This dataset comprises the geochemical and mineralogical analysis of six samples of massive sulphide deposit. Three samples were obtained from seafloor massive sulphide (SMS) systems obtained during RV Celtic Explorer cruise CE11009 (Mid-Atlantic Ridge 45° N, 2011) and RRS James Cook cruises JC082 (Mid-Cayman Spreading Centre, 2013) and JC138 (Mid-Atlantic Ridge at 26° N, 2016). Three samples were obtained from land-based volcanogenic massive sulphide (VMS) deposits on Wetar Island, Indonesia. It is thought these samples were obtained in 2002 at Kali Kuning and Lerokis Zones 4 and 5, but users should be aware there is little to no metadata about the Wetar Island sample origins. The sample analyses includes: (1) bulk geochemical analysis of sulphide samples by inductively coupled plasma mass spectrometry (ICP-MS) for bulk and effluent analysis and inductively coupled plasma orbital emission spectrometry (ICP-OES), (2) petrographic descriptions of samples by reflective microscopy, (3) geochemical analysis of seawater samples during experiments by ICP-MS, (4) mineralogical analyses (X-ray Diffraction) of sulphide samples, (5) mineralogical analyses by Scanning Electron Microscope and energy dispersive X-ray spectroscopy (SEM-EDS) on sulphide grains, (6) SEM backscattered electron (BSE) images of reacted sulphide grains, and (7) surface areas determined by Brunauuer-Emmett-Teller (BET) surface area analysis. All analyses were undertaken as part of a PhD project which aimed to enhance understanding of sulphide oxidation kinetics, the formation of Fe-oxyhydroxide from sulphide oxidation, its capacity to retain metals that would otherwise be lost to seawater in SMS systems, and the implications for potential seafloor mining operations. Analyses took place at the University of Southampton and the National Oceanography Centre Southampton, funded under the Natural Environment Research Council (NERC) project Ultramafic-hosted mineral Resource Assessment (ULTRA) grant, NE/S004068/1. This collection consists only of the data collected under the PhD project and not all data associated with the ULTRA project.

This dataset consists of measurements of 224Ra and macronutrients in core top water, porewaters and sediments, as well as calculated 224Ra and macronutrient fluxes (via 224Ra/228Th disequilibrium) from benthic incubations of replicate mesocosms containing selected benthic macrofauna. The experiments were conducted at the Biodiversity Ecosystem Futures Facility (BEFF lab) at the National Oceanography Centre Southampton during 2022. Sediment was collected from Rame Mud, Plymouth, and benthic organisms were collected from Rame Mud and from Loch Linhe, Scotland. For each incubation, homogenised, sieved (500 µm) sediment was added to a mesocosm to 10 cm depth, overlain by approximately 15 cm (approx. 1.3 L) seawater (0.45 µm filtered, UV sterilised, salinity 33), and left to settle for 24 hours before conducting a full water exchange. After water exchange, 1 individual of either Paraleptopentacta elongata , Edwardsia claparedii, Turritellinella tricarinata, or Amphiura chiajei was weighed and morphological measurements were taken before being added to the mesocosm. 3 replicates containing 1 individual were run for each species, in addition to 3 replicate control mesocosms containing no macrofauna. All mesocosms were continually aerated and maintained in a temperature-controlled water bath for 10 days under a 12:12h on/off light cycle. On days 4 and 8, 2.5ml of a mixed Phaeodactylum tricornutum: Tetraselmis suecica phytoplankton culture was added to all mesocosms. For a subset of mesocosms (mesocosms 14 and 15 ), daily water column nutrient samples (10 ml, 0.2 µm filtered) were taken ~5 cm below the water surface and frozen at -20°C for subsequent analysis. Experiments 1 & 2 were set up in the same manner, except that in experiment 2 only one species was included, but at higher replication (8 replicate mesocosms containing 1 individual each of E. claparedii + 1 control mesocosm). Water samples for macronutrient concentrations were analysed using a QuAAtro 39 autoanalyser (Seal Analytical) and samples for Ra activity were analysed using a Radium Delayed Coincidence Counter (RaDeCC) system.The work was conducted to quantify the influence of different species and individuals of benthic macrofauna on benthic flux, using 224Ra as a naturally occurring tracer of sediment-seawater exchange. For further information, please see the associated research paper doi: 10.1002/lno.70033

