MIME regional assessment of status and trends in PAH 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 PAH concentrations in biota, where the PAHs are PA, ANT, FLU, PYR, BAA, CHR, BAP, BGHIP, ICDP. 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 PAH 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 78 of 1753 PAH 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 PAHs. The magenta circles are stations where there is a trend assessment for at least one PAH, 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 PAH 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


PA


ANT


FLU


PYR


BAA


CHR


BAP


BGHIP


ICDP


Trend summary (numbers)

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

OSPAR region MIME region status PA ANT FLU PYR BAA CHR BAP BGHIP ICDP total
1 Barents Sea upward trend 0 0 0 0 0 0 0 0 0 0
no trend 1 1 1 1 0 1 0 0 0 5
downward trend 0 0 0 0 1 0 1 1 1 4
Norwegian Sea upward trend 0 0 0 0 0 0 0 0 0 0
no trend 2 1 1 1 1 1 1 1 1 10
downward trend 1 0 2 2 2 2 1 2 1 13
total upward trend 0 0 0 0 0 0 0 0 0 0
no trend 3 2 2 2 1 2 1 1 1 15
downward trend 1 0 2 2 3 2 2 3 2 17
2 Norwegian Trench upward trend 0 0 0 0 0 0 0 0 0 0
no trend 1 0 0 0 0 0 0 0 0 1
downward trend 1 2 2 2 2 2 2 2 2 17
Northern North Sea upward trend 1 0 4 1 1 0 0 0 0 7
no trend 26 13 22 23 8 13 1 8 8 122
downward trend 3 1 1 2 2 0 0 2 0 11
Skagerrak and Kattegat upward trend 0 0 0 0 1 1 0 0 0 2
no trend 10 7 10 10 9 9 7 10 4 76
downward trend 3 1 3 3 2 3 0 0 1 16
Southern North Sea upward trend 0 0 0 0 0 0 0 0 0 0
no trend 9 5 6 6 7 5 5 7 6 56
downward trend 4 3 4 3 5 3 3 2 2 29
Channel upward trend 0 0 0 0 0 0 2 0 0 2
no trend 4 8 13 16 15 14 17 23 24 134
downward trend 20 6 12 9 10 10 1 1 0 69
total upward trend 1 0 4 1 2 1 2 0 0 11
no trend 50 33 51 55 39 41 30 48 42 389
downward trend 31 13 22 19 21 18 6 7 5 142
3 Irish and Scottish West Coast upward trend 0 0 0 0 0 0 0 0 0 0
no trend 9 1 10 10 2 3 0 2 4 41
downward trend 2 0 2 1 2 2 3 2 0 14
Irish Sea upward trend 4 1 3 1 1 0 0 0 0 10
no trend 14 8 17 16 6 8 3 5 8 85
downward trend 3 0 1 3 4 5 2 5 1 24
Celtic Sea upward trend 0 0 0 0 0 0 0 0 0 0
no trend 1 1 0 0 0 0 1 1 1 5
downward trend 0 0 1 1 1 1 0 0 0 4
total upward trend 4 1 3 1 1 0 0 0 0 10
no trend 24 10 27 26 8 11 4 8 13 131
downward trend 5 0 4 5 7 8 5 7 1 42
4 Northern Bay of Biscay upward trend 0 0 0 0 0 0 4 0 0 4
no trend 6 6 11 12 13 12 10 15 14 99
downward trend 9 1 4 3 2 3 1 0 1 24
Iberian Sea upward trend 0 1 0 0 0 0 1 0 0 2
no trend 20 13 15 14 17 16 19 18 16 148
downward trend 3 7 8 9 6 7 3 5 5 53
total upward trend 0 1 0 0 0 0 5 0 0 6
no trend 26 19 26 26 30 28 29 33 30 247
downward trend 12 8 12 12 8 10 4 5 6 77


Trend summary (proportions)

