Regional assessment of status and trends in metal concentrations in biota

  • Overview
  • Summary of individual time series results
  • Regional assessment - methods
  • Regional assessment - availability of time series
  • Regional trends
  • Regional status compared to the Quality Standard secondary poisoning (QSsp)
  • Regional status compared to the Background Assessment Concentration (BAC)

Overview

The 2022 OSPAR CEMP assessment describes the status and trends 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 and tissue (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 metal concentrations in biota, where the metals are AS, CD, CR, CO, CU, PB, HG, NI, SE, AG, SN, ZN. For simplicity, the term ‘region’ is used throughout to describe MIME regions. OSPAR regions are always referred to as such.

The regional status assessments presented in this document are based on environmental thresholds. Regional status assessments based on human health tresholds can be found here.

The regional status assessments presented in this document are integrated with regional status assessments for other contaminants and biological effects using the CHASE approach. Details can be found here.

The following sections:

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


Summary of individual time series results

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

  • there is at least one year with data in the period 2015 to 2020
  • 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 2015 to 2020
  • 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 concentration

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. 3 of the 3848 metal 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 metals. The purple circles are stations where there is a trend assessment for at least one metal, and the light blue cirles are stations where there are only status assessments.

The next set of tabs show the trend and status assessments for each metal 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 Quality Standard secondary poisoning (QSsp)
  • orange: there is no QSsp and the mean concentration is not significantly below the BAC
  • red: the mean concentration is not signficantly below the QSsp
  • 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) or there are too few years to test for trends
  • 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, orange or red status in each MIME and OSPAR region
  • the same information presented as proportions

Note that:

  • all metals are considered in the regional trend assessment
  • only cadmium, copper, lead, mercury and zinc have assessment criteria, so these are the only metals considered in the regional status assessment
  • mercury is the only metal with a QSsp; this is applied to the individual time series without any adjustment for trophic level; however, a trophic adjustment is incorporated in the regional status assessment
  • mercury timeseries in mammals and birds are assessed against the AMAP no risk concentration (instead of the BAC) and low risk concentration (instead of the QSsp) and are not considered in the regional status assessment


Stations


AS


CD


CR


CO


CU


PB


HG


NI


SE


AG


SN


ZN


Trend summary (numbers)

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

OSPAR region MIME region status AS CD CR CO CU PB HG NI SE AG SN ZN total
1 Barents Sea upward trend 0 1 1 0 0 0 2 1 0 2 0 2 9
no trend 7 7 8 8 8 7 6 8 0 3 5 5 72
downward trend 2 1 0 0 1 1 2 0 0 2 0 2 11
Greenland-Scotland ridge upward trend 0 3 0 0 0 1 5 0 0 0 0 1 10
no trend 7 10 0 0 8 5 12 0 15 0 0 6 63
downward trend 2 2 0 0 1 1 1 0 0 0 0 2 9
East of Iceland upward trend 0 0 0 0 0 0 3 0 0 0 0 0 3
no trend 0 0 0 0 0 0 7 0 0 0 0 0 7
downward trend 0 0 0 0 0 0 0 0 0 0 0 0 0
Norwegian Sea upward trend 1 0 0 1 0 0 1 0 0 0 0 0 3
no trend 3 4 5 3 4 3 3 3 0 3 3 5 39
downward trend 1 1 0 0 1 2 1 2 0 0 0 0 8
total upward trend 1 4 1 1 0 1 11 1 0 2 0 3 25
no trend 17 21 13 11 20 15 28 11 15 6 8 16 181
downward trend 5 4 0 0 3 4 4 2 0 2 0 4 28
2 Norwegian Trench upward trend 1 0 2 1 1 0 3 1 0 3 0 1 13
no trend 12 6 11 13 9 8 11 13 0 6 4 10 103
downward trend 2 9 1 1 5 7 3 1 0 1 0 4 34
Northern North Sea upward trend 5 7 2 1 2 4 9 1 5 0 0 2 38
no trend 25 16 10 8 30 20 29 26 11 5 0 29 209
downward trend 4 8 0 0 9 7 5 2 1 0 0 11 47
Skagerrak and Kattegat upward trend 1 6 2 3 2 6 12 3 0 0 2 2 39
no trend 29 22 19 17 21 17 18 18 0 19 4 27 211
downward trend 0 3 9 1 8 8 3 10 0 3 0 2 47
Southern North Sea upward trend 5 12 3 0 7 7 10 0 1 0 0 5 50
no trend 12 27 9 0 41 30 41 9 3 1 0 34 207
downward trend 0 4 5 0 1 5 4 2 2 1 0 2 26
Channel upward trend 0 17 8 0 12 15 15 8 0 1 0 23 99
no trend 0 11 11 0 20 13 17 16 0 20 0 9 117
downward trend 0 0 2 0 0 0 0 0 0 2 0 0 4
total upward trend 12 42 17 5 24 32 49 13 6 4 2 33 239
no trend 78 82 60 38 121 88 116 82 14 51 8 109 847
downward trend 6 24 17 2 23 27 15 15 3 7 0 19 158
3 Irish and Scottish West Coast upward trend 2 3 2 0 1 2 2 0 0 0 0 1 13
no trend 20 22 27 13 31 26 23 23 16 19 0 30 250
downward trend 11 6 2 3 2 4 0 7 1 7 0 4 47
Irish Sea upward trend 3 4 3 1 10 4 5 1 1 1 0 3 36
no trend 28 25 21 5 44 34 35 29 14 10 0 48 293
downward trend 3 11 4 3 1 7 6 2 2 4 0 2 45
Celtic Sea upward trend 0 6 1 1 5 5 8 7 0 1 0 9 43
no trend 8 16 23 5 24 18 11 21 7 18 0 19 170
downward trend 6 7 2 0 3 7 5 0 0 2 0 4 36
total upward trend 5 13 6 2 16 11 15 8 1 2 0 13 92
no trend 56 63 71 23 99 78 69 73 37 47 0 97 713
downward trend 20 24 8 6 6 18 11 9 3 13 0 10 128
4 Northern Bay of Biscay upward trend 0 9 6 0 12 9 13 9 0 3 0 11 72
no trend 0 28 27 0 24 27 21 27 0 29 0 25 208
downward trend 0 0 0 0 1 1 0 1 0 1 0 1 5
Iberian Sea upward trend 0 5 0 0 13 1 2 0 0 0 0 0 21
no trend 11 20 1 0 11 19 20 1 0 1 0 19 103
downward trend 12 7 0 0 0 11 8 0 0 0 0 5 43
Gulf of Cadiz upward trend 0 0 0 0 0 0 0 0 0 0 0 0 0
no trend 0 1 0 0 0 2 1 0 0 0 0 0 4
downward trend 0 0 0 0 0 0 1 0 0 0 0 0 1
total upward trend 0 14 6 0 25 10 15 9 0 3 0 11 93
no trend 11 49 28 0 35 48 42 28 0 30 0 44 315
downward trend 12 7 0 0 1 12 9 1 0 1 0 6 49


