MIME regional assessment of status and trends in CB concentrations in biota

Overview

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 CB concentrations in biota, where the CBs are CB28, CB52, CB101, CB118, CB138, CB153, CB180. For simplicity, the term ‘region’ is used throughout to describe MIME regions. OSPAR regions are always referred to as such.

The following sections:

  • summarise the individual time series results
  • describe the methods used to combine the individual time series results to estimate regional trends and status
  • present the estimates of regional trends
  • present the estimates of regional status


Summary of individual time series results

A time series of CB concentrations is assessed for status if:

  • there is at least one year with data in the period 2010 to 2015
  • there are at least three years of data over the whole time series
  • a parametric model can be fitted to the data and used to estimate the mean concentration in the final monitoring year (or, occasionally, if a non-parametric test of status is applied)

The conditions are more stringent for trends. Specifically, a time series is assessed for trends if:

  • there is at least one year with data in the period 2010 to 2015
  • there are at least five years of data over the whole time series
  • a parametric model can be fitted to the data and used to estimate the trend in mean concentrations

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 210 of 2185 CB 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 CBs. The magenta circles are stations where there is a trend assessment for at least one CB, 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 CB in turn. The colours have the following meaning:

  • blue: the mean concentration is significantly (p < 0.05) below the Background Assessment Concentration (BAC)
  • green: the mean concentration is significantly (p < 0.05) below the Environmental Assessment Criterion (EAC)
  • red: the mean concentration is not signficantly below the Environmental Assessment Criterion (EAC)
  • black: there are no assessment criteria available

And the shapes have the following meaning:

  • downward triangle: the mean concentration is significantly decreasing (p < 0.05)
  • circle: there is no significant change in mean concentration (p > 0.05)
  • upward triangle: the mean concentration is significantly increasing (p < 0.05)

The final set of tabs give:

  • the number of time series with upwards, downwards or no trend in each MiME and OSPAR region
  • the same information presented as proportions
  • the number of time series with blue, green, or red status in each MIME and OSPAR region
  • the same information presented as proportions


Stations


CB28


CB52


CB101


CB118


CB138


CB153


CB180


Trend summary (numbers)

Number of time series with upwards, downwards or no trend by MIME and OSPAR region

OSPAR region MIME region status CB28 CB52 CB101 CB118 CB138 CB153 CB180 total
1 Barents Sea upward trend 0 0 0 0 0 0 0 0
no trend 1 1 1 1 1 2 2 9
downward trend 3 3 4 7 7 6 3 33
Norwegian Sea upward trend 0 0 0 0 0 0 0 0
no trend 0 0 0 0 0 0 0 0
downward trend 1 1 1 1 1 1 1 7
total upward trend 0 0 0 0 0 0 0 0
no trend 1 1 1 1 1 2 2 9
downward trend 4 4 5 8 8 7 4 40
2 Norwegian Trench upward trend 1 0 0 0 0 1 0 2
no trend 3 7 8 7 9 5 7 46
downward trend 9 9 13 14 12 15 8 80
Northern North Sea upward trend 0 0 2 1 0 0 0 3
no trend 4 2 9 16 18 26 9 84
downward trend 3 5 6 6 8 5 4 37
Skagerrak and Kattegat upward trend 0 0 0 0 0 0 1 1
no trend 14 13 9 6 9 8 8 67
downward trend 8 13 20 22 19 20 10 112
Southern North Sea upward trend 0 0 0 0 0 0 0 0
no trend 12 16 19 13 13 18 16 107
downward trend 7 6 12 16 15 12 10 78
Channel upward trend 0 0 0 0 0 0 0 0
no trend 7 20 9 8 3 5 4 56
downward trend 16 7 20 21 25 24 25 138
total upward trend 1 0 2 1 0 1 1 6
no trend 40 58 54 50 52 62 44 360
downward trend 43 40 71 79 79 76 57 445
3 Irish and Scottish West Coast upward trend 0 0 0 0 0 1 0 1
no trend 7 7 7 14 13 13 14 75
downward trend 6 10 7 5 5 5 0 38
Irish Sea upward trend 1 1 0 2 1 1 2 8
no trend 19 19 31 30 27 38 24 188
downward trend 10 11 11 14 14 7 4 71
Celtic Sea upward trend 0 0 0 0 0 0 0 0
no trend 6 4 3 6 5 5 5 34
downward trend 2 3 5 2 4 4 3 23
total upward trend 1 1 0 2 1 2 2 9
no trend 32 30 41 50 45 56 43 297
downward trend 18 24 23 21 23 16 7 132
4 Northern Bay of Biscay upward trend 1 0 0 0 0 0 0 1
no trend 9 12 9 12 2 2 2 48
downward trend 3 4 7 4 13 14 14 59
Iberian Sea upward trend 0 0 0 4 0 0 0 4
no trend 8 4 7 9 6 5 7 46
downward trend 7 12 18 12 19 20 14 102
Gulf of Cadiz upward trend 0 0 0 0 0 0 0 0
no trend 1 1 1 1 1 1 1 7
downward trend 0 0 0 0 0 0 0 0
total upward trend 1 0 0 4 0 0 0 5
no trend 18 17 17 22 9 8 10 101
downward trend 10 16 25 16 32 34 28 161


Trend summary (proportions)

Proportion of time series with upwards, downwards or no trend by MIME and OSPAR region

