Studying a vast and dynamic ocean
Australia has the world's third-largest marine jurisdiction – 13.86 million km2 – which stretches from the warm tropical waters off our northern shores to the wild, remote ocean surrounding Antarctica. This territory is twice that of our land mass and is incredibly diverse in life, characteristics and resources.
We are a marine nation. This has been the case since First Nations people settled the continent more than 65,000 years ago. The ocean plays an integral role in our climate, culture, and economy. Emphasising its importance, Australia’s marine industries are predicted to contribute $100 billion each year to the Australian economy by 2025.
Globally, oceans play an important role in the regulation of climate, absorbing both carbon dioxide and 90% of the excess heat from the atmosphere. Significantly, our marine jurisdiction contains many global currents and dynamic regions of ocean that drive and influence global systems.
However, due in part to the vast area they cover, their remoteness and their inaccessibility, our oceans are largely unstudied and there are many gaps in our understanding. Many areas of our oceans remain a mystery. Measuring, monitoring and understanding our oceans is vital for ensuring both their health and prosperity as well as our own.
A dedicated and flexible platform to deliver ocean research
RV Investigator is a state-of-the-art research vessel that enables multidisciplinary study of the ocean anywhere across our vast marine jurisdiction. The vessel’s range (up to 10,000 nautical miles) and endurance (up to 60 days) allow it to conduct research in the farthest reaches of our marine estate and beyond. Combined with the vessel’s extensive suite of scientific equipment and systems, and teams of specialist seagoing technical staff to operate them, this allows researchers to collect both high-quantity and high-quality data from our oceans.
RV Investigator’s physical, biological and biogeochemical oceanographic capabilities include a 24 and 36 bottle CTD (conductivity, temperature, depth) rosette. The CTD can be deployed to depths of 6000 metres and various auxiliary sensors can be attached to it including PAR (Photosynthetically Active Radiation), various fluorometers, transmissometer, nitrate and altimeter. In addition to the in situ measurements, seawater can be collected via the CTD in 12 litre sampling bottles from up to 36 different depths. Researchers can then conduct a wide variety of seawater analysis in the vessel’s onboard laboratories. Available laboratory spaces include a Hydrochemistry Laboratory and Underway Seawater Laboratory.
The vessel provides researchers with the capability to study trace elements dissolved in seawater, which are present in exceedingly low levels, but which are fundamental to sustain biological food chains in the ocean. Facilities to support these studies include containerised cleanroom laboratories, a separate trace-metal-clean CTD system for collecting water samples from the deep ocean, and a trace-metal-clean pump to bring surface seawater onto the vessel with least possible contamination.
RV Investigator has two scientific drop keels fitted with ADCP (Acoustic Doppler Current Profilers) – high (150 kHz) and low (75 kHz) frequency – to measure water current velocities. One drop keel can also be fitted with voyage-specific equipment.
The oceanographic systems are integrated with the atmospheric measurements to provide better estimates of air-sea heat fluxes, and carbon dioxide fluxes, into and out of the ocean. The vessel’s deck capacity also mean it can recover and deploy multiple large ocean moorings on a single voyage. This capacity also allows for the inclusion of a wide range of deployable ocean monitoring equipment on voyages such as Triaxus (towed remotely operated instrumentation platform), VMP (vertical microstructure profiler), and various autonomous underwater vehicles including floats and gliders.
Since commissioning on 12 December 2014, RV Investigator has delivered 27 voyages with a primary focus on oceanographic research (as at December 2022). However, it should be noted that every voyage includes oceanographic data collection via underway systems regardless of the primary research project. These voyages contribute to global programs and are collaborative, delivered by Australian research partners and their international collaborators.
Significant contributions by RV Investigator to global ocean survey and monitoring efforts include:
- IN2020_V08: Quantifying carbon sequestration in subpolar and polar waters. Led by the University of Tasmania, researchers investigated, quantified and obtained the first accurate baseline measurements of carbon sequestration in subpolar and polar waters in the Southern Ocean as part of an international research program (called JETZON).
- IN2019_V03: Repeat survey of the International Indian Ocean Expedition line (IIOE-2). Led by Murdoch University, researchers undertook a coupled bio-physical, ecosystem-scale, examination of the 110°E International Indian Ocean Expedition line, a repeat of a 1963 survey (which was conducted over a year).
- IN2018_V01: Detecting Southern Ocean change via repeat sampling. Led by CSIRO, researchers investigated Southern Ocean changes via repeat hydrography, deep Argo float deployment and trace element biogeochemistry.
- IN2016_V03: Monitoring ocean change and variability along 170⁰W from ice edge to the equator. Led by CSIRO, researchers undertook a program of full ocean depth measurements from the Antarctic ice-edge to the equator in order to monitor ocean change and variability along the GO-SHIP P15S section.
The catalogue of research delivered by RV Investigator includes annual voyages to support the Integrated Marine Observing System (IMOS) deep-water automated mooring arrays for monitoring of the Southern Ocean via Southern Ocean Time Series (SOTS) array and East Australian Current via East Australian Current array (ceased in 2022). These moorings enable scientists to study large ocean processes through continuous data collection. RV Investigator also provides important and ongoing support for the international Argo float program, deploying floats across our vast marine estate while the vessel is underway.
