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 2024 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 9 9 6 24
downward trend 1 2 4 7
Greenland-Scotland ridge upward trend 5 1 3 9
no trend 4 5 11 20
downward trend 3 1 1 5
East of Iceland upward trend 0 0 3 3
no trend 0 0 5 5
downward trend 0 0 0 0
Norwegian Sea upward trend 0 0 0 0
no trend 5 4 4 13
downward trend 1 2 2 5
total upward trend 6 1 7 14
no trend 18 18 26 62
downward trend 5 5 7 17
2 Norwegian Trench upward trend 0 0 3 3
no trend 6 6 9 21
downward trend 9 9 4 22
Northern North Sea upward trend 5 4 9 18
no trend 18 18 27 63
downward trend 7 8 5 20
Skagerrak and Kattegat upward trend 5 6 6 17
no trend 24 17 25 66
downward trend 3 8 3 14
Southern North Sea upward trend 14 4 15 33
no trend 22 30 29 81
downward trend 4 6 5 15
Channel upward trend 4 3 2 9
no trend 24 20 26 70
downward trend 2 8 5 15
total upward trend 28 17 35 80
no trend 94 91 116 301
downward trend 25 39 22 86
3 Irish and Scottish West Coast upward trend 3 2 2 7
no trend 36 35 47 118
downward trend 10 12 4 26
Irish Sea upward trend 5 4 5 14
no trend 38 39 50 127
downward trend 8 9 8 25
Celtic Sea upward trend 1 0 5 6
no trend 33 27 37 97
downward trend 11 17 11 39
total upward trend 9 6 12 27
no trend 107 101 134 342
downward trend 29 38 23 90
4 Northern Bay of Biscay upward trend 0 0 1 1
no trend 32 27 31 90
downward trend 9 14 9 32
Iberian Coast upward trend 4 0 1 5
no trend 25 19 20 64
downward trend 4 12 8 24
Gulf of Cadiz upward trend 1 0 0 1
no trend 0 2 3 5
downward trend 0 1 0 1
total upward trend 5 0 2 7
no trend 57 48 54 159
downward trend 13 27 17 57


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 9 0 9 6
no trend 82 82 55 73
downward trend 9 18 36 21
Greenland-Scotland ridge upward trend 42 14 20 26
no trend 33 72 73 59
downward trend 25 14 7 15
East of Iceland upward trend 38 38
no trend 62 62
downward trend 0 0
Norwegian Sea upward trend 0 0 0 0
no trend 83 67 67 72
downward trend 17 33 33 28
total upward trend 21 4 17 15
no trend 62 75 65 67
downward trend 17 21 18 18
2 Norwegian Trench upward trend 0 0 19 6
no trend 40 40 56 46
downward trend 60 60 25 48
Northern North Sea upward trend 17 13 22 18
no trend 60 60 66 62
downward trend 23 27 12 20
Skagerrak and Kattegat upward trend 16 19 18 18
no trend 75 55 73 68
downward trend 9 26 9 14
Southern North Sea upward trend 35 10 31 25
no trend 55 75 59 63
downward trend 10 15 10 12
Channel upward trend 13 10 6 10
no trend 80 64 79 74
downward trend 7 26 15 16
total upward trend 19 12 20 17
no trend 64 62 67 65
downward trend 17 26 13 18
3 Irish and Scottish West Coast upward trend 6 4 4 5
no trend 74 71 89 78
downward trend 20 25 7 17
Irish Sea upward trend 10 8 8 8
no trend 74 75 79 77
downward trend 16 17 13 15
Celtic Sea upward trend 2 0 9 4
no trend 73 61 70 68
downward trend 25 39 21 28
total upward trend 6 4 7 6
no trend 74 70 79 74
downward trend 20 26 14 20
4 Northern Bay of Biscay upward trend 0 0 2 1
no trend 78 66 76 73
downward trend 22 34 22 26
Iberian Coast upward trend 12 0 3 5
no trend 76 61 69 69
downward trend 12 39 28 26
Gulf of Cadiz upward trend 100 0 0 14
no trend 0 67 100 72
downward trend 0 33 0 14
total upward trend 7 0 3 3
no trend 76 64 74 71
downward trend 17 36 23 26


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 10 11 32
red 0 1 0 1
Greenland-Scotland ridge green 8 11 12 31
red 3 0 0 3
Norwegian Sea green 6 6 6 18
red 0 0 0 0
total green 25 27 29 81
red 3 1 0 4
2 Norwegian Trench green 15 13 16 44
red 0 2 0 2
Northern North Sea green 36 44 35 115
red 7 3 0 10
Skagerrak and Kattegat green 39 37 40 116
red 0 2 0 2
Southern North Sea green 41 55 47 143
red 6 0 0 6
Channel green 35 38 34 107
red 0 0 0 0
total green 166 187 172 525
red 13 7 0 20
3 Irish and Scottish West Coast green 55 56 57 168
red 1 0 0 1
Irish Sea green 67 72 62 201
red 0 4 0 4
Celtic Sea green 63 64 64 191
red 0 1 1 2
total green 185 192 183 560
red 1 5 1 7
4 Northern Bay of Biscay green 45 47 47 139
red 2 0 0 2
Iberian Coast green 40 39 40 119
red 0 1 0 1
Gulf of Cadiz green 3 3 3 9
red 0 0 0 0
total green 88 89 90 267
red 2 1 0 3