OSPAR region MIME region status CB28 CB52 CB101 CB118 CB138 CB153 CB180 total
1 Barents Sea upward trend 0 0 0 0 0 0 0 0
no trend 25 25 20 12 12 25 40 21
downward trend 75 75 80 88 88 75 60 79
Norwegian Sea upward trend 0 0 0 0 0 0 0 0
no trend 0 0 0 0 0 0 0 0
downward trend 100 100 100 100 100 100 100 100
total upward trend 0 0 0 0 0 0 0 0
no trend 20 20 17 11 11 22 33 18
downward trend 80 80 83 89 89 78 67 82
2 Norwegian Trench upward trend 8 0 0 0 0 5 0 2
no trend 23 44 38 33 43 24 47 36
downward trend 69 56 62 67 57 71 53 62
Northern North Sea upward trend 0 0 12 4 0 0 0 2
no trend 57 29 53 70 69 84 69 68
downward trend 43 71 35 26 31 16 31 30
Skagerrak and Kattegat upward trend 0 0 0 0 0 0 5 1
no trend 64 50 31 21 32 29 42 37
downward trend 36 50 69 79 68 71 53 62
Southern North Sea upward trend 0 0 0 0 0 0 0 0
no trend 63 73 61 45 46 60 62 58
downward trend 37 27 39 55 54 40 38 42
Channel upward trend 0 0 0 0 0 0 0 0
no trend 30 74 31 28 11 17 14 29
downward trend 70 26 69 72 89 83 86 71
total upward trend 1 0 2 1 0 1 1 1
no trend 48 59 42 38 40 44 43 44
downward trend 51 41 56 61 60 55 56 55
3 Irish and Scottish West Coast upward trend 0 0 0 0 0 5 0 1
no trend 54 41 50 74 72 69 100 66
downward trend 46 59 50 26 28 26 0 33
Irish Sea upward trend 3 3 0 4 3 2 7 3
no trend 64 61 74 65 64 83 80 70
downward trend 33 36 26 31 33 15 13 27
Celtic Sea upward trend 0 0 0 0 0 0 0 0
no trend 75 57 38 75 56 56 62 60
downward trend 25 43 62 25 44 44 38 40
total upward trend 2 2 0 3 2 3 4 2
no trend 63 54 64 68 65 76 83 68
downward trend 35 44 36 29 33 21 13 30
4 Northern Bay of Biscay upward trend 8 0 0 0 0 0 0 1
no trend 69 75 56 75 13 12 12 44
downward trend 23 25 44 25 87 88 88 55
Iberian Sea upward trend 0 0 0 16 0 0 0 3
no trend 53 25 28 36 24 20 33 30
downward trend 47 75 72 48 76 80 67 67
Gulf of Cadiz upward trend 0 0 0 0 0 0 0 0
no trend 100 100 100 100 100 100 100 100
downward trend 0 0 0 0 0 0 0 0
total upward trend 3 0 0 10 0 0 0 2
no trend 62 52 40 52 22 19 26 38
downward trend 35 48 60 38 78 81 74 60


Status summary (numbers)

Number of time series with each status by MIME and OSPAR region

OSPAR region MIME region status CB28 CB52 CB101 CB118 CB138 CB153 CB180 total
1 Barents Sea blue 3 3 1 3 2 0 3 15
green 6 5 8 3 7 9 5 43
red 0 0 0 3 0 0 0 3
Norwegian Sea blue 0 0 0 0 0 0 0 0
green 2 3 2 0 3 3 2 15
red 0 0 1 3 0 0 0 4
total blue 3 3 1 3 2 0 3 15
green 8 8 10 3 10 12 7 58
red 0 0 1 6 0 0 0 7
2 Norwegian Trench blue 6 5 5 3 0 0 8 27
green 16 17 18 9 24 25 14 123
red 1 1 2 13 1 0 0 18
Northern North Sea blue 1 0 0 0 0 0 1 2
green 29 28 35 11 36 45 29 213
red 8 2 10 32 1 0 0 53
Skagerrak and Kattegat blue 12 11 3 2 0 0 16 44
green 17 20 25 13 26 29 12 142
red 2 0 3 15 4 1 2 27
Southern North Sea blue 2 1 0 0 0 0 0 3
green 21 25 27 6 27 35 32 173
red 9 6 7 28 2 0 1 53
Channel blue 15 1 0 0 0 0 10 26
green 12 25 23 5 23 26 19 133
red 2 4 7 25 5 4 0 47
total blue 36 18 8 5 0 0 35 102
green 95 115 128 44 136 160 106 784
red 22 13 29 113 13 5 3 198
3 Irish and Scottish West Coast blue 16 14 9 6 2 0 13 60
green 6 6 22 15 24 35 10 118
red 1 3 1 16 0 0 0 21
Irish Sea blue 7 3 2 0 0 0 5 17
green 27 39 36 12 47 52 42 255
red 16 9 14 43 6 1 2 91
Celtic Sea blue 6 5 2 1 0 0 5 19
green 2 4 8 4 9 11 5 43
red 2 0 0 5 0 0 0 7
total blue 29 22 13 7 2 0 23 96
green 35 49 66 31 80 98 57 416
red 19 12 15 64 6 1 2 119
4 Northern Bay of Biscay blue 13 2 0 0 0 0 7 22
green 3 14 15 4 15 16 9 76
red 0 0 1 12 1 0 0 14
Iberian Sea blue 16 14 3 0 0 0 8 41
green 13 15 29 13 33 40 29 172
red 3 4 8 27 8 1 0 51
Gulf of Cadiz blue 1 0 0 0 0 0 0 1
green 0 1 1 0 1 1 1 5
red 0 0 0 1 0 0 0 1
total blue 30 16 3 0 0 0 15 64
green 16 30 45 17 49 57 39 253
red 3 4 9 40 9 1 0 66


