Sampling of estuarine chemistry and organic matter for 16 estuaries in Great Britain in 2017/8 as part of the LOCATE project.

Water measurements were taken quarterly from 16 estuaries across England, Scotland and Wales from April 2017 until April 2018, to provide information on the geographical and seasonal variation in carbon fluxes. The estuaries were chosen such that their catchments reflected different land use types. The parameters measured were: temperature; specific electrical conductivity (SEC); salinity; concentrations of ammonium, nitrate, phosphate, non-particulate organic carbon, total dissolved carbon, total nitrogen and total phosphorous; alkalinity; pH; dissolved organic matter fluorescence (fDOM); absorbance; particulate organic carbon; particulate organic nitrogen; 13C; 15N. Samples were also taken for molecular analysis, and are reported elsewhere. Water samples were collected from six fixed sites on each estuary, within the span of the same 2-3 days in a given quarter, wherever possible. Water was sampled using a single bottle before being split for different analyses. Coordination of the sampling was carried out by Andy Tye of the British Geological Survey. The samples were taken for Land Ocean CArbon TransfEr (LOCATE), which is a multidisciplinary NERC project involving the National Oceanography Centre, the British Geological Survey, the UK Centre for Ecology and Hydrology and the Plymouth Marine Laboratory, with assistance from the University of Lancaster, University of Durham, University of Hull, the University of the Highlands and Islands and the Environment Agency. LOCATE aims to improve understanding of the flow of carbon from land into the ocean, with this dataset concerning the flow through estuaries. There is a companion LOCATE dataset covering the river data (doi:10.5285/08223cdd-5e01-43ad-840d-15ff81e58acf).