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 2024 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) or matrix (for sediment) 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 2017 to 2022
  • 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 2017 to 2022
  • 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. 21 of the 4533 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 0 0 0 0 1 1 0 2 0 2 8
no trend 7 9 11 10 11 9 6 10 0 4 8 7 92
downward trend 3 1 0 0 0 2 4 0 0 2 0 2 14
Greenland-Scotland ridge upward trend 0 5 0 0 0 1 3 0 0 0 0 2 11
no trend 8 4 0 0 8 5 11 0 12 0 0 6 54
downward trend 1 3 0 0 1 1 1 0 0 0 0 1 8
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 5 0 0 0 0 0 5
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 0 1 0 2 0 0 5
no trend 3 5 5 4 6 4 4 2 0 1 4 5 43
downward trend 1 1 1 1 0 2 2 3 0 0 0 1 12
total upward trend 3 6 0 0 0 1 7 2 0 4 0 4 27
no trend 18 18 16 14 25 18 26 12 12 5 12 18 194
downward trend 5 5 1 1 1 5 7 3 0 2 0 4 34
2 Norwegian Trench upward trend 1 0 3 1 1 0 3 1 0 1 1 2 14
no trend 12 6 11 13 11 6 9 13 0 6 6 11 104
downward trend 2 9 1 1 3 9 4 1 0 1 1 2 34
Northern North Sea upward trend 6 5 2 1 3 4 9 1 5 0 0 3 39
no trend 24 18 9 8 29 18 27 26 11 4 0 28 202
downward trend 4 7 0 0 9 8 5 2 1 0 0 11 47
Skagerrak and Kattegat upward trend 1 5 2 3 5 6 6 2 0 1 1 6 38
no trend 30 24 22 14 24 17 25 22 9 23 14 25 249
downward trend 0 3 7 2 5 8 3 10 0 2 0 3 43
Southern North Sea upward trend 3 14 1 0 13 4 15 4 1 0 0 10 65
no trend 11 22 10 0 30 30 29 11 2 2 0 29 176
downward trend 1 4 4 0 2 6 5 2 3 2 0 1 30
Channel upward trend 0 4 3 0 12 3 2 5 0 0 0 8 37
no trend 1 24 22 0 21 20 26 20 1 3 0 25 163
downward trend 0 2 2 0 0 8 5 2 0 0 0 0 19
total upward trend 11 28 11 5 34 17 35 13 6 2 2 29 193
no trend 78 94 74 35 115 91 116 92 23 38 20 118 894
downward trend 7 25 14 3 19 39 22 17 4 5 1 17 173
3 Irish and Scottish West Coast upward trend 1 3 2 1 5 2 2 0 3 0 0 3 22
no trend 40 36 42 25 45 35 47 34 27 38 0 45 414
downward trend 12 10 4 4 2 12 4 12 1 6 0 5 72
Irish Sea upward trend 5 5 1 1 15 4 5 3 1 2 0 8 50
no trend 32 38 28 9 52 39 50 36 19 16 0 59 378
downward trend 7 8 2 3 2 9 8 2 2 5 0 2 50
Celtic Sea upward trend 1 1 3 1 6 0 5 2 3 1 0 8 31
no trend 22 33 32 9 39 27 37 36 9 21 0 41 306
downward trend 9 11 7 0 9 17 11 1 0 3 0 8 76
