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 2023 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 thresholds 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 2016 to 2021
  • 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 2016 to 2021
  • 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. 7 of the 3882 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 1 1 1 0 0 0 1 0 0 2 0 2 8
no trend 8 8 9 9 9 7 8 10 0 4 5 6 83
downward trend 1 1 0 0 1 2 2 0 0 2 0 2 11
Greenland-Scotland ridge upward trend 1 3 0 0 0 1 3 0 0 0 0 1 9
no trend 7 9 0 0 9 5 13 0 14 0 0 6 63
downward trend 1 2 0 0 0 1 1 0 0 0 0 2 7
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 6 0 0 0 0 0 6
downward trend 0 0 0 0 0 0 0 0 0 0 0 0 0
Norwegian Sea upward trend 2 0 0 0 0 0 1 0 0 1 0 0 4
no trend 2 5 5 4 6 3 2 3 0 2 4 5 41
downward trend 2 1 1 1 0 3 3 3 0 0 0 1 15
total upward trend 4 4 1 0 0 1 8 0 0 3 0 3 24
no trend 17 22 14 13 24 15 29 13 14 6 9 17 193
downward trend 4 4 1 1 1 6 6 3 0 2 0 5 33
2 Norwegian Trench upward trend 2 0 2 1 1 0 3 1 0 2 0 2 14
no trend 11 5 11 13 9 7 10 13 0 7 5 10 101
downward trend 2 11 1 1 6 9 4 1 0 1 1 4 41
Northern North Sea upward trend 6 7 2 1 3 5 10 1 5 0 0 3 43
no trend 24 17 10 8 30 20 28 26 11 5 0 28 207
downward trend 4 8 0 0 8 7 5 2 1 0 0 11 46
Skagerrak and Kattegat upward trend 1 7 1 4 5 8 11 2 0 0 1 4 44
no trend 30 22 21 16 22 18 22 21 9 22 14 28 245
downward trend 2 4 8 1 8 6 2 9 0 5 0 3 48
Southern North Sea upward trend 8 14 4 0 13 5 16 5 1 0 0 9 75
no trend 12 24 11 0 30 32 31 9 3 2 0 29 183
downward trend 0 4 5 0 2 5 4 2 2 2 0 1 27
Channel upward trend 0 5 2 0 10 1 1 3 0 0 0 4 26
no trend 0 20 21 0 19 20 23 19 0 3 0 24 149
downward trend 0 1 0 0 0 5 5 1 0 0 0 1 13
total upward trend 17 33 11 6 32 19 41 12 6 2 1 22 202
no trend 77 88 74 37 110 97 114 88 23 39 19 119 885
downward trend 8 28 14 2 24 32 20 15 3 8 1 20 175
3 Irish and Scottish West Coast upward trend 1 3 2 0 1 2 2 0 1 0 0 1 13
no trend 21 17 22 13 26 21 17 18 15 14 0 25 209
downward trend 8 6 2 3 2 4 1 7 1 7 0 4 45
Irish Sea upward trend 2 4 2 1 13 4 5 3 1 1 0 3 39
no trend 27 27 21 5 44 36 34 31 15 10 0 46 296
downward trend 3 9 3 3 1 6 6 1 2 4 0 2 40
Celtic Sea upward trend 0 2 2 1 4 0 0 1 0 0 0 5 15
no trend 8 21 25 5 26 20 22 28 7 12 0 24 198
downward trend 6 8 2 0 3 12 5 0 0 0 0 4 40
