MIME regional assessment of status and trends in CB concentrations in sediment

Overview

The 2017 MIME assessment describes the trends and status 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 (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 CB concentrations in sediment, where the CBs are CB28, CB52, CB101, CB118, CB138, CB153, CB180. For simplicity, the term ‘region’ is used throughout to describe MIME regions. OSPAR regions are always referred to as such.

The following sections:

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


Summary of individual time series results

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

  • there is at least one year with data in the period 2010 to 2015
  • 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 2010 to 2015
  • 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 concentrations

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. Only 119 of 1016 CB 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 CBs. The magenta circles are stations where there is a trend assessment for at least one CB, and the cyan cirles are stations where there are only status assessments.

The next set of tabs show the trend and status assessments for each CB 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 Environmental Assessment Criterion (EAC)
  • red: the mean concentration is not signficantly below the Environmental Assessment Criterion (EAC)

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)
  • 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, or red status in each MIME and OSPAR region
  • the same information presented as proportions

Note that there are no BACs for the Gulf of Cadiz and the Iberian Sea. Time series in these regions are only assessed against the EAC, so can only be coloured green and red.


Stations


CB28


CB52


CB101


CB118


CB138


CB153


CB180


Trend summary (numbers)

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

OSPAR region MIME region status CB28 CB52 CB101 CB118 CB138 CB153 CB180 total
2 Northern North Sea upward trend 2 1 1 1 1 1 1 8
no trend 2 2 7 8 7 13 6 45
downward trend 1 5 4 3 3 1 1 18
Southern North Sea upward trend 0 0 1 0 0 0 0 1
no trend 20 16 21 17 14 21 17 126
downward trend 9 6 10 14 18 10 10 77
Channel upward trend 0 0 0 0 0 0 0 0
no trend 0 0 1 1 0 1 1 4
downward trend 0 0 1 1 2 1 0 5
total upward trend 2 1 2 1 1 1 1 9
no trend 22 18 29 26 21 35 24 175
downward trend 10 11 15 18 23 12 11 100
3 Irish and Scottish West Coast upward trend 0 0 0 1 0 1 1 3
no trend 2 2 2 4 5 4 2 21
downward trend 0 2 3 1 1 1 0 8
Irish Sea upward trend 2 1 1 1 1 2 2 10
no trend 6 6 7 9 7 9 5 49
downward trend 3 4 4 2 4 1 3 21
Celtic Sea upward trend 0 0 0 0 0 0 0 0
no trend 0 1 0 0 0 0 0 1
downward trend 1 0 1 1 1 1 1 6
total upward trend 2 1 1 2 1 3 3 13
no trend 8 9 9 13 12 13 7 71
downward trend 4 6 8 4 6 3 4 35
4 Iberian Sea upward trend 0 4 0 0 0 0 0 4
no trend 13 10 15 15 15 15 15 98
downward trend 0 0 0 0 0 0 0 0
Gulf of Cadiz upward trend 0 0 0 1 0 0 0 1
no trend 6 7 5 5 9 12 8 52
downward trend 0 5 0 0 0 0 0 5
total upward trend 0 4 0 1 0 0 0 5
no trend 19 17 20 20 24 27 23 150
downward trend 0 5 0 0 0 0 0 5


Trend summary (proportions)

