Regional assessment of status against human health thresholds in metal concentrations in biota

Overview

This document provides additional regional assessments of the status of metal concentrations in biota based on human health rather than environmental thresholds. The regional assessments are part of the 2023 OSPAR CEMP assessment and concern the metals CD, PB, and HG which are compared against the Maximum Permissible Concentration (MPC). Methodological details are only described briefly: further information can be found here.


Summary of individual time series results

This section summarises the individual time series assessments of trend and status for each metal. This is the only place where trends are presented as the focus of this document is on status relative to the MPC.

The first set of tabs show the trend and status assessments for each metal in turn. The colours have the following meaning:

  • green: the mean concentration is significantly (p < 0.05) below the MPC
  • red: the mean concentration is not signficantly below the MPC
  • 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 second 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 green or red status in each MIME and OSPAR region
  • the same information presented as proportions


CD


PB


HG


Trend summary (numbers)

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

OSPAR region MIME region status CD PB HG total
1 Barents Sea upward trend 1 0 1 2
no trend 8 7 8 23
downward trend 1 2 2 5
Greenland-Scotland ridge upward trend 3 1 3 7
no trend 9 5 13 27
downward trend 2 1 1 4
East of Iceland upward trend 0 0 3 3
no trend 0 0 6 6
downward trend 0 0 0 0
Norwegian Sea upward trend 0 0 1 1
no trend 5 3 2 10
downward trend 1 3 3 7
total upward trend 4 1 8 13
no trend 22 15 29 66
downward trend 4 6 6 16
2 Norwegian Trench upward trend 0 0 3 3
no trend 5 7 10 22
downward trend 11 9 4 24
Northern North Sea upward trend 7 5 10 22
no trend 17 20 28 65
downward trend 8 7 5 20
Skagerrak and Kattegat upward trend 7 8 11 26
no trend 22 18 22 62
downward trend 4 6 2 12
Southern North Sea upward trend 14 5 16 35
no trend 24 32 31 87
downward trend 4 5 4 13
Channel upward trend 5 1 1 7
no trend 20 20 23 63
downward trend 1 5 5 11
total upward trend 33 19 41 93
no trend 88 97 114 299
downward trend 28 32 20 80
3 Irish and Scottish West Coast upward trend 3 2 2 7
no trend 17 21 17 55
downward trend 6 4 1 11
Irish Sea upward trend 4 4 5 13
no trend 27 36 34 97
downward trend 9 6 6 21
Celtic Sea upward trend 2 0 0 2
no trend 21 20 22 63
downward trend 8 12 5 25
total upward trend 9 6 7 22
no trend 65 77 73 215
downward trend 23 22 12 57
4 Northern Bay of Biscay upward trend 3 0 2 5
no trend 32 27 31 90
downward trend 3 11 5 19
Iberian Sea upward trend 4 1 1 6
no trend 26 17 22 65
downward trend 5 16 10 31
Gulf of Cadiz upward trend 1 0 0 1
no trend 0 2 2 4
downward trend 0 0 0 0
total upward trend 8 1 3 12
no trend 58 46 55 159
downward trend 8 27 15 50


Trend summary (proportions)