total upward trend 3 9 6 2 18 6 7 4 2 1 0 9 67
no trend 56 65 68 23 96 77 73 77 37 36 0 95 703
downward trend 17 23 7 6 6 22 12 8 3 11 0 10 125
4 Northern Bay of Biscay upward trend 0 3 1 0 5 0 2 8 0 0 0 3 22
no trend 0 32 36 0 32 27 31 29 0 5 0 35 227
downward trend 0 3 1 0 1 11 5 1 0 1 0 0 23
Iberian Sea upward trend 0 4 0 0 9 1 1 0 0 0 0 0 15
no trend 20 26 0 0 18 17 22 1 0 0 0 15 119
downward trend 3 5 1 0 0 16 10 0 0 0 0 12 47
Gulf of Cadiz upward trend 0 1 0 0 0 0 0 0 0 0 0 0 1
no trend 0 0 0 0 0 2 2 0 0 0 0 0 4
downward trend 0 0 0 0 0 0 0 0 0 0 0 0 0
total upward trend 0 8 1 0 14 1 3 8 0 0 0 3 38
no trend 20 58 36 0 50 46 55 30 0 5 0 50 350
downward trend 3 8 2 0 1 27 15 1 0 1 0 12 70


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 10 10 10 0 0 0 9 0 25 0 20 8
no trend 80 80 90 100 90 78 73 100 50 100 60 81
downward trend 10 10 0 0 10 22 18 0 25 0 20 11
Greenland-Scotland ridge upward trend 11 22 0 14 18 0 11 11
no trend 78 64 100 72 76 100 67 80
downward trend 11 14 0 14 6 0 22 9
East of Iceland upward trend 33 33
no trend 67 67
downward trend 0 0
Norwegian Sea upward trend 34 0 0 0 0 0 17 0 33 0 0 7
no trend 33 83 83 80 100 50 33 50 67 100 83 68
downward trend 33 17 17 20 0 50 50 50 0 0 17 25
total upward trend 16 13 6 0 0 5 19 0 0 27 0 12 10
no trend 68 74 88 93 96 68 67 81 100 55 100 68 77
downward trend 16 13 6 7 4 27 14 19 0 18 0 20 13
2 Norwegian Trench upward trend 13 0 14 7 6 0 18 7 20 0 13 9
no trend 74 31 79 86 56 44 59 86 70 83 62 65
downward trend 13 69 7 7 38 56 23 7 10 17 25 26
Northern North Sea upward trend 18 22 17 11 7 16 23 3 29 0 7 14
no trend 70 53 83 89 73 62 65 90 65 100 67 70
downward trend 12 25 0 0 20 22 12 7 6 0 26 16
Skagerrak and Kattegat upward trend 3 21 3 19 14 25 31 6 0 0 7 11 13
no trend 91 67 70 76 63 56 63 66 100 81 93 80 73
downward trend 6 12 27 5 23 19 6 28 0 19 0 9 14
Southern North Sea upward trend 40 33 20 29 12 31 31 17 0 23 26
no trend 60 57 55 67 76 61 56 50 50 74 64
downward trend 0 10 25 4 12 8 13 33 50 3 10
Channel upward trend 19 9 34 4 4 13 0 14 14
no trend 77 91 66 77 79 83 100 83 79
downward trend 4 0 0 19 17 4 0 3 7
total upward trend 17 22 11 13 19 13 24 10 19 4 5 14 16
no trend 75 59 75 82 66 65 65 77 72 80 90 74 70
downward trend 8 19 14 5 15 22 11 13 9 16 5 12 14
3 Irish and Scottish West Coast upward trend 3 12 8 0 3 7 10 0 6 0 3 5
no trend 70 65 84 81 90 78 85 72 88 67 84 78