total upward trend 7 9 6 3 26 6 12 5 7 3 0 19 103
no trend 94 107 102 43 136 101 134 106 55 75 0 145 1098
downward trend 28 29 13 7 13 38 23 15 3 14 0 15 198
4 Northern Bay of Biscay upward trend 0 0 2 0 11 0 1 5 0 0 0 5 24
no trend 0 32 36 0 27 27 31 35 0 6 0 35 229
downward trend 0 9 3 0 3 14 9 1 0 2 0 1 42
Iberian Coast upward trend 0 4 0 0 5 0 1 0 0 0 0 1 11
no trend 18 25 1 0 15 19 20 1 0 0 0 11 110
downward trend 1 4 0 0 0 12 8 0 0 0 0 8 33
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 3 0 0 0 0 0 5
downward trend 0 0 0 0 0 1 0 0 0 0 0 0 1
total upward trend 0 5 2 0 16 0 2 5 0 0 0 6 36
no trend 18 57 37 0 42 48 54 36 0 6 0 46 344
downward trend 1 13 3 0 3 27 17 1 0 2 0 9 76


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 9 9 0 0 0 0 9 9 25 0 18 7
no trend 64 82 100 100 100 82 55 91 50 100 64 81
downward trend 27 9 0 0 0 18 36 0 25 0 18 12
Greenland-Scotland ridge upward trend 0 42 0 14 20 0 22 15
no trend 89 33 89 72 73 100 67 74
downward trend 11 25 11 14 7 0 11 11
East of Iceland upward trend 38 38
no trend 62 62
downward trend 0 0
Norwegian Sea upward trend 33 0 0 0 0 0 0 17 67 0 0 8
no trend 50 83 83 80 100 67 67 33 33 100 83 72
downward trend 17 17 17 20 0 33 33 50 0 0 17 20
total upward trend 12 21 0 0 0 4 17 12 0 36 0 16 11
no trend 69 62 94 93 96 75 65 70 100 46 100 69 76
downward trend 19 17 6 7 4 21 18 18 0 18 0 15 13
2 Norwegian Trench upward trend 7 0 20 7 7 0 19 7 13 13 13 9
no trend 80 40 73 86 73 40 56 86 75 75 74 69
downward trend 13 60 7 7 20 60 25 7 12 12 13 22
Northern North Sea upward trend 18 17 18 11 7 13 22 3 29 0 7 14
no trend 70 60 82 89 71 60 66 90 65 100 67 70
downward trend 12 23 0 0 22 27 12 7 6 0 26 16
Skagerrak and Kattegat upward trend 3 16 6 16 15 19 18 6 0 4 7 18 12
no trend 97 75 71 74 70 55 73 65 100 88 93 73 75
downward trend 0 9 23 10 15 26 9 29 0 8 0 9 13
Southern North Sea upward trend 20 35 7 29 10 31 23 17 0 25 24
no trend 73 55 66 67 75 59 65 33 50 72 65
downward trend 7 10 27 4 15 10 12 50 50 3 11
Channel upward trend 0 13 11 36 10 6 19 0 0 24 17
no trend 100 80 82 64 64 79 74 100 100 76 74
downward trend 0 7 7 0 26 15 7 0 0 0 9
total upward trend 12 19 11 12 20 12 20 11 18 4 9 18 15
no trend 81 64 75 81 69 62 67 75 70 85 87 72 71
downward trend 7 17 14 7 11 26 13 14 12 11 4 10 14
3 Irish and Scottish West Coast upward trend 2 6 4 3 10 4 4 0 10 0 6 4
