Jo King: OSPAR case study data flow comparability, streamlining and synergies of assessments of chemical loads and burdens The presentation summarises the experience of the Working Group of Monitoring (MON), which is where OSPAR assesses data on hazardous substances.

Why Cd, Hg, Pb, PCB, HCH, TBT & DDT? OSPAR list of chemicals for priority action toxic, persistent, liable to bio-accumulate DDT: OSPAR candidate list The MON assessments look at a range of chemicals on the OSPAR list for priority action, provided that there are sufficient data in the ICES database to warrant an assessment. Cd, Hg, Pb, PCB, HCH, TBT are some of these, but the at the last assessment we also looked at ~ 200 PAH time series and we are currently building in assessments of biological effects data.

Indicators Ecological Quality Elements and Objectives: hg concentrations in sea bird eggs organohalogen concentrations in sea bird eggs Vas Deferens Sequence Index (VDSI) in whelks – a biological effect resulting from exposure to TBT The nearest thing OSPAR has to an indicator is its Ecological Quality Elements, with associated Ecological Quality Objectives. There are three that are relevant to the hazardous substances that we are talking about, but at present only VDSI data are assessed by MON. .

Indicators Trends and levels used as ‘indicators’ Trends: have there been significant changes in concentration in the last ten years? Levels: is the fitted concentration in the last monitoring year significantly below the Background Assessment Concentrations; i.e. are concentrations ‘close to background’? However, we treat the levels and trends of the hazardous substances on the priority list as if they were indicators. In particular, we assess whether there have been any significant changes in concentration over the past ten years and whether concentrations are currently ‘close to background’; i.e. if concentrations are significantly below a reference value known as the Background Assessment Concentration.

Indicators - application Here’s an example of an assessment of CB153 concentrations in blue mussel. We summarise the concentration measurements each year by the median log-concentration …

Indicators - application … and then fit a smoother to the data. The grey area shows confidence bands around the fitted smoother. We use the smoother to test for trends. Here, there is evidence of a reduction in concentration over the whole monitoring period, but no evidence of a change in the last ten years.

Indicators - application We also compare the fitted concentration in the final monitoring year to the Background Assessment Concentration. Here, the confidence bands do not lie wholly below the BAC so, invoking the precautionary approach, we cannot say that concentrations are close to background.

Indicators - application Having assessed each time series individually, we then aggregate the results by OSPAR region, pick out interesting time series for further scrutiny, and display the results on maps. But this has problems because we mix the results from sites monitoring point sources with those monitoring diffuse sources, with no consistency within or between OSPAR regions. So we are also beginning to identify groups of stations that are monitoring diffuse inputs and modelling the data from these stations simultaneously to make regional assessments.

Data needs Background Concentrations Is location of sites adequate for regional assessments? What are the data needs? Assessments are far more meaningful when there are realistic targets. In particular, we need to establish Background Concentrations. We are there for many contaminants in sediments, but it is proving much harder for biota, particularly for fish. At a broader level, we need to sort out what we want from a regional assessment. In part, we must analyse the data we currently have to tell us whether the current network of monitoring stations is adequate. But there are also strategic questions. For example, do we want full coverage of each region, or are we mostly interested in the coastal strip, which is what we currently monitor in the North Sea. And is shellfish monitoring too localised to make regional assessments meaningful at the OSPAR scale?

Data needs Background Concentrations Is location of sites adequate for regional assessments? Time series in other priority substances, such as brominated flame retardants And we also need data for other priority substances. Brominated flame retardants is an obvious example. The substances we have historically focussed on are probably not the most important substances for the future.

Improving the process Annual assessments has shifted focus from software to interpretation Tools that allow data providers to examine their data and assessments have improved data quality control Involvement of data providers in the assessment has increased engagement in the process Until recently, the biggest obstacle to the process was doing periodic assessments, typically more than five years apart, because all efforts went on reproducing what was done before. Recently, we have started doing annual assessments, data submissions have improved, technical problems have been resolved, and we have moved from a technical and organisational challenge to an assessment that is broader and focussing on interpretation (e.g. contaminant ratios, TBT and imposex). We have also started to provide tools, in the R statistical package (free) that allow data providers to check their data and see preliminary assessments. For the first time this year, we were able to weed out historic data that were dubious, and modern data that were submitted incorrectly, rather than just putting caveats in the report. There is now a period after the assessment meeting when data providers are encouraged to supply supplementary information to interpret particular results. Two benefits: the results become more meaningful, and there is greater engagement in the whole process at the grass roots level.

Applicable offshore? Yes, but hard to establish Background Concentrations for fish. Finally, the OSPAR process already operates in both coastal and offshore waters. The one difference is that it appears to be much harder to establish Background Concentrations for fish.

And finally … Involvement of data providers throughout the process enhances data quality and assessment relevance Advice more meaningful on a regional scale, but requires detailed investigation of multiple time series Finally, the OSPAR process already operates in both coastal and offshore waters. The one difference is that it appears to be much harder to establish Background Concentrations for fish.