Trend summary (proportions)

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

OSPAR region MIME region status AS CD CR CO CU PB HG NI SE AG SN ZN total
1 Barents Sea upward trend 0 11 11 0 0 0 20 11 28 0 22 10
no trend 78 78 89 100 89 88 60 89 43 100 56 78
downward trend 22 11 0 0 11 12 20 0 29 0 22 12
Greenland-Scotland ridge upward trend 0 20 0 14 28 0 11 12
no trend 78 67 89 72 67 100 67 77
downward trend 22 13 11 14 5 0 22 11
East of Iceland upward trend 30 30
no trend 70 70
downward trend 0 0
Norwegian Sea upward trend 20 0 0 25 0 0 20 0 0 0 0 6
no trend 60 80 100 75 80 60 60 60 100 100 100 78
downward trend 20 20 0 0 20 40 20 40 0 0 0 16
total upward trend 4 14 7 8 0 5 26 7 0 20 0 13 11
no trend 74 72 93 92 87 75 65 79 100 60 100 70 77
downward trend 22 14 0 0 13 20 9 14 0 20 0 17 12
2 Norwegian Trench upward trend 7 0 14 7 7 0 17 7 30 0 7 8
no trend 80 40 79 86 60 53 65 86 60 100 66 69
downward trend 13 60 7 7 33 47 18 7 10 0 27 23
Northern North Sea upward trend 15 22 17 11 5 13 21 3 29 0 5 13
no trend 73 52 83 89 73 64 67 90 65 100 69 71
downward trend 12 26 0 0 22 23 12 7 6 0 26 16
Skagerrak and Kattegat upward trend 3 19 7 14 6 19 36 10 0 33 7 13
no trend 97 71 63 81 68 55 55 58 86 67 87 71
downward trend 0 10 30 5 26 26 9 32 14 0 6 16
Southern North Sea upward trend 29 28 18 14 17 18 0 17 0 12 18
no trend 71 63 53 84 71 75 82 50 50 83 73
downward trend 0 9 29 2 12 7 18 33 50 5 9
Channel upward trend 61 38 38 54 47 33 4 72 45
no trend 39 52 62 46 53 67 87 28 53
downward trend 0 10 0 0 0 0 9 0 2
total upward trend 13 28 18 11 14 22 27 12 26 7 20 20 19
no trend 81 56 64 85 72 60 65 74 61 82 80 68 68
downward trend 6 16 18 4 14 18 8 14 13 11 0 12 13
3 Irish and Scottish West Coast upward trend 6 10 7 0 3 6 8 0 0 0 3 4
no trend 61 71 87 81 91 81 92 77 94 73 86 81
downward trend 33 19 6 19 6 13 0 23 6 27 11 15
Irish Sea upward trend 9 10 11 11 18 9 11 3 6 7 6 10
no trend 82 62 75 56 80 75 76 91 82 66 90 78
downward trend 9 28 14 33 2 16 13 6 12 27 4 12
Celtic Sea upward trend 0 21 4 17 16 17 33 25 0 5 28 17
no trend 57 55 88 83 75 60 46 75 100 86 59 68
downward trend 43 24 8 0 9 23 21 0 0 9 13 15
total upward trend 6 13 7 7 13 10 16 9 3 3 11 10
no trend 69 63 84 74 82 73 73 81 90 76 81 76
downward trend 25 24 9 19 5 17 11 10 7 21 8 14
4 Northern Bay of Biscay upward trend 24 18 32 24 38 24 9 30 25
no trend 76 82 65 73 62 73 88 67 73
downward trend 0 0 3 3 0 3 3 3 2
Iberian Sea upward trend 0 16 0 54 3 7 0 0 0 12
no trend 48 62 100 46 61 66 100 100 79 62
downward trend 52 22 0 0 36 27 0 0 21 26
Gulf of Cadiz upward trend 0 0 0 0
no trend 100 100 50 80
downward trend 0 0 50 20
total upward trend 0 20 18 41 14 23 24 9 18 20
no trend 48 70 82 57 69 63 74 88 72 69
downward trend 52 10 0 2 17 14 2 3 10 11


