Southern Ocean phytoplankton calcification

Remotely-sensing the Southern Ocean distribution of calcifying phytoplankton and their role in regional ecology and biogeochemistry

Degree type


Closing date

29 October 2021



Citizenship requirement

Domestic/International Onshore

About the research project

Calcifying phytoplankton (coccolithophores) play an important role in carbon cycling in the Southern Ocean. They expand across the subpolar Southern Ocean in a circumpolar band called the “Great Calcite Belt (GCB)”. The prevalence of coccolithophores in the GCB leads to the formation of large amounts of pelagic Calcium Carbonate (CaCO3), which constitutes more than 80% of the carbon sinking to 1000 m depth or below (SOTS time-series data; Wynn-Edwards et al., 2020, Frontiers in Marine Science). The efficient export of CaCO3 in the sub-polar Southern Ocean has implications for the global carbon cycle as it traps alkalinity in the Southern Ocean thereby reducing the atmospheric uptake of CO2 outside the Southern Ocean (Krumhardt et al., 2020, Global Biogeochemical Cycles). Thus, it is important to understand the distribution and abundance of coccolithophores in the Southern Ocean and how calcification alters carbon cycling in this ocean basin.

This PhD project will investigate the relevance of calcifying phytoplankton on contemporary and future carbon cycling in the Great Calcite Belt of the sub-Antarctic Southern Ocean. It will utilize satellite and BioGeoChemical-Argo (BGC-Argo) profiling float data to map regional imprints of calcifying phytoplankton on nutrient and carbon stoichiometry as well as alkalinity as a key variable to determine the CO2 uptake capacity of the sub-Antarctic Southern Ocean. It will further use laboratory incubations to assess the influence of calcifying phytoplankton on retention (as opposed to deep sequestration) of carbon and alkalinity in the surface. Goal is to generate a mechanistic understanding of retention-versus-export processes and link this with in BGC-Argo and satellite observations on a regional scale. The project will also generate flow cytometric and/or microscopic datasets of phytoplankton communities from the sub-antarctic during ship voyages to ground-truth characterizations of the phytoplankton community derived from BGC-Argo and satellite data.

Primary Supervisor

Meet Dr Lennart Bach


Applicants will be considered for a Research Training Program (RTP) scholarship or Tasmania Graduate Research Scholarship (TGRS) which, if successful, provides:

  • a living allowance stipend of $28,597 per annum (2021 rate, indexed annually) for 3.5 years
  • a relocation allowance of up to $2,000
  • a tuition fees offset covering the cost of tuition fees for up to four years (domestic applicants only)

If successful, international applicants will receive a University of Tasmania Fees Offset for up to four years.

As part of the application process you may indicate if you do not wish to be considered for scholarship funding.


The project is open to domestic (Australian and New Zealand) and international applicants who are already in Australia (onshore) at the time of submitting their application.

Due to current Australian COVID-19 travel restrictions the University cannot accept applications from international applicants who are currently overseas.

Applicants should review the Higher Degree by Research minimum entry requirements.

Selection Criteria

The project is competitively assessed and awarded.  Selection is based on academic merit and suitability to the project as determined by the College.

Additional essential selection criteria specific to this project:

  • Honours or Master degree in biological or chemical oceanography or closely related field
  • Experience with computational software such as R, Python, or Matlab to handle large datasets
  • Great abilities to work in teams and collaborative environments
  • Ability to spend extended periods abroad during field studies
  • Enthusiasm for scientific discourse and progress
  • Fluent English skills
  • Very good writing skills
  • Reliable and highly motivated

Additional desirable selection criteria specific to this project:

  • Culturing phytoplankton or other microbes.
  • Fieldwork experience

Application process

There is a three-step application process:

  1. Select the project, and check you meet the eligibility and selection criteria;
  2. Contact the Primary Supervisor, Dr Lennart Bach, if you have any questions about the project; and
  3. Click here to submit an application by the closing date listed above.
    • Copy and paste the title of the project from this advertisement into your application. If you don’t correctly do this your application may be rejected.
    • As part of your application you will be required to submit a covering letter, a CV including contact details of two referees and your project research proposal.

Following the application closing date applications will be assessed within the College. Applicants should expect to receive notification of the outcome by email.

Apply now Explore other projects

Why the University of Tasmania?

Worldwide reputation for research excellence

Quality supervision and support

Tasmania offers a unique study lifestyle experience