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.

The dataset contains hydrographic, biogeochemical and biological measurements of ocean and seabed sediment properties. Hydrographic profiles provided measurements of temperature, salinity, dissolved oxygen and fluorescence to accompany biogeochemical and biological samples, including concentrations of nutrients, particulate organic carbon (POC) and particulate organic nitrogen (PON). Emphasis was placed on the collection of benthic data, with numerous core samples being collected and analysed for pigments, biomarkers, lipids and other organic compounds. Samples were also collected and analysed for Holothurian species, while a large volume in situ filtration system was used to measure biogeochemical variables including POC and PON, and particulate iron. Station data were supplemented by continuous underway measurements of bathymetry, current velocities, sea surface salinity, temperature, fluorescence and beam attenuation across the survey area. These were accompanied by underway measurements of surface meteorological parameters including irradiance, air temperature, humidity, sea level pressure and wind velocities. The data were collected across the Crozet Plateau in the Southern Indian Ocean between 1st December 2005 and 14th January 2006 on RRS Discovery cruise D300. Data collection focused on four sites, with repeated hydrographic profiles, water and sediment samples collected at each location. In total, 89 instrumentation deployments were carried out at the four stations, including a conductivity-temperature-depth (CTD) package and a Megacorer (for sediment sampling). The underway system utilised a hull-mounted acoustic Doppler current profiler (ADCP) as well as a thermosalinograph and other standard surface hydrographic and meteorological instruments. Further data were collected using a variety of equipment including an otter trawl (net) and submersible cameras but these data are currently held by the data originators and are undergoing processing so are not included in the parameter and instrument lists above. The principal objective of Benthic CROZEX was to assess the manner in which biogeochemical composition and flux of organic matter to the deep-sea floor drives benthic community structure, dynamics and diversity at sites with contrasting primary production regimes. Investigators from British Antarctic Survey (BAS), Natural History Museum (NHM), National Oceanographic Centre (NOC) and the National University of Ireland, Galway (NUIG) were involved. Data management is being undertaken by the British Oceanographic Data Centre (BODC) but data processing is ongoing and various data are yet to be submitted to BODC.

The dataset contains physical, biogeochemical and biological data, including measurements of water temperature, salinity, fluorescence, dissolved gases and current velocities; plankton samples from nets and plankton recorders; water samples for analysis of nutrients, phytoplankton, radioactivity and biogeochemical parameters; benthic cores; meteorological time series (pressure, temperature, humidity, wind velocities); atmospheric samples and ocean-atmosphere fluxes; and results from incubation experiments. The data were collected north of the Crozet Plateau in the Southern Ocean/Southwest Indian Ocean on RRS Discovery cruises D285 (3rd November - 10th December 2004) and D286 (13th December 2004 - 21st January 2005). Much of the data collection focussed on a series of Major Stations (called M1 to M10), with measurements being collected at these stations every two or three days. Conductivity-temperature-depth (CTD) casts were undertaken at each station, providing both hydrographic data and water samples from a range of depths. Other work at each Major Station included zooplankton nets, Longhurst-Hardy Plankton Recorder (LHPR) tows, sediment coring and Argo float deployment. In between Major Stations some additional CTD casts were undertaken. The SeaSoar oceanographic undulator provided further hydrographic data, while hull-mounted acoustic Doppler current profilers (ADCPs) provided current velocity data across the survey area. In addition, continuous underway measurements of hydrographic and meteorological parameters and surface water samples were collected along the cruise track. Five moorings were deployed, one of which was recovered at the end of D286. The other four, including sediment traps, current profilers and CTDs were deployed for one year. CROZEX (CROZet circulation, iron fertilization and Export production experiment) is a complex, multidisciplinary project to examine, from surface to sediment, the structure, causes and consequences of a naturally occurring annual phytoplankton bloom that forms. This collaborative project involved researchers in Ireland and the UK, and was administered by the National Oceanography Centre (NOC), Southampton. Data are managed by the British Oceanographic Data Centre. Much of the CROZEX data processing is ongoing and a number of datasets have yet to be submitted to BODC. The data described here are those presently held by BODC, with the exception of the Argo floats (these data are not expected by BODC and should be accessible via the Argo website) and the four year-long mooring deployments (data from these will be submitted to BODC in the future).

The data set includes hydrographic profiles (including temperature, salinity, attenuance, chlorophyll, oxygen, irradiance, turbulence, sound velocity and currents), hydrographic time series (temperature, currents, fluorescence, bottom pressure), water samples (>70 parameters measured), sediment samples (>160 parameters measured), sediment trap samples (>10 parameters measured), production experiments and marine snow camera profiles. Additional meteorological and wave records are also available, as well as satellite imagery and underwater photography (water column and seabed). The data were collected on the Hebridean Slope (NW of Ireland) between March 1995 and September 1996. Measurements were collected via a combination of shipboard instrument deployments, including >1,800 conductivity-temperature-depth (CTD) and SeaSoar (undulating oceanographic recorder) profiles, >100 expendable bathythermograph (XBT) profiles, >38,000 acoustic Doppler current profiler (ADCP) profiles, >35 core profiles, >800 turbulence profiles, >40 marine snow camera profiles, >55 radiometer profiles and >25 sound velocity and travel time experiments. Benthic lander deployments were also undertaken, along with shipboard incubation experiments and drifting buoy deployments (48 tracks). An intensive water sampling programme provided >2,500 samples for biological and biogeochemical analysis. An extensive moored instrument array was maintained throughout the experiment, including sediment traps, recording current meters (104 series), electromagnetic current meters (9 series), ADCPs (16 series), thermistor chain and temperature probes (70 series), fluorometers (18 series), transmissometers (16 series), light meter (5 series), bottom pressure recorders (11 series), plus one waverider buoy series and three meteorological buoy time series. The Shelf Edge Study (SES) was an intensive multidisciplinary experiment and formed part of the NERC Land Ocean Interaction Study. The British Oceanographic Data Centre (BODC) assembled over 95% of the data sets collected during SES into its project database system. Once basic quality control procedures had been completed the data set was published, complete with extensive data documentation, on CD-ROM.