downward trend 27 23 8 19 7 15 5 28 6 33 13 17
Irish Sea upward trend 6 10 8 11 22 9 11 8 6 7 6 10
no trend 85 68 81 56 76 78 76 89 83 66 90 79
downward trend 9 22 11 33 2 13 13 3 11 27 4 11
Celtic Sea upward trend 0 6 7 17 12 0 0 3 0 0 15 6
no trend 57 68 86 83 79 62 81 97 100 100 73 78
downward trend 43 26 7 0 9 38 19 0 0 0 12 16
total upward trend 4 9 7 7 15 6 8 4 5 2 8 7
no trend 74 67 84 74 80 73 79 87 88 75 83 79
downward trend 22 24 9 19 5 21 13 9 7 23 9 14
4 Northern Bay of Biscay upward trend 8 2 13 0 5 21 0 8 8
no trend 84 95 84 71 82 76 83 92 84
downward trend 8 3 3 29 13 3 17 0 8
Iberian Sea upward trend 0 12 0 33 3 3 0 0 8
no trend 87 74 0 67 50 67 100 56 66
downward trend 13 14 100 0 47 30 0 44 26
Gulf of Cadiz upward trend 100 0 0 20
no trend 0 100 100 80
downward trend 0 0 0 0
total upward trend 0 11 3 21 1 4 20 0 5 8
no trend 87 78 92 77 62 75 77 83 77 77
downward trend 13 11 5 2 37 21 3 17 18 15


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 1 0 7 4 0 12
green 0 0 0 4 0 4
orange 10 6 4 0 6 26
red 0 0 0 6 0 6
Greenland-Scotland ridge blue 0 0 8 8 0 16
green 0 0 0 4 0 4
orange 10 8 2 0 8 28
red 0 0 0 6 0 6
East of Iceland blue 0 0 0 2 0 2
green 0 0 0 7 0 7
orange 0 0 0 0 0 0
red 0 0 0 0 0 0
Norwegian Sea blue 3 0 4 2 0 9
green 0 0 0 1 0 1
orange 3 3 2 0 3 11
red 0 0 0 3 0 3
total blue 4 0 19 16 0 39
green 0 0 0 16 0 16
orange 23 17 8 0 17 65
red 0 0 0 15 0 15
2 Norwegian Trench blue 5 3 5 1 0 14
green 0 0 0 3 0 3
orange 11 8 11 0 11 41
red 0 0 0 13 0 13
Northern North Sea blue 11 3 0 0 0 14
green 0 0 0 0 0 0
orange 25 17 36 0 20 98
red 0 0 0 51 0 51
Skagerrak and Kattegat blue 5 1 18 6 0 30
green 0 0 0 13 0 13
orange 35 28 21 0 29 113
red 0 0 0 25 0 25
Southern North Sea blue 5 0 11 1 0 17
green 0 0 0 1 0 1
orange 40 22 33 0 16 111
red 0 0 0 56 0 56
Channel blue 21 0 6 0 0 27
green 0 0 0 2 0 2
orange 10 27 25 0 27 89
red 0 0 0 33 0 33
total blue 47 7 40 8 0 102
green 0 0 0 19 0 19
orange 121 102 126 0 103 452
red 0 0 0 178 0 178
3 Irish and Scottish West Coast blue 18 1 19 6 0 44
green 0 0 0 9 0 9
orange 9 23 8 0 24 64
red 0 0 0 15 0 15
Irish Sea blue 18 0 3 3 2 26
green 0 0 0 7 0 7
orange 32 32 47 0 30 141
red 0 0 0 57 0 57
Celtic Sea blue 25 3 19 10 2 59
green 0 0 0 7 0 7
orange 10 30 16 0 31 87
red 0 0 0 25 0 25
total blue 61 4 41 19 4 129
green 0 0 0 23 0 23