Status summary (proportions)

Proportion of time series with each status by MIME and OSPAR region

OSPAR region MIME region status CB28 CB52 CB101 CB118 CB138 CB153 CB180 total
1 Barents Sea blue 33 38 11 34 22 0 38 25
green 67 62 89 33 78 100 62 70
red 0 0 0 33 0 0 0 5
Norwegian Sea blue 0 0 0 0 0 0 0 0
green 100 100 67 0 100 100 100 79
red 0 0 33 100 0 0 0 21
total blue 27 27 9 25 17 0 30 19
green 73 73 83 25 83 100 70 72
red 0 0 8 50 0 0 0 9
2 Norwegian Trench blue 26 22 20 12 0 0 36 16
green 70 74 72 36 96 100 64 73
red 4 4 8 52 4 0 0 11
Northern North Sea blue 3 0 0 0 0 0 3 1
green 76 93 78 26 97 100 97 79
red 21 7 22 74 3 0 0 20
Skagerrak and Kattegat blue 39 35 10 7 0 0 53 20
green 55 65 80 43 87 97 40 67
red 6 0 10 50 13 3 7 13
Southern North Sea blue 6 3 0 0 0 0 0 1
green 66 78 79 18 93 100 97 76
red 28 19 21 82 7 0 3 23
Channel blue 52 3 0 0 0 0 34 13
green 41 84 77 17 82 87 66 64
red 7 13 23 83 18 13 0 23
total blue 24 12 5 3 0 0 24 10
green 62 79 78 27 91 97 74 72
red 14 9 17 70 9 3 2 18
3 Irish and Scottish West Coast blue 70 61 28 16 8 0 57 30
green 26 26 69 41 92 100 43 59
red 4 13 3 43 0 0 0 11
Irish Sea blue 14 6 4 0 0 0 10 5
green 54 76 69 22 89 98 86 70
red 32 18 27 78 11 2 4 25
Celtic Sea blue 60 56 20 10 0 0 50 28
green 20 44 80 40 100 100 50 62
red 20 0 0 50 0 0 0 10
total blue 35 27 14 7 2 0 28 15
green 42 59 70 30 91 99 70 66
red 23 14 16 63 7 1 2 19
4 Northern Bay of Biscay blue 81 12 0 0 0 0 44 20
green 19 88 94 25 94 100 56 68
red 0 0 6 75 6 0 0 12
Iberian Sea blue 50 42 8 0 0 0 22 16
green 41 46 72 32 80 98 78 65
red 9 12 20 68 20 2 0 19
Gulf of Cadiz blue 100 0 0 0 0 0 0 14
green 0 100 100 0 100 100 100 72
red 0 0 0 100 0 0 0 14
total blue 61 32 5 0 0 0 28 17
green 33 60 79 30 84 98 72 66
red 6 8 16 70 16 2 0 17


MIME regional assessment - methods

Tabulating the number of time series with each status category by region provides a quick summary of the individual time series results. However, it does not provide an objective regional assessment of status. Similarly, tabulating the number of time series with an upward or downward trend does not provide an objective regional assessment of trend. This section describes how the individual time series results can by synthesised in a meta-analysis to assess both status and trend at the regional level.

Trends

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:

  • response: trend (yearly change in log concentration)
  • fixed model: region
  • random model: CB + region.CB + station + trend estimation variation + residual variation

The fixed model means that a trend is estimated for each region. Trends in the different CBs are assumed to be broadly similar, because inputs and control measures are likely to affect all CBs in a similar way. Each regional trend can thus be interpreted as the common trend in CB concentrations in that region (i.e. the trend averaged across all CBs).

The random model has five terms:

  • CB allows for variation in trend between CBs common to all regions
  • region.CB allows for additional variation in trend between CBs within regions
  • station allows for variation in trend between stations common to all CBs
  • trend estimation variation is the variance of the trend estimates from the individual time series analysis, assumed known and fixed
  • residual variation is the variation that cannot be explained by any of the fixed effects or the other random effects

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:

  • regions with at least three trend stations with good geographic spread. Three stations is considered the minimum required to provide some sort of evidence base at the regional level
  • CBs with trend information for at least three stations (over all regions): CBs are treated as random effects in the meta-anlaysis, so information about trends in one CB can be ‘borrowed’ from the trend information in the other CBs

Status

For a regional status assessment, the status of each time series is summarised by the difference between the estimated mean log concentration in the final monitoring year and the log assessment concentration. This ensures that status is always measured on the same scale, even though the assessment criterion might vary between CBs and time series. Essentially the same linear mixed model as for trends is then fitted:

  • response: status (mean log concentration - log assessment concentration)
  • fixed model: region
  • random model: CB + region.CB + station + status estimation variation + residual variation

where status estimation variation is the variation in the status estimates from the individual time series analysis, assumed known and fixed.

There are no restrictions on the time series used in the status meta-analysis based on the classification of the monitoring station; time series from baseline, representative and impacted stations are all included. However, the few time series with a non-parametric assessment of status must be excluded, because there is no summary measure of status to use in the mixed model.

Again, the meta-analysis is restricted to regions with at least three status stations with good geographic spread and to CBs with status information for at least three stations (over all regions).

