This dataset comprises the Multi-net plankton sampling collected during the SEA-MES program across four RV Investigator voyages (IN2023_V05, IN2024_V03, IN2024_V05, IN2025_V04). A total of 173 Multi-net operations were conducted, using 100 µm and 500 µm mesh nets to collect depth-stratified samples through the water column, capturing both day and night to assess diel vertical migration. The dataset includes 560 samples from 100 µm nets and 140 samples from 500 µm nets, providing information on zooplankton composition, biomass, and community structure, including 58,246 individuals from 105 genera and 70 families identified to date. These data provide a detailed view of pelagic biodiversity across the south-eastern continental shelf and upper slope of Australia.

This record describes the CTD data collected on Investigator voyage IN2024_V05, titled: "Multi-year: Untangling the causes of change over 25 years in the southeast marine ecosystem (SEA-MES Voyage 3)." The voyage took place between November 13, 2024 and December 12, 2024 (AEST), departing from Hobart and returning to Hobart. Data for 94 CTD deployments were acquired using the Sea-Bird SBE911 CTD unit #24 (Serial Number 1332), fitted with 36 twelve-litre bottles on the rosette sampler. Sea-Bird-supplied calibration factors were used to compute the pressures and preliminary conductivity values. CSIRO-supplied calibrations were applied to the temperature data. The data were subjected to automated QC to remove spikes and out-of-range values. Calibration for Active Heave Compensation (AHC) appears to have changed post dry dock, resulting in loops on SeaSave plots after AHC is turned on. This also caused the CTD wire to become slack due to the compensation sending out too much wire. Rapp McGregor assisted the Chief Engineer to dial down the maximum winch speed to prevent wire slack from occurring on up heave, in the event the winch compensation was in phase with the actual heave. The issue was observed to cause an additive effect instead of the intended effect of keeping the CTD steady. The issue was further investigated and resolved following the voyage. The final conductivity calibration was based on a single deployment grouping. The final calibration from the primary sensor had a standard deviation (SD) of 0.0015089 PSU, well within our target of ‘better than 0.002 PSU’. The standard product of 1-decibar binned averages were produced using data from the primary sensors. The dissolved oxygen data calibration fit had a SD of 0.83742 μM. The agreement between the CTD and bottle data was good. Fluorometer, transmissometer, PAR, CDOM and turbidity sensors were also installed on the auxiliary A/D channels of the CTD. The collected data were processed (quality-controlled), and subsequently archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC). Additional information regarding this dataset may be contained in the Voyage Summary and the Data Processing Report.

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2024_V05, titled: "Multi-year: Untangling the causes of change over 25 years in the southeast marine ecosystem - Voyage 3." The voyage took place between November 13, 2024 and December 12, 2024 (AEST), departing from Hobart and returning to Hobart. 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 the End of Voyage (EOV) data archive from the Marine National Facility (MNF) RV Investigator voyage IN2024_V05, titled "Multi-year: Untangling the causes of change over 25 years in the southeast marine ecosystem (SEA-MES Voyage 3)." The voyage took place between November 13, 2024 and December 12, 2024 (AEST), departing from Hobart and returning to Hobart. For further information please refer to the voyage documentation links. Instruments used and data collected include: Regular measurements: Lowered ADCP (LADCP), Acoustic Doppler Current Profiler (ADCP; 38, 75, 150 KHz ), CTD, Hydrochemistry, Gravimeter, Fisheries Echosounder (EK80), Multibeam Echosounder (EM712, EM124), Sub-bottom Profiler (SBP29), Starboard and Portside Radiometers, Air Sampler, Ultra Short BaseLine Underwater Positioning System (USBL), GPS Positioning System, Doppler Velocity Log, Thermosalinographs (TSG), Fluorometer, Oxygen Optode, Atmospheric Temperature, Humidity, Pressure, Wind and Rain sensors, Photosynthetically Active Radiation (PAR) sensor, Precision Infrared Radiometer (PIR), Precision Spectral Pyranometer (PSP), ITI Trawl Net. Voyage-specific measurements: Demersal Trawl, Multiple Plankton Sampler (HydroBIOS Multinet), Video, Wildlife Observations (seabirds, cetaceans and seals). The archive for the IN2024_V05 EOV raw data is curated by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart, with a permanent archive at the CSIRO Data Access Portal (https://data.csiro.au/), providing access to voyage participants and processors of the data collected on the voyage. All voyage documentation is available electronically to MNF support via the local network. Applications to access voyage documentation by non-CSIRO participants can be made via data-requests-hf@csiro.au All processed data from this voyage are made publicly available through the MNF Data Trawler (in the related links)

This record describes the Underway (UWY) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2024_V05, titled "Multi-year: Untangling the causes of change over 25 years in the southeast marine ecosystem (SEA-MES Voyage 3)." The voyage took place between November 13, 2024 and December 12, 2024 (AEST), departing from Hobart and returning to Hobart. Standard Underway data is continuously recorded, consisting of: (1) Navigation data (NAV): Latitude, Longitude, Speed, Heading, Course Over Ground, Gyros, and Doppler Log (dual GPS instrument). (2) Thermosalinograph (TSG): Water Salinity, Flow-Rate, Temperature, Fluorescence, pCO2 and Optode/Oxygen. (3) Atmospheric (MET): Humidity, Wind Speed and Direction (vane and ultrasonic), Radiometer/Sea Surface Temperature, Pyranometer/Solar Radiation, Photosynthetically Active Radiation (PAR), Air Temperature, Air Pressure, Rain, Ozone and Trace Gases (port and starboard instruments). The quality-controlled RV Investigator underway meteorological and SST data are supplied to the IMOS AODN and other global data repositories and distributors, and made available for satellite SST validation by the Australian Bureau of Meteorology (BoM). Near real-time, unprocessed data are available via the link "Visualisation tool for Underway Data." This dataset has been processed (quality-controlled), and archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC). Data are available at time intervals of 5 sec (NetCDF format), 5 sec, 10 sec, 1 min and 5 min (ASCII format). Note: not all variables are quality controlled; please check for existing QC flags in the datasets. Additional information regarding this dataset is contained in the Voyage Summary and/or the Data Processing Reports for this voyage.