no trend 75 74 88 84 86 71 89 74 87 86 85 82
downward trend 23 20 8 13 4 25 7 26 3 14 9 14
Irish Sea upward trend 11 10 3 8 22 8 8 7 5 9 12 11
no trend 73 74 90 69 75 75 79 88 86 69 85 79
downward trend 16 16 7 23 3 17 13 5 9 22 3 10
Celtic Sea upward trend 3 2 7 10 11 0 9 5 25 4 14 8
no trend 69 73 76 90 72 61 70 92 75 84 72 74
downward trend 28 25 17 0 17 39 21 3 0 12 14 18
total upward trend 5 6 5 6 15 4 7 4 11 3 11 7
no trend 73 74 84 81 78 70 79 84 84 82 81 79
downward trend 22 20 11 13 7 26 14 12 5 15 8 14
4 Northern Bay of Biscay upward trend 0 5 27 0 2 12 0 12 8
no trend 78 88 66 66 76 85 75 85 78
downward trend 22 7 7 34 22 3 25 3 14
Iberian Coast upward trend 0 12 0 25 0 3 0 5 7
no trend 95 76 100 75 61 69 100 55 72
downward trend 5 12 0 0 39 28 0 40 21
Gulf of Cadiz upward trend 100 0 0 14
no trend 0 67 100 72
downward trend 0 33 0 14
total upward trend 0 7 5 26 0 3 12 0 10 8
no trend 95 76 88 69 64 74 86 75 75 75
downward trend 5 17 7 5 36 23 2 25 15 17


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 5 0 13
green 0 0 0 2 0 2
orange 10 6 4 0 6 26
red 0 0 0 6 0 6
Greenland-Scotland ridge blue 0 0 9 9 0 18
green 0 0 0 4 0 4
orange 11 9 2 0 9 31
red 0 0 0 5 0 5
East of Iceland blue 0 0 0 2 0 2
green 0 0 0 6 0 6
orange 0 0 0 0 0 0
red 0 0 0 0 0 0
Norwegian Sea blue 3 0 4 3 0 10
green 0 0 0 0 0 0
orange 3 3 2 0 3 11
red 0 0 0 3 0 3
total blue 4 0 20 19 0 43
green 0 0 0 12 0 12
orange 24 18 8 0 18 68
red 0 0 0 14 0 14
2 Norwegian Trench blue 5 3 5 2 0 15
green 0 0 0 1 0 1
orange 10 8 10 0 11 39
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 24 17 35 0 20 96
red 0 0 0 50 0 50
Skagerrak and Kattegat blue 4 1 19 5 0 29
green 0 0 0 13 0 13
orange 34 27 19 0 28 108
red 0 0 0 24 0 24
Southern North Sea blue 4 0 11 1 0 16
green 0 0 0 1 0 1
orange 40 23 32 0 18 113
red 0 0 0 55 0 55
Channel blue 18 0 9 0 0 27
green 0 0 0 6 0 6
orange 14 28 23 0 28 93
red 0 0 0 32 0 32
total blue 42 7 44 8 0 101
green 0 0 0 21 0 21
orange 122 103 119 0 105 449
red 0 0 0 174 0 174
3 Irish and Scottish West Coast blue 40 0 42 9 0 91
green 0 0 0 11 0 11
orange 11 48 9 0 48 116
red 0 0 0 40 0 40
Irish Sea blue 24 0 6 6 3 39
green 0 0 0 10 0 10
orange 29 36 47 0 33 145
red 0 0 0 63 0 63
Celtic Sea blue 35 3 27 13 2 80
green 0 0 0 9 0 9
orange 11 40 19 0 41 111
red 0 0 0 45 0 45
total blue 99 3 75 28 5 210
green 0 0 0 30 0 30
orange 51 124 75 0 122 372