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

OSPAR region MIME region status PA ANT FLU PYR BAA CHR BAP BGHIP ICDP total
1 Barents Sea upward trend 0 0 0 0 0 0 0 0 0 0
no trend 100 100 100 100 0 100 0 0 0 56
downward trend 0 0 0 0 100 0 100 100 100 44
Norwegian Sea upward trend 0 0 0 0 0 0 0 0 0 0
no trend 67 100 33 33 33 33 50 33 50 43
downward trend 33 0 67 67 67 67 50 67 50 57
total upward trend 0 0 0 0 0 0 0 0 0 0
no trend 75 100 50 50 25 50 33 25 33 47
downward trend 25 0 50 50 75 50 67 75 67 53
2 Norwegian Trench upward trend 0 0 0 0 0 0 0 0 0 0
no trend 50 0 0 0 0 0 0 0 0 6
downward trend 50 100 100 100 100 100 100 100 100 94
Northern North Sea upward trend 3 0 15 4 9 0 0 0 0 5
no trend 87 93 81 88 73 100 100 80 100 87
downward trend 10 7 4 8 18 0 0 20 0 8
Skagerrak and Kattegat upward trend 0 0 0 0 8 8 0 0 0 2
no trend 77 88 77 77 75 69 100 100 80 81
downward trend 23 12 23 23 17 23 0 0 20 17
Southern North Sea upward trend 0 0 0 0 0 0 0 0 0 0
no trend 69 62 60 67 58 62 62 78 75 66
downward trend 31 38 40 33 42 38 38 22 25 34
Channel upward trend 0 0 0 0 0 0 10 0 0 1
no trend 17 57 52 64 60 58 85 96 100 65
downward trend 83 43 48 36 40 42 5 4 0 34
total upward trend 1 0 5 2 3 2 5 0 0 2
no trend 61 72 66 73 63 68 79 87 89 72
downward trend 38 28 29 25 34 30 16 13 11 26
3 Irish and Scottish West Coast upward trend 0 0 0 0 0 0 0 0 0 0
no trend 82 100 83 91 50 60 0 50 100 75
downward trend 18 0 17 9 50 40 100 50 0 25
Irish Sea upward trend 19 11 14 5 9 0 0 0 0 8
no trend 67 89 81 80 55 62 60 50 89 72
downward trend 14 0 5 15 36 38 40 50 11 20
Celtic Sea upward trend 0 0 0 0 0 0 0 0 0 0
no trend 100 100 0 0 0 0 100 100 100 56
downward trend 0 0 100 100 100 100 0 0 0 44
total upward trend 12 9 9 3 6 0 0 0 0 5
no trend 73 91 79 81 50 58 44 53 93 72
downward trend 15 0 12 16 44 42 56 47 7 23
4 Northern Bay of Biscay upward trend 0 0 0 0 0 0 27 0 0 3
no trend 40 86 73 80 87 80 66 100 93 78
downward trend 60 14 27 20 13 20 7 0 7 19
Iberian Sea upward trend 0 5 0 0 0 0 4 0 0 1
no trend 87 62 65 61 74 70 83 78 76 73
downward trend 13 33 35 39 26 30 13 22 24 26
total upward trend 0 3 0 0 0 0 13 0 0 2
no trend 68 68 68 68 79 74 76 87 83 75
downward trend 32 29 32 32 21 26 11 13 17 23


Status summary (numbers)