orange 51 85 71 0 85 292
red 0 0 0 97 0 97
4 Northern Bay of Biscay blue 33 0 15 0 0 48
green 0 0 0 0 0 0
orange 8 41 26 0 41 116
red 0 0 0 45 0 45
Iberian Sea blue 29 5 17 11 0 62
green 0 0 0 14 0 14
orange 15 33 26 0 38 112
red 0 0 0 24 0 24
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 62 5 32 11 0 110
green 0 0 0 16 0 16
orange 24 74 53 0 79 230
red 0 0 0 70 0 70


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 9 0 64 28 0 25
green 0 0 0 29 0 8
orange 91 100 36 0 100 54
red 0 0 0 43 0 13
Greenland-Scotland ridge blue 0 0 80 45 0 30
green 0 0 0 22 0 7
orange 100 100 20 0 100 52
red 0 0 0 33 0 11
East of Iceland blue 22 22
green 78 78
orange 0 0
red 0 0
Norwegian Sea blue 50 0 67 33 0 38
green 0 0 0 17 0 4
orange 50 100 33 0 100 46
red 0 0 0 50 0 12
total blue 15 0 70 34 0 29
green 0 0 0 34 0 12
orange 85 100 30 0 100 48
red 0 0 0 32 0 11
2 Norwegian Trench blue 31 27 31 6 0 20
green 0 0 0 18 0 4
orange 69 73 69 0 100 58
red 0 0 0 76 0 18
Northern North Sea blue 31 15 0 0 0 9
green 0 0 0 0 0 0
orange 69 85 100 0 100 60
red 0 0 0 100 0 31
Skagerrak and Kattegat blue 12 3 46 14 0 17
green 0 0 0 29 0 7
orange 88 97 54 0 100 62
red 0 0 0 57 0 14
Southern North Sea blue 11 0 25 2 0 9
green 0 0 0 2 0 1
orange 89 100 75 0 100 60
red 0 0 0 96 0 30
Channel blue 68 0 19 0 0 18
green 0 0 0 6 0 1
orange 32 100 81 0 100 59
red 0 0 0 94 0 22
total blue 28 6 24 4 0 14
green 0 0 0 9 0 2
orange 72 94 76 0 100 60
red 0 0 0 87 0 24
3 Irish and Scottish West Coast blue 67 4 70 20 0 33
green 0 0 0 30 0 7
orange 33 96 30 0 100 49
red 0 0 0 50 0 11
Irish Sea blue 36 0 6 5 6 11
green 0 0 0 10 0 3
orange 64 100 94 0 94 61
red 0 0 0 85 0 25
Celtic Sea blue 71 9 54 24 6 33
green 0 0 0 17 0 4
orange 29 91 46 0 94 49
red 0 0 0 59 0 14
total blue 54 4 37 14 4 24
green 0 0 0 16 0 4
orange 46 96 63 0 96 54
red 0 0 0 70 0 18
4 Northern Bay of Biscay blue 80 0 37 0 0 23
green 0 0 0 0 0 0
orange 20 100 63 0 100 55
red 0 0 0 100 0 22
Iberian Sea blue 66 13 40 22 0 29
green 0 0 0 29 0 7
orange 34 87 60 0 100 53
red 0 0 0 49 0 11
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 72 6 38 11 0 26
green 0 0 0 17 0 4
orange 28 94 62 0 100 54
red 0 0 0 72 0 16


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 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 of 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.