Status summary (numbers)

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

OSPAR region MIME region status CD CU PB HG ZN total
1 Barents Sea blue 2 0 5 3 0 10
green 0 0 0 2 0 2
orange 9 6 6 0 6 27
red 0 0 0 7 0 7
Greenland-Scotland ridge blue 0 0 8 6 0 14
green 0 0 0 3 0 3
orange 10 8 2 0 8 28
red 0 0 0 7 0 7
East of Iceland blue 0 0 0 2 0 2
green 0 0 0 8 0 8
orange 0 0 0 0 0 0
red 0 0 0 0 0 0
Norwegian Sea blue 3 1 4 2 0 10
green 0 0 0 0 0 0
orange 3 2 2 0 3 10
red 0 0 0 4 0 4
total blue 5 1 17 13 0 36
green 0 0 0 13 0 13
orange 22 16 10 0 17 65
red 0 0 0 18 0 18
2 Norwegian Trench blue 4 4 5 1 0 14
green 0 0 0 2 0 2
orange 11 6 10 0 10 37
red 0 0 0 14 0 14
Northern North Sea blue 11 3 0 0 0 14
green 0 0 0 0 0 0
orange 23 17 34 0 20 94
red 0 0 0 49 0 49
Skagerrak and Kattegat blue 5 1 18 6 0 30
green 0 0 0 10 0 10
orange 35 28 22 0 29 114
red 0 0 0 28 0 28
Southern North Sea blue 5 0 9 1 0 15
green 0 0 0 2 0 2
orange 41 23 37 0 17 118
red 0 0 0 56 0 56
Channel blue 18 0 5 0 0 23
green 0 0 0 1 0 1
orange 15 29 28 0 29 101
red 0 0 0 36 0 36
total blue 43 8 37 8 0 96
green 0 0 0 15 0 15
orange 125 103 131 0 105 464
red 0 0 0 183 0 183
3 Irish and Scottish West Coast blue 21 1 23 6 1 52
green 0 0 0 11 0 11
orange 11 28 9 0 28 76
red 0 0 0 18 0 18
Irish Sea blue 18 0 3 3 2 26
green 0 0 0 7 0 7
orange 34 34 49 0 32 149
red 0 0 0 59 0 59
Celtic Sea blue 26 4 18 10 2 60
green 0 0 0 8 0 8
orange 12 32 20 0 34 98
red 0 0 0 21 0 21
total blue 65 5 44 19 5 138
green 0 0 0 26 0 26
orange 57 94 78 0 94 323
red 0 0 0 98 0 98
4 Northern Bay of Biscay blue 35 0 16 1 0 52
green 0 0 0 0 0 0
orange 8 43 27 0 43 121
red 0 0 0 44 0 44
Iberian Sea blue 24 0 10 9 0 43
green 0 0 0 8 0 8
orange 6 24 20 0 24 74
red 0 0 0 19 0 19
Gulf of Cadiz blue 0 0 0 0 0 0
green 0 0 0 2 0 2
orange 1 0 1 0 0 2
red 0 0 0 1 0 1
total blue 59 0 26 10 0 95
green 0 0 0 10 0 10
orange 15 67 48 0 67 197
red 0 0 0 64 0 64


