The 2017 MIME assessment describes the trends and status of contaminant concentrations in biota and sediment at monitoring stations in the OSPAR area. Assessments are made for a large number of time series, each of a single contaminant in a single species (for biota) at a single monitoring station. This document is one of a series that synthesises the results of the individual time series to assess status and trends at the MIME regional level. In particular, it considers BDE concentrations in biota, where the BDEs are BDE28, BDE47, BDE99, BD100, BD153, BD154. For simplicity, the term ‘region’ is used throughout to describe MIME regions. OSPAR regions are always referred to as such.
The following sections:
A time series of BDE concentrations is assessed for status if:
The conditions are more stringent for trends. Specifically, a time series is assessed for trends if:
Note that all trend assessments for individual time series and most status assessments are based on the fit of a parametric model. This is important because only the parametric results are passed into the regional assessments in the following sections. Only 0 of 583 BDE time series were assessed for status using a non-parametric test.
The first tab below shows all the monitoring stations where there are individual time series assessments of trend or status for BDEs. The magenta circles are stations where there is a trend assessment for at least one BDE, and the cyan cirles are stations where there are only status assessments.
The next set of tabs show the trend and status assessments for each BDE in turn. The colours have the following meaning:
And the shapes have the following meaning:
The final set of tabs give:
Number of time series with upwards, downwards or no trend by MIME and OSPAR region
OSPAR region | MIME region | status | BDE28 | BDE47 | BDE99 | BD100 | BD153 | BD154 | total |
---|---|---|---|---|---|---|---|---|---|
1 | Barents Sea | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
no trend | 1 | 1 | 1 | 2 | 0 | 2 | 7 | ||
downward trend | 1 | 2 | 1 | 0 | 0 | 0 | 4 | ||
Norwegian Sea | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
no trend | 0 | 0 | 1 | 1 | 0 | 1 | 3 | ||
downward trend | 1 | 1 | 0 | 0 | 0 | 0 | 2 | ||
total | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
no trend | 1 | 1 | 2 | 3 | 0 | 3 | 10 | ||
downward trend | 2 | 3 | 1 | 0 | 0 | 0 | 6 | ||
2 | Norwegian Trench | upward trend | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
no trend | 2 | 1 | 0 | 2 | 2 | 1 | 8 | ||
downward trend | 0 | 1 | 2 | 0 | 0 | 0 | 3 | ||
Northern North Sea | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
no trend | 0 | 4 | 2 | 4 | 0 | 0 | 10 | ||
downward trend | 1 | 4 | 2 | 2 | 1 | 2 | 12 | ||
Skagerrak and Kattegat | upward trend | 0 | 0 | 0 | 1 | 1 | 1 | 3 | |
no trend | 1 | 3 | 3 | 6 | 1 | 1 | 15 | ||
downward trend | 2 | 5 | 4 | 1 | 1 | 1 | 14 | ||
Southern North Sea | upward trend | 0 | 0 | 0 | 0 | 1 | 0 | 1 | |
no trend | 4 | 2 | 4 | 8 | 3 | 1 | 22 | ||
downward trend | 2 | 8 | 1 | 1 | 0 | 1 | 13 | ||
Channel | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
no trend | 0 | 0 | 1 | 2 | 1 | 0 | 4 | ||
downward trend | 0 | 3 | 1 | 1 | 0 | 1 | 6 | ||
total | upward trend | 0 | 0 | 0 | 1 | 2 | 2 | 5 | |
no trend | 7 | 10 | 10 | 22 | 7 | 3 | 59 | ||
downward trend | 5 | 21 | 10 | 5 | 2 | 5 | 48 | ||
3 | Irish and Scottish West Coast | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
no trend | 3 | 6 | 4 | 4 | 1 | 1 | 19 | ||
downward trend | 0 | 1 | 2 | 1 | 0 | 0 | 4 | ||
Irish Sea | upward trend | 0 | 0 | 0 | 0 | 0 | 1 | 1 | |
no trend | 5 | 7 | 5 | 11 | 7 | 7 | 42 | ||
downward trend | 2 | 13 | 10 | 8 | 5 | 6 | 44 | ||