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

OSPAR region MIME region status PA ANT FLU PYR BAA CHR BAP BGHIP ICDP total
1 Barents Sea blue 1 0 1 0 0 1 0 0 0 3
green 1 2 0 1 1 0 2 2 0 9
orange 0 0 0 0 0 1 0 0 2 3
red 0 0 1 1 1 0 0 0 0 3
Norwegian Sea blue 0 0 1 1 0 1 0 1 0 4
green 3 3 1 1 2 0 3 2 0 15
orange 0 0 0 0 0 2 0 0 3 5
red 0 0 1 1 1 0 0 0 0 3
total blue 1 0 2 1 0 2 0 1 0 7
green 4 5 1 2 3 0 5 4 0 24
orange 0 0 0 0 0 3 0 0 5 8
red 0 0 2 2 2 0 0 0 0 6
2 Norwegian Trench blue 0 0 0 0 0 0 0 0 0 0
green 2 2 2 2 2 0 2 2 0 14
orange 0 0 0 0 0 2 0 0 2 4
red 0 0 0 0 0 0 0 0 0 0
Northern North Sea blue 0 0 0 0 0 0 0 0 0 0
green 35 23 28 25 25 0 6 19 0 161
orange 0 0 0 0 0 33 0 0 17 50
red 0 1 5 8 3 0 0 1 0 18
Skagerrak and Kattegat blue 2 0 2 2 1 4 2 0 0 13
green 15 14 12 12 13 0 14 14 0 94
orange 0 0 0 0 0 13 0 0 14 27
red 0 0 3 3 3 0 0 1 0 10
Southern North Sea blue 0 0 0 0 0 0 0 0 0 0
green 14 13 11 12 14 0 11 13 0 88
orange 0 0 0 0 0 14 0 0 9 23
red 1 0 1 0 0 0 1 0 0 3
Channel blue 7 0 2 2 4 8 6 1 4 34
green 18 25 21 19 20 0 19 24 0 146
orange 0 0 0 0 0 17 0 0 21 38
red 0 0 2 4 1 0 0 0 0 7
total blue 9 0 4 4 5 12 8 1 4 47
green 84 77 74 70 74 0 52 72 0 503
orange 0 0 0 0 0 79 0 0 63 142
red 1 1 11 15 7 0 1 2 0 38
3 Irish and Scottish West Coast blue 1 0 2 2 1 5 2 0 1 14
green 21 11 21 20 14 0 6 13 0 106
orange 0 0 0 0 0 11 0 0 12 23
red 0 0 0 0 0 0 0 0 0 0
Irish Sea blue 0 0 0 0 0 1 0 0 0 1
green 32 30 22 21 25 0 20 28 0 178
orange 0 0 0 0 0 29 0 0 26 55
red 0 1 8 9 6 0 1 4 0 29
Celtic Sea blue 0 0 1 0 0 3 1 1 2 8
green 6 6 4 4 4 0 4 4 0 32
orange 0 0 0 0 0 3 0 0 3 6
red 0 0 0 0 1 0 1 1 0 3
total blue 1 0 3 2 1 9 3 1 3 23
green 59 47 47 45 43 0 30 45 0 316
orange 0 0 0 0 0 43 0 0 41 84
red 0 1 8 9 7 0 2 5 0 32
4 Northern Bay of Biscay blue 5 0 3 0 1 2 1 0 1 13
green 11 16 13 16 15 0 15 16 0 102
orange 0 0 0 0 0 14 0 0 15 29
red 0 0 0 0 0 0 0 0 0 0
Iberian Sea blue 7 0 13 8 6 6 4 5 9 58
green 35 33 27 32 29 0 33 31 0 220
orange 0 0 0 0 0 34 0 0 29 63
red 0 1 2 2 3 0 1 1 0 10
Gulf of Cadiz blue 0 0 1 0 0 1 0 0 0 2
green 3 0 2 3 0 0 0 0 0 8
orange 0 0 0 0 0 1 0 0 0 1
red 0 0 0 0 0 0 0 0 0 0
total blue 12 0 17 8 7 9 5 5 10 73
green 49 49 42 51 44 0 48 47 0 330
orange 0 0 0 0 0 49 0 0 44 93
red 0 1 2 2 3 0 1 1 0 10


Status summary (proportions)

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