red 0 0 0 148 0 148
4 Northern Bay of Biscay blue 35 0 21 0 0 56
green 0 0 0 4 0 4
orange 6 41 20 0 41 108
red 0 0 0 43 0 43
Iberian Coast blue 20 1 14 8 0 43
green 0 0 0 14 0 14
orange 9 22 15 0 23 69
red 0 0 0 18 0 18
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 55 1 35 8 0 99
green 0 0 0 20 0 20
orange 16 63 36 0 64 179
red 0 0 0 62 0 62


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 39 0 28
green 0 0 0 15 0 4
orange 91 100 36 0 100 55
red 0 0 0 46 0 13
Greenland-Scotland ridge blue 0 0 82 50 0 31
green 0 0 0 22 0 7
orange 100 100 18 0 100 53
red 0 0 0 28 0 9
East of Iceland blue 25 25
green 75 75
orange 0 0
red 0 0
Norwegian Sea blue 50 0 67 50 0 42
green 0 0 0 0 0 0
orange 50 100 33 0 100 46
red 0 0 0 50 0 12
total blue 14 0 71 42 0 31
green 0 0 0 27 0 9
orange 86 100 29 0 100 50
red 0 0 0 31 0 10
2 Norwegian Trench blue 33 27 33 13 0 22
green 0 0 0 6 0 2
orange 67 73 67 0 100 57
red 0 0 0 81 0 19
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 11 4 50 12 0 17
green 0 0 0 31 0 7
orange 89 96 50 0 100 62
red 0 0 0 57 0 14
Southern North Sea blue 9 0 26 2 0 9
green 0 0 0 2 0 0
orange 91 100 74 0 100 61
red 0 0 0 96 0 30
Channel blue 56 0 28 0 0 17
green 0 0 0 16 0 4
orange 44 100 72 0 100 59
red 0 0 0 84 0 20
total blue 26 6 27 4 0 14
green 0 0 0 10 0 3
orange 74 94 73 0 100 60
red 0 0 0 86 0 23
3 Irish and Scottish West Coast blue 78 0 82 15 0 35
green 0 0 0 18 0 4
orange 22 100 18 0 100 45
red 0 0 0 67 0 16
Irish Sea blue 45 0 11 7 8 15
green 0 0 0 13 0 4
orange 55 100 89 0 92 56
red 0 0 0 80 0 25
Celtic Sea blue 76 7 59 19 5 33
green 0 0 0 14 0 4
orange 24 93 41 0 95 45
red 0 0 0 67 0 18
total blue 66 2 50 14 4 28
green 0 0 0 14 0 4
orange 34 98 50 0 96 49
red 0 0 0 72 0 19
4 Northern Bay of Biscay blue 85 0 51 0 0 27
green 0 0 0 9 0 2
orange 15 100 49 0 100 51
red 0 0 0 91 0 20
Iberian Coast blue 69 4 48 20 0 30
green 0 0 0 35 0 10
orange 31 96 52 0 100 48
red 0 0 0 45 0 12
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 77 2 49 9 0 27
green 0 0 0 22 0 6
orange 23 98 51 0 100 50
red 0 0 0 69 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 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
  • 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 -1.40 1.45 -4.24 1.43 -1.39 -4.15 1.44
Cadmium -0.48 1.43 -3.27 2.32 -0.48 -3.22 2.35
Chromium -0.51 2.16 -4.74 3.72 -0.51 -4.63 3.79
