The file D9_Scotland.csv contains the metal concentrations in shellfish from Scottish waters used in 'Contaminants in Seafood', a Descriptor 9 Indicator in the UK's 2025 Marine Strategy Assessment. The data were reported by Food Standards Scotland and extracted from the MERMAN database on 12 December 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:
MSFD_subregion
Description: Marine Strategy Framework Directive subregion
Unit:
Type: categorical
Levels: Greater North Sea, Celtic Seas
Note: in the map of biogeographic regions the Greater North Sea comprises the Northern North Sea, Southern North Sea, and Eastern Channel, whilst the Celtic Seas comprises the Western Channel and Celtic Sea, Irish Sea, Minches and Western Scotland, Scottish Continental Shelf, and Atlantic North-West Approaches.
biogeographic_region
Description: biogeographic region
Unit:
Type: categorical
Levels: Northern North Sea, Irish Sea, Minches and Western Scotland, Scottish Continental Shelf
Note: there are 8 biogeographic regions but only 4 with data
CSEMP_region
Description: monitoring region in the UK's Clean Seas Environment Monitoring Programme (CSEMP)
Unit:
Type: categorical
Levels: 9
Note: there are 22 monitoring regions in the CSEMP but only 9 with data
CSEMP_stratum
Description: subdivision of the CSEMP monitoring region
Unit:
Type: categorical
Levels: 62
Note: there are 818 CSEMP strata, most of which are WFD water bodies, but only 62 with data
station_code
Description: monitoring station identifier
Unit:
Type: categorical
Levels: 85
Note:
station_name
Description: name associated with the monitoring station
Unit:
Type: categorical
Levels: 83
Note:
station_latitude
Description: station latitude
Unit: decimal degrees
Type: continuous
Range: 54.54, 60.64
Note: this is a nominal position: sampling occurs in a pre-defined area broadly centred on this position
station_longitude
Description: station longitude
Unit: decimal degrees
Type: continuous
Range: -7.42, -1.14
Note: this is a nominal position: sampling occurs in a pre-defined area broadly centred on this position
monitoring_year
Description: monitoring year
Unit:
Type: discrete
Range: 2016, 2020
Note:
sample_id
Description: sample identifier
Unit:
Type: categorical
Levels: 1, 2
Note: used to identify measurements made on the same individual or pool
sample_latitude
Description: sampling latitude
Unit: decimal degrees
Type: continuous
Range: 54.54, 60.64
Note:
sample_longitude
Description: sampling longitude
Unit: decimal degrees
Type: continuous
Range: -7.43, -1.14
Note:
sample_date
Description: sampling date
Unit: YYYY-MM-DD
Type: discrete
Range: 2016-01-12, 2020-02-20
Note:
species
Description: species
Unit:
Type: categorical
Levels: Cerastoderma edule, Crassostrea gigas, Ensis, Ensis arcuatus, Mytilus edulis, Ostrea edulis, Spisula solida, Spisula solidissima, Venerupis senegalensis
Note:
tissue
Description: tissue
Unit:
Type: categorical
Levels: Whole soft-body
Note:
determinand
Decscription: metal
Unit:
Type: categorical
Levels: cadmium, lead, mercury
Note:
analysis_method
Description: method of chemical analysis
Unit:
Type: categorical
Levels: ICP-MS with collision cell
Note:
extraction_method
Description: method of chemical extraction
Unit:
Type: categorical
Levels: Nitric acid digestion in closed vessel with microwave energy
Note:
pretreatment_method
Description: method of pretreatment
Unit:
Type: categorical
Levels: No pretreatment
Note:
basis
Description: basis on which the measurement is expressed
Unit:
Type: categorical
Levels: Wet (fresh) weight
Note:
unit
Description: unit of the concentration measurement
Unit:
Type: categorical
Levels: ug/kg
Note:
concentration
Description: metal concentration
Unit: see unit
Type: continuous
Range: 5.55, 1180
Note:
censoring
Description: less-than qualifier for the concentration measurement
Unit:
Type: categorical
Levels: "", <
Notes:
* "" (a blank or missing value) indicates a non-censored measurement
* < 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
detection_limit
Description: limit of detection
Unit: see unit
Type: continuous
Range: 2, 2
Note: