The file sediment_data.csv contains the contaminant data in sediment used in the 2020 assessment of the UK's Clean Seas Environment Monitoring Programme (CSEMP). The data are a cleaned and processed subset of the data extracted from the MERMAN database on 30 March 2022.
The file 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: 5619
Note: identifies the data (a station / contaminant combination) that were grouped together into a timeseries and modelled to assess status and trends
CSEMP_region
Description: monitoring region
Unit:
Type: categorical
Levels: 17
Note: there are 22 monitoring regions in the CSEMP but only 17 with data; the CSEMP regions are aggregated into 8 biogeographic regions for regional assessments
biogeographic_region
Description: biogeographic region used for regional assessments
Unit:
Type: categorical
Levels: Northern North Sea, Southern North Sea, Eastern Channel, Western Channel & Celtic Sea, Irish Sea, Minches & Western Scotland, Scottish Continental Shelf
Note: there are 8 biogeographic regions in total, but only 7 with data
station
Description: monitoring station
Unit:
Type: categorical
Levels: 99
Note:
latitude
Description: station latitude
Unit: decimal degrees
Type: continuous
Range: 49.97, 61.03
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: -8.58, 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: B, RH, IH
Note: baseline (B), reference (RH) or impacted (IH)
WLTYP
Description: station typography
Unit:
Type: categorical
Levels: Estuary, Coast, Open Sea
Note:
monitoring_year
Description: monitoring year
Unit:
Type: discrete
Range: 1999, 2019
Note: for some data suppliers, monitoring is in winter and e.g. sampling in December 2018 and January 2019 would be regarded as having come from the same monitoring year
sample_id
Description: sample identifier
Unit:
Type: categorical
Levels: 3597
Note:
sample_date
Description: sampling date
Unit:
Type: discrete
Range: 1999-01-18, 2019-07-18
Note:
sample_time
Description: sampling time
Unit:
Type: continuous
Range: 00:00:00, 23:59:00
Note:
sample_latitude
Description: sampling latitude
Unit: decimal degrees
Type: continuous
Range: 49.97, 61.03
Note:
sample_longitude
Description: sampling longitude
Unit: decimal degrees
Type: continuous
Range: -8.76, 2.52
Note:
sample_depth
Description: depth of sediment sample
Unit: m
Type: continuous
Range: 0.01, 0.5
Note: all samples are surface samples and this is the lowest depth sampled
matrix
Description: sample matrix
Unit:
Type: categorical
Levels: SED63, SEDTOT
Note: see ICES reference codes for MATRX
determinand_group
Description: contaminant group
Unit:
Type: categorical
Levels: Metals, Organotins, PAH parent compounds, PAH alkylated compounds, Polybrominated diphenyl ethers, Organobromines (other), Polychlorinated biphenyls, Dioxins, Organochlorines (other)
Note:
determinand
Description: contaminant
Unit:
Type: categorical
Levels: 76
Notes:
* see ICES reference codes for PARAM
* data submitted as CHRTR have been relabelled as CHR
* TEQDFP is the code used for the WHO TEQ_DFP (where DFP indicates dioxins, furans and planar polychlorinated biphenyls)
metoa
Description: method of chemical analysis
Unit:
Type: categorical
Levels: 16
Note: see ICES reference codes for METOA
basis
Description: basis on which the measurement is expressed
Unit:
Type: discrete
Levels: dry weight (D)
Note:
unit
Description: unit of the concentration measurement and its uncertainty
Unit:
Type: discrete
Levels: mg/kg, TEQ ug/kg, ug/kg
Note:
concentration
Description: concentration of contaminant
Unit: see unit column
Type: continuous
Range: 0.0001, 14900
Note:
qflag
Description: less-than qualifier for the concentration measurement
Unit:
Type: categorical
Levels: "", D, Q, <
Notes:
* "" (a blank or missing value) indicates a non-censored measurement
* D indicates the measurement is left-censored at the limit of detection; i.e. the measurement is below the limit of detection, but it is not known by how much; the limit of detection is given in the concentration column
* Q indicates the measurement is left-censored at the limit of quantification; i.e. the measurement is below the limit of quantification, but it is not known by how much; the limit of quantification is given in the concentration column
* < indicates the measurement is left-censored by an unspecified censoring criterion (which could be the limit of detection or quantification); the value of the censoring criterion is given in the concentration column
uncertainty
Description: uncertainty in the concentration measurement
Unit: see unit column
Type: continuous
Range: 0.0000035, 1017
Note: analytical uncertainty expressed as the standard deviation
concentration_norm
Description: normalised concentration of contaminant
Unit: see unit column
Type: continuous
Range: 0.00019, 87057
Notes:
* the concentration normalised to 5% aluminium (metals) or 2.5% organic carbon (organics)
* the normalisation process is explained here
* some normalised concentrations are ‘missing’ because the normaliser (aluminium or organic carbon) concentration was not reported or because the uncertainty in the normalised concentration was greater than the normalised concentration
qflag_norm
Description: less-than qualifier for the normalised measurement
Unit:
Type: categorical
Levels: "", D, Q, <
Note: see qflag
uncertainty_norm
Description: uncertainty in the normalised measurement
Unit: see unit column
Type: continuous
Range: 0.0000099, 62953
Note: analytical uncertainty expressed as the standard deviation
AL
Description: aluminium concentration
Unit: %
Type: continuous
Range: 0.013, 48.2
Note: all values are above the limit of detection
AL_uncertainty
Description: uncertainty in the aluminium measurement
Unit: %
Type: continuous
Range: 0.0005, 3.06
Note: analytical uncertainty expressed as the standard deviation
CORG
Description: organic carbon concentration
Unit: %
Type: continuous
Range: 0.03, 9.2
Note:
CORG_qflag
Description: less-than qualifier for the organic carbon measurement
Unit:
Type: categorical
Levels: "", D, <
Note: see qflag
CORG_uncertainty
Description: uncertainty in the organic carbon measurement
Unit: %
Type: continuous
Range: 0.003, 2.86
Note: analytical uncertainty expressed as the standard deviation
DRYWT
Description: dry weight of the sample
Unit: %
Type: continuous
Range: 5.76, 93.3
Note: all values are above the limit of detection
DRYWT_uncertainty
Description: uncertainty in the dry weight measurement
Unit: %
Type: continuous
Range: 0.025, 3.29
Note: analytical uncertainty expressed as the standard deviation