OSPAR region MIME region status PA ANT FLU PYR BAA CHR BAP BGHIP ICDP total
1 Barents Sea blue 50 0 50 0 0 50 0 0 0 16
green 50 100 0 50 50 0 100 100 0 50
orange 0 0 0 0 0 50 0 0 100 17
red 0 0 50 50 50 0 0 0 0 17
Norwegian Sea blue 0 0 34 34 0 33 0 33 0 15
green 100 100 33 33 67 0 100 67 0 56
orange 0 0 0 0 0 67 0 0 100 18
red 0 0 33 33 33 0 0 0 0 11
total blue 20 0 40 20 0 40 0 20 0 16
green 80 100 20 40 60 0 100 80 0 53
orange 0 0 0 0 0 60 0 0 100 18
red 0 0 40 40 40 0 0 0 0 13
2 Norwegian Trench blue 0 0 0 0 0 0 0 0 0 0
green 100 100 100 100 100 0 100 100 0 78
orange 0 0 0 0 0 100 0 0 100 22
red 0 0 0 0 0 0 0 0 0 0
Northern North Sea blue 0 0 0 0 0 0 0 0 0 0
green 100 96 85 76 89 0 100 95 0 70
orange 0 0 0 0 0 100 0 0 100 22
red 0 4 15 24 11 0 0 5 0 8
Skagerrak and Kattegat blue 12 0 12 12 6 24 12 0 0 9
green 88 100 70 70 76 0 88 93 0 65
orange 0 0 0 0 0 76 0 0 100 19
red 0 0 18 18 18 0 0 7 0 7
Southern North Sea blue 0 0 0 0 0 0 0 0 0 0
green 93 100 92 100 100 0 92 100 0 77
orange 0 0 0 0 0 100 0 0 100 20
red 7 0 8 0 0 0 8 0 0 3
Channel blue 28 0 8 8 16 32 24 4 16 15
green 72 100 84 76 80 0 76 96 0 65
orange 0 0 0 0 0 68 0 0 84 17
red 0 0 8 16 4 0 0 0 0 3
total blue 10 0 5 4 6 13 13 1 6 6
green 89 99 83 79 86 0 85 96 0 69
orange 0 0 0 0 0 87 0 0 94 20
red 1 1 12 17 8 0 2 3 0 5
3 Irish and Scottish West Coast blue 5 0 9 9 7 31 25 0 8 10
green 95 100 91 91 93 0 75 100 0 74
orange 0 0 0 0 0 69 0 0 92 16
red 0 0 0 0 0 0 0 0 0 0
Irish Sea blue 0 0 0 0 0 3 0 0 0 0
green 100 97 73 70 81 0 95 88 0 68
orange 0 0 0 0 0 97 0 0 100 21
red 0 3 27 30 19 0 5 12 0 11
Celtic Sea blue 0 0 20 0 0 50 16 16 40 17
green 100 100 80 100 80 0 67 67 0 65
orange 0 0 0 0 0 50 0 0 60 12
red 0 0 0 0 20 0 17 17 0 6
total blue 2 0 5 4 2 17 8 2 7 5
green 98 98 81 80 84 0 86 88 0 69
orange 0 0 0 0 0 83 0 0 93 19
red 0 2 14 16 14 0 6 10 0 7
4 Northern Bay of Biscay blue 31 0 19 0 6 12 6 0 6 9
green 69 100 81 100 94 0 94 100 0 71
orange 0 0 0 0 0 88 0 0 94 20
red 0 0 0 0 0 0 0 0 0 0
Iberian Sea blue 17 0 31 19 16 15 10 13 24 16
green 83 97 64 76 76 0 87 84 0 63
orange 0 0 0 0 0 85 0 0 76 18
red 0 3 5 5 8 0 3 3 0 3
Gulf of Cadiz blue 0 33 0 50 18
green 100 67 100 0 73
orange 0 0 0 50 9
red 0 0 0 0 0
total blue 20 0 28 13 13 16 9 9 19 15
green 80 98 69 84 81 0 89 89 0 65
orange 0 0 0 0 0 84 0 0 81 18
red 0 2 3 3 6 0 2 2 0 2