Presentation

The results of both the trend and status regional assessments are back-transformed for presentation. The estimated regional trend is then interpreted as the percentage yearly change in concentration and the estimated regional status as the ratio of the mean regional concentration to the assessment concentration. To illustrate the latter, a value of 1 indicates that the mean regional concentration is equal to the assessment concentration; a value of 0.5 indicates that it is half the assessment concentration, and a value of 2 indicates that it is twice the assessment concentration.


Regional assessment - availability of time series

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 CB, and the cyan cirles are stations where there are only status assessments.

The following regions have an insufficient number or time series or spread of stations and are excluded from the regional assessment:

  • trend: Barents Sea, Gulf of Cadiz, Norwegian Sea
  • status: Gulf of Cadiz, Norwegian Sea


OSPAR region 1


OSPAR region 2


OSPAR region 3


OSPAR region 4


Regional trends

The first 4 tabs show:

  • Regional trends: estimates of the regional trend (averaged over CBs) with pointwise 95% confidence limits
  • Regional trends by CB: regional trend estimates for each CB with pointwise 95% confidence limits plotted by CB
  • Regional trends by region: regional trend estimates for each CB with pointwise 95% confidence limits plotted by biogeographic region
  • Individual time series: the trend estimates from the individual time series on which the regional assessment is based. The estimates from regions with insufficient geographic spread (and excluded from the meta-analysis) are also shown.
  • The symbols in all these plots have the following interpretation:

    • downward triangle: the mean concentration is significantly decreasing (p < 0.05)
    • circle: there is no change in mean concentration (p > 0.05)
    • upward triangle: the mean concentration is significantly increasing (p < 0.05)

    The final 2 tabs show the estimates of the regional trend (averaged over CBs) and the regional trend by CB.


    Regional trends


    Regional trends by CB


    Regional trends by region


    Individual time series


    Estimates by region

    This table shows the estimates of the regional trend:

    • trend: the estimated mean yearly change in log concentration across the region (multiplied by 100 for presentation)
    • se: the corresponding standard error
    • lower, upper: the corresponding pointwise 95% confidence limits
    • % yearly change: the estimated mean % yearly change in concentration across the region
    • %yc lower, %yc upper: the corresponding pointwise 95% confidence limits


    MIME region trend se lower upper % yearly change %yc lower %yc upper
    Norwegian Trench -4.39 1.32 -6.98 -1.80 -4.30 -6.75 -1.79
    Northern North Sea -4.34 1.07 -6.44 -2.24 -4.25 -6.24 -2.21
    Skagerrak and Kattegat -5.09 1.17 -7.38 -2.81 -4.97 -7.11 -2.77
    Southern North Sea -5.29 0.93 -7.12 -3.46 -5.15 -6.87 -3.40
    Channel -6.94 0.91 -8.73 -5.15 -6.70 -8.36 -5.02
    Irish and Scottish West Coast -7.96 1.38 -10.67 -5.25 -7.65 -10.12 -5.12
    Irish Sea -3.27 0.79 -4.82 -1.72 -3.22 -4.71 -1.71
    Celtic Sea -4.69 2.56 -9.70 0.32 -4.58 -9.25 0.32
    Northern Bay of Biscay -5.41 1.21 -7.77 -3.04 -5.26 -7.47 -3.00
    Iberian Sea -10.85 1.04 -12.88 -8.82 -10.28 -12.09 -8.44


    Estimates by region and CB

    This table shows the estimates of the regional trend by determinand:

    • trend: the estimated mean yearly change in log concentration across the region (multiplied by 100 for presentation)
    • se: the corresponding standard error
    • lower, upper: the corresponding pointwise 95% confidence limits
    • % yearly change: the estimated mean % yearly change in concentration across the region
    • %yc lower, %yc upper: the corresponding pointwise 95% confidence limits