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 Arsenic -1.52 1.61 -4.66 1.63 -1.50 -4.56 1.65
Cadmium 0.03 1.56 -3.02 3.07 0.03 -2.98 3.12
Chromium 2.68 2.07 -1.38 6.74 2.71 -1.38 6.97
Cobalt -0.68 1.71 -4.02 2.67 -0.67 -3.94 2.70
Copper -1.17 1.54 -4.19 1.84 -1.17 -4.10 1.86
Lead -1.47 1.67 -4.73 1.80 -1.46 -4.62 1.81
Mercury -0.71 1.38 -3.41 2.00 -0.70 -3.35 2.02
Nickel 0.24 1.95 -3.57 4.06 0.24 -3.51 4.15
Silver -2.20 1.81 -5.74 1.35 -2.17 -5.58 1.36
Zinc -0.17 1.50 -3.11 2.77 -0.17 -3.06 2.81
Greenland-Scotland ridge Arsenic 0.36 1.18 -1.94 2.67 0.37 -1.92 2.71
Cadmium 0.15 1.13 -2.07 2.37 0.15 -2.05 2.40
Copper -1.15 1.22 -3.55 1.25 -1.14 -3.49 1.26
Lead -0.48 1.53 -3.48 2.52 -0.48 -3.42 2.55
Mercury 0.62 1.05 -1.43 2.67 0.63 -1.42 2.71
Selenium 0.70 1.13 -1.52 2.91 0.70 -1.51 2.95
Zinc 0.05 1.17 -2.24 2.33 0.05 -2.21 2.36
Norwegian Sea Arsenic -1.33 2.02 -5.29 2.62 -1.32 -5.15 2.66
Cadmium -0.95 2.18 -5.22 3.32 -0.95 -5.09 3.37
Chromium -5.18 3.42 -11.89 1.52 -5.05 -11.21 1.53
Cobalt -0.26 2.27 -4.71 4.18 -0.26 -4.60 4.26
Copper -1.48 2.20 -5.79 2.82 -1.47 -5.63 2.86
Lead -7.68 2.09 -11.79 -3.58 -7.40 -11.12 -3.51
Mercury 0.18 2.22 -4.16 4.53 0.18 -4.07 4.63
Nickel -3.22 2.83 -8.76 2.33 -3.16 -8.39 2.35
Silver 8.17 3.43 1.45 14.90 8.52 1.46 16.06
Tin 5.48 3.78 -1.92 12.88 5.63 -1.91 13.75
Zinc -3.28 1.91 -7.01 0.46 -3.22 -6.77 0.46
Norwegian Trench Arsenic -1.55 1.40 -4.29 1.19 -1.54 -4.20 1.20
Cadmium -4.45 1.19 -6.79 -2.11 -4.35 -6.56 -2.09
Chromium 7.31 1.87 3.64 10.98 7.58 3.71 11.61
Cobalt 0.23 1.31 -2.33 2.79 0.23 -2.31 2.83
Copper 0.84 1.19 -1.48 3.17 0.85 -1.47 3.22
Lead -2.26 1.23 -4.67 0.16 -2.23 -4.56 0.16
Mercury 1.22 1.20 -1.14 3.58 1.23 -1.13 3.64
Nickel 2.06 1.65 -1.17 5.29 2.08 -1.17 5.43
Silver 1.43 1.91 -2.31 5.17 1.44 -2.29 5.31
Tin 0.02 3.20 -6.25 6.28 0.02 -6.06 6.48
Zinc -0.01 1.17 -2.30 2.27 -0.01 -2.27 2.30
Northern North Sea Arsenic 0.14 0.74 -1.32 1.60 0.14 -1.31 1.61
Cadmium -0.05 0.75 -1.51 1.41 -0.05 -1.50 1.42
Chromium 4.96 1.76 1.51 8.40 5.08 1.52 8.77
Cobalt 0.28 1.56 -2.79 3.34 0.28 -2.75 3.40
Copper -0.94 0.72 -2.34 0.47 -0.93 -2.31 0.47
Lead -0.92 0.78 -2.46 0.61 -0.92 -2.43 0.61
Mercury 0.57 0.72 -0.83 1.97 0.57 -0.83 1.99
Nickel 0.07 0.87 -1.63 1.78 0.07 -1.62 1.79
Selenium 0.05 0.94 -1.80 1.90 0.05 -1.79 1.92
Silver 1.05 2.99 -4.82 6.91 1.05 -4.70 7.15
Zinc -1.03 0.69 -2.38 0.33 -1.02 -2.36 0.33