Status summary (proportions)

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

OSPAR region MIME region status CD CU PB HG ZN total
1 Barents Sea blue 18 0 45 25 0 22
green 0 0 0 17 0 4
orange 82 100 55 0 100 59
red 0 0 0 58 0 15
Greenland-Scotland ridge blue 0 0 80 37 0 27
green 0 0 0 19 0 6
orange 100 100 20 0 100 54
red 0 0 0 44 0 13
East of Iceland blue 20 20
green 80 80
orange 0 0
red 0 0
Norwegian Sea blue 50 33 67 33 0 41
green 0 0 0 0 0 0
orange 50 67 33 0 100 42
red 0 0 0 67 0 17
total blue 19 6 63 29 0 27
green 0 0 0 30 0 10
orange 81 94 37 0 100 49
red 0 0 0 41 0 14
2 Norwegian Trench blue 27 40 33 6 0 21
green 0 0 0 12 0 3
orange 73 60 67 0 100 55
red 0 0 0 82 0 21
Northern North Sea blue 32 15 0 0 0 9
green 0 0 0 0 0 0
orange 68 85 100 0 100 60
red 0 0 0 100 0 31
Skagerrak and Kattegat blue 12 3 45 13 0 16
green 0 0 0 23 0 6
orange 88 97 55 0 100 63
red 0 0 0 64 0 15
Southern North Sea blue 11 0 20 2 0 8
green 0 0 0 3 0 1
orange 89 100 80 0 100 62
red 0 0 0 95 0 29
Channel blue 55 0 15 0 0 14
green 0 0 0 3 0 1
orange 45 100 85 0 100 63
red 0 0 0 97 0 22
total blue 26 7 22 4 0 13
green 0 0 0 7 0 2
orange 74 93 78 0 100 61
red 0 0 0 89 0 24
3 Irish and Scottish West Coast blue 66 3 72 17 3 33
green 0 0 0 32 0 7
orange 34 97 28 0 97 48
red 0 0 0 51 0 12
Irish Sea blue 35 0 6 4 6 11
green 0 0 0 10 0 3
orange 65 100 94 0 94 62
red 0 0 0 86 0 24
Celtic Sea blue 68 11 47 26 6 32
green 0 0 0 20 0 4
orange 32 89 53 0 94 53
red 0 0 0 54 0 11
total blue 53 5 36 13 5 24
green 0 0 0 18 0 4
orange 47 95 64 0 95 55
red 0 0 0 69 0 17
4 Northern Bay of Biscay blue 81 0 37 2 0 24
green 0 0 0 0 0 0
orange 19 100 63 0 100 56
red 0 0 0 98 0 20
Iberian Sea blue 80 0 33 25 0 30
green 0 0 0 22 0 6
orange 20 100 67 0 100 51
red 0 0 0 53 0 13
Gulf of Cadiz blue 0 0 0 0
green 0 0 67 40
orange 100 100 0 40
red 0 0 33 20
total blue 80 0 35 12 0 26
green 0 0 0 12 0 3
orange 20 100 65 0 100 54
red 0 0 0 76 0 17


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.metal
  • random model: station + station.metal + trend estimation variation + residual variation

The fixed model means that a separate regional trend is estimated for each metal. The random model has four terms:

  • station allows for variation in trend between stations common to all metals
  • station.metal allows for additional variation in trend between stations and metals common to all tissues and species within stations
  • 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’ or ‘baseline’ (near pristine conditions or only subject to very diffuse inputs). ‘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 region and metal combinations 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.

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 concentration might vary between metals and species. The regional status against the BAC is assessed by fitting essentially the same linear mixed model as for trends:

  • response: status (mean log concentration - log assessment concentration)
  • fixed model: region.metal
  • random model: station + station.metal + 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.

The regional status assessment against the QSsp has only one metal (mercury) and incorporates a trophic adjustment in the fixed model. This is in the form of a two-level categorical variable, labelled class, that distinguishes bivalves from fish. The model is:

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

Essentially, the class effect adjusts mercury concentrations in bivalves to fish equivalents giving regional mean concentrations standardized to fish. These can be thought of as the mean concentrations that would have been observed had fish been monitored at every station. The model also includes a species random effect to allow for variation between bivalve species and between fish species. The development of this model was based on the data in the 2021 OSPAR CEMP assessment and is described here.

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 and metal combinations with at least three status stations with good geographic spread.