This dataset comprises a variety of sediment core data from the Semenov Hydrothermal Field region of the Mid-Atlantic Ridge, collected during RRS James Cook cruises JC224 (March - April 2022) and JC254 (October - November 2023). A total of 29 gravity cores, 9 mega-cores, and 25 push cores were successfully recovered. Analysis of the sediment core samples was conducted at the British Ocean Sediment Core Research Facility (BOSCORF), where the cores are held for long term storage, and included: imaging, spectrometry, geophysical and geochemical measurements of sediment and porewaters, radiocarbon dating, and stable isotope analysis. The main coring equipment used during both cruises was a gravity corer to collect sediment cores of up to 3 m in length. For JC224, a mega-core, with a USBL transponder attached to the frame, was used to obtain undisturbed cores from the upper 40 cm of the sediment surface. For JC254, push cores were also collected during several Remotely Operated Vehicle (ROV) dives using the Isis vehicle. The key objectives of the sediment coring were: (1) to reconstruct the history of the hydrothermal activity by dating plume fallout layers in the sedimentary record, and (2) to assess the role of the sediment cover in the preservation of seafloor massive sulphide (SMS) deposits in an ultra-slow spreading scenario. The data were collected as part of a PhD project funded under the Natural Environment Research Council (NERC) project Ultramafic-hosted mineral Resource Assessment (ULTRA) grant, NE/S004068/1. This collection consists only of the data collected under the PhD project and not all data associated with the ULTRA project.

The Rapid Climate Change (RAPID) data set comprises a diverse collection of oceanographic and benthic observations, including profiles of temperature, salinity, dissolved gases and currents. The dataset also includes discrete measurements of plankton, stable isotopes, dissolved metals, chlorofluorocarbons (CFCs) and nutrients in the water column, sediment grain size parameters and geochemistry, and atmospheric concentrations of inorganic halogens. The RAPID data were collected from numerous locations in the North Atlantic, North Sea, Greenland and Europe via over 30 cruises between 2004 and 2008. Many of the oceanographic data resulted from an extensive mooring array in the North Atlantic devoted to monitoring the Atlantic overturning circulation. These mooring arrays are continuing to return data in the follow-on programmes, Rapid Climate Change - Will the Atlantic Thermohaline Circulation Halt? (RAPID-WATCH, 2008-2015) and RAPID - Atlantic Meridional Overturning Circulation (RAPID-AMOC, 2015 onwards) which will result in a decadal time series spanning the North Atlantic. RAPID, RAPID-WATCH and RAPID-AMOC aim to investigate and understand the causes of rapid climate change, with a primary (but not exclusive) focus on the role of the Atlantic Ocean thermohaline circulation. A Rapid Climate Change project office has been established at the National Oceanography Centre, Southampton. The cruise and mooring data are managed by the British Oceanographic Data Centre and are supplemented by atmospheric model output held at the British Atmospheric Data Centre (BADC).

The Autosub Under Ice (AUI) data set comprises hydrographic measurements including temperature, salinity, fluorescence, attenuance, dissolved oxygen concentrations and current velocities. Water samples were also collected for salinity and geochemical analysis, and the data set also includes bathymetric and sediment data. The measurements were collected near Greenland and Antarctica in the respective summer seasons for each hemisphere during 2003, 2004 and 2005. The programme consisted of four cruises onboard the ice-capable research vessel RRS James Clark Ross (JCR106, JCR106B, JCR84, JCR97). Data were collected by both shipboard sensors and those attached to the Autosub (an Autonomous Underwater Vehicle) package. Shipboard data collection included deployment of a conductivity-temperature-depth (CTD) package with attached auxiliary sensors. Lowered acoustic Dopper current profilers (LADCPs) were also attached to the CTD frame, while discrete water samples were collected from the CTD stations. Oceanographic, bathymetric and sediment data were collected along the ship's track, while further current data were collected from two mooring deployments. Autosub measurements included standard environmental parameters and acoustic instruments were used to measure ice shelf, sea ice and ocean bottom relief at high resolution. A camera was also attached to the vehicle, permitting the collection of detailed photographs of the seabed. Autosub had been upgraded to achieve 1000 km range and 2500 m water depth, which provided unprecedented access to ice covered regions. The AUI programme was established to investigate the marine environment of floating ice shelves with a view to advancing our understanding of their role in the climate system. It brought together researchers and engineers from a number of UK institutions, with the project being coordinated by the National Oceanography Centre, Southampton.