    MIME region CB trend se lower upper % yearly change %yc lower %yc upper
    Norwegian Trench CB28 -5.54 1.45 -8.38 -2.70 -5.39 -8.04 -2.66
    CB52 -4.78 1.45 -7.62 -1.93 -4.67 -7.34 -1.91
    CB101 -4.69 1.37 -7.37 -2.01 -4.58 -7.11 -1.99
    CB118 -4.66 1.36 -7.33 -1.98 -4.55 -7.07 -1.96
    CB138 -3.71 1.36 -6.37 -1.05 -3.65 -6.17 -1.05
    CB153 -3.29 1.36 -5.95 -0.63 -3.24 -5.78 -0.63
    CB180 -4.09 1.42 -6.88 -1.31 -4.01 -6.65 -1.30
    Northern North Sea CB28 -7.76 1.72 -11.13 -4.39 -7.47 -10.53 -4.30
    CB52 -7.29 1.92 -11.05 -3.52 -7.03 -10.46 -3.46
    CB101 -4.11 1.36 -6.78 -1.44 -4.02 -6.55 -1.43
    CB118 -2.49 1.18 -4.79 -0.19 -2.46 -4.68 -0.19
    CB138 -4.00 1.10 -6.15 -1.84 -3.92 -5.96 -1.83
    CB153 -2.09 1.08 -4.21 0.03 -2.07 -4.12 0.03
    CB180 -2.64 1.27 -5.13 -0.16 -2.61 -5.00 -0.16
    Skagerrak and Kattegat CB28 -4.84 1.30 -7.39 -2.30 -4.73 -7.12 -2.27
    CB52 -4.41 1.28 -6.92 -1.91 -4.32 -6.69 -1.89
    CB101 -5.57 1.21 -7.94 -3.20 -5.42 -7.63 -3.15
    CB118 -6.35 1.20 -8.71 -3.99 -6.15 -8.34 -3.91
    CB138 -4.63 1.20 -6.98 -2.28 -4.52 -6.74 -2.25
    CB153 -4.69 1.20 -7.03 -2.34 -4.58 -6.79 -2.31
    CB180 -5.16 1.29 -7.70 -2.63 -5.03 -7.41 -2.59
    Southern North Sea CB28 -5.33 1.12 -7.53 -3.13 -5.19 -7.26 -3.08
    CB52 -3.90 1.08 -6.02 -1.78 -3.83 -5.84 -1.76
    CB101 -5.35 1.01 -7.33 -3.36 -5.21 -7.07 -3.31
    CB118 -5.90 1.00 -7.86 -3.93 -5.73 -7.56 -3.86
    CB138 -6.14 1.04 -8.18 -4.10 -5.95 -7.85 -4.02
    CB153 -4.54 0.98 -6.46 -2.61 -4.44 -6.26 -2.58
    CB180 -5.86 1.04 -7.89 -3.83 -5.69 -7.59 -3.76
    Channel CB28 -7.68 1.04 -9.72 -5.65 -7.40 -9.26 -5.49
    CB52 -5.29 1.07 -7.38 -3.19 -5.15 -7.12 -3.14
    CB101 -5.92 0.96 -7.80 -4.04 -5.75 -7.50 -3.96
    CB118 -6.15 0.95 -8.00 -4.29 -5.96 -7.69 -4.20
    CB138 -7.82 0.95 -9.67 -5.96 -7.52 -9.22 -5.79
    CB153 -6.89 0.93 -8.70 -5.07 -6.66 -8.34 -4.95
    CB180 -8.82 0.95 -10.69 -6.95 -8.44 -10.14 -6.72
    Irish and Scottish West Coast CB28 -11.05 1.82 -14.63 -7.48 -10.46 -13.61 -7.20
    CB52 -12.23 1.71 -15.58 -8.88 -11.51 -14.43 -8.50
    CB101 -10.90 1.64 -14.11 -7.70 -10.33 -13.16 -7.41
    CB118 -7.49 1.52 -10.48 -4.51 -7.22 -9.95 -4.41
    CB138 -6.29 1.53 -9.28 -3.30 -6.10 -8.86 -3.24
    CB153 -4.24 1.48 -7.15 -1.33 -4.15 -6.90 -1.32
    CB180 -3.53 1.73 -6.92 -0.13 -3.47 -6.69 -0.13
    Irish Sea CB28 -5.39 1.01 -7.36 -3.41 -5.24 -7.10 -3.35
    CB52 -4.79 1.02 -6.78 -2.80 -4.68 -6.56 -2.77
    CB101 -3.60 0.86 -5.28 -1.91 -3.53 -5.15 -1.89
    CB118 -3.07 0.82 -4.68 -1.46 -3.03 -4.58 -1.45
    CB138 -3.04 0.82 -4.65 -1.43 -2.99 -4.55 -1.42
    CB153 -1.60 0.81 -3.18 -0.01 -1.59 -3.13 -0.01
    CB180 -1.43 0.93 -3.25 0.39 -1.42 -3.20 0.39
    Celtic Sea CB28 -6.21 3.03 -12.16 -0.27 -6.03 -11.45 -0.27
    CB52 -5.72 3.00 -11.59 0.15 -5.56 -10.95 0.15
    CB101 -3.90 2.85 -9.48 1.68 -3.83 -9.05 1.69
    CB118 -4.18 2.85 -9.76 1.40 -4.10 -9.30 1.41
    CB138 -4.37 2.72 -9.71 0.96 -4.28 -9.25 0.97
    CB153 -2.70 2.73 -8.05 2.65 -2.66 -7.73 2.68
    CB180 -5.75 2.87 -11.38 -0.13 -5.59 -10.76 -0.13
    Northern Bay of Biscay CB28 -4.41 1.42 -7.19 -1.63 -4.32 -6.94 -1.62
    CB52 -4.27 1.33 -6.88 -1.66 -4.18 -6.65 -1.64
    CB101 -4.07 1.29 -6.59 -1.55 -3.99 -6.38 -1.54
    CB118 -3.93 1.31 -6.49 -1.36 -3.85 -6.29 -1.36
    CB138 -7.96 1.29 -10.50 -5.42 -7.65 -9.97 -5.28
    CB153 -5.01 1.26 -7.48 -2.55 -4.89 -7.20 -2.52
    CB180 -8.19 1.30 -10.74 -5.64 -7.86 -10.18 -5.49
    Iberian Sea CB28 -11.54 1.27 -14.02 -9.05 -10.90 -13.09 -8.65
    CB52 -13.95 1.24 -16.38 -11.52 -13.02 -15.11 -10.88
    CB101 -10.41 1.11 -12.58 -8.25 -9.89 -11.82 -7.91
    CB118 -9.20 1.11 -11.38 -7.02 -8.79 -10.76 -6.78
    CB138 -9.70 1.06 -11.79 -7.62 -9.25 -11.12 -7.34
    CB153 -9.13 1.07 -11.23 -7.04 -8.73 -10.62 -6.80
    CB180 -12.02 1.16 -14.28 -9.75 -11.32 -13.31 -9.29


    Regional status compared to the Environmental Assessment Criterion (EAC)

    The first 4 tabs show:

