Impacts of alkalinity enhancement on SO plankton

Impacts of carbonate chemistry and trace metal perturbations related to ocean alkalinity enhancement on Southern Ocean plankton communities

Degree type


Closing date

24 September 2021



Citizenship requirement

Domestic/International Onshore

About the research project

Keeping global warming below 2°C will require rapid carbon dioxide (CO2) emission reductions. Additionally, 100-900 gigatons of CO2 must be removed from the atmosphere by the end of the 21st century using a range of negative emission technologies (NETs). One of the most promising NETs is to accelerate natural rock weathering, whereby suitable rocks are extracted, pulverised, and dispersed over land and the oceans (known as “Enhanced Weathering” or “Ocean Alkalinity Enhancement”). CO2 is chemically absorbed in this process, and safely stored mainly as bicarbonate in the oceans for geological timescales. However, the desired consumption of atmospheric CO2 would inevitably be accompanied by release