This dataset comprises both raw and reprocessed clumped oxygen and carbon stable isotope values of the shell layers of the brachiopods Novocrania anomala and Terebratulina retusa, the bivalve molluscs Crassostrea gigas and Mytilus edulis, and thallus of the coralline algae Lithothamnion glaciale. Data also include calibration and other parameters associated with data acquisition. Shells and thalli samples were collected from five localities around the UK, (Loch Etive, the Sound of Kerrera, Loch Fyne, Lyme Bay, and Loch Sween). All shells and thalli were sampled manually and kept cold during transportation, before preparation at the University of Stirling. Samples were cleaned and air-dried. Micro-sampling of individual bimineral layers was performed manually with carbide drill bits and/or engraving tools. Powdered samples were treated with hydrogen peroxide to remove organics and air-dried for isotope analyses. Clumped isotope measurements were performed at the Scottish Universities Environmental Research Centre (SUERC) during 2018. Samples were digested with 103% phosphoric acid and the resulting carbon dioxide purified and analysed with a Thermo Scientific 253 Isotope Ratio Mass Spectrometer (IRMS) configured to measure clumped isotopes. Temperatures were calculated from raw delta47 by re-projecting these in the carbon dioxide equilibrium scale (delta47CDES) using the carbonate standards ETH-1, ETH-2, ETH3 and ETH-4 (Bernasconi et al., 2018) and applying the empirical calibration of Bonifacie et al., (2017). The formula to calculate temperatures from delta47 measurements is included in the data file. This work was carried out by Maggie Cusack and Javier Medina-Sánchez – University of Stirling; Matthieu Clog – Scottish Universities Environmental Research Centre; Huabing Yin and Nicholas Kamenos – University of Glasgow. It was funded by the UK's Natural Environment Research Council (NERC) Discovery Science project entitled “When isotopes don’t clump” (grant reference NE/P011063/1) active from 1st May 2017 – 1st July 2020.

The dataset comprises a diverse set of physical, chemical and biological data including: bacteria, carbon, chlorophyll, dissolved gases, light levels, nutrients, phytoplankton, productivity, respiration, salinity, temperature, trace elements and zooplankton. Measurements were gathered from the North Atlantic and Norwegian fjord waters between 1971 and 1998. The data arise from three sources: biological and hydrographic data collected between 1971 and 1975 at Ocean Weather Ship (OWS) India in the North Atlantic; conductivity-temperature-depth (CTD) casts, water samples, net samples and meteorological data from the four week Bergen Mesocosm experiment at Espegrend Marine Biological Field Station (Norway) in 1995; and the six week RRS Discovery cruise 221 to the North East Atlantic in 1996, where physical, chemical and biological data were collected. The data were collected using a variety of methods including: more than 500 CTD and SeaSoar profiles; nearly 1000 water bottle samples; over 600 net hauls; over 450 Secchi disk deployments; nearly 4000 multisizer samples; 23 production experiments; four drifting buoy tracks and 40 days of weather observations. The PRIME programme aimed to lay the basis for mathematical models to describe the role of plankton in biogeochemical fluxes within the oceans which have implications for climate regulation. The project was hosted by the School of Ocean Sciences, University of Wales, Bangor. Data management was undertaken by the British Oceanographic Data Centre and over 95% of the data collected are now assembled on a CD-ROM. The data are accompanied by an extensive users' guide (covering sampling protocol documentation), the structures used to store the data, and the data interrogation tools.