Cobalt -2.99 1.68 -6.28 0.30 -2.94 -6.09 0.30
Copper -1.11 1.45 -3.96 1.74 -1.11 -3.88 1.75
Lead -1.94 1.53 -4.95 1.07 -1.92 -4.83 1.08
Mercury -1.86 1.44 -4.67 0.96 -1.84 -4.56 0.96
Nickel 1.25 1.79 -2.25 4.75 1.26 -2.23 4.87
Silver -2.29 1.71 -5.63 1.06 -2.26 -5.48 1.06
Tin 2.30 4.02 -5.58 10.19 2.33 -5.43 10.73
Zinc -0.83 1.38 -3.54 1.88 -0.83 -3.48 1.90
Greenland-Scotland ridge Arsenic 0.12 1.11 -2.06 2.30 0.12 -2.04 2.33
Cadmium 0.47 1.06 -1.61 2.55 0.47 -1.60 2.58
Copper -0.80 1.17 -3.09 1.49 -0.80 -3.05 1.50
Lead -0.55 1.45 -3.40 2.30 -0.55 -3.34 2.32
Mercury 0.55 0.97 -1.36 2.46 0.55 -1.35 2.49
Selenium 0.62 1.03 -1.40 2.64 0.62 -1.39 2.68
Zinc 0.39 1.10 -1.77 2.54 0.39 -1.76 2.58
Norwegian Sea Arsenic -0.84 1.84 -4.45 2.77 -0.84 -4.36 2.81
Cadmium -0.59 1.99 -4.49 3.32 -0.58 -4.39 3.37
Chromium -7.19 3.29 -13.63 -0.75 -6.94 -12.75 -0.75
Cobalt -0.79 2.23 -5.17 3.59 -0.78 -5.04 3.66
Copper -1.18 1.99 -5.08 2.72 -1.18 -4.96 2.75
Lead -6.92 1.96 -10.75 -3.08 -6.68 -10.19 -3.04
Mercury -1.91 1.88 -5.60 1.78 -1.89 -5.44 1.79
Nickel -4.19 2.59 -9.27 0.88 -4.11 -8.85 0.88
Silver 6.96 3.15 0.79 13.12 7.20 0.79 14.02
Tin 4.38 3.33 -2.14 10.91 4.48 -2.12 11.52
Zinc -2.59 1.76 -6.04 0.87 -2.55 -5.86 0.87
Norwegian Trench Arsenic -1.59 1.34 -4.21 1.03 -1.58 -4.12 1.03
Cadmium -4.02 1.14 -6.26 -1.78 -3.94 -6.07 -1.77
Chromium 5.48 1.75 2.04 8.92 5.63 2.06 9.33
Cobalt -0.21 1.24 -2.64 2.22 -0.21 -2.60 2.25
Copper 0.95 1.16 -1.31 3.22 0.96 -1.30 3.28
Lead -2.45 1.20 -4.79 -0.11 -2.42 -4.68 -0.11
Mercury 1.37 1.16 -0.90 3.64 1.38 -0.89 3.70
Nickel 1.72 1.56 -1.33 4.77 1.73 -1.32 4.88
Silver 1.17 1.91 -2.58 4.93 1.18 -2.54 5.05
Tin 2.05 3.40 -4.61 8.71 2.07 -4.51 9.10
Zinc 0.37 1.14 -1.87 2.60 0.37 -1.85 2.64
Northern North Sea Arsenic 0.05 0.70 -1.33 1.43 0.05 -1.32 1.44
Cadmium -0.38 0.71 -1.77 1.02 -0.38 -1.75 1.02
Chromium 4.40 1.80 0.87 7.93 4.50 0.88 8.25
Cobalt 0.29 1.57 -2.79 3.37 0.29 -2.75 3.43
Copper -1.02 0.67 -2.34 0.29 -1.02 -2.31 0.29
Lead -0.98 0.75 -2.46 0.49 -0.98 -2.43 0.49
Mercury 0.49 0.68 -0.85 1.82 0.49 -0.84 1.84
Nickel -0.18 0.83 -1.81 1.46 -0.18 -1.80 1.47
Selenium 0.14 0.94 -1.70 1.99 0.14 -1.68 2.01
Silver 2.55 3.26 -3.85 8.94 2.58 -3.77 9.35
Zinc -1.11 0.65 -2.38 0.16 -1.10 -2.35 0.17
Skagerrak and Kattegat Arsenic -0.57 0.91 -2.35 1.20 -0.57 -2.32 1.21
Cadmium 0.02 0.83 -1.61 1.64 0.02 -1.59 1.66