  • Regional status: estimates of the regional status (averaged over CBs) with pointwise upper one-sided 95% confidence limits
  • Regional status by CB: regional status estimates for each CB with pointwise upper one-sided 95% confidence limits plotted by CB
  • Regional status by region: regional status estimates for each CB with pointwise upper one-sided 95% confidence limits plotted by biogeographic region
  • Individual time series: the status estimates from the individual time series on which the regional assessment is based. The estimates from regions with insufficient geographic spread (and excluded from the meta-analysis) are also shown.
  • The symbols in all the plots have the following interpretation:

    • blue: the mean concentration is significantly (p < 0.05) below the Background Assessment Concentration (BAC)
    • green: the mean concentration is significantly (p < 0.05) below the EAC
    • red: the estimate of the mean concentration is not significantly below the EAC

    Note that to see why some points are coloured blue, it is necessary to look ahead to the next section, where status is compared to the BAC. Unfortunately, it isn’t easy to present the assessment of status relative to the EAC with the assessment of status relative to the BAC because the ratio of the BAC to the EAC can vary between CBs, between regions and, for biota, between species.

    The final 2 tabs show the estimates of the regional status (averaged over CBs) and the regional status by CB.


    Regional status


    Regional status by CB


    Regional status by region


    Individual time series


    Estimates by region

    This table shows the estimates of the regional status:

    • status: the estimated mean log concentration minus the log EAC
    • se: the corresponding standard error
    • upper: the corresponding pointwise upper one-sided 95% confidence limit
    • concentration: the estimated mean concentration relative to the EAC
    • conc upper: the corresponding pointwise upper one-sided 95% confidence limit


    MIME region status se upper concentration conc upper
    Barents Sea -3.32 0.56 -2.40 0.04 0.09
    Norwegian Trench -2.49 0.50 -1.67 0.08 0.19
    Northern North Sea -2.35 0.48 -1.55 0.10 0.21
    Skagerrak and Kattegat -2.33 0.49 -1.53 0.10 0.22
    Southern North Sea -1.86 0.49 -1.06 0.16 0.35
    Channel -1.81 0.49 -1.00 0.16 0.37
    Irish and Scottish West Coast -3.55 0.49 -2.75 0.03 0.06
    Irish Sea -1.81 0.47 -1.03 0.16 0.36
    Celtic Sea -2.83 0.54 -1.93 0.06 0.14
    Northern Bay of Biscay -2.34 0.52 -1.49 0.10 0.22
    Iberian Sea -2.39 0.48 -1.60 0.09 0.20


    Estimates by region and CB

    This table shows the estimates of regional status by determinand:

    • status: the estimated mean log concentration minus the log EAC
    • se: the corresponding standard error
    • upper: the corresponding pointwise upper one-sided 95% confidence limit
    • concentration: the estimated mean concentration relative to the EAC
    • conc upper: the corresponding pointwise upper one-sided 95% confidence limit