Celtic Sea | upward trend | 0 | 1 | 1 | 0 | 0 | 0 | 2 | |
no trend | 3 | 3 | 2 | 3 | 1 | 2 | 14 | ||
downward trend | 0 | 1 | 2 | 1 | 0 | 0 | 4 | ||
total | upward trend | 0 | 1 | 1 | 0 | 0 | 1 | 3 | |
no trend | 11 | 16 | 11 | 18 | 9 | 10 | 75 | ||
downward trend | 2 | 15 | 14 | 10 | 5 | 6 | 52 | ||
4 | Iberian Sea | upward trend | 0 | 1 | 1 | 1 | 0 | 0 | 3 |
no trend | 0 | 15 | 11 | 12 | 6 | 10 | 54 | ||
downward trend | 0 | 5 | 9 | 7 | 0 | 3 | 24 | ||
total | upward trend | 0 | 1 | 1 | 1 | 0 | 0 | 3 | |
no trend | 0 | 15 | 11 | 12 | 6 | 10 | 54 | ||
downward trend | 0 | 5 | 9 | 7 | 0 | 3 | 24 |
Proportion of time series with upwards, downwards or no trend by MIME and OSPAR region
OSPAR region | MIME region | status | BDE28 | BDE47 | BDE99 | BD100 | BD153 | BD154 | total |
---|---|---|---|---|---|---|---|---|---|
1 | Barents Sea | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | |
no trend | 50 | 33 | 50 | 100 | 100 | 64 | |||
downward trend | 50 | 67 | 50 | 0 | 0 | 36 | |||
Norwegian Sea | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | ||
no trend | 0 | 0 | 100 | 100 | 100 | 60 | |||
downward trend | 100 | 100 | 0 | 0 | 0 | 40 | |||
total | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | ||
no trend | 33 | 25 | 67 | 100 | 100 | 62 | |||
downward trend | 67 | 75 | 33 | 0 | 0 | 38 | |||
2 | Norwegian Trench | upward trend | 0 | 0 | 0 | 0 | 0 | 50 | 8 |
no trend | 100 | 50 | 0 | 100 | 100 | 50 | 67 | ||
downward trend | 0 | 50 | 100 | 0 | 0 | 0 | 25 | ||
Northern North Sea | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
no trend | 0 | 50 | 50 | 67 | 0 | 0 | 45 | ||
downward trend | 100 | 50 | 50 | 33 | 100 | 100 | 55 | ||
Skagerrak and Kattegat | upward trend | 0 | 0 | 0 | 13 | 34 | 34 | 9 | |
no trend | 33 | 38 | 43 | 75 | 33 | 33 | 47 | ||
downward trend | 67 | 62 | 57 | 12 | 33 | 33 | 44 | ||
Southern North Sea | upward trend | 0 | 0 | 0 | 0 | 25 | 0 | 3 | |
no trend | 67 | 20 | 80 | 89 | 75 | 50 | 61 | ||
downward trend | 33 | 80 | 20 | 11 | 0 | 50 | 36 | ||
Channel | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | ||
no trend | 0 | 50 | 67 | 100 | 0 | 40 | |||
downward trend | 100 | 50 | 33 | 0 | 100 | 60 | |||
total | upward trend | 0 | 0 | 0 | 4 | 18 | 20 | 4 | |
no trend | 58 | 32 | 50 | 78 | 64 | 30 | 53 | ||
downward trend | 42 | 68 | 50 | 18 | 18 | 50 | 43 | ||
3 | Irish and Scottish West Coast | upward trend | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
no trend | 100 | 86 | 67 | 80 | 100 | 100 | 83 | ||
downward trend | 0 | 14 | 33 | 20 | 0 | 0 | 17 | ||
Irish Sea | upward trend | 0 | 0 | 0 | 0 | 0 | 7 | 1 | |
no trend | 71 | 35 | 33 | 58 | 58 | 50 | 48 | ||
downward trend | 29 | 65 | 67 | 42 | 42 | 43 | 51 | ||
Celtic Sea | upward trend | 0 | 20 | 20 | 0 | 0 | 0 | 10 | |
no trend | 100 | 60 | 40 | 75 | 100 | 100 | 70 | ||
downward trend | 0 | 20 | 40 | 25 | 0 | 0 | 20 | ||
total | upward trend | 0 | 3 | 4 | 0 | 0 | 6 | 2 | |
no trend | 85 | 50 | 42 | 64 | 64 | 59 | 58 | ||
downward trend | 15 | 47 | 54 | 36 | 36 | 35 | 40 | ||
4 | Iberian Sea | upward trend | 5 | 5 | 5 | 0 | 0 | 4 | |
no trend | 71 | 52 | 60 | 100 | 77 | 67 | |||
downward trend | 24 | 43 | 35 | 0 | 23 | 29 | |||
total | upward trend | 5 | 5 | 5 | 0 | 0 | 4 | ||
no trend | 71 | 52 | 60 | 100 | 77 | 67 | |||
downward trend | 24 | 43 | 35 | 0 | 23 | 29 |
Tabulating the number of time series with an upward or downward trend provides a quick summary of the individual time series results. However, it does not provide an objective regional assessment of trends. This section describes how the individual time series results can by synthesised in a meta-analysis to assess trends at the regional level.