All voyages of RV Investigator collect and deliver important oceanographic data via the vessel’s underway data collection capabilities. These systems continuously collect seawater for sampling providing measurements of water temperature, salinity, dissolved carbon dioxide, dissolved oxygen and chlorophyll levels. These data provide an important baseline data for long term monitoring of ocean change. They also support researchers to make correlations with other research activities on board, such as marine mammal and sea bird surveys.
The MNF Publications database records 65 journal articles primarily related to oceanographic research delivered by RV Investigator (representing approximately 20% of all articles and reports). While likely an incomplete record of all research publications related to the research by RV Investigator, the impact on knowledge creation is substantial. Insights and research findings are published in many of the world’s leading scientific journals. Commonly, publications from research delivered have a high diversity in co-authorship, demonstrating engagement between Australian researchers and the global scientific community. This signals that the research being conducted is of global importance.
Significantly, in the absence of RV Investigator, some areas of research would remain understudied.
The IMOS publications database further illustrates the research outputs delivered by RV Investigator. For the equivalent time period, and related to the Southern Ocean Time Series (SOTS) mooring array, the IMOS database records approximately 100 research publications.
Beyond the research publications, there is also a significant contribution to training and development of future generations of marine researchers on RV Investigator voyages through student participation, as well as education and outreach activities. Supporting such activities is one of the strategic pillars for the operation of the Marine National Facility (refer MNF2030).
An increased understanding of our oceans and high-quality data to inform decision making
The oceanographic research delivered by RV Investigator is globally significant and provides data to address the grand challenges being faced by Australia, our region and globally. The data collected provides significant insights about our oceans, weather and climate, some of which may have remained unstudied without this capability. Similarly, the data we collect helps address major gaps in our understanding of regional ocean processes, including our understanding of the importance and influence of the Southern Ocean on the global climate.
These data address key challenges we face including building resilient and valuable environments, protecting food security and quality, and safeguarding maritime security and sovereignty.
Using our capabilities, researchers have delivered oceanographic research to:
- Better map, model and understand the dynamics and movement of ocean currents in our region. Ocean currents influence the movement of water masses, heat, nutrients and chemicals in our oceans, and dictates global climate. The research and data we deliver provides information vital for safety of navigation, management of fisheries, coastal development, and modelling of impacts from climate change.
- Provide baseline data for monitoring and understanding ocean chemistry and biogeochemistry, including capture and storage of carbon in our oceans. Climate change is driving significant changes in the chemical and physical properties of the ocean, including the capture of carbon through both chemical and biological processes. The ocean research we deliver is helping us understand these systems and how they are being impacted by climate change. Targeted projects, such as the study of the 'Sinking Dead', complement the long-time series data we help deliver, building greater understanding of ocean systems as a whole.
- Increase our understanding of the factors and ocean processes that control species distribution, productivity and biodiversity in our waters. The wide suite of data we deliver from both targeted research and during continuous monitoring undertaken by RV Investigator at sea provides information vital for understanding how ocean systems impact on ecosystem function and biodiversity. The research we deliver has helped identify that Australia’s oceans are undergoing rapid change and warming at a rate faster than most of the rest of the world’s oceans. Concurrently, complementary research has shown the resultant impact of these changes on primary production, coastal fisheries and the movement and range of marine species.
- Calibration and complementing remote sensing through in situ measurement of ocean properties. Increasingly, data about our oceans is being collected through remote means such as sea surface temperature and wave height via satellite measurement. However, the calibration and accuracy of these measurements requires the collection of in situ data for comparison. Project and underway data collected by RV Investigator, including measurement of sea surface temperature, for example, is used by various agencies in the calibration and improvement of their remote sensing data. This better ensures the quality of remote-sensing data.
- Support of long-time series ocean data collection through partnership with IMOS. The IMOS deep water moorings provide vital data to track multi-decadal ocean change, improve our understanding of climate variability, improve the capacity to predict ocean currents, and discover the links between ocean and climate variability, marine chemical cycling and biological productivity of the ocean.
These data streams, combined with real-time data about ocean characteristics and properties by RV Investigator, provide tangible real-world benefits. For example, the research delivered supports improved understanding and modelling of ocean-atmosphere interactions. This improves our capacity to predict future changes and their impacts. It also enables improved weather forecasting and warnings issued to the public, as well as industry and the maritime community.
Data we deliver is used by researchers, industry and other stakeholders to inform their operational activities and decision making. It informs government decision making and policy development. The data is also of strategic importance to marine stakeholders to help improve industry understanding about climate change-induced factors causing economic and social harm to Australia. The research we deliver enables government and industry to be informed about the impacts of climate change, better plan their operations, mitigate associated risk, and make the most of new opportunities.
Importantly, all data collected on voyages and through MNF capability, whether from CSIRO or user supplied equipment, are made freely available for the use and benefit of all. Data can be accessed through a CSIRO Data Portal where it can be discovered, accessed, used and reused. Data is also served through various external platforms such as the IMOS Australian Ocean Data Network (AODN) Portal. CSIRO engages directly with various end-users of our data to ensure data is accessible and meeting their needs.
This ensures the greatest benefit is delivered from every voyage and from every unit of data collected by RV Investigator.