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: PAH + region.PAH + station + trend estimation variation + residual variation

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

The random model has five terms:

  • PAH allows for variation in trend between PAHs common to all regions
  • region.PAH allows for additional variation in trend between PAHs within regions
  • station allows for variation in trend between stations common to all PAHs
  • 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
  • PAHs with trend information for at least three stations (over all regions): PAHs are treated as random effects in the meta-anlaysis, so information about trends in one PAH can be ‘borrowed’ from the trend information in the other PAHs

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 PAHs 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: PAH + region.PAH + 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 PAHs 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 PAH, 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: Norwegian Sea
  • status: Barents Sea, Norwegian Sea, Norwegian Trench


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 PAHs) with pointwise 95% confidence limits
  • Regional trends by PAH: regional trend estimates for each PAH with pointwise 95% confidence limits plotted by PAH
  • Regional trends by region: regional trend estimates for each PAH 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 PAHs) and the regional trend by PAH.


    Regional trends


    Regional trends by PAH


    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
    Northern North Sea -0.89 1.12 -3.08 1.31 -0.88 -3.04 1.32
    Skagerrak and Kattegat -2.95 2.31 -7.48 1.58 -2.91 -7.20 1.59
    Southern North Sea -5.81 1.46 -8.67 -2.95 -5.64 -8.31 -2.91
    Channel -3.21 0.95 -5.08 -1.33 -3.15 -4.95 -1.33
    Irish and Scottish West Coast -4.85 1.66 -8.11 -1.59 -4.73 -7.79 -1.58
    Irish Sea -1.48 1.17 -3.76 0.81 -1.47 -3.69 0.81
    Northern Bay of Biscay -1.37 1.22 -3.76 1.01 -1.36 -3.69 1.02
    Iberian Sea -6.73 1.03 -8.76 -4.71 -6.51 -8.39 -4.60