    MIME region CB status se upper concentration conc upper
    Barents Sea CB28 -3.82 0.37 -3.21 0.02 0.04
    CB52 -3.67 0.37 -3.06 0.03 0.05
    CB101 -3.02 0.36 -2.43 0.05 0.09
    CB118 -1.07 0.35 -0.50 0.34 0.61
    CB138 -2.91 0.35 -2.34 0.05 0.10
    CB153 -4.24 0.35 -3.67 0.01 0.03
    CB180 -4.54 0.37 -3.93 0.01 0.02
    Norwegian Trench CB28 -2.98 0.22 -2.62 0.05 0.07
    CB52 -2.80 0.22 -2.45 0.06 0.09
    CB101 -2.00 0.21 -1.66 0.14 0.19
    CB118 -0.31 0.21 0.03 0.73 1.03
    CB138 -2.10 0.21 -1.76 0.12 0.17
    CB153 -3.45 0.21 -3.11 0.03 0.04
    CB180 -3.78 0.22 -3.42 0.02 0.03
    Northern North Sea CB28 -3.01 0.20 -2.68 0.05 0.07
    CB52 -2.72 0.20 -2.39 0.07 0.09
    CB101 -1.80 0.18 -1.51 0.16 0.22
    CB118 -0.16 0.17 0.12 0.85 1.13
    CB138 -2.04 0.17 -1.75 0.13 0.17
    CB153 -3.33 0.17 -3.06 0.04 0.05
    CB180 -3.37 0.19 -3.06 0.03 0.05
    Skagerrak and Kattegat CB28 -2.65 0.19 -2.33 0.07 0.10
    CB52 -2.40 0.19 -2.08 0.09 0.12
    CB101 -1.83 0.19 -1.52 0.16 0.22
    CB118 -0.14 0.19 0.17 0.87 1.18
    CB138 -1.97 0.19 -1.66 0.14 0.19
    CB153 -3.36 0.19 -3.05 0.03 0.05
    CB180 -3.99 0.19 -3.67 0.02 0.03
    Southern North Sea CB28 -2.66 0.19 -2.35 0.07 0.09
    CB52 -2.23 0.18 -1.93 0.11 0.15
    CB101 -1.26 0.18 -0.96 0.28 0.38
    CB118 0.29 0.18 0.59 1.34 1.80
    CB138 -1.41 0.18 -1.11 0.25 0.33
    CB153 -2.60 0.18 -2.31 0.07 0.10
    CB180 -3.15 0.18 -2.85 0.04 0.06
    Channel CB28 -2.73 0.20 -2.40 0.07 0.09
    CB52 -1.86 0.20 -1.53 0.16 0.22
    CB101 -0.93 0.19 -0.62 0.39 0.54
    CB118 0.63 0.19 0.95 1.88 2.58
    CB138 -1.31 0.19 -1.00 0.27 0.37
    CB153 -2.46 0.19 -2.15 0.09 0.12
    CB180 -3.99 0.19 -3.67 0.02 0.03
    Irish and Scottish West Coast CB28 -3.96 0.21 -3.62 0.02 0.03
    CB52 -3.66 0.20 -3.33 0.03 0.04
    CB101 -3.07 0.19 -2.75 0.05 0.06
    CB118 -1.21 0.18 -0.91 0.30 0.40
    CB138 -3.36 0.19 -3.05 0.03 0.05
    CB153 -4.53 0.18 -4.23 0.01 0.01
    CB180 -5.04 0.20 -4.71 0.01 0.01
    Irish Sea CB28 -2.13 0.15 -1.88 0.12 0.15
    CB52 -1.97 0.15 -1.73 0.14 0.18
    CB101 -1.37 0.14 -1.13 0.25 0.32
    CB118 0.31 0.14 0.54 1.36 1.72
    CB138 -1.67 0.14 -1.44 0.19 0.24
    CB153 -2.80 0.14 -2.56 0.06 0.08
    CB180 -3.06 0.15 -2.82 0.05 0.06
    Celtic Sea CB28 -3.46 0.34 -2.90 0.03 0.06
    CB52 -3.15 0.34 -2.59 0.04 0.07
    CB101 -2.36 0.33 -1.82 0.09 0.16
    CB118 -0.63 0.32 -0.10 0.53 0.90
    CB138 -2.39 0.32 -1.86 0.09 0.16
    CB153 -3.46 0.31 -2.95 0.03 0.05
    CB180 -4.36 0.33 -3.81 0.01 0.02
    Northern Bay of Biscay CB28 -3.07 0.27 -2.62 0.05 0.07
    CB52 -2.48 0.26 -2.05 0.08 0.13
    CB101 -1.51 0.26 -1.08 0.22 0.34
    CB118 -0.04 0.26 0.39 0.96 1.48
    CB138 -2.08 0.26 -1.65 0.12 0.19
    CB153 -2.71 0.26 -2.28 0.07 0.10
    CB180 -4.49 0.26 -4.06 0.01 0.02
    Iberian Sea CB28 -3.27 0.18 -2.97 0.04 0.05
    CB52 -3.31 0.18 -3.01 0.04 0.05
    CB101 -1.80 0.16 -1.53 0.17 0.22
    CB118 -0.17 0.16 0.10 0.85 1.11
    CB138 -1.59 0.16 -1.32 0.20 0.27
    CB153 -2.72 0.16 -2.45 0.07 0.09
    CB180 -3.89 0.17 -3.61 0.02 0.03


    Regional status compared to the Background Assessment Concentration (BAC)

    The first 4 tabs show:

  • Regional status: estimates of the regional status (averaged over CBs) with pointwise upper one-sided 95% confidence limits
  • Regional status by CB: regional status estimates for each CB with pointwise upper one-sided 95% confidence limits plotted by CB
  • Regional status by region: regional status estimates for each CB with pointwise upper one-sided 95% confidence limits plotted by biogeographic region
  • Individual time series: the status estimates from the individual time series on which the regional assessment is based. The estimates from regions with insufficient geographic spread (and excluded from the meta-analysis) are also shown.
  • The symbols in all the plots have the following interpretation:

    • blue: the mean concentration is significantly (p < 0.05) below the BAC
    • green: the mean concentration is significantly (p < 0.05) below the Environmental Assessment Criterion (EAC)
    • red: the estimate of the mean concentration is not significantly below the EAC

    The final 2 tabs show the estimates of the regional status (averaged over CBs) and the regional status by CB.


    Regional status


    Regional status by CB


    Regional status by region


    Individual time series


    Estimates by region

    This table shows the estimates of the regional status:

    • status: the estimated mean log concentration minus the log EAC
    • se: the corresponding standard error
    • upper: the corresponding pointwise upper one-sided 95% confidence limit
    • concentration: the estimated mean concentration relative to the EAC
    • conc upper: the corresponding pointwise upper one-sided 95% confidence limit


    MIME region status se upper concentration conc upper
    Barents Sea 1.44 0.68 2.56 4.22 12.96
    Norwegian Trench 1.68 0.52 2.54 5.35 12.67
    Northern North Sea 1.38 0.49 2.18 3.98 8.86
    Skagerrak and Kattegat 1.52 0.50 2.35 4.57 10.47
    Southern North Sea 2.63 0.50 3.44 13.85 31.26
    Channel 1.61 0.51 2.44 4.98 11.48
    Irish and Scottish West Coast -0.21 0.50 0.61 0.81 1.83
    Irish Sea 2.09 0.47 2.86 8.10 17.44
    Celtic Sea 0.70 0.64 1.75 2.00 5.77
    Northern Bay of Biscay 0.84 0.58 1.79 2.32 6.01
    Iberian Sea 0.80 0.48 1.60 2.23 4.95


    Estimates by region and CB

    This table shows the estimates of regional status by determinand:

    • status: the estimated mean log concentration minus the log BAC
    • se: the corresponding standard error
    • upper: the corresponding pointwise upper one-sided 95% confidence limit
    • concentration: the estimated mean concentration relative to the BAC
    • conc upper: the corresponding pointwise upper one-sided 95% confidence limit


