A team effort. Photo: Alina Madita Wieczorek/NIWA
Tangaroa voyage 2025
The Antarctic Science Platform was the primary science funder of the RV Tangaroa's 16th Antarctic campaign, in January-February 2025.
The vessel spent approximately 39 days at sea, including 30 within the Antarctic Treaty area (south of 60°S). The main survey area was the Western Ross Sea from Iselin Bank to Cape Adare, and as far south as The Ross Ice Shelf front.
The voyage made a significant contribution to Ross Sea observations, including:
- Visiting over 250 sampling sites
- Conducting 72 Deep Towed Imaging System (DTIS) surveys, gathering 22 hours of video footage
- Collecting close to 2,500 biological specimens
- Deploying the CTD (Conductivity, Temperature, Depth) 53 times
- Conducting one glider mission covering 220km
- Deploying the Continuous Plankton Recorder seven times
- Deploying 12 Argo floats
- Collecting 1,110 Niskin bottle samples – used to collect water samples from varying depths.
The work contributes to a range of our research themes, and a Platform priority has been to enhance the internationally coordinated network of oceanographic observations within the Ross Sea. Among the many highlights, as detailed in the voyage reports listed below, is the retrieval of hydrographic moorings from the front of the Ross Ice Shelf, which were deployed by our team from the Italian icebreaker Laura Bassi last year. These data will help us understand what’s forcing warm water into the cavity below the shelf, and how much meltwater is coming out.
Voyage updates
Voyage co-leaders Dr Craig Stevens and Dr Denise Fernandez provided updates from the ship:
Update #1: Departing Wellington for the Ross Sea 14 January
Update #2: A long, straight line south 17 January
Update #3: Biology and physics the Antarctic Polar Front 20 January
Update #4: CTD sampling as huge icebergs start to appear 24 January
Update #5: Bethnic sampling, the continental shelf, turning westward 28 January
Update #6: NZ's first biochemical Argo floats 31 January
Update #7: We got them! Retrieval of hydrographic moorings 4 February
Update #8: Benthic surveys and the ocean glider 8 February
Update #9: The deep ocean troughs 12 February
Update #10: eDNA, fisheries acoustics and zooplankton 17 February
Update #11: Ocean surface and atmospheric data, all the way home 21 February
There is a gallery of photos on NIWA’s website.
The voyage deployed NZ’s first biogeochemical Argo floats in the Ross Sea, expanding the international marine monitoring network. Argo floats are ocean-monitoring robots that drift in the ocean, rising and falling to depths of 1-2km at pre-programmed intervals to collect profile measurements of temperature and salinity as they drift. The "souped up" biogeochemical floats deployed this year capture even more data, including oxygen and chlorophyll levels. This new information will help fill observational gaps and begin to provide a better, year-round picture of the state of the ocean and the marine food web. Congratulations to NIWA and our Australian partners at CSIRO for collaborating with us on this milestone - the Argo programme is a truly international effort, and all data is freely available. Photo: Svenja Halfter/NIWA
Voyage science
Science objectives for the voyage include:
- Heat, salt and meltwater fluxes in the Ross Sea, through moorings, floats and hydrographic operations
- Benthic community sampling for biogeographic analysis, including eDNA, connectivity analysis, and resampling of historic era locations
- NZ’s first deployment of Biogeochemical Argos
- Polynya processes, though recovery of moorings and hydrographic operations close to the Ross Ice Shelf
- Integration of eDNA, acoustics and direct sampling to document mesopelagic species presence
- Zooplankton population abundance and composition
- Biogenic aerosol production processes
- Ocean surface biogeochemistry and bio-optics
- Recovery and redeployment of marine mammal acoustic monitoring buoys
- Current sources of freshwater in the Ross Sea.
These objectives align with Project 2 – Ocean Mechanics and Project 3 – Ross Sea Ecosystems, and follow on from Tangaroa voyages in 2023, 2021 and 2019, and from the NZ-Italy Ross Voyage 2024.
Impact
Our research aims to:
- Better understand the far-reaching impacts of ice sheet melt on sea-ice, biological systems, global ocean circulation and climate informs adaptation options and critical assessment of mitigation pathways
- Reduce uncertainty in future climate scenarios through improved understanding of how oceanic and atmospheric processes influence the cryosphere
- Improve management of the Antarctic and Southern Ocean environment through greater understanding of the implications of regional climate change on biological systems
- Sufficiently understand the structure and dynamics of the Ross Sea region ecosystem to forecast large scale biological responses to environmental change
- Detect ecosystem changes in support of New Zealand’s Ross Sea region Marine Protected Area monitoring strategy and decision-making, both in New Zealand an internationally.
Collaboration
The multidisciplinary team onboard the Tangaroa included participants from Australia, Europe, India and the United Kingdom.
The voyage is supported by funding from the Ministry of Business, Innovation, and Employment (MBIE), the Antarctic Science Platform, NIWA Strategic Science Investment Funds, University of Auckland, University of Otago – Ōtākou Whakaihu Waka, University of Canterbury and overseas funding agencies.
Thank you to everyone who contributed to the voyage’s success.
Media
Venture south to track impact of warming world | Otago Daily Times Online News
Scientists head to Antarctica to study climate change impacts | RNZ
Indian researcher exploring Ross Sea area in Antarctica - The Hindu
For media inquiries, please contact d.diaz@antarcticanz.govt.nz
Photo: Gert-Jan Jeunen/University of Otago - Ōtākou Whakaihu Waka