    Estimates by region and PAH

    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 PAH trend se lower upper % yearly change %yc lower %yc upper
    Northern North Sea PA -3.39 1.20 -5.75 -1.03 -3.33 -5.59 -1.02
    ANT 0.40 1.67 -2.88 3.68 0.40 -2.84 3.75
    FLU 1.31 1.20 -1.05 3.67 1.32 -1.04 3.73
    PYR -0.80 1.18 -3.11 1.52 -0.79 -3.07 1.53
    BAA -1.58 1.85 -5.20 2.04 -1.57 -5.07 2.07
    CHR -2.35 1.65 -5.59 0.88 -2.33 -5.44 0.88
    BAP -0.49 2.53 -5.44 4.46 -0.49 -5.29 4.56
    BGHIP -1.05 1.78 -4.53 2.43 -1.04 -4.43 2.46
    ICDP -0.03 2.26 -4.46 4.39 -0.03 -4.36 4.49
    Skagerrak and Kattegat PA -3.91 2.63 -9.07 1.26 -3.83 -8.67 1.26
    ANT -2.13 2.75 -7.53 3.27 -2.11 -7.25 3.32
    FLU -3.13 2.84 -8.70 2.44 -3.08 -8.33 2.47
    PYR -5.04 2.71 -10.36 0.27 -4.92 -9.84 0.27
    BAA -1.49 2.72 -6.82 3.84 -1.48 -6.59 3.92
    CHR -1.30 2.72 -6.63 4.03 -1.30 -6.42 4.11
    BAP -1.69 2.83 -7.23 3.85 -1.68 -6.98 3.93
    BGHIP -3.55 3.02 -9.46 2.36 -3.49 -9.03 2.39
    ICDP -4.30 3.11 -10.39 1.79 -4.21 -9.87 1.81
    Southern North Sea PA -6.75 1.67 -10.02 -3.49 -6.53 -9.53 -3.43
    ANT -4.82 1.79 -8.33 -1.32 -4.71 -7.99 -1.31
    FLU -6.48 1.72 -9.85 -3.11 -6.28 -9.38 -3.07
    PYR -6.40 1.72 -9.76 -3.03 -6.20 -9.30 -2.99
    BAA -6.22 1.70 -9.56 -2.88 -6.03 -9.12 -2.84
    CHR -6.04 1.71 -9.39 -2.70 -5.87 -8.96 -2.66
    BAP -5.99 1.73 -9.38 -2.60 -5.82 -8.96 -2.57
    BGHIP -4.96 1.73 -8.35 -1.57 -4.83 -8.01 -1.55
    ICDP -4.62 1.77 -8.09 -1.15 -4.52 -7.77 -1.14
    Channel PA -6.45 1.09 -8.58 -4.32 -6.25 -8.22 -4.23
    ANT -5.38 1.38 -8.10 -2.67 -5.24 -7.78 -2.64
    FLU -3.97 1.05 -6.03 -1.90 -3.89 -5.85 -1.88
    PYR -2.97 1.05 -5.03 -0.92 -2.93 -4.91 -0.91
    BAA -4.82 1.09 -6.95 -2.69 -4.71 -6.72 -2.65
    CHR -4.00 1.08 -6.11 -1.89 -3.92 -5.93 -1.87
    BAP -0.31 1.20 -2.65 2.04 -0.31 -2.62 2.06
    BGHIP -0.87 1.05 -2.93 1.19 -0.87 -2.89 1.20
    ICDP -0.08 1.07 -2.18 2.02 -0.08 -2.15 2.04
    Irish and Scottish West Coast PA -3.94 2.00 -7.86 -0.02 -3.86 -7.56 -0.02
    ANT -5.41 2.64 -10.59 -0.23 -5.26 -10.05 -0.23
    FLU -2.82 1.81 -6.36 0.73 -2.78 -6.16 0.73
    PYR -3.21 1.88 -6.89 0.46 -3.16 -6.66 0.47
    BAA -5.78 2.09 -9.87 -1.68 -5.61 -9.40 -1.67
    CHR -7.08 2.03 -11.07 -3.10 -6.84 -10.48 -3.05
    BAP -7.47 2.32 -12.01 -2.93 -7.20 -11.32 -2.89
    BGHIP -5.59 2.14 -9.78 -1.40 -5.44 -9.32 -1.39
    ICDP -2.34 2.33 -6.91 2.22 -2.32 -6.67 2.24
    Irish Sea PA 1.58 1.47 -1.30 4.46 1.60 -1.29 4.56
    ANT -1.58 2.02 -5.53 2.38 -1.56 -5.38 2.41
    FLU 0.83 1.32 -1.75 3.41 0.83 -1.74 3.47
    PYR -0.89 1.36 -3.56 1.77 -0.89 -3.50 1.79
    BAA -2.17 1.57 -5.25 0.92 -2.14 -5.12 0.92
    CHR -6.39 1.43 -9.20 -3.58 -6.19 -8.79 -3.52
    BAP -1.74 1.94 -5.54 2.07 -1.72 -5.39 2.09
    BGHIP -2.43 1.56 -5.48 0.62 -2.40 -5.34 0.62
    ICDP -0.50 1.65 -3.74 2.74 -0.50 -3.67 2.77
    Northern Bay of Biscay PA -5.06 1.37 -7.74 -2.37 -4.93 -7.45 -2.35
    ANT -1.51 1.60 -4.65 1.62 -1.50 -4.54 1.63
    FLU -2.92 1.39 -5.64 -0.19 -2.87 -5.48 -0.19
    PYR -1.71 1.37 -4.39 0.98 -1.69 -4.30 0.98
    BAA -2.59 1.38 -5.29 0.10 -2.56 -5.15 0.10
    CHR -2.22 1.40 -4.97 0.52 -2.20 -4.85 0.53
    BAP 3.06 1.57 -0.01 6.13 3.11 -0.01 6.33
    BGHIP -0.32 1.37 -3.01 2.37 -0.32 -2.96 2.40
    ICDP 0.91 1.40 -1.83 3.64 0.91 -1.81 3.71
    Iberian Sea PA -5.56 1.28 -8.07 -3.04 -5.41 -7.76 -3.00
    ANT -6.98 1.51 -9.94 -4.01 -6.74 -9.46 -3.93
    FLU -8.25 1.24 -10.69 -5.82 -7.92 -10.14 -5.65
    PYR -8.77 1.26 -11.25 -6.29 -8.39 -10.64 -6.09
    BAA -7.45 1.33 -10.06 -4.85 -7.18 -9.57 -4.73
    CHR -7.44 1.30 -9.99 -4.90 -7.17 -9.51 -4.78
    BAP -3.94 1.40 -6.69 -1.19 -3.86 -6.47 -1.18
    BGHIP -6.07 1.24 -8.50 -3.64 -5.89 -8.15 -3.57
    ICDP -6.14 1.31 -8.70 -3.58 -5.96 -8.34 -3.52