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 purple circles are stations where there is a trend assessment for at least one metal, and the light blue 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: East of Iceland, Gulf of Cadiz
  • status:


OSPAR region 1


OSPAR region 2


OSPAR region 3


OSPAR region 4


Regional trends

The first 3 tabs show:

  • Regional trends by metal: regional trend estimates for each metal with pointwise 95% confidence intervals plotted by metal
  • Regional trends by region: regional trend estimates for each metal with pointwise 95% confidence intervals plotted by region
  • Individual time series: the trend estimates from the individual time series on which the regional assessment is based. The estimates for regions with insufficient geographic spread (and excluded from the meta-analysis) are also shown. Remember that the QSsp has not been adjusted for trophic level when applied to the individual time series.

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 significant change in mean concentration (p > 0.05)
  • upward triangle: the mean concentration is significantly increasing (p < 0.05)

The final tab shows the estimates of the regional trend by metal.


Regional trends by metal


Regional trends by region


Individual time series


Estimates by region and metal

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 metal trend se lower upper % yearly change %yc lower %yc upper
Barents Sea AS -1.64 1.55 -4.67 1.39 -1.62 -4.56 1.40
CD 0.12 1.46 -2.75 2.99 0.12 -2.71 3.03
CR 2.87 2.04 -1.12 6.86 2.91 -1.12 7.11
CO -0.08 1.71 -3.42 3.27 -0.08 -3.36 3.32
CU -0.94 1.43 -3.74 1.87 -0.93 -3.67 1.89
PB -1.47 1.53 -4.46 1.53 -1.45 -4.37 1.55
HG -0.26 1.29 -2.80 2.27 -0.26 -2.76 2.30
NI 0.00 1.80 -3.52 3.52 0.00 -3.46 3.59
AG -2.58 1.76 -6.04 0.88 -2.55 -5.86 0.88
ZN -0.03 1.42 -2.82 2.75 -0.03 -2.78 2.79
Greenland-Scotland ridge AS -0.14 1.05 -2.19 1.92 -0.14 -2.17 1.94
CD -0.05 1.00 -2.02 1.92 -0.05 -2.00 1.94
CU -1.52 1.11 -3.70 0.65 -1.51 -3.63 0.65
PB 0.08 1.43 -2.73 2.88 0.08 -2.69 2.92
HG 1.11 0.90 -0.67 2.88 1.11 -0.66 2.92
SE 0.57 1.05 -1.49 2.63 0.57 -1.48 2.66
ZN -0.10 1.04 -2.14 1.94 -0.10 -2.12 1.96
Norwegian Sea AS -0.27 2.22 -4.62 4.07 -0.27 -4.51 4.15
CD -1.24 2.67 -6.47 3.98 -1.24 -6.27 4.07
CR -5.96 3.85 -13.51 1.59 -5.78 -12.63 1.60
CO 0.00 2.41 -4.73 4.74 0.00 -4.62 4.85
CU -3.23 2.34 -7.81 1.35 -3.18 -7.52 1.36
PB -9.96 2.57 -15.00 -4.91 -9.48 -13.93 -4.79
HG 0.02 2.22 -4.34 4.38 0.02 -4.25 4.47
NI -4.70 3.05 -10.68 1.28 -4.59 -10.13 1.29
AG 5.75 3.78 -1.66 13.17 5.92 -1.64 14.07
SN 10.32 4.33 1.84 18.80 10.87 1.85 20.68
ZN -2.39 1.93 -6.16 1.38 -2.36 -5.98 1.39
Norwegian Trench AS -1.80 1.30 -4.35 0.75 -1.78 -4.25 0.75
CD -4.74 1.09 -6.88 -2.61 -4.63 -6.65 -2.57
CR 8.89 1.92 5.13 12.65 9.30 5.26 13.49
CO -0.21 1.23 -2.63 2.20 -0.21 -2.59 2.22
CU 0.84 1.08 -1.29 2.96 0.84 -1.28 3.00
PB -2.50 1.12 -4.69 -0.31 -2.47 -4.59 -0.31
HG 1.44 1.10 -0.71 3.59 1.45 -0.70 3.66
NI 3.50 1.70 0.17 6.82 3.56 0.17 7.06
AG 1.28 1.84 -2.33 4.89 1.28 -2.31 5.01
ZN -0.32 1.06 -2.40 1.76 -0.32 -2.37 1.77
Northern North Sea AS -0.04 0.67 -1.36 1.28 -0.04 -1.35 1.29
CD -0.07 0.68 -1.41 1.27 -0.07 -1.40 1.28
CR 5.68 1.71 2.33 9.02 5.84 2.36 9.44
CO 0.22 1.50 -2.73 3.16 0.22 -2.69 3.21
CU -1.15 0.65 -2.43 0.12 -1.15 -2.40 0.12
PB -0.83 0.72 -2.24 0.58 -0.83 -2.22 0.58
