The file sediment_regional_data.csv contains the summary measures used to make regional assessments of status and trends in contaminants in sediment in the 2020 assessment of the UK's Clean Seas Environment Monitoring Programme (CSEMP). The summary measures are obtained from timeseries models fitted to the contaminant data in sediment_data.csv which in turn are based on data extracted from the MERMAN database on 30 March 2022. Details of the modelling procedures can be found here.

For sediment, there are regional assessments for metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls and polybrominated diphenyl ethers. These are described in the resources:
* sediment_regional_assessment_metals.html
* sediment_regional_assessment_pahs.html
* sediment_regional_assessment_pcbs.html
* sediment_regional_assessment_pbdes.html

The file sediment_regional_data.csv is UTF-8-BOM encoded so can be read directly into Excel, or into R using the function read.csv with the argument fileEncoding = “UTF-8-BOM”.

The variables in the file are:

series
Description: timeseries identifier
Unit:
Type: categorical
Levels: 1664
Note: links to the timeseries data in sediment_data.csv

CSEMP_region
Description: CSEMP region where the monitoring station is located
Unit:
Type: categorical
Levels: 15
Note: see map of CSEMP regions

biogeographic_region
Description: biogeographic region where the monitoring station is located
Unit:
Type: categorical
Levels: Northern North Sea, Southern North Sea, Eastern Channel, Western Channel & Celtic Sea, Irish Sea, Minches & Western Scotland
Notes:
* see map of biogeographic regions
* regional assessments are conducted at the biogeographic regional scale, rather than the CSEMP regional scale

station
Description: monitoring station
Unit:
Type: categorical
Levels: 52
Note:

latitude
Description: station latitude
Unit: decimal degrees
Type: continuous
Range: 50.30, 60.04
Note: this is a nominal position: sampling occurs in a pre-defined area broadly centred on this position

longitude
Description: station longitude
Unit: decimal degrees
Type: continuous
Range: -7.01, 2.33
Note: this is a nominal position: sampling occurs in a pre-defined area broadly centred on this position

MSTAT
Description: type of monitoring station
Unit:
Type: categorical
Levels: RH, IH
Note: reference (RH) or impacted (IH)

last_year
Description: last year of the timeseries
Unit: y
Type: discrete
Range: 2015, 2019
Note: only timeseries with some data in the last six monitoring years are included in the assessment (i.e. 2014-2019 for the 2020 assessment)

determinand_group
Description: contaminant group
Unit:
Type: categorical
Levels: Metals, PAH parent compounds, Polybrominated diphenyl ethers, Polychlorinated biphenyls
Note:

determinand
Description: contaminant
Unit:
Type: categorical
Levels: 43
Note: see ICES reference codes for PARAM

basis
Description: basis of the assessment
Unit:
Type: discrete
Levels: dry weight (D)
Note:

unit
Description: unit of measurement
Unit:
Type: discrete
Levels: mg/kg, ug/kg
Note:

mean_last_year
Description: the fitted mean concentration in last_year
Unit: see unit column
Type: continuous
Range: 0.0051, 921
Note:

BAC_type
Description: the name of the Background Assessment Concentration (BAC) or equivalent
Unit:
Type: categorical
Levels: BAC
Note:

BAC_value
Description: the value of the BAC (or equivalent)
Unit: see unit column
Type: continuous
Range: 0.05, 122
Note: more details can be found in the help file on assessment criteria for contaminants in sediment

status_BAC
Description: the log ratio of mean_last_year to the BAC
Unit: dimensionless
Type: continuous
Range: -3.9, 8.69
Note: status_BAC = log(mean_last_year / BAC_value), with a value above / below 0 indicating that the fitted mean concentration in the last monitoring year is above / below the BAC; the standard error is given by status_se

EAC_type
Description: the name of the Environmenal Assessment Criterion (EAC) or equivalent
Unit:
Type: categorical
Levels: EAC, ERL, FEQG
Notes:
* EAC = Environmental Assessment Criterion
* ERL = Effects Range Low
* FEQG = Federal Environmental Quality Guideline

EAC_value
Description: the value of the EAC (or equivalent)
Unit: see unit column
Type: continuous
Range: 0.15, 14000
Note: more details can be found in the help file on assessment criteria for contaminants in sediment

status_EAC
Description: the log ratio of mean_last_year to the EAC
Unit: dimensionless
Type: continuous
Range: -15, 1.83
Note: status_EAC = log(mean_last_year / EAC_value), with a value above / below 0 indicating that the fitted mean concentration in the last monitoring year is above / below the EAC; the standard error is given by status_se

status_profile
Description: the log of mean_last_year standardised to a common basis
Unit: log unit
Type: continuous
Range: -5.3, 6.82
Note: these values are used to investigate concentration profiles of selected PAH parent compounds, Polybrominated diphenyl ethers and Polychlorinated biphenyls, and have been standardised to the basis given in basis_profile

basis_profile
Description: the basis of status_profile
Unit:
Type: categorical
Levels: dry weight (D)
Note:

status_se
Description: the standard error of log mean_last_year
Unit:
Type: continuous
Range: 0.019, 2.26
Note: this is the also the standard error of status_BAC, status_EAC and status_profile

trend
Description: the estimated yearly change in log concentration in the last 20 years
Unit:
Type: continuous
Range: -29, 19.9
Note: trend can loosely be interpreted as the percentage annual change in concentration in the last 20 years assuming the trend in concentration is log-linear; values below / above 0 indicate a decreasing / increasing trend

trend_se
Description: the standard error of trend
Unit:
Type: continuous
Range: 0.37, 30
Note: