Prof Tom Trull
Antarctic Climate and Ecosystem CRC
Research voyage to the Southern Ocean, southwest of Tasmania, to support maintenance of Southern Ocean Time Series (SOTS) automated moorings which collect data for long-term monitoring of the Southern Ocean.
The primary objective of the voyage is to deploy a new set of SOTS moorings (SAZ-19 and SOFS-6) and then recover the existing SOTS moorings (FluxPulse-1 and SAZ-18).
Two supplementary projects will be undertaken on the voyage:
- International Nutrient Intercalibration Exercise (Mark Rayner, CSIRO): Project to measure profiles of trace elements dissolved and particulate concentrations, and examine the processes that produce and recycle them.
- Spatial and Temporal Variability in the Distribution and Abundance of Seabirds (Dr Eric Woehler, BirdLife Australia): Ongoing project to quantify the distribution and abundance of seabirds around Australia.
Two piggyback projects will be undertaken on the voyage:
- Acoustic estimates of zooplankton and fish (Rudy Kloser, CSIRO): Project to map the top 1000 m of the water column for micronekton at the SOTS site using a profiling lagrangian acoustic and optical probe acoustic optical system (PLAOS).
- Trace element cycling (Philip Boyd, UTAS): Project to measure profiles of trace element dissolved and particulate concentrations, their stable isotopes and to examine the processes that produce and recycle them.
As a result of this voyage, researchers have deployed moored platforms that assemble an integrated view of the seasonality of the processes that control the productivity of the sub-Antarctic microbial foodweb. This analysis extends from the physics of ocean mixing and insolation, to the chemistry of ocean nutrients and the biological responses of phytoplankton and zooplankton.
This research will contribute to global datasets and increase understanding of Southern Ocean characteristics, variability and processes. This information is vital for informing ocean and climate modelling.
As a result of the nutrients supplementary project, there is improved knowledge of nutrient analysis techniques, meaning future data will be potentially of higher accuracy and precision, lowering the uncertainty associated with analysis of samples.
Data collected from the seabirds project will complement existing data from the survey area collected between 1980 and 2005. These data were collected from Australian Antarctic Division research and resupply voyages.
The scientific highlight of the seabirds project was the observation of a Gibson’s Albatross (a subspecies of the Wandering Albatross) originally banded in 1991 as a breeding adult. The bird, likely close to 50 years old, was observed sitting on the surface close to the vessel on several occasions and was photographed when it was observed to be banded. The colour band allowed the bird to be uniquely identified.