HG 0.45 0.65 -0.83 1.73 0.45 -0.83 1.74
NI 0.13 0.81 -1.45 1.71 0.13 -1.44 1.73
SE -0.16 0.84 -1.82 1.50 -0.16 -1.80 1.51
AG 0.76 2.94 -5.00 6.53 0.77 -4.87 6.74
ZN -1.08 0.62 -2.30 0.15 -1.07 -2.27 0.15
Skagerrak and Kattegat AS -0.51 0.93 -2.34 1.32 -0.51 -2.31 1.33
CD -0.23 0.81 -1.82 1.36 -0.23 -1.80 1.37
CR -6.98 1.11 -9.16 -4.80 -6.75 -8.76 -4.69
CO -1.23 1.14 -3.46 1.00 -1.22 -3.40 1.01
CU -0.97 0.79 -2.53 0.58 -0.97 -2.50 0.58
PB -1.50 0.85 -3.17 0.17 -1.49 -3.12 0.17
HG 0.80 0.80 -0.77 2.38 0.81 -0.77 2.41
NI -1.78 0.99 -3.72 0.16 -1.76 -3.66 0.16
AG 0.52 1.31 -2.05 3.09 0.52 -2.03 3.14
ZN -0.03 0.79 -1.57 1.52 -0.03 -1.56 1.53
Southern North Sea AS 5.23 0.83 3.60 6.86 5.37 3.67 7.10
CD 3.43 0.68 2.10 4.76 3.49 2.12 4.87
CR -0.42 1.28 -2.93 2.08 -0.42 -2.88 2.10
CU 2.60 0.64 1.34 3.86 2.63 1.35 3.93
PB 1.45 0.71 0.07 2.84 1.46 0.07 2.88
HG 3.50 0.62 2.28 4.72 3.56 2.31 4.83
NI 1.11 1.16 -1.18 3.39 1.11 -1.17 3.44
SE 2.48 1.25 0.02 4.93 2.51 0.02 5.06
ZN 2.12 0.61 0.92 3.33 2.15 0.93 3.38
Channel CD 3.28 0.70 1.91 4.65 3.33 1.93 4.76
CR 3.79 0.93 1.96 5.62 3.87 1.98 5.79
CU 1.78 0.66 0.49 3.07 1.80 0.49 3.12
PB 4.17 0.72 2.77 5.58 4.26 2.81 5.73
HG 3.82 0.69 2.46 5.18 3.89 2.49 5.31
NI 3.63 0.84 1.97 5.28 3.70 1.99 5.43
AG -0.83 0.86 -2.52 0.86 -0.83 -2.49 0.86
ZN 3.99 0.66 2.70 5.27 4.07 2.73 5.42
Irish and Scottish West Coast AS -2.35 0.70 -3.72 -0.99 -2.32 -3.65 -0.98
CD -1.31 0.72 -2.72 0.10 -1.30 -2.68 0.10
CR -0.14 0.82 -1.75 1.47 -0.14 -1.73 1.48
CO -3.70 1.12 -5.89 -1.50 -3.63 -5.72 -1.49
CU -0.02 0.72 -1.42 1.39 -0.02 -1.41 1.40
PB -0.89 0.77 -2.40 0.62 -0.88 -2.37 0.62
HG -0.05 0.83 -1.67 1.57 -0.05 -1.66 1.59
NI -2.59 0.83 -4.22 -0.96 -2.56 -4.14 -0.96
SE -0.70 0.94 -2.55 1.15 -0.69 -2.51 1.16
AG -3.67 0.96 -5.56 -1.79 -3.61 -5.40 -1.77
ZN -0.68 0.68 -2.01 0.64 -0.68 -1.99 0.64
Irish Sea AS -0.09 0.67 -1.40 1.22 -0.09 -1.39 1.23
CD -1.36 0.64 -2.61 -0.11 -1.35 -2.57 -0.11
CR -0.48 0.88 -2.20 1.24 -0.48 -2.17 1.25
CO -3.77 1.67 -7.04 -0.50 -3.70 -6.79 -0.50
CU 1.84 0.60 0.65 3.02 1.86 0.66 3.07
PB 0.20 0.66 -1.09 1.49 0.20 -1.08 1.50
HG -0.28 0.62 -1.48 0.93 -0.27 -1.47 0.94
NI 0.29 0.80 -1.29 1.86 0.29 -1.28 1.88
SE 0.78 0.94 -1.07 2.62 0.78 -1.07 2.66
AG -4.24 1.15 -6.50 -1.98 -4.15 -6.30 -1.96
ZN 0.57 0.58 -0.57 1.72 0.57 -0.57 1.73
Celtic Sea AS -0.70 0.90 -2.47 1.07 -0.70 -2.44 1.07
CD -0.24 0.71 -1.64 1.16 -0.24 -1.62 1.17
CR 0.86 0.97 -1.03 2.76 0.87 -1.02 2.79
CO 7.00 2.50 2.09 11.90 7.25 2.11 12.64
CU 0.64 0.69 -0.72 1.99 0.64 -0.71 2.01
PB -0.06 0.71 -1.46 1.34 -0.06 -1.45 1.35
HG -0.03 0.76 -1.53 1.46 -0.03 -1.52 1.47
NI 2.16 0.80 0.59 3.73 2.18 0.59 3.80
SE 2.94 1.42 0.16 5.73 2.99 0.16 5.89
AG -1.21 0.88 -2.94 0.52 -1.20 -2.90 0.52
ZN 0.97 0.69 -0.38 2.32 0.97 -0.38 2.35
Northern Bay of Biscay CD 1.43 0.60 0.26 2.59 1.44 0.26 2.63
CR 4.09 0.90 2.34 5.85 4.18 2.36 6.03
CU 1.86 0.61 0.66 3.06 1.88 0.66 3.11
PB 1.29 0.59 0.13 2.46 1.30 0.13 2.49
HG 2.20 0.61 1.00 3.40 2.23 1.01 3.46
NI 3.78 0.65 2.49 5.06 3.85 2.52 5.19
AG 0.36 0.70 -1.02 1.74 0.36 -1.01 1.75
ZN 2.05 0.61 0.85 3.24 2.07 0.85 3.30
Iberian Sea AS -4.33 0.79 -5.87 -2.79 -4.24 -5.70 -2.75
CD 0.03 0.69 -1.33 1.38 0.03 -1.32 1.39
CU 2.70 0.71 1.30 4.10 2.74 1.31 4.19
PB -2.38 0.71 -3.78 -0.98 -2.35 -3.71 -0.98
HG -1.11 0.71 -2.51 0.28 -1.11 -2.47 0.28
ZN -1.51 0.71 -2.91 -0.11 -1.50 -2.87 -0.11