    MIME region CB status se upper concentration conc upper
    Barents Sea CB28 -0.11 0.57 0.82 0.90 2.28
    CB52 0.68 0.57 1.62 1.98 5.05
    CB101 1.43 0.56 2.36 4.17 10.54
    CB118 1.75 0.56 2.66 5.74 14.30
    CB138 2.49 0.55 3.40 12.06 30.03
    CB153 2.72 0.55 3.63 15.20 37.84
    CB180 1.12 0.57 2.06 3.05 7.81
    Norwegian Trench CB28 0.11 0.34 0.67 1.12 1.95
    CB52 0.88 0.34 1.44 2.41 4.21
    CB101 1.81 0.33 2.35 6.09 10.53
    CB118 1.93 0.33 2.48 6.91 11.96
    CB138 2.72 0.33 3.27 15.21 26.31
    CB153 2.95 0.33 3.50 19.09 33.00
    CB180 1.33 0.34 1.89 3.78 6.60
    Northern North Sea CB28 -0.33 0.28 0.13 0.72 1.14
    CB52 0.51 0.29 0.98 1.67 2.66
    CB101 1.56 0.27 2.00 4.75 7.41
    CB118 1.64 0.27 2.08 5.16 8.01
    CB138 2.35 0.27 2.79 10.47 16.26
    CB153 2.64 0.26 3.07 13.95 21.56
    CB180 1.31 0.28 1.76 3.70 5.84
    Skagerrak and Kattegat CB28 0.13 0.30 0.62 1.13 1.87
    CB52 0.94 0.30 1.43 2.55 4.20
    CB101 1.67 0.30 2.16 5.29 8.65
    CB118 1.80 0.30 2.30 6.07 9.93
    CB138 2.55 0.30 3.04 12.76 20.86
    CB153 2.73 0.30 3.22 15.37 25.13
    CB180 0.82 0.30 1.32 2.28 3.75
    Southern North Sea CB28 0.77 0.29 1.24 2.16 3.47
    CB52 1.83 0.29 2.30 6.22 9.96
    CB101 2.92 0.28 3.38 18.46 29.43
    CB118 2.82 0.28 3.28 16.74 26.70
    CB138 3.74 0.28 4.21 42.04 67.17
    CB153 4.08 0.28 4.55 59.38 94.44
    CB180 2.24 0.29 2.71 9.41 15.06
    Channel CB28 -0.42 0.31 0.09 0.66 1.10
    CB52 0.97 0.31 1.49 2.65 4.42
    CB101 2.07 0.31 2.58 7.95 13.15
    CB118 2.17 0.30 2.67 8.73 14.41
    CB138 2.78 0.31 3.28 16.05 26.54
    CB153 3.22 0.30 3.72 25.14 41.46
    CB180 0.45 0.31 0.95 1.56 2.59
    Irish and Scottish West Coast CB28 -1.69 0.30 -1.20 0.18 0.30
    CB52 -0.88 0.30 -0.39 0.42 0.68
    CB101 -0.13 0.29 0.35 0.87 1.41
    CB118 0.22 0.29 0.69 1.24 1.99
    CB138 0.64 0.29 1.12 1.90 3.05
    CB153 1.06 0.29 1.53 2.88 4.60
    CB180 -0.68 0.30 -0.20 0.51 0.82
    Irish Sea CB28 0.71 0.23 1.09 2.03 2.97
    CB52 1.44 0.23 1.82 4.22 6.15
    CB101 2.18 0.23 2.56 8.87 12.89
    CB118 2.29 0.23 2.66 9.89 14.32
    CB138 2.89 0.23 3.26 17.98 26.04
    CB153 3.34 0.23 3.71 28.11 40.71
    CB180 1.79 0.23 2.17 6.01 8.76
    Celtic Sea CB28 -1.01 0.52 -0.15 0.36 0.86
    CB52 -0.18 0.52 0.67 0.83 1.95
    CB101 0.78 0.51 1.62 2.18 5.05
    CB118 1.00 0.51 1.83 2.71 6.26
    CB138 1.80 0.51 2.63 6.05 13.92
    CB153 2.31 0.50 3.13 10.07 22.98
    CB180 0.17 0.51 1.02 1.19 2.76
    Northern Bay of Biscay CB28 -0.98 0.42 -0.28 0.38 0.75
    CB52 0.09 0.42 0.78 1.10 2.19
    CB101 1.25 0.42 1.93 3.48 6.91
    CB118 1.27 0.42 1.96 3.57 7.10
    CB138 1.78 0.42 2.47 5.91 11.78
    CB153 2.76 0.42 3.44 15.77 31.28
    CB180 -0.27 0.42 0.42 0.76 1.52
    Iberian Sea CB28 -1.19 0.27 -0.74 0.31 0.48
    CB52 -0.72 0.27 -0.28 0.48 0.76
    CB101 0.97 0.26 1.40 2.65 4.07
    CB118 1.15 0.26 1.58 3.14 4.83
    CB138 2.29 0.26 2.72 9.87 15.11
    CB153 2.76 0.26 3.19 15.86 24.31
    CB180 0.36 0.26 0.80 1.44 2.22


    CB profiles

    The profile of concentrations across CBs 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:

    • response: mean log concentration
    • fixed model: region
    • random model: CB + region.CB + station + estimation variation + residual variation

    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 CB concentration profiles by region are shown below with pointwise 95% confidence limits. The units are ug/kg ww.