visited one year in six, and sampling at Colonsay will be stopped.
Working with SEPA, contaminants and effects were determined in mussels as part of the MSS research project on the integrated assessment of contaminants and effects. Samples were analysed from the Forth, the Clyde and east Scotland coast sea areas. It is intended to continue using this monitoring using a rolling sampling design to cover each of the Scottish coastal sea areas at least once per OSPAR/MSFD reporting cycle.
Monitoring Responsibilities / Practicalities
The division of marine monitoring work between SEPA and MSS is regularly reviewed and organised through the Scottish Clean and Safe Seas Coordination Group, which meet biannually.
Monitoring for the WFD is the responsibility of SEPA, and under MSFD this responsibility extends to the limit of territorial waters (12 nm) for chemical status. Current monitoring activity by SEPA and MSS was reviewed above. Briefly, SEPA monitor contaminants in mussels and inshore sediments; MSS monitor effects and contaminants in fish, effects in mussels, contaminants in offshore sediments, and contaminants in some inshore sediments from the Clyde. Both organisations have historically monitored coastal imposex.
Under the monitoring programme proposed here, SEPA would continue to undertake coastal mussels monitoring, and MSS will co-ordinate with this in order to undertake biological effects monitoring in mussels on a rolling basis. Imposex monitoring (except for SOTEAG) will probably cease after the small 2014 survey. SEPA will be responsible for sediment monitoring within 12 nm, whilst MSS will be responsible for sediment monitoring beyond 12 nm. The current stratified random/fixed sediment sampling programme undertaken by SEPA and MSS for CSEMP will also fulfil the sediment monitoring requirements of MSFD. However, to ensure a greater coverage of all Scottish sea areas, areas not currently monitored will be sampled using a stratified random/fixed sampling design, with the frequency being dependent on the concentrations found (annual to 6 yearly).
MSS will be responsible for monitoring of contaminants and biological effects in fish from Scottish waters and will coordinate this with SEPA's WFD monitoring of fish ecology in transitional waters. Co-ordination of research vessels for efficiency in sample collection will be through the Scottish Clean and Safe Seas Coordination Group and the MSS/SEPA ships officers.
Conclusions
1. The Marine Strategy Framework Directive's Descriptor 8 states that 'Concentrations of contaminants are at levels not giving rise to pollution effects' . Therefore, for Descriptor 8 assessment, contaminant concentrations and effects measurements must be assessed against the relevant assessment criteria. For common indicator contaminants this will be the WFD EQS (biota), or OSPAR EAC, and for effects measurements the ICES EAC.
2. Currently EQSs and EACs are not available for all common indicators. However, the EC WFD Working Group E (Chemicals) is expected to develop additional EQSs. Where suitable EQSs/EACs are not available, alternative criteria ( e.g. Effects Range-Low) will be used for assessment purposes, but not for compliance purposes. However, if EQSs/EACs do not become available, sediment ERLs will be used.
3. The ultimate aim of the WFD (Article 1; and by extension the MSFD), and of the OSPAR Hazardous Substances Strategy, is for contaminant concentrations to be close-to-background; this will be assessed by comparison with OSPAR BACs.
4. Descriptor 8 covers those substances which are classed as priority substances for WFD. However, many of these substances will not be relevant for marine waters. OSPAR MIME recently reviewed the contaminants and effects that Member States were intending to monitor for Descriptor 8 and developed a list of common indicators: concentrations of Hg, Cd, Pb, PCBs and PBDEs in sediment and biota, PAHs and TBT in sediment, and presence or otherwise of imposex/intersex. All are OSPAR CEMP determinands. In addition, PAHs and TBT in biota and HCB and HCBD in sediment and biota were classed as candidate indicators. Five biological effects measurements were proposed as candidate indicators: externally visible fish disease, EROD, bile metabolites, lysosomal stability and micronuclei. This is a minimum list of what should be measured to allow comparisons across regions to be made.
5. TBT in sediment is the only common indicator not routinely monitored, since the impact of TBT is assessed by its effects on gastropods. TBT in biota is also a candidate indictor and monitoring in sediment or biota is required for the CEMP. Sediment monitoring in Scotland stopped in 2006, as concentrations were found to be below detection limits. In most areas the biological effects of TBT (imposex) are also low and declining. No additional monitoring of TBT in sediments will be undertaken for MSFD.
