The variables in biota_stations.csv describe the biota monitoring stations used in the 2018 assessment of the UK's Clean Seas Environment Monitoring Programme. The column headings are:

biogeo_region
Description: biogeographic region
Unit:
Type: categorical
Levels: 7
Note: biogeographic regions used for MSFD reporting purposes; there are 8 regions in total but only 7 with data

CSEMP_region
Description: monitoring region
Unit:
Type: categorical
Levels: 19
Note: monitoring regions for the UK’s Clean Seas Environmental Monitoring Programme (CSEMP); there are 22 regions in total (see pdf resource for map), but only 19 with data; the CSEMP regions are aggregated into 8 biogeographic regions for MSFD assessment purposes

stratum
Description: subdivision of monitoring region
Unit:
Type: categorical
Levels: 164
Note: subdivisions of the CSEMP monitoring regions, most of which are WFD water bodies; there are 818 strata in total, but only 164 with data