Chromium -5.35 1.15 -7.60 -3.09 -5.21 -7.32 -3.04
Cobalt -1.36 1.14 -3.60 0.88 -1.35 -3.54 0.88
Copper -0.14 0.79 -1.69 1.41 -0.14 -1.68 1.42
Lead -1.34 0.85 -3.02 0.33 -1.34 -2.97 0.33
Mercury 0.03 0.82 -1.58 1.63 0.03 -1.57 1.64
Nickel -2.25 0.96 -4.12 -0.37 -2.22 -4.04 -0.37
Selenium -0.30 1.41 -3.06 2.46 -0.30 -3.02 2.49
Silver 0.79 1.17 -1.51 3.09 0.79 -1.50 3.13
Tin 0.02 3.92 -7.66 7.69 0.02 -7.37 8.00
Zinc 0.25 0.78 -1.29 1.78 0.25 -1.28 1.80
Southern North Sea Arsenic 3.18 0.85 1.50 4.85 3.23 1.51 4.97
Cadmium 2.58 0.65 1.31 3.86 2.62 1.32 3.93
Chromium -1.81 1.09 -3.95 0.33 -1.79 -3.87 0.33
Copper 1.60 0.64 0.36 2.85 1.62 0.36 2.89
Lead 0.19 0.66 -1.11 1.49 0.19 -1.11 1.51
Mercury 2.44 0.62 1.22 3.66 2.47 1.23 3.73
Nickel 1.34 0.99 -0.61 3.28 1.35 -0.61 3.34
Selenium 1.08 1.26 -1.39 3.55 1.08 -1.38 3.61
Silver -15.25 2.41 -19.97 -10.54 -14.15 -18.10 -10.00
Zinc 1.58 0.62 0.37 2.79 1.59 0.37 2.83
Channel Cadmium 1.17 0.87 -0.53 2.87 1.18 -0.53 2.91
Chromium 0.01 1.26 -2.45 2.48 0.01 -2.42 2.51
Copper 4.10 0.82 2.50 5.71 4.19 2.53 5.88
Lead -1.69 0.90 -3.44 0.07 -1.67 -3.38 0.07
Mercury -1.61 0.87 -3.31 0.09 -1.60 -3.26 0.09
Nickel 3.25 1.16 0.98 5.53 3.31 0.98 5.69
Silver -5.08 5.94 -16.71 6.55 -4.95 -15.39 6.77
Zinc 2.49 0.78 0.95 4.02 2.52 0.96 4.10
Irish and Scottish West Coast Arsenic -2.31 0.55 -3.38 -1.24 -2.28 -3.32 -1.23
Cadmium -1.29 0.59 -2.45 -0.14 -1.28 -2.42 -0.14
Chromium -2.13 0.70 -3.50 -0.76 -2.11 -3.44 -0.76
Cobalt -2.66 0.77 -4.17 -1.15 -2.63 -4.09 -1.15
Copper -0.14 0.59 -1.31 1.02 -0.14 -1.30 1.02
Lead -2.74 0.62 -3.95 -1.52 -2.70 -3.88 -1.51
Mercury -0.74 0.66 -2.03 0.55 -0.74 -2.01 0.55
Nickel -3.85 0.68 -5.17 -2.52 -3.77 -5.04 -2.49
Selenium 0.04 0.71 -1.35 1.43 0.04 -1.34 1.44
Silver -2.24 0.75 -3.70 -0.78 -2.22 -3.63 -0.78
Zinc -0.63 0.56 -1.73 0.46 -0.63 -1.72 0.47
Irish Sea Arsenic 0.23 0.63 -1.02 1.47 0.23 -1.01 1.48
Cadmium -0.80 0.60 -1.98 0.37 -0.80 -1.96 0.38
Chromium -1.10 0.85 -2.77 0.56 -1.10 -2.73 0.56
Cobalt -2.34 1.35 -5.00 0.31 -2.32 -4.87 0.31
Copper 2.12 0.57 1.01 3.23 2.15 1.02 3.28
Lead 0.19 0.62 -1.02 1.39 0.19 -1.01 1.40
Mercury -0.18 0.58 -1.32 0.97 -0.18 -1.31 0.97
Nickel 0.65 0.75 -0.83 2.12 0.65 -0.82 2.15
Selenium 1.98 0.86 0.30 3.67 2.00 0.30 3.73
Silver -2.13 0.97 -4.04 -0.22 -2.11 -3.96 -0.22
Zinc 0.79 0.54 -0.27 1.84 0.79 -0.27 1.86
Celtic Sea Arsenic -1.45 0.70 -2.82 -0.08 -1.44 -2.78 -0.08
Cadmium -0.91 0.63 -2.15 0.33 -0.90 -2.12 0.33
Chromium -0.91 0.77 -2.42 0.60 -0.90 -2.39 0.60
Cobalt 3.56 1.49 0.63 6.49 3.63 0.63 6.70
Copper -0.34 0.63 -1.58 0.89 -0.34 -1.56 0.89
Lead -3.75 0.66 -5.03 -2.46 -3.68 -4.91 -2.43
Mercury -2.38 0.69 -3.72 -1.03 -2.35 -3.66 -1.02
Nickel -1.06 0.79 -2.61 0.49 -1.06 -2.58 0.49
Selenium 3.86 1.11 1.68 6.03 3.93 1.69 6.22
Silver -0.94 1.01 -2.92 1.05 -0.93 -2.87 1.05
Zinc 0.36 0.62 -0.86 1.58 0.36 -0.85 1.59
Northern Bay of Biscay Cadmium -2.42 0.67 -3.75 -1.10 -2.39 -3.68 -1.09
Chromium -0.77 1.02 -2.77 1.23 -0.77 -2.73 1.24
Copper 2.79 0.73 1.35 4.23 2.83 1.36 4.32
Lead -4.61 0.71 -5.99 -3.23 -4.51 -5.82 -3.18
Mercury -3.86 0.73 -5.30 -2.43 -3.79 -5.16 -2.40
Nickel 1.69 0.88 -0.03 3.42 1.71 -0.03 3.47
Silver -3.62 1.81 -7.16 -0.07 -3.55 -6.91 -0.07
Zinc 1.65 0.71 0.26 3.03 1.66 0.26 3.08
Iberian Coast Arsenic -0.04 0.83 -1.66 1.58 -0.04 -1.65 1.60
Cadmium 0.22 0.71 -1.18 1.62 0.22 -1.17 1.63
Copper 1.41 0.78 -0.12 2.94 1.42 -0.11 2.98
Lead -2.79 0.75 -4.26 -1.33 -2.75 -4.17 -1.32
Mercury -1.63 0.73 -3.05 -0.20 -1.61 -3.01 -0.20
Zinc -1.01 0.76 -2.50 0.48 -1.01 -2.47 0.48
Gulf of Cadiz Lead -5.14 3.35 -11.70 1.43 -5.01 -11.05 1.44
Mercury -4.25 2.66 -9.46 0.97 -4.16 -9.03 0.97


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 0.36 0.21 0.70 1.43 2.02
Zinc
Greenland-Scotland ridge Cadmium
Copper
Lead
Mercury 0.32 0.20 0.65 1.37 1.92
Zinc
Norwegian Sea Cadmium
Copper
Lead
Mercury 0.84 0.25 1.26 2.31 3.51
Zinc
Norwegian Trench Cadmium
Copper
Lead
Mercury 1.30 0.19 1.61 3.67 5.02
Zinc
Northern North Sea Cadmium
Copper
Lead
Mercury 1.80 0.16 2.07 6.06 7.92
Zinc
Skagerrak and Kattegat Cadmium
Copper
Lead
Mercury 1.04 0.16 1.30 2.83 3.68
Zinc
Southern North Sea Cadmium
Copper
Lead
Mercury 1.55 0.16 1.81 4.70 6.08
Zinc
Channel Cadmium
Copper
Lead
Mercury 1.29 0.17 1.56 3.63 4.77
Zinc
Irish and Scottish West Coast Cadmium
Copper
Lead
Mercury 0.89 0.16 1.16 2.44 3.18
Zinc
Irish Sea Cadmium
Copper
Lead
Mercury 1.18 0.15 1.43 3.25 4.19
Zinc
Celtic Sea Cadmium
Copper
Lead
Mercury 0.86 0.16 1.12 2.36 3.07
Zinc
Northern Bay of Biscay Cadmium
Copper
Lead
Mercury 1.42 0.17 1.70 4.15 5.45
Zinc
Iberian Coast Cadmium
Copper
Lead
Mercury 0.83 0.17 1.11 2.30 3.04
Zinc
Gulf of Cadiz Mercury -0.10 0.35 0.47 0.90 1.60


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 0.70 0.29 1.18 2.01 3.25
Copper 0.21 0.37 0.83 1.24 2.29
Lead -0.41 0.30 0.08 0.66 1.08
Mercury -0.33 0.37 0.28 0.72 1.32
Zinc 0.61 0.37 1.22 1.84 3.39
Greenland-Scotland ridge Cadmium 1.42 0.30 1.91 4.13 6.72
Copper 0.16 0.32 0.69 1.17 1.98
Lead -2.09 0.34 -1.53 0.12 0.22
Mercury -0.49 0.32 0.03 0.61 1.04
Zinc 0.82 0.32 1.34 2.26 3.81
Norwegian Sea Cadmium -0.21 0.40 0.45 0.81 1.56
Copper 0.07 0.53 0.94 1.08 2.57
Lead -0.77 0.40 -0.11 0.47 0.90
Mercury -0.62 0.53 0.25 0.54 1.28
Zinc 0.26 0.52 1.12 1.29 3.06
Norwegian Trench Cadmium -0.04 0.25 0.37 0.96 1.45
Copper -0.08 0.28 0.38 0.92 1.46
Lead 0.12 0.25 0.53 1.12 1.70
Mercury 0.25 0.27 0.70 1.28 2.01
Zinc 0.40 0.28 0.86 1.48 2.36
Northern North Sea Cadmium 1.00 0.17 1.28 2.72 3.59
Copper 0.44 0.21 0.77 1.55 2.17
Lead 1.07 0.17 1.35 2.91 3.84
Mercury 1.38 0.21 1.72 3.98 5.59
Zinc 0.77 0.21 1.11 2.16 3.03
Skagerrak and Kattegat Cadmium 0.29 0.16 0.55 1.33 1.73
Copper 0.19 0.18 0.48 1.21 1.62
Lead -0.29 0.16 -0.03 0.75 0.97
Mercury 0.11 0.18 0.41 1.12 1.50
Zinc 0.64 0.18 0.93 1.89 2.53
Southern North Sea Cadmium 0.99 0.15 1.23 2.68 3.44
Copper 0.90 0.19 1.22 2.47 3.39
Lead 0.25 0.15 0.50 1.28 1.64
Mercury 1.06 0.20 1.40 2.90 4.04
Zinc 1.10 0.21 1.45 3.01 4.28
Channel Cadmium -0.21 0.17 0.08 0.81 1.08
Copper 0.90 0.18 1.20 2.45 3.31
Lead 0.05 0.17 0.34 1.05 1.40
Mercury 0.65 0.19 0.97 1.91 2.63
Zinc 1.07 0.18 1.37 2.91 3.93
Irish and Scottish West Coast Cadmium -0.66 0.14 -0.43 0.52 0.65
Copper 1.17 0.14 1.40 3.21 4.07
Lead -1.14 0.14 -0.91 0.32 0.40
Mercury 0.18 0.19 0.49 1.19 1.64
Zinc 1.69 0.14 1.92 5.42 6.84
Irish Sea Cadmium 0.07 0.14 0.30 1.08 1.35
Copper 0.89 0.16 1.15 2.43 3.16
Lead 0.75 0.14 0.98 2.12 2.67
Mercury 0.48 0.17 0.76 1.62 2.13
Zinc 0.82 0.16 1.08 2.27 2.95
Celtic Sea Cadmium -0.69 0.14 -0.45 0.50 0.64
Copper 1.00 0.15 1.24 2.71 3.45
Lead -0.39 0.15 -0.15 0.68 0.86
Mercury 0.10 0.18 0.39 1.11 1.48
Zinc 1.51 0.15 1.76 4.54 5.79
Northern Bay of Biscay Cadmium -0.49 0.15 -0.24 0.61 0.79
Copper 2.67 0.15 2.92 14.38 18.48
Lead -0.19 0.15 0.06 0.82 1.06
Mercury 1.02 0.24 1.41 2.78 4.11
Zinc 2.82 0.15 3.07 16.75 21.50
Iberian Coast Cadmium -0.42 0.19 -0.11 0.65 0.89
Copper 0.23 0.21 0.58 1.26 1.78
Lead -0.17 0.19 0.14 0.84 1.16
Mercury 0.14 0.20 0.47 1.15 1.61
Zinc 1.12 0.21 1.46 3.06 4.31
Gulf of Cadiz Mercury