Regional status compared to the Quality Standard secondary poisoning (QSsp)

The first 3 tabs show:

  • Regional status by metal: regional status estimates for each metal with pointwise upper one-sided 95% confidence intervals plotted by metal
  • Regional status by region: regional status estimates for each metal with pointwise upper one-sided 95% confidence intervals plotted by region
  • Individual time series: the status estimates from the individual time series on which the regional assessment is based. The estimates for regions with insufficient geographic spread (and excluded from the meta-analysis) are also shown. Remember that the QSsp has not been adjusted for trophic level when applied to the individual time series.

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 QSsp
  • red: the mean concentration is not significantly below the QSsp

Note that to see why some points might be 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 QSsp with the assessment of status relative to the BAC because the ratio of the BAC to the QSsp can vary between metals and species.

The final tab shows the estimates of the regional status by metal.


Regional status by metal


Regional status by region


Individual time series


Estimates by region and metal

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

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


MIME region metal status se upper concentration conc upper
Barents Sea CD
CU
PB
HG 0.44 0.26 0.86 1.55 2.37
ZN
Greenland-Scotland ridge CD
CU
PB
HG 0.20 0.26 0.63 1.22 1.87
ZN
Norwegian Sea CD
CU
PB
HG 0.87 0.30 1.36 2.38 3.90
ZN
Norwegian Trench CD
CU
PB
HG 1.35 0.24 1.75 3.87 5.73
ZN
Northern North Sea CD
CU
PB
HG 1.70 0.22 2.06 5.47 7.81
ZN
Skagerrak and Kattegat CD
CU
PB
HG 1.07 0.21 1.41 2.90 4.11
ZN
Southern North Sea CD
CU
PB
HG 1.50 0.21 1.85 4.49 6.35
ZN
Channel CD
CU
PB
HG 1.30 0.22 1.66 3.67 5.28
ZN
Irish and Scottish West Coast CD
CU
PB
HG 0.75 0.22 1.12 2.11 3.06
ZN
Irish Sea CD
CU
PB
HG 1.15 0.21 1.49 3.14 4.45
ZN
Celtic Sea CD
CU
PB
HG 0.79 0.22 1.15 2.20 3.17
ZN
Northern Bay of Biscay CD
CU
PB
HG 1.39 0.22 1.76 4.01 5.79
ZN
Iberian Sea CD
CU
PB
HG 0.90 0.22 1.26 2.45 3.51
ZN
Gulf of Cadiz HG 0.26 0.42 0.94 1.30 2.57


Regional status compared to the Background Assessment Concentration (BAC)

The first 3 tabs show:

  • Regional status by metal: regional status estimates for each metal with pointwise upper one-sided 95% confidence intervals plotted by metal
  • Regional status by region: regional status estimates for each metal with pointwise upper one-sided 95% confidence intervals plotted by region
  • Individual time series: the status estimates from the individual time series on which the regional assessment is based. The estimates for regions with insufficient geographic spread (and excluded from the meta-analysis) are also shown. Remember that the QSsp has not been adjusted for trophic level when applied to the individual time series.