    Regional status compared to the Environmental Assessment Criterion (EAC)

    The first 4 tabs show:

  • Regional status: estimates of the regional status (averaged over PAHs) with pointwise upper one-sided 95% confidence limits
  • Regional status by PAH: regional status estimates for each PAH with pointwise upper one-sided 95% confidence limits plotted by PAH
  • Regional status by region: regional status estimates for each PAH 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 PAHs, between regions and, for biota, between species.

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


    Regional status


    Regional status by PAH


    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
    Northern North Sea -2.67 0.61 -1.68 0.07 0.19
    Skagerrak and Kattegat -3.50 0.62 -2.48 0.03 0.08
    Southern North Sea -3.12 0.62 -2.09 0.04 0.12
    Channel -3.75 0.61 -2.75 0.02 0.06
    Irish and Scottish West Coast -3.62 0.61 -2.61 0.03 0.07
    Irish Sea -2.67 0.61 -1.68 0.07 0.19
    Celtic Sea -3.36 0.67 -2.26 0.03 0.10
    Northern Bay of Biscay -3.84 0.62 -2.82 0.02 0.06
    Iberian Sea -3.67 0.60 -2.68 0.03 0.07
    Gulf of Cadiz -4.08 0.75 -2.84 0.02 0.06


    Estimates by region and PAH

    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 PAH status se upper concentration conc upper
    Northern North Sea PA -4.44 0.14 -4.21 0.01 0.01
    ANT -3.95 0.16 -3.69 0.02 0.03
    FLU -1.14 0.14 -0.90 0.32 0.40
    PYR -1.07 0.14 -0.83 0.34 0.43
    BAA -1.81 0.14 -1.57 0.16 0.21
    CHR
    BAP -4.17 0.21 -3.83 0.02 0.02
    BGHIP -2.14 0.16 -1.89 0.12 0.15
    ICDP
    Skagerrak and Kattegat PA -4.92 0.20 -4.59 0.01 0.01
    ANT -4.99 0.22 -4.63 0.01 0.01
    FLU -1.73 0.21 -1.39 0.18 0.25
    PYR -1.88 0.21 -1.54 0.15 0.22
    BAA -2.47 0.21 -2.13 0.08 0.12
    CHR
    BAP -5.18 0.22 -4.81 0.01 0.01
    BGHIP -3.35 0.21 -3.01 0.03 0.05
    ICDP
    Southern North Sea PA -4.55 0.22 -4.18 0.01 0.02
    ANT -4.93 0.24 -4.55 0.01 0.01
    FLU -1.39 0.23 -1.02 0.25 0.36
    PYR -1.37 0.22 -1.00 0.25 0.37
    BAA -2.33 0.22 -1.96 0.10 0.14
    CHR
    BAP -4.66 0.23 -4.29 0.01 0.01
    BGHIP -2.61 0.23 -2.23 0.07 0.11
    ICDP
    Channel PA -5.19 0.17 -4.91 0.01 0.01
    ANT -5.83 0.20 -5.50 0.00 0.00
    FLU -1.74 0.17 -1.47 0.18 0.23
    PYR -1.80 0.17 -1.52 0.17 0.22
    BAA -2.98 0.17 -2.69 0.05 0.07
    CHR
    BAP -5.62 0.18 -5.32 0.00 0.00
    BGHIP -3.13 0.17 -2.85 0.04 0.06
    ICDP
    Irish and Scottish West Coast PA -4.80 0.18 -4.51 0.01 0.01
    ANT -4.84 0.21 -4.50 0.01 0.01
    FLU -2.05 0.17 -1.77 0.13 0.17
    PYR -2.08 0.17 -1.80 0.12 0.17
    BAA -2.72 0.18 -2.41 0.07 0.09
    CHR
    BAP -5.78 0.21 -5.43 0.00 0.00
    BGHIP -3.09 0.19 -2.78 0.05 0.06
    ICDP
    Irish Sea PA -4.21 0.15 -3.96 0.01 0.02
    ANT -4.08 0.16 -3.81 0.02 0.02
    FLU -0.90 0.15 -0.66 0.41 0.52
    PYR -0.82 0.15 -0.57 0.44 0.56
    BAA -1.77 0.15 -1.52 0.17 0.22
    CHR
    BAP -4.62 0.17 -4.34 0.01 0.01
    BGHIP -2.33 0.15 -2.08 0.10 0.12
    ICDP
    Celtic Sea PA -4.36 0.34 -3.80 0.01 0.02
    ANT -4.65 0.35 -4.08 0.01 0.02
    FLU -1.65 0.34 -1.09 0.19 0.34
    PYR -1.61 0.35 -1.03 0.20 0.36
    BAA -2.60 0.35 -2.02 0.07 0.13
    CHR
    BAP -5.43 0.35 -4.85 0.00 0.01
    BGHIP -3.24 0.35 -2.67 0.04 0.07
    ICDP
    Northern Bay of Biscay PA -5.49 0.21 -5.15 0.00 0.01
    ANT -5.68 0.23 -5.30 0.00 0.00
    FLU -2.03 0.21 -1.68 0.13 0.19
    PYR -1.92 0.21 -1.57 0.15 0.21
    BAA -2.95 0.21 -2.60 0.05 0.07
    CHR
    BAP -5.57 0.22 -5.20 0.00 0.01
    BGHIP -3.26 0.21 -2.91 0.04 0.05
    ICDP
    Iberian Sea PA -4.90 0.13 -4.69 0.01 0.01
    ANT -5.65 0.14 -5.42 0.00 0.00
    FLU -1.86 0.13 -1.65 0.16 0.19
    PYR -1.91 0.13 -1.70 0.15 0.18
    BAA -2.78 0.13 -2.56 0.06 0.08
    CHR
    BAP -5.31 0.13 -5.08 0.00 0.01
    BGHIP -3.28 0.13 -3.07 0.04 0.05
    ICDP
    Gulf of Cadiz PA -5.20 0.48 -4.42 0.01 0.01
    ANT
    FLU -2.47 0.47 -1.70 0.08 0.18
    PYR -2.46 0.48 -1.68 0.09 0.19
    BAA
    CHR
    BAP
    BGHIP
    ICDP


    Regional status compared to the Background Assessment Concentration (BAC)

    The first 4 tabs show:

  • Regional status: estimates of the regional status (averaged over PAHs) with pointwise upper one-sided 95% confidence limits
  • Regional status by PAH: regional status estimates for each PAH with pointwise upper one-sided 95% confidence limits plotted by PAH
  • Regional status by region: regional status estimates for each PAH 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 PAHs) and the regional status by PAH.


    Regional status


    Regional status by PAH


    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
    Northern North Sea 1.27 0.16 1.53 3.55 4.63
    Skagerrak and Kattegat 0.49 0.21 0.83 1.63 2.29
    Southern North Sea 0.93 0.22 1.29 2.53 3.64
    Channel 0.38 0.18 0.68 1.47 1.97
    Irish and Scottish West Coast 0.30 0.19 0.61 1.35 1.84
    Irish Sea 1.26 0.17 1.53 3.51 4.61
    Celtic Sea 0.39 0.33 0.93 1.48 2.55
    Northern Bay of Biscay 0.31 0.21 0.66 1.36 1.93
    Iberian Sea 0.45 0.15 0.70 1.57 2.02
    Gulf of Cadiz -0.30 0.46 0.46 0.74 1.58