6. Of the contaminant candidate indicators, HCB and HCBD are not routinely monitored in sediment or biota in Scotland. Due to the low concentrations of both these contaminants in water, sediment and biota they are not considered to be an issue in Scotland and monitoring of HCB and HCBD will not be undertaken for MSFD. PAHs in biota are also a candidate indicator, and are already monitored in Scotland through SEPA's mussel monitoring; no additional monitoring is required for MSFD.
7. WFD contaminants monitoring data will be used for Descriptor 8 assessments of coastal waters. Due to the very low concentrations of most WFD priority substances in water samples (less than LoDs and EQSs for organic contaminants) collected from Scottish transitional and coastal waters, monitoring of most has been stopped. Therefore, there is no requirement to undertake any additional analysis in offshore waters other than where there may be a recognised source e.g. from oil and gas installations.
8. UK CSEMP monitoring of OSPAR CEMP determinands, including biological effects measurements, can be used for MSFD assessments.
9. No areas are below BACs for all contaminant groups in sediment and biota. For contaminant groups that have reached background (and there are no upwards trends) monitoring should be reduced to once every reporting cycle. For areas where concentrations are greater than BACs, but less than EQSs/ EACs/ ERL/ EC levels and showing no upward trends (or < BACs but increasing trend) monitoring should be reduced to every 3 years. Annual monitoring of contaminants should only continue if concentrations exceed EACs/ ERLs/ EC levels, or if > BACs and there is also an upward trend. Stratified random/fixed sampling of fine sediments will be applied to all sea areas, including the sea areas not previously monitored.
10. OSPAR CEMP determinands ( PAHs, PCBs and PBDEs) have previously been assessed in fish and sediment from Scottish sea areas. Contaminant concentrations in some areas (Fladen and east Shetland) are < EACs (and often below BACs) and concentrations are either stable or decreasing. Monitoring in these areas should be reduced to every 3 or 6 years (depending on contaminant group and area).
11. PBDEs in sediment are mainly below LoDs and generally only found in the Clyde and Forth sediment. Monitoring of PBDEs in all areas except the Clyde and Forth should be reduced to every 6 years.
12. Contaminant concentrations in the Solway and North Channel, Minches and Malin Sea, Moray Firth and east Scotland coast are mainly below EQS/ EACs/ ERLs/ EC levels and therefore, monitoring should be reduced to 3 yearly ( PAHs in sediment and PCBs and trace metals in fish). Annual monitoring should continue for PCBs and trace metals in sediment as EACs/ ERLs/ EC levels are exceeded
13. Some areas have not been routinely monitored to date for contaminants, such as Forties and Hebrides. Concentrations are likely to be low. These areas should be sampled on a rolling basis (every 6 years, unless concentrations are found to be higher than expected). The sediment type in a number of areas is not suitable for contaminant monitoring, being mainly sand, gravel or rock, (west Shetland, north Scotland coast), therefore, sediment monitoring in these areas is not required.
14. Whilst land-based inputs of contaminants to the Forties, Fladen, east Shetland and west Shetland sea areas are very limited, there are potential inputs from the oil and gas industry, and a potential for cumulative impacts due to the number of installations. A review should be conducted of what substances are discharged, whether any are PSs, and whether any of the discharged substances may require consideration as Specific Pollutants.
15. WFD monitoring does not include biological effects. The only biological effect in the OSPAR CEMP is imposex, which is monitored every 3 years. The levels of this have declined such that it should only be monitored at sites where it has not reached a classification consistent with GES in two consecutive surveys.
16. In fish, effects monitoring (including the OSPAR pre- CSEMP and candidate indicators) should be undertaken annually in the Forth, Clyde, Moray Firth and at Montrose Bank, every 3 years at the Solway Firth and North Channel and every 6 years elsewhere. Currently SEPA and MSS undertake effects monitoring in mussels as part of a research project and propose to continue with this programme. These data can be used for Descriptor 8 assessments.
17. Most Scottish contaminants and effects data are currently held in MERMAN and are readily available for Descriptor 8 assessments. Station Dictionary Names will be obtained for any additional sites proposed for Descriptor 8 monitoring and this data will be submitted to MERMAN. However, there may be resourcing issues for the addition of any new contaminants/effects to MERMAN, as this will require changes to the database structure.
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