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

OSPAR region MIME region status CD PB HG total
1 Barents Sea upward trend 10 0 9 7
no trend 80 78 73 76
downward trend 10 22 18 17
Greenland-Scotland ridge upward trend 22 14 18 18
no trend 64 72 76 71
downward trend 14 14 6 11
East of Iceland upward trend 33 33
no trend 67 67
downward trend 0 0
Norwegian Sea upward trend 0 0 17 5
no trend 83 50 33 56
downward trend 17 50 50 39
total upward trend 13 5 19 14
no trend 74 68 67 69
downward trend 13 27 14 17
2 Norwegian Trench upward trend 0 0 18 6
no trend 31 44 59 45
downward trend 69 56 23 49
Northern North Sea upward trend 22 16 23 20
no trend 53 62 65 61
downward trend 25 22 12 19
Skagerrak and Kattegat upward trend 21 25 31 26
no trend 67 56 63 62
downward trend 12 19 6 12
Southern North Sea upward trend 33 12 31 26
no trend 57 76 61 64
downward trend 10 12 8 10
Channel upward trend 19 4 4 9
no trend 77 77 79 78
downward trend 4 19 17 13
total upward trend 22 13 24 20
no trend 59 65 65 63
downward trend 19 22 11 17
3 Irish and Scottish West Coast upward trend 12 7 10 10
no trend 65 78 85 75
downward trend 23 15 5 15
Irish Sea upward trend 10 9 11 10
no trend 68 78 76 74
downward trend 22 13 13 16
Celtic Sea upward trend 6 0 0 2
no trend 68 62 81 70
downward trend 26 38 19 28
total upward trend 9 6 8 8
no trend 67 73 79 73
downward trend 24 21 13 19
4 Northern Bay of Biscay upward trend 8 0 5 4
no trend 84 71 82 79
downward trend 8 29 13 17
Iberian Sea upward trend 12 3 3 6
no trend 74 50 67 64
downward trend 14 47 30 30
Gulf of Cadiz upward trend 100 0 0 20
no trend 0 100 100 80
downward trend 0 0 0 0
total upward trend 11 1 4 5
no trend 78 62 75 72
downward trend 11 37 21 23


Status summary (numbers)

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

OSPAR region MIME region status CD PB HG total
1 Barents Sea green 11 11 11 33
red 0 0 0 0
Greenland-Scotland ridge green 8 10 11 29
red 2 0 0 2
Norwegian Sea green 6 6 6 18
red 0 0 0 0
total green 25 27 28 80
red 2 0 0 2
2 Norwegian Trench green 16 14 17 47
red 0 2 0 2
Northern North Sea green 36 45 36 117
red 8 3 0 11
Skagerrak and Kattegat green 42 39 42 123
red 0 2 0 2
Southern North Sea green 42 56 48 146
red 6 0 0 6
Channel green 31 34 31 96
red 0 0 0 0
total green 167 188 174 529
red 14 7 0 21
3 Irish and Scottish West Coast green 29 30 27 86
red 1 0 0 1
Irish Sea green 56 62 49 167
red 0 3 0 3
Celtic Sea green 40 42 40 122
red 0 0 0 0
total green 125 134 116 375
red 1 3 0 4
4 Northern Bay of Biscay green 43 45 45 133
red 2 0 0 2
Iberian Sea green 53 50 49 152
red 0 2 0 2
Gulf of Cadiz green 3 3 3 9
red 0 0 0 0
total green 99 98 97 294
red 2 2 0 4


Status summary (proportions)

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

OSPAR region MIME region status CD PB HG total
1 Barents Sea green 100 100 100 100
red 0 0 0 0
Greenland-Scotland ridge green 80 100 100 94
red 20 0 0 6
Norwegian Sea green 100 100 100 100
red 0 0 0 0
total green 93 100 100 98
red 7 0 0 2
2 Norwegian Trench green 100 88 100 96
red 0 12 0 4
Northern North Sea green 82 94 100 91
red 18 6 0 9
Skagerrak and Kattegat green 100 95 100 98
red 0 5 0 2
Southern North Sea green 88 100 100 96
red 12 0 0 4
Channel green 100 100 100 100
red 0 0 0 0
total green 92 96 100 96
red 8 4 0 4
3 Irish and Scottish West Coast green 97 100 100 99
red 3 0 0 1
Irish Sea green 100 95 100 98
red 0 5 0 2
Celtic Sea green 100 100 100 100
red 0 0 0 0
total green 99 98 100 99
red 1 2 0 1
4 Northern Bay of Biscay green 96 100 100 99
red 4 0 0 1
Iberian Sea green 100 96 100 99
red 0 4 0 1
Gulf of Cadiz green 100 100 100 100
red 0 0 0 0
total green 98 98 100 99
red 2 2 0 1


Regional assessment - methods

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 MPC. The regional status for each metal is then estimated by fitting the following linear mixed model by restricted maximum likelihood:

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

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.