    Estimates by region and PAH

    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 PAH status se upper concentration conc upper
    Northern North Sea PA 0.60 0.14 0.83 1.82 2.29
    ANT
    FLU 1.06 0.14 1.29 2.89 3.63
    PYR 1.34 0.14 1.57 3.81 4.78
    BAA 1.65 0.14 1.89 5.22 6.59
    CHR 0.86 0.14 1.09 2.35 2.97
    BAP 1.78 0.20 2.10 5.93 8.18
    BGHIP 1.63 0.15 1.87 5.09 6.52
    ICDP 1.22 0.16 1.48 3.40 4.40
    Skagerrak and Kattegat PA 0.13 0.20 0.45 1.13 1.57
    ANT
    FLU 0.47 0.20 0.80 1.59 2.22
    PYR 0.54 0.20 0.87 1.71 2.39
    BAA 0.99 0.20 1.32 2.69 3.75
    CHR 0.13 0.20 0.46 1.14 1.58
    BAP 0.87 0.21 1.22 2.39 3.40
    BGHIP 0.46 0.21 0.80 1.59 2.23
    ICDP 0.31 0.22 0.67 1.36 1.96
    Southern North Sea PA 0.51 0.22 0.86 1.66 2.37
    ANT
    FLU 0.82 0.22 1.18 2.27 3.26
    PYR 1.04 0.22 1.40 2.83 4.05
    BAA 1.14 0.22 1.50 3.12 4.49
    CHR 0.36 0.22 0.72 1.43 2.05
    BAP 1.38 0.22 1.75 3.98 5.74
    BGHIP 1.17 0.22 1.54 3.23 4.65
    ICDP 1.00 0.23 1.38 2.72 3.96
    Channel PA -0.12 0.17 0.16 0.89 1.17
    ANT
    FLU 0.47 0.17 0.74 1.60 2.10
    PYR 0.62 0.17 0.90 1.87 2.45
    BAA 0.51 0.17 0.78 1.66 2.19
    CHR 0.09 0.17 0.36 1.09 1.44
    BAP 0.46 0.17 0.75 1.59 2.12
    BGHIP 0.67 0.16 0.94 1.95 2.56
    ICDP 0.37 0.16 0.64 1.44 1.89
    Irish and Scottish West Coast PA 0.25 0.17 0.53 1.28 1.70
    ANT
    FLU 0.15 0.17 0.43 1.16 1.53
    PYR 0.32 0.17 0.61 1.38 1.83
    BAA 0.70 0.18 1.00 2.02 2.71
    CHR -0.24 0.18 0.05 0.78 1.05
    BAP 0.29 0.20 0.62 1.34 1.86
    BGHIP 0.64 0.18 0.94 1.90 2.56
    ICDP 0.31 0.19 0.63 1.37 1.87
    Irish Sea PA 0.83 0.15 1.07 2.29 2.93
    ANT
    FLU 1.29 0.15 1.53 3.63 4.63
    PYR 1.58 0.15 1.83 4.87 6.21
    BAA 1.68 0.15 1.93 5.38 6.86
    CHR 0.86 0.15 1.11 2.37 3.02
    BAP 1.42 0.16 1.69 4.16 5.41
    BGHIP 1.44 0.15 1.69 4.24 5.40
    ICDP 0.93 0.15 1.18 2.54 3.25
    Celtic Sea PA 0.55 0.33 1.10 1.74 3.01
    ANT
    FLU 0.45 0.34 1.00 1.56 2.71
    PYR 0.67 0.34 1.24 1.96 3.45
    BAA 0.72 0.34 1.28 2.05 3.60
    CHR -0.25 0.34 0.30 0.78 1.35
    BAP 0.51 0.34 1.07 1.67 2.93
    BGHIP 0.42 0.34 0.99 1.53 2.68
    ICDP 0.06 0.35 0.63 1.06 1.87
    Northern Bay of Biscay PA -0.41 0.21 -0.06 0.67 0.94
    ANT
    FLU 0.21 0.21 0.55 1.23 1.73
    PYR 0.51 0.21 0.85 1.67 2.35
    BAA 0.54 0.21 0.88 1.72 2.41
    CHR 0.06 0.21 0.41 1.07 1.50
    BAP 0.52 0.22 0.88 1.68 2.41
    BGHIP 0.54 0.20 0.88 1.72 2.41
    ICDP 0.47 0.21 0.81 1.60 2.25
    Iberian Sea PA 0.14 0.13 0.35 1.15 1.42
    ANT
    FLU 0.35 0.13 0.56 1.42 1.75
    PYR 0.51 0.13 0.72 1.66 2.05
    BAA 0.70 0.13 0.91 2.01 2.49
    CHR 0.37 0.13 0.58 1.44 1.78
    BAP 0.76 0.13 0.97 2.13 2.65
    BGHIP 0.50 0.13 0.71 1.65 2.04
    ICDP 0.29 0.13 0.50 1.33 1.64
    Gulf of Cadiz PA -0.31 0.47 0.46 0.73 1.58
    ANT
    FLU -0.38 0.46 0.38 0.68 1.46
    PYR -0.17 0.47 0.60 0.84 1.82
    BAA
    CHR -0.98 0.49 -0.18 0.38 0.84
    BAP
    BGHIP
    ICDP


    PAH profiles

    The profile of concentrations across PAHs 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: PAH + region.PAH + 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 PAH concentration profiles by region are shown below with pointwise 95% confidence limits. The units are ug/kg ww.