Skagerrak and Kattegat Arsenic -0.14 0.95 -2.00 1.71 -0.14 -1.98 1.73
Cadmium -0.00 0.88 -1.72 1.72 -0.00 -1.70 1.73
Chromium -5.26 1.20 -7.60 -2.92 -5.12 -7.32 -2.87
Cobalt -0.77 1.17 -3.06 1.52 -0.77 -3.01 1.54
Copper -0.18 0.85 -1.84 1.49 -0.18 -1.83 1.50
Lead -0.47 0.90 -2.24 1.30 -0.47 -2.22 1.31
Mercury 1.01 0.87 -0.69 2.71 1.02 -0.68 2.75
Nickel -1.56 1.03 -3.57 0.45 -1.55 -3.51 0.45
Selenium -0.94 1.57 -4.02 2.14 -0.94 -3.94 2.16
Silver -0.35 1.25 -2.79 2.10 -0.35 -2.76 2.12
Tin 0.52 3.54 -6.43 7.46 0.52 -6.23 7.75
Zinc 0.25 0.84 -1.40 1.89 0.25 -1.39 1.91
Southern North Sea Arsenic 4.38 0.79 2.83 5.93 4.48 2.87 6.11
Cadmium 2.63 0.68 1.30 3.96 2.66 1.31 4.04
Chromium 0.53 1.03 -1.49 2.55 0.53 -1.48 2.58
Copper 1.64 0.66 0.34 2.94 1.65 0.34 2.98
Lead 0.70 0.69 -0.65 2.05 0.71 -0.65 2.08
Mercury 2.86 0.65 1.59 4.13 2.90 1.61 4.21
Nickel 1.95 1.08 -0.18 4.07 1.97 -0.18 4.16
Selenium 2.38 1.34 -0.24 5.00 2.41 -0.24 5.13
Silver -14.65 2.39 -19.33 -9.98 -13.63 -17.58 -9.50
Zinc 2.00 0.65 0.72 3.28 2.02 0.72 3.33
Channel Cadmium 1.56 1.06 -0.52 3.64 1.57 -0.51 3.70
Chromium -0.23 1.64 -3.44 2.98 -0.23 -3.38 3.03
Copper 3.50 0.93 1.69 5.31 3.56 1.70 5.46
Lead -2.00 1.09 -4.14 0.15 -1.98 -4.05 0.15
Mercury -1.90 1.05 -3.95 0.15 -1.88 -3.87 0.15
Nickel 3.55 1.36 0.89 6.20 3.61 0.89 6.40
Silver -4.23 7.06 -18.07 9.61 -4.14 -16.53 10.08
Zinc 1.75 0.89 -0.00 3.50 1.77 -0.00 3.56
Irish and Scottish West Coast Arsenic -1.94 0.78 -3.47 -0.41 -1.92 -3.41 -0.41
Cadmium -1.02 0.83 -2.64 0.60 -1.02 -2.61 0.61
Chromium -0.38 0.92 -2.19 1.43 -0.38 -2.16 1.44
Cobalt -3.79 1.19 -6.11 -1.47 -3.72 -5.93 -1.46
Copper 0.09 0.82 -1.51 1.69 0.09 -1.50 1.70
Lead -1.81 0.90 -3.59 -0.04 -1.80 -3.52 -0.04
Mercury 0.03 1.04 -2.02 2.07 0.03 -2.00 2.10
Nickel -2.68 0.94 -4.53 -0.84 -2.65 -4.43 -0.83
Selenium -0.58 1.04 -2.61 1.45 -0.58 -2.57 1.46
Silver -4.41 1.12 -6.59 -2.22 -4.31 -6.38 -2.19
Zinc -0.76 0.78 -2.30 0.77 -0.76 -2.28 0.78
Irish Sea Arsenic 0.40 0.74 -1.05 1.85 0.40 -1.04 1.87
Cadmium -0.37 0.70 -1.75 1.00 -0.37 -1.73 1.01
Chromium -0.46 0.96 -2.33 1.42 -0.45 -2.30 1.43
Cobalt -3.09 1.75 -6.51 0.34 -3.04 -6.30 0.34
Copper 2.68 0.66 1.38 3.97 2.71 1.39 4.05
Lead 0.97 0.71 -0.42 2.37 0.98 -0.42 2.40
Mercury 0.27 0.68 -1.06 1.61 0.27 -1.06 1.62
Nickel 1.20 0.85 -0.46 2.87 1.21 -0.46 2.91
Selenium 1.63 0.98 -0.30 3.55 1.64 -0.30 3.61