For a regional trend assessment, the trend in each time series is summarised by the estimated change in log concentration over the last twenty years (or shorter if the time series doesn’t extend that far back). Regional trends are then estimated by fitting the following linear mixed model by restricted maximum likelihood:
The fixed model means that a trend is estimated for each region. Trends in the different BDEs are assumed to be broadly similar, because inputs and control measures are likely to affect all BDEs in a similar way. Each regional trend can thus be interpreted as the common trend in BDE concentrations in that region (i.e. the trend averaged across all BDEs).
The random model has five terms:
The meta-analysis is restricted to time series from monitoring stations that are classified as ‘representative’. ‘Baseline’ stations (those with near pristine conditions or only subject to very diffuse inputs) are omitted because any trends there will likely be caused by different processes to those at representative stations. Similarly ‘impacted’ stations (those close to a point source) are omitted because trends there will likely reflect changes due to the point source, and will be ‘unrepresentative’ at the regional level.
The meta-analysis is further restricted to:
Unfortunately, no assessment criteria have yet been adopted for BDEs in biota, so no formal assessment of status is possible. However, an informal ranking of regions can be made by comparing the regional mean concentrations. This is considered in the final section of this document which looks at concentration profiles.
The results of the regional assessment of trends are back-transformed for presentation. The estimated regional trend is then interpreted as the percentage yearly change in concentration.
This section provides more detail on the number and geographic spread of the time series available for the meta-analyses. The tabs show the stations with parametric trend and status assessments for each OSPAR region in turn, having excluded trend assessments at baseline and impacted stations. The magenta circles are stations where there is a trend assessment for at least one BDE, and the cyan cirles are stations where there are only status assessments.
Note that, although there are no asssessment criteria available, the cyan circles show where there are time series with estimates of the mean concentration in the final montitoring year. These can be used to construct concentration profiles at the regional level, and to compare mean concentrations across regions.
The following regions have an insufficient number or time series or spread of stations and are excluded from the regional assessment:
The first 4 tabs show:
The symbols in all these plots have the following interpretation:
The final 2 tabs show the estimates of the regional trend (averaged over BDEs) and the regional trend by BDE.
This table shows the estimates of the regional trend:
MIME region | trend | se | lower | upper | % yearly change | %yc lower | %yc upper |
---|---|---|---|---|---|---|---|
Northern North Sea | -10.76 | 4.58 | -19.74 | -1.78 | -10.20 | -17.91 | -1.76 |
Skagerrak and Kattegat | 0.01 | 4.60 | -9.00 | 9.03 | 0.01 | -8.61 | 9.44 |
Southern North Sea | -11.87 | 3.72 | -19.17 | -4.58 | -11.20 | -17.44 | -4.47 |
Channel | -14.98 | 6.28 | -27.29 | -2.66 | -13.91 | -23.89 | -2.63 |
Irish and Scottish West Coast | -9.94 | 4.88 | -19.49 | -0.38 | -9.46 | -17.71 | -0.38 |
Irish Sea | -13.09 | 3.02 | -19.02 | -7.16 | -12.27 | -17.32 | -6.91 |
Iberian Sea | -10.76 | 3.02 | -16.68 | -4.84 | -10.20 | -15.36 | -4.72 |
This table shows the estimates of the regional trend by determinand:
MIME region | BDE | trend | se | lower | upper | % yearly change | %yc lower | %yc upper |
---|---|---|---|---|---|---|---|---|
Northern North Sea | BDE28 | -8.27 | 5.12 | -18.30 | 1.75 | -7.94 | -16.72 | 1.77 |
BDE47 | -9.33 | 4.33 | -17.81 | -0.85 | -8.91 | -16.31 | -0.85 | |
BDE99 | -18.85 | 5.00 | -28.65 | -9.06 | -17.18 | -24.91 | -8.66 | |
BD100 | -9.62 | 4.63 | -18.69 | -0.54 | -9.17 | -17.05 | -0.54 | |
BD153 | -7.14 | 4.93 | -16.80 | 2.53 | -6.89 | -15.47 | 2.56 | |
BD154 | -11.34 | 4.68 | -20.51 | -2.17 | -10.72 | -18.54 | -2.15 | |
Skagerrak and Kattegat | BDE28 | -0.46 | 5.36 | -10.96 | 10.05 | -0.46 | -10.38 | 10.57 |
BDE47 | -6.89 | 4.23 | -15.18 | 1.40 | -6.66 | -14.08 | 1.41 | |
BDE99 | -7.88 | 4.34 | -16.38 | 0.62 | -7.58 | -15.11 | 0.62 | |
BD100 | 5.27 | 4.55 | -3.66 | 14.19 | 5.41 | -3.59 | 15.25 | |
BD153 | 6.78 | 5.43 | -3.87 | 17.44 | 7.02 | -3.79 | 19.05 | |
BD154 | 3.25 | 5.35 | -7.23 | 13.73 | 3.30 | -6.98 | 14.71 | |
Southern North Sea | BDE28 | -11.25 | 3.91 | -18.91 | -3.59 | -10.64 | -17.23 | -3.52 |
BDE47 | -14.80 | 3.48 | -21.63 | -7.97 | -13.76 | -19.45 | -7.66 | |
BDE99 | -16.58 | 4.21 | -24.83 | -8.32 | -15.27 | -21.98 | -7.99 | |
BD100 | -13.05 | 3.65 | -20.21 | -5.89 | -12.24 | -18.30 | -5.72 | |
BD153 | -5.30 | 4.32 | -13.77 | 3.16 | -5.16 | -12.86 | 3.21 | |
BD154 | -10.25 | 4.19 | -18.47 | -2.04 | -9.75 | -16.87 | -2.01 | |
Channel | BDE28 | -13.90 | 7.25 | -28.10 | 0.31 | -12.97 | -24.49 | 0.31 |
BDE47 | -16.01 | 6.05 | -27.86 | -4.16 | -14.80 | -24.32 | -4.08 | |
BDE99 | -22.37 | 6.72 | -35.54 | -9.20 | -20.05 | -29.91 | -8.79 | |
BD100 | -14.12 | 6.40 | -26.66 | -1.58 | -13.17 | -23.40 | -1.56 | |
BD153 | -11.33 | 6.98 | -25.00 | 2.35 | -10.71 | -22.12 | 2.38 | |
BD154 | -12.14 | 6.48 | -24.85 | 0.56 | -11.43 | -22.00 | 0.56 | |
Irish and Scottish West Coast | BDE28 | -7.90 | 5.72 | -19.12 | 3.31 | -7.60 | -17.40 | 3.37 |
BDE47 | -9.43 | 4.66 | -18.55 | -0.30 | -9.00 | -16.93 | -0.30 | |
BDE99 | -17.50 | 4.95 | -27.21 | -7.79 | -16.06 | -23.82 | -7.50 | |
BD100 | -10.77 | 5.31 | -21.17 | -0.36 | -10.21 | -19.08 | -0.36 | |
BD153 | -5.44 | 5.73 | -16.67 | 5.80 | -5.29 | -15.36 | 5.97 | |
BD154 | -8.59 | 5.69 | -19.74 | 2.55 | -8.23 | -17.91 | 2.59 | |
Irish Sea | BDE28 | -11.69 | 3.45 | -18.45 | -4.93 | -11.03 | -16.85 | -4.81 |
BDE47 | -13.78 | 2.62 | -18.93 | -8.64 | -12.88 | -17.24 | -8.28 | |
BDE99 | -21.08 | 2.92 | -26.81 | -15.36 | -19.01 | -23.52 | -14.24 | |
BD100 | -13.03 | 2.79 | -18.50 | -7.56 | -12.21 | -16.89 | -7.28 | |
BD153 | -10.53 | 3.06 | -16.52 | -4.54 | -9.99 | -15.23 | -4.44 | |
BD154 | -8.42 | 2.85 | -14.00 | -2.84 | -8.07 | -13.06 | -2.80 | |
Iberian Sea | BDE28 | -9.67 | 4.71 | -18.91 | -0.44 | -9.22 | -17.23 | -0.44 |
BDE47 | -10.52 | 2.65 | -15.72 | -5.33 | -9.99 | -14.55 | -5.19 | |
BDE99 | -16.59 | 2.60 | -21.68 | -11.50 | -15.29 | -19.49 | -10.86 | |
BD100 | -11.05 | 2.64 | -16.23 | -5.88 | -10.46 | -14.98 | -5.71 | |
BD153 | -8.38 | 3.91 | -16.05 | -0.72 | -8.04 | -14.82 | -0.72 | |
BD154 | -8.32 | 3.23 | -14.64 | -2.00 | -7.98 | -13.62 | -1.98 |
The profile of concentrations across BDEs can sometimes be useful for examining sources, and for comparing concentrations across regions where assessment criteria are not available. Profiles were examined by fitting the following linear mixed model by restricted maximum likelihood:
where, for each time series, the mean log concentration is the estimated mean log concentration in the final monitoring year and the estimation variance is the variance associated with this estimate.
The estimated BDE concentration profiles by region are shown below with pointwise 95% confidence limits. The units are ug/kg ww.