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 91 100 97
red 0 9 0 3
Greenland-Scotland ridge green 73 100 100 91
red 27 0 0 9
Norwegian Sea green 100 100 100 100
red 0 0 0 0
total green 89 96 100 95
red 11 4 0 5
2 Norwegian Trench green 100 87 100 96
red 0 13 0 4
Northern North Sea green 84 94 100 92
red 16 6 0 8
Skagerrak and Kattegat green 100 95 100 98
red 0 5 0 2
Southern North Sea green 87 100 100 96
red 13 0 0 4
Channel green 100 100 100 100
red 0 0 0 0
total green 93 96 100 96
red 7 4 0 4
3 Irish and Scottish West Coast green 98 100 100 99
red 2 0 0 1
Irish Sea green 100 95 100 98
red 0 5 0 2
Celtic Sea green 100 98 98 99
red 0 2 2 1
total green 99 97 99 99
red 1 3 1 1
4 Northern Bay of Biscay green 96 100 100 99
red 4 0 0 1
Iberian Coast green 100 98 100 99
red 0 2 0 1
Gulf of Cadiz green 100 100 100 100
red 0 0 0 0
total green 98 99 100 99
red 2 1 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 -1.95 0.26 -1.52 0.14 0.22
Lead -3.31 0.27 -2.86 0.04 0.06
Mercury -3.34 0.26 -2.91 0.04 0.05
Greenland-Scotland ridge Cadmium -0.75 0.27 -0.31 0.47 0.73
Lead -4.09 0.31 -3.58 0.02 0.03
Mercury -3.74 0.25 -3.32 0.02 0.04
Norwegian Sea Cadmium -2.92 0.36 -2.33 0.05 0.10
Lead -3.75 0.36 -3.16 0.02 0.04
Mercury -2.77 0.36 -2.18 0.06 0.11
Norwegian Trench Cadmium -2.37 0.23 -2.00 0.09 0.14
Lead -2.38 0.23 -2.00 0.09 0.13
Mercury -2.73 0.22 -2.37 0.07 0.09
Northern North Sea Cadmium -1.59 0.15 -1.34 0.20 0.26
Lead -1.83 0.15 -1.58 0.16 0.21
Mercury -2.15 0.15 -1.91 0.12 0.15
Skagerrak and Kattegat Cadmium -2.03 0.14 -1.79 0.13 0.17
Lead -2.79 0.14 -2.55 0.06 0.08
Mercury -3.06 0.14 -2.83 0.05 0.06
Southern North Sea Cadmium -1.73 0.13 -1.51 0.18 0.22
Lead -2.90 0.13 -2.69 0.06 0.07
Mercury -2.26 0.13 -2.04 0.10 0.13
Channel Cadmium -2.14 0.15 -1.89 0.12 0.15
Lead -2.32 0.15 -2.07 0.10 0.13
Mercury -2.99 0.15 -2.74 0.05 0.06
Irish and Scottish West Coast Cadmium -1.98 0.13 -1.78 0.14 0.17
Lead -3.16 0.13 -2.95 0.04 0.05
Mercury -3.33 0.12 -3.12 0.04 0.04
Irish Sea Cadmium -2.30 0.12 -2.10 0.10 0.12
Lead -2.05 0.12 -1.85 0.13 0.16
Mercury -2.83 0.12 -2.63 0.06 0.07
Celtic Sea Cadmium -2.22 0.12 -2.01 0.11 0.13
Lead -2.47 0.12 -2.27 0.08 0.10
Mercury -3.36 0.12 -3.16 0.03 0.04
Northern Bay of Biscay Cadmium -1.66 0.13 -1.45 0.19 0.24
Lead -2.15 0.13 -1.94 0.12 0.14
Mercury -2.83 0.13 -2.62 0.06 0.07
Iberian Coast Cadmium -2.53 0.16 -2.28 0.08 0.10
Lead -2.55 0.16 -2.30 0.08 0.10
Mercury -3.65 0.16 -3.38 0.03 0.03
Gulf of Cadiz Cadmium -4.80 0.56 -3.89 0.01 0.02
Lead -4.17 0.52 -3.31 0.02 0.04
Mercury -4.08 0.50 -3.25 0.02 0.04