The meta-analysis is restricted to regions and metal combinations with at least three status stations with good geographic spread.

The results of the status regional assessments are back-transformed for presentation. The estimated regional status is then interpreted as the ratio of the mean regional concentration to the assessment concentration. For example, 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 status assessments for each OSPAR region in turn. `


OSPAR region 1


OSPAR region 2


OSPAR region 3


OSPAR region 4


Regional status compared to the Maximum Permissible Concentration (MPC)

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.

The symbols in all the plots have the following interpretation:

  • green: the mean concentration is significantly (p < 0.05) below the MPC
  • red: the mean concentration is not significantly below the MPC

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


MIME region metal status se upper concentration conc upper
Barents Sea Cadmium -1.93 0.27 -1.49 0.14 0.23
Lead -3.26 0.28 -2.81 0.04 0.06
Mercury -3.22 0.27 -2.78 0.04 0.06
Greenland-Scotland ridge Cadmium -0.85 0.29 -0.38 0.43 0.69
Lead -4.25 0.34 -3.69 0.01 0.02
Mercury -3.71 0.27 -3.27 0.02 0.04
Norwegian Sea Cadmium -2.90 0.37 -2.30 0.05 0.10
Lead -3.71 0.37 -3.11 0.02 0.04
Mercury -2.71 0.36 -2.11 0.07 0.12
Norwegian Trench Cadmium -2.30 0.23 -1.93 0.10 0.15
Lead -2.25 0.23 -1.87 0.11 0.15
Mercury -2.60 0.22 -2.25 0.07 0.11
Northern North Sea Cadmium -1.56 0.15 -1.31 0.21 0.27
Lead -1.85 0.15 -1.60 0.16 0.20
Mercury -2.14 0.15 -1.89 0.12 0.15
Skagerrak and Kattegat Cadmium -2.03 0.14 -1.80 0.13 0.16
Lead -2.76 0.14 -2.52 0.06 0.08
Mercury -2.98 0.14 -2.75 0.05 0.06
Southern North Sea Cadmium -1.75 0.13 -1.53 0.17 0.22
Lead -2.94 0.13 -2.73 0.05 0.07
Mercury -2.21 0.13 -2.00 0.11 0.14
Channel Cadmium -2.13 0.16 -1.86 0.12 0.16
Lead -2.25 0.16 -1.99 0.11 0.14
Mercury -2.97 0.16 -2.70 0.05 0.07
Irish and Scottish West Coast Cadmium -2.15 0.17 -1.87 0.12 0.15
Lead -3.00 0.18 -2.71 0.05 0.07
Mercury -3.51 0.18 -3.22 0.03 0.04
Irish Sea Cadmium -2.28 0.13 -2.07 0.10 0.13
Lead -1.99 0.13 -1.78 0.14 0.17
Mercury -2.74 0.13 -2.52 0.06 0.08
Celtic Sea Cadmium -2.25 0.14 -2.01 0.11 0.13
Lead -2.32 0.14 -2.09 0.10 0.12
Mercury -3.34 0.14 -3.10 0.04 0.05
Northern Bay of Biscay Cadmium -1.53 0.13 -1.31 0.22 0.27
Lead -2.07 0.13 -1.85 0.13 0.16
Mercury -2.77 0.13 -2.56 0.06 0.08
Iberian Sea Cadmium -2.40 0.13 -2.19 0.09 0.11
Lead -2.24 0.13 -2.03 0.11 0.13
Mercury -3.55 0.13 -3.33 0.03 0.04
Gulf of Cadiz Lead -4.11 0.53 -3.23 0.02 0.04
Mercury -3.94 0.51 -3.09 0.02 0.05