This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2016_V04, titled: "Influence of temperature and nutrient supply on the biogeochemical function and diversity of ocean microbes." The voyage took place between August 31 and September 22, 2016 departing from Sydney(NSW) and arriving in Brisbane (QLD). Hydrology samples were collected from Niskin bottles sampled at various depths during Conductivity-Temperature-Depth (CTD) deployments. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. This dataset has been archived at the CSIRO O&A Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage in2016_v02, titled "IMOS Southern Ocean Time Series Automated Moorings for Climate and Carbon Cycle Studies Southwest of Tasmania." This voyage took place between the 14th of March, 2016 and the 16th of April, 2016, departing from Hobart (TAS) and returning to Hobart. Hydrology samples were collected from Niskin bottles sampled at various depths during a Conductivity-Temperature-Depth (CTD) deployment. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. Samples were also collected every 2 hours for nutrient analysis from the underway system which collects water from 7 m depth and is not filtered. This dataset has been archived at the CSIRO O&A Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2019_V03, titled: "A coupled bio-physical, ecosystem-scale, examination of Australia’s International Indian Ocean Expedition line 110E." The voyage took place from Fremantle (WA) to Fremantle between May 14 and June 14, 2019. Hydrology samples were collected from Niskin bottles sampled at various depths during Conductivity-Temperature-Depth (CTD) deployments. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. This dataset has been archived at the CSIRO O&A Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2021_V03, titled "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27S." The voyage took place between May 8 and June 3, 2021 departing from Hobart (TAS) and arriving in Brisbane (QLD). Nutrient samples were analysed using segmented flow SEAL AA3 and results are in µmol/L. In-house methods SOP 001, SOP 002, SOP 003 and SOP 004 were used to analyse nutrients. Please cite the following paper when using Hydrochemistry data for silicate, phosphate, nitrate+nitrite (NOx) and nitrite analysis: Rees, C., L. Pender, K. Sherrin, C. Schwanger, P. Hughes, S. Tibben, A. Marouchos, and M. Rayner. 2018. Methods for reproducible shipboard SFA nutrient measurement using RMNS and automated data processing. Limnol. Oceanogr: Methods Doi:10.1002/Iom3.10294 Salinities were analysed using Guildline 8400B Autosal Lab Salinometer and OSIL software. The salinometer was calibrated with IAPSO standard seawater P163 and P164. In-house method SOP 006 was used to analyse salinity, units are Practical Salinity Unit (PSU). Dissolved Oxygens were analysed using Scripps UV titrator and software, units measured in ml/L and converted to µmol/L. Dissolved oxygen was analysed using in-house method SOP 005. All data was processed with HyPro 5.7 on the ship and any data re-processed on shore was with HyPro 5.7. A copy of HyPro is available with the data. Nutrient data decimal places within the CSV file; silicate is 1 decimal place, nitrite is 3 decimal places and NOx (nitrate + nitrite), phosphate and ammonium is 2 decimal places. Previously values below detection limit were set to zero these values are now displayed as the measured value even if that is a negative value. Oxygen Data is displayed to 3 decimal places. Salinity data is displayed to 4 decimal places, prior to in2018_t01 voyage it was 3 decimal places in the csv file. Data processing notes are in the process report (in2021_v03_HYD_ProcessingReport.pdf). This dataset has been archived at the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator research voyage in2017_c01, titled "GAB deep water geological and benthic ecology program." The voyage took place from Hobart (TAS) to Hobart between April 11 and April 28, 2017. Hydrology samples were collected from Niskin bottles sampled at various depths during a Conductivity-Temperature-Depth (CTD) deployment. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. Underway samples were also collected every 12 hours (or once every 24 if a CTD coincided with collection time) for nutrient analysis from the underway system which collects water from 7 m depth and is not filtered. This dataset has been archived at the CSIRO O&A Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage: in2016_v03, titled "Monitoring Ocean Change and Variability along 170 W from the ice edge to the equator." The voyage consisted of two legs: Leg-1 from Hobart (TAS) to Wellington (NZ) between April 27 and May 26 and Leg-2 from Wellington (NZ) to Lautoka (Fiji) from May 27 to June 28, 2016. Hydrology samples were collected from Niskin bottles sampled at various depths during a Conductivity-Temperature-Depth (CTD) deployment. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. Underway samples were also collected every 12 hours (or once every 24 if a CTD coincided with collection time) for nutrient analysis from the underway system which collects water from 7 m depth and is not filtered. This dataset has been archived at the CSIRO O&A Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes Hydrology (HYD) data collected collected from the Marine National Facility RV Investigator Voyage IN2018_V03, titled: "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27S." The voyage took place between April 19 and May 10, 2018 departing Brisbane (QLD) and returning to Brisbane. Five nutrients were analysed; silicate, phosphate, nitrate + nitrite, nitrite and ammonium. Certified reference materials for nutrients in seawater were within the specified limits of the certified value. The Guildline salinometers were problematic at sea, samples from CTD 12, 13, 14, the underway thermosalinograph and Triaxus samples were collected in crimped top bottles and brought back to Hobart for analysis. High quality data was produced for the three measured parameters. This dataset has been archived at the CSIRO O&A Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2023_V06, titled: "Understanding Eddy Interactions and Their Impacts In the East Australian Current System." The voyage took place between October 9 and November 2, 2023, departing from Sydney (NSW) and returning to Sydney. Hydrology samples were collected from Niskin bottles sampled at various depths during Conductivity-Temperature-Depth (CTD) deployments. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. This dataset has been processed (quality-controlled), and archived at the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes Hydrology (HYD) data collected from the Marine National Facility RV Investigator voyage in2016_v01 Titled: "HEOBI: Heard Earth-Ocean-Biosphere Interactions". The voyage took place between the 7th January to 27th February, 2016 departing Freemantle (WA) and returning to Hobart (TAS). Hydrology samples were collected from Niskin bottles sampled at various depths during a Conductivity-Temperature-Depth (CTD) deployment. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. Samples were also collected every 2 hours for nutrient analysis from the underway system which collects water from a 7 m depth and is not filtered. This dataset has been archived within the CSIRO O&A Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the voyage report and data processing report.

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2024_V03, titled: "Untangling the causes of change over 25 years in the southeast marine ecosystem (SEA-MES Voyage 2)." The voyage took place between May 1 and May 31, 2024, departing from Hobart (TAS) and arriving in Sydney (NSW) Hydrology samples were collected from Niskin bottles sampled at various depths during Conductivity-Temperature-Depth (CTD) deployments. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. This dataset has been processed (quality-controlled), and archived at the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.