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 Quality Standard secondary poisoning (QSsp)
  • orange: there is no QSsp and the mean concentration is not significantly below the BAC
  • red: the mean concentration is not significantly below the QSsp

The final tab shows the estimates of the regional status by metal.


Regional status by metal


Regional status by region


Individual time series


Estimates by region and metal

This table shows the estimates of the regional trend 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 metal status se upper concentration conc upper
Barents Sea CD 0.70 0.29 1.18 2.01 3.26
CU 0.12 0.37 0.73 1.13 2.07
PB -0.39 0.30 0.11 0.68 1.12
HG -0.16 0.37 0.45 0.85 1.56
ZN 0.65 0.36 1.25 1.91 3.48
Greenland-Scotland ridge CD 1.37 0.31 1.89 3.95 6.61
CU 0.22 0.34 0.78 1.24 2.18
PB -2.12 0.36 -1.54 0.12 0.22
HG -0.46 0.34 0.09 0.63 1.10
ZN 0.80 0.33 1.35 2.22 3.85
Norwegian Sea CD -0.17 0.40 0.49 0.84 1.63
CU 0.02 0.52 0.87 1.02 2.39
PB -0.72 0.40 -0.06 0.49 0.94
HG -0.35 0.51 0.49 0.70 1.64
ZN 0.27 0.51 1.11 1.30 3.02
Norwegian Trench CD 0.14 0.25 0.55 1.15 1.74
CU 0.10 0.29 0.57 1.11 1.77
PB 0.25 0.25 0.67 1.29 1.95
HG 0.44 0.27 0.89 1.56 2.43
ZN 0.54 0.29 1.01 1.71 2.75
Northern North Sea CD 0.96 0.17 1.24 2.62 3.46
CU 0.49 0.20 0.83 1.64 2.29
PB 1.06 0.17 1.34 2.87 3.81
HG 1.41 0.20 1.75 4.09 5.73
ZN 0.82 0.20 1.15 2.27 3.17
Skagerrak and Kattegat CD 0.37 0.16 0.63 1.45 1.88
CU 0.20 0.17 0.48 1.22 1.62
PB -0.20 0.16 0.06 0.82 1.06
HG 0.18 0.17 0.47 1.20 1.60
ZN 0.68 0.17 0.96 1.97 2.62
Southern North Sea CD 1.11 0.15 1.35 3.03 3.87
CU 1.20 0.19 1.51 3.32 4.55
PB 0.43 0.15 0.67 1.53 1.96
HG 1.38 0.20 1.71 3.96 5.51
ZN 1.32 0.21 1.67 3.76 5.31
Channel CD -0.20 0.17 0.08 0.82 1.08
CU 0.81 0.18 1.10 2.24 3.00
PB 0.17 0.17 0.45 1.19 1.57
HG 0.86 0.19 1.18 2.36 3.24
ZN 1.11 0.18 1.41 3.05 4.09
Irish and Scottish West Coast CD -0.43 0.18 -0.13 0.65 0.88
CU 0.63 0.19 0.94 1.88 2.55
PB -0.83 0.18 -0.53 0.44 0.59
HG 0.08 0.20 0.41 1.08 1.50
ZN 0.93 0.18 1.23 2.52 3.41
Irish Sea CD 0.15 0.14 0.38 1.17 1.47
CU 0.63 0.16 0.90 1.88 2.46
PB 0.89 0.14 1.12 2.44 3.07
HG 0.50 0.16 0.77 1.65 2.15
ZN 0.64 0.16 0.90 1.89 2.46
Celtic Sea CD -0.53 0.16 -0.26 0.59 0.77
CU 0.81 0.17 1.08 2.25 2.95
PB -0.09 0.16 0.18 0.91 1.20
HG 0.24 0.19 0.55 1.27 1.73
ZN 1.36 0.17 1.64 3.91 5.13
Northern Bay of Biscay CD -0.39 0.15 -0.15 0.68 0.86
CU 2.53 0.15 2.77 12.50 15.98
PB -0.04 0.15 0.21 0.97 1.23
HG 1.22 0.22 1.59 3.37 4.88
ZN 2.73 0.15 2.98 15.34 19.61
Iberian Sea CD -0.44 0.18 -0.15 0.64 0.86
CU 0.23 0.19 0.54 1.25 1.72
PB 0.12 0.18 0.41 1.13 1.51
HG 0.23 0.18 0.53 1.25 1.70
ZN 1.14 0.19 1.45 3.11 4.26
Gulf of Cadiz HG