The dataset comprises measurements of hydrographic, bathymetric, sedimentary and meteorological parameters. These include water currents, temperature, salinity and wave parameters; suspended and seabed sediment; coastal geomorphological characteristics; and atmospheric temperature, pressure, humidity, irradiance and wind velocities. The study area was centred on the tidal inlet within the Peninsula do Ancao, Ria Formosa National Park, Algarve, Portugal. Field measurements were collected in the offshore area, the surf zone, beach experiments, the inlet areas and the inlet mouth between January and March 1999. The study utilised moorings, sediment grabs, tidal predictions, radar systems, acoustic Doppler current profiler (ACDP) surveys, a jack-up barge, beach experiments, video tower images, aerial surveys, seabed photographs and field campaign images. INDIA aimed to gain a better understanding of the interactions between tides, waves, currents and sedimentary processes at work in the European coastal zone with a view to predicting change. INDIA was coordinated by the University of Liverpool, Department of Civil Engineering. Data have been provided and/or modelled by a number of organisations from countries including France, Poland, Portugal, Australia, Netherlands, USA and the UK. Data management support for the project was provided by the British Oceanographic Data Centre. All data collected as part of the project were lodged with BODC who had responsibility for assembling and fully documenting the data.

The dataset contains a diverse range of environmental data ranging from estuary properties including geomorphology, water depth and habitat characterisation to detailed time series of parameters such as salinity and chemical and nutrient concentrations. The data are stored in a database containing a directory of existing data sources for estuaries; data for the broad properties of 79 UK estuaries; and detailed hydrodynamic, bathymetric, and sedimentary information for six estuaries: Blackwater, Humber, Mersey, Ribble, Southampton Water and Tamar. The data range from 1965 to 2002 and include both historic datasets and those collected during a recent effort (1997-2002) to enhance our knowledge of estuaries. Data collection employed a variety of instrumentation and techniques, including water, biota and sediment sample collection and analysis and the deployment of hydrographic instruments such as sea level, temperature, salinity and optical backscatter recorders. The Estuaries Research Programme (ERP) began in 1997 with the EMPHASYS project, which aimed to improve our understanding of processes operating in estuaries and use this knowledge to enhance broad scale modelling techniques that can be applied to estuarine processes. This work was funded by the Environment Agency/Department for Environment, Food and Rural Affairs (DEFRA) Flood and Coastal Defence Research and Development Programme. The data are managed by the British Oceanographic Data Centre (BODC) and are available on CD-ROM.

The dataset contains hydrographic and biogeochemical data, including continuous underway measurements of surface temperature, salinity, nutrients, chlorophyll and attenuance, irradiance and bathymetric depth. Underway dissolved oxygen and/or trace metal measurements were also collected on occasion. Hydrographic profiles of temperature, salinity, transmittance, fluorescence, dissolved oxygen (data often of poor quality) and scalar irradiance were undertaken, and associated water samples were routinely analysed for suspended particulate material (SPM), chlorophyll, nutrients and particulate organic carbon/particulate organic nitrogen (POC/PON). In addition, dissolved and particulate trace metals, production, contaminants, dissolved organic carbon/total dissolved nitrogen (DOC/TDN) were determined in some cases. Benthic measurements were also collected, including benthic flux determinations (microcosm experiments), sediment characterisation, pore water chemistry measurements and the quantification of the benthic macrofauna. The coastal oceanographic data set was collected along the east coast of England between Great Yarmouth and Berwick upon Tweed. Data were collected between December 1992 and July 1995 during a series of 17 RRS Challenger cruise legs. Most cruises covered two survey grids: one from Great Yarmouth to the Humber designed around the distribution of the sandbanks and a second simple zig-zag grid from the Humber to Berwick on Tweed. A large number of anchor stations, usually over one or two tidal cycles, were worked in the vicinity of the Humber mouth or the Holderness coast. Each cruise leg returned underway data and conductivity-temperature-depth (CTD) data and water bottle rosette samples from grid nodes. A Lasentech in-situ particle sizer was used to obtain grain size distributions at spot depths for each CTD station on many of the cruise legs. Box and multicorer samples were collected on approximately one third of the cruise legs. The River-Atmosphere-Coast Study (RACS) was the component of the Land Ocean Interaction Study (LOIS) programme looking at processes from the river catchment into the coastal sea. Investigators include representatives of Plymouth University, Southampton University, Liverpool University, University of East Anglia, Newcastle University, Plymouth Marine Laboratory, and the University of Wales, Bangor. All data sets collected during the RACS Challenger cruises are held by the British Oceanographic Data Centre (BODC). All underway and CTD data have been fully calibrated and quality controlled by BODC. The water sample and benthic data sets have been quality controlled by the data originators and submitted to BODC. The data are held in the BODC project database and have been published as part of a fully documented CD-ROM product.

