DOI: 10.14466/cefasdatahub.141
title: Dissolved oxygen, temperature and salinity measurements in coastal and estuarine waters in the UK from 1990 to 2018

description: Data on dissolved oxygen, temperature and salinity in estuarine and coastal waters were obtained from field-based monitoring programmes in England, Scotland, Wales and Northern Ireland under EU Directives (the Water Framework Directive, WFD, the Urban Waste Water Treatment Directive, UWWTD, and the Nitrates Directive, ND). These data have been held in institutional databases, and used in national and regional assessments of ecological or environmental status, which describe summary statistics and overall outcomes using physical, chemical and biological parameters/indicators and generally do not present the underlying data. For recent work on trends in dissolved oxygen concentrations in UK waters from 1990 to 2018 (Painting et al. in prep), the raw data on dissolved oxygen (DO) concentrations and all supporting metadata (e.g. latitude, longitude, water column depth, sample depth, temperature, salinity) for coastal and estuarine waters were extracted from institutional databases and combined into one dataset, which is provided here. Sampling was carried out during fieldwork by the Environment Agency (EA), Natural Resources Wales (NRW), the Scottish Environmental Protection Agency (SEPA) and the Department of Agriculture, Environment and Rural Affairs (DAERA) in Northern Ireland. Data were collected and quality assured following agreed protocols in the UK’s Coordinated Environmental Monitoring Programme (CEMP).

All fieldwork was conducted using boat- or shore- based sampling. Sampling and analytical methods followed standard procedures and guidelines, as described in reports and scientific publications (e.g. Best et al 2007, Greenwood et al 2010, Queste et al 2013). All methods were based on SCA (1979) protocols, with traceable quality assurance (QA) and external QA, e.g. through QUASIMEME (Quality Assurance of Information on Marine Environmental Monitoring in Europe), although methods have changed since the 1990's. For the EA, for example, physical samples were originally collected, preserved with a mercury solution and analysed later in the lab using Winkler titrations. Spot or semi continuous data were obtained for development and calibration of probes. The National Laboratory Service (NLS) then moved to sensor-based monitoring. Data were collected from survey vessel/s using an Idronaught instrument with a dissolved oxygen (DO) probe (diffusion initially, then optical), typically as spot samples from about 1-2m (lowered or from a pump supply). DO was measured as percentage saturation and concentration (mg/l) using daily in air calibration and 6 monthly laboratory zeroing if necessary. Close to shore, data were collected with a YSI instrument with a DO probe.

Waterbodies are defined by the European Union’s Water Framework Directive, of which there are 743 around Scotland, Wales and England, ranging in size from 0.02km2 to 183,331.20 km2. Waterbodies are grouped into 29 regions. Water samples were available from 208 of the waterbodies and 25 regions

References:

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