Silver -3.58 1.24 -6.00 -1.16 -3.52 -5.83 -1.15
Zinc 1.12 0.65 -0.16 2.39 1.12 -0.16 2.42
Celtic Sea Arsenic -1.56 0.99 -3.49 0.37 -1.55 -3.43 0.37
Cadmium -1.22 0.82 -2.83 0.39 -1.21 -2.79 0.39
Chromium 0.97 0.98 -0.95 2.90 0.98 -0.95 2.94
Cobalt 5.93 2.57 0.89 10.97 6.11 0.89 11.60
Copper 0.65 0.81 -0.93 2.23 0.65 -0.93 2.26
Lead -3.79 0.86 -5.48 -2.10 -3.72 -5.34 -2.07
Mercury -4.04 0.94 -5.89 -2.19 -3.96 -5.72 -2.17
Nickel 0.36 0.99 -1.59 2.31 0.36 -1.58 2.33
Selenium 2.16 1.52 -0.82 5.13 2.18 -0.81 5.26
Silver -0.74 1.45 -3.59 2.10 -0.74 -3.53 2.13
Zinc 1.09 0.81 -0.51 2.69 1.10 -0.50 2.73
Northern Bay of Biscay Cadmium -0.70 0.79 -2.25 0.85 -0.70 -2.22 0.86
Chromium 0.14 1.26 -2.32 2.60 0.14 -2.29 2.64
Copper 2.27 0.86 0.59 3.94 2.29 0.59 4.02
Lead -4.44 0.85 -6.11 -2.78 -4.34 -5.92 -2.74
Mercury -2.44 0.86 -4.13 -0.74 -2.41 -4.04 -0.74
Nickel 5.02 1.07 2.91 7.12 5.14 2.95 7.38
Silver -1.31 2.09 -5.41 2.79 -1.30 -5.26 2.83
Zinc 2.09 0.85 0.43 3.75 2.11 0.43 3.82
Iberian Sea Arsenic -0.75 0.80 -2.31 0.82 -0.74 -2.28 0.82
Cadmium 0.14 0.71 -1.25 1.52 0.14 -1.24 1.54
Copper 1.55 0.73 0.12 2.97 1.56 0.12 3.02
Lead -2.65 0.72 -4.07 -1.23 -2.61 -3.99 -1.22
Mercury -1.63 0.72 -3.04 -0.22 -1.62 -2.99 -0.22
Zinc -1.55 0.72 -2.96 -0.13 -1.53 -2.92 -0.13


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 Cadmium
Copper
Lead
Mercury 0.47 0.25 0.88 1.59 2.42
Zinc
Greenland-Scotland ridge Cadmium
Copper
Lead
Mercury 0.31 0.25 0.72 1.36 2.06
Zinc
Norwegian Sea Cadmium
Copper
Lead
Mercury 0.90 0.29 1.38 2.45 3.96
Zinc
Norwegian Trench Cadmium
Copper
Lead
Mercury 1.36 0.24 1.75 3.89 5.75
Zinc
Northern North Sea Cadmium
Copper
Lead
Mercury 1.74 0.22 2.10 5.72 8.16
Zinc
Skagerrak and Kattegat Cadmium
Copper
Lead
Mercury 1.09 0.21 1.44 2.99 4.24
Zinc
Southern North Sea Cadmium
Copper
Lead
Mercury 1.50 0.21 1.85 4.50 6.35
Zinc
Channel Cadmium
Copper
Lead
Mercury 1.28 0.22 1.65 3.60 5.19
Zinc
Irish and Scottish West Coast Cadmium
Copper
Lead
Mercury 0.74 0.23 1.12 2.10 3.05
Zinc
Irish Sea Cadmium
Copper
Lead
Mercury 1.20 0.21 1.54 3.31 4.68
Zinc
Celtic Sea Cadmium
Copper
Lead
Mercury 0.85 0.22 1.22 2.34 3.37
Zinc
Northern Bay of Biscay Cadmium
Copper
Lead
Mercury 1.39 0.22 1.76 4.01 5.80
Zinc
Iberian Sea Cadmium
Copper
Lead
Mercury 0.93 0.21 1.29 2.54 3.62
Zinc
Gulf of Cadiz Mercury 0.23 0.38 0.85 1.25 2.34


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 Cadmium 0.72 0.29 1.19 2.05 3.30
Copper 0.13 0.36 0.72 1.14 2.06
Lead -0.37 0.29 0.12 0.69 1.12
Mercury -0.20 0.36 0.39 0.81 1.47
Zinc 0.65 0.36 1.24 1.92 3.46
Greenland-Scotland ridge Cadmium 1.36 0.31 1.87 3.90 6.46
Copper 0.20 0.33 0.75 1.22 2.11
Lead -2.23 0.35 -1.65 0.11 0.19
Mercury -0.47 0.33 0.07 0.62 1.07
Zinc 0.84 0.33 1.38 2.31 3.97
Norwegian Sea Cadmium -0.20 0.40 0.45 0.82 1.57
Copper 0.12 0.51 0.96 1.13 2.61
Lead -0.72 0.39 -0.08 0.49 0.93
Mercury -0.47 0.50 0.36 0.63 1.43
Zinc 0.25 0.50 1.07 1.28 2.93
Norwegian Trench Cadmium 0.12 0.24 0.52 1.13 1.68
Copper -0.02 0.27 0.43 0.98 1.54
Lead 0.36 0.24 0.76 1.43 2.13
Mercury 0.35 0.27 0.78 1.41 2.18
Zinc 0.46 0.27 0.90 1.58 2.47
Northern North Sea Cadmium 1.06 0.16 1.32 2.88 3.76
Copper 0.54 0.20 0.86 1.71 2.37
Lead 1.10 0.16 1.37 3.00 3.93
Mercury 1.47 0.20 1.80 4.35 6.04
Zinc 0.86 0.20 1.19 2.36 3.28
Skagerrak and Kattegat Cadmium 0.33 0.15 0.58 1.39 1.79
Copper 0.20 0.17 0.48 1.22 1.61
Lead -0.20 0.16 0.06 0.82 1.06
Mercury 0.15 0.17 0.43 1.16 1.53
Zinc 0.67 0.17 0.94 1.94 2.57
Southern North Sea Cadmium 1.02 0.15 1.26 2.76 3.51
Copper 0.99 0.19 1.30 2.68 3.66
Lead 0.28 0.15 0.52 1.32 1.68
Mercury 1.19 0.20 1.51 3.27 4.53
Zinc 1.24 0.21 1.59 3.46 4.91
Channel Cadmium -0.30 0.18 -0.01 0.74 0.99
Copper 0.82 0.18 1.11 2.26 3.05
Lead 0.02 0.18 0.31 1.02 1.36
Mercury 0.68 0.19 1.00 1.97 2.71
Zinc 1.01 0.18 1.31 2.74 3.69
Irish and Scottish West Coast Cadmium -0.38 0.19 -0.07 0.69 0.93
Copper 0.60 0.19 0.92 1.83 2.51
Lead -0.87 0.19 -0.55 0.42 0.57
Mercury 0.08 0.21 0.42 1.08 1.53
Zinc 0.90 0.19 1.21 2.46 3.37
Irish Sea Cadmium 0.17 0.14 0.40 1.19 1.50
Copper 0.80 0.16 1.06 2.22 2.90
Lead 0.90 0.14 1.13 2.46 3.10
Mercury 0.50 0.17 0.77 1.64 2.15
Zinc 0.65 0.16 0.92 1.92 2.50
Celtic Sea Cadmium -0.57 0.16 -0.30 0.57 0.74
Copper 0.89 0.16 1.16 2.44 3.20
Lead -0.19 0.16 0.08 0.83 1.08
Mercury 0.21 0.18 0.51 1.23 1.67
Zinc 1.38 0.16 1.65 3.99 5.22
Northern Bay of Biscay Cadmium -0.42 0.15 -0.17 0.66 0.84
Copper 2.63 0.15 2.87 13.81 17.67
Lead -0.14 0.15 0.11 0.87 1.11
Mercury 1.21 0.23 1.58 3.34 4.85
Zinc 2.82 0.15 3.06 16.76 21.43
Iberian Sea Cadmium -0.36 0.14 -0.12 0.70 0.89
Copper 0.13 0.15 0.38 1.14 1.46
Lead 0.02 0.15 0.26 1.02 1.29
Mercury 0.13 0.15 0.37 1.14 1.45
Zinc 1.13 0.15 1.38 3.09 3.96
Gulf of Cadiz Mercury