This dataset includes physical, biological and biogeochemical measurements of both the water column and seabed sediments. Hydrographic data include temperature, salinity, attenuance, dissolved oxygen, fluorescence, photosynthetically active radiation (PAR), sound velocity and current velocities, while biogeochemical analyses of water samples provided measurements of nutrients and biological sampling provided measurements of zooplankton abundance. A large number of benthic parameters were measured, including concentrations of substances such as nutrients, metals and carbon in both sediments and sediment pore waters. Benthic fauna were also studied, while rates of sedimentation flux were quantified. These oceanographic and benthic data were supplemented by satellite ocean colour imagery. The data were collected in the North Atlantic Ocean at the Mouth of Rockall Trough, Hatton-Rockall Basin and the Flank of Feni Drift between August 1997 and June 1999 over four cruises, comprising a preliminary site assessment (CD 107 August, 1997) followed by two process cruises (CD 111, April-May 1998, and CD 113, June-July 1998). A further cruise (CH 143) was part-funded by BENBO to retrieve moorings. The data were collected using a variety of instrumentation, including shipboard deployment of conductivity-temperature-depth (CTD) profilers with attached auxiliary sensors, benthic samplers, landers, cameras and incubation chambers, water samplers and continuous underway sensors. These were supplemented by moored sensor and satellite data. The BENBO programme was led by the Scottish Association for Marine Science/Dunstaffnage Marine Laboratory involved researchers from Southampton Oceanography Centre, Scottish Universities Research and Reactor Centre, Plymouth Marine Laboratory, Lancaster University, Leeds University, Edinburgh University, Cambridge University and the University of Wales, Bangor.

The dataset comprises physical, biogeochemical and biological oceanographic, surface meteorological and benthic measurements. Hydrographic profiles including temperature, salinity, fluorescence, transmissance and suspended sediment concentration were collected at numerous stations, while surface hydrographic (fluorescence, transmissance, sea surface temperature, salinity) and meteorological (irradiance, air temperature, humidity, wind speed/direction) data were collected across the survey areas. Sediment, pore water and water column samples were also collected for biogeochemical analysis, as were biological samples for the purposes of species classification and abundance analyses. The data were collected across the Indian Ocean, Arabian Sea and Pakistan margin areas between March and October 2003. Data collection was undertaken by the RRS Charles Darwin during four cruises: CD145 (12 March 2003 to 9 April 2003), CD146 (12 April 2003 to 30 May 2003), CD150 (22 August 2003 to 15 September 2003) and CD151 (17 September 2003 to 20 October 2003). Conductivity-temperature-depth (CTD) profilers with auxiliary sensors, benthic samplers and nets were deployed from the ship, while underway sensors provided continuous surface ocean, meteorological and bathymetric data. The study was designed to investigate an oxygen-minimum zone (OMZ) in the northern Arabian Sea. Chief Investigators include Gregory L Cowie (University of Edinburgh School of GeoSciences) and Brian J Bett (Southampton Oceanography Centre), while other institutions including the Dunstaffnage Marine Laboratory, University of Liverpool and Netherlands Institute of Ecology were also involved in the research. Data management is being undertaken by BODC. Some of the data are still undergoing processing at BODC and further data are expected from originators in the future.