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

OSPAR region MIME region status CB28 CB52 CB101 CB118 CB138 CB153 CB180 total
2 Northern North Sea upward trend 40 13 9 8 9 7 13 11
no trend 40 25 58 67 64 86 75 64
downward trend 20 62 33 25 27 7 12 25
Southern North Sea upward trend 0 0 3 0 0 0 0 0
no trend 69 73 66 55 44 68 63 62
downward trend 31 27 31 45 56 32 37 38
Channel upward trend 0 0 0 0 0 0
no trend 50 50 0 50 100 44
downward trend 50 50 100 50 0 56
total upward trend 6 3 4 2 2 2 3 3
no trend 65 60 63 58 47 73 67 62
downward trend 29 37 33 40 51 25 30 35
3 Irish and Scottish West Coast upward trend 0 0 0 16 0 16 33 9
no trend 100 50 40 67 83 67 67 66
downward trend 0 50 60 17 17 17 0 25
Irish Sea upward trend 18 9 9 8 9 17 20 13
no trend 55 55 58 75 58 75 50 61
downward trend 27 36 33 17 33 8 30 26
Celtic Sea upward trend 0 0 0 0 0 0 0 0
no trend 0 100 0 0 0 0 0 14
downward trend 100 0 100 100 100 100 100 86
total upward trend 14 6 6 11 5 16 21 11
no trend 57 56 50 68 63 68 50 60
downward trend 29 38 44 21 32 16 29 29
4 Iberian Sea upward trend 0 29 0 0 0 0 0 4
no trend 100 71 100 100 100 100 100 96
downward trend 0 0 0 0 0 0 0 0
Gulf of Cadiz upward trend 0 0 0 17 0 0 0 2
no trend 100 58 100 83 100 100 100 90
downward trend 0 42 0 0 0 0 0 8
total upward trend 0 15 0 5 0 0 0 3
no trend 100 66 100 95 100 100 100 94
downward trend 0 19 0 0 0 0 0 3


Status summary (numbers)

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

OSPAR region MIME region status CB28 CB52 CB101 CB118 CB138 CB153 CB180 total
2 Northern North Sea blue 7 0 0 3 4 5 5 24
green 12 22 21 8 19 18 18 118
red 1 1 2 12 0 0 0 16
Southern North Sea blue 0 1 0 1 1 0 0 3
green 37 33 37 11 39 42 42 241
red 6 5 6 31 3 1 1 53
Channel blue 0 0 0 0 0 0 0 0
green 2 5 8 1 3 34 23 76
red 10 12 19 31 0 0 0 72
total blue 7 1 0 4 5 5 5 27
green 51 60 66 20 61 94 83 435
red 17 18 27 74 3 1 1 141
3 Irish and Scottish West Coast blue 4 1 1 1 0 0 1 8
green 6 8 9 5 9 10 9 56
red 0 0 0 4 1 0 0 5
Irish Sea blue 2 0 0 1 0 0 1 4
green 15 19 18 4 19 19 18 112
red 3 0 1 15 1 0 0 20
Celtic Sea blue 0 0 0 0 0 0 0 0
green 1 1 1 0 1 1 1 6
red 0 0 0 1 0 0 0 1
total blue 6 1 1 2 0 0 2 12
green 22 28 28 9 29 30 28 174
red 3 0 1 20 2 0 0 26
4 Iberian Sea blue 0 0 0 0 0 0 0 0
green 14 14 9 0 9 15 11 72
red 1 1 6 15 6 0 4 33
Gulf of Cadiz blue 0 0 0 0 0 0 0 0
green 12 12 12 11 14 14 14 89
red 1 1 2 3 0 0 0 7
total blue 0 0 0 0 0 0 0 0
green 26 26 21 11 23 29 25 161
red 2 2 8 18 6 0 4 40


Status summary (proportions)

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

OSPAR region MIME region status CB28 CB52 CB101 CB118 CB138 CB153 CB180 total
2 Northern North Sea blue 35 0 0 13 17 22 22 15
green 60 96 91 35 83 78 78 75
red 5 4 9 52 0 0 0 10
Southern North Sea blue 0 2 0 2 2 0 0 1
green 86 85 86 26 91 98 98 81
red 14 13 14 72 7 2 2 18
Channel blue 0 0 0 0 0 0 0 0
green 17 29 30 3 100 100 100 51
red 83 71 70 97 0 0 0 49
total blue 9 1 0 4 7 5 6 5
green 68 76 71 20 89 94 93 72
red 23 23 29 76 4 1 1 23
3 Irish and Scottish West Coast blue 40 11 10 10 0 0 10 12
green 60 89 90 50 90 100 90 81
red 0 0 0 40 10 0 0 7
Irish Sea blue 10 0 0 5 0 0 5 3
green 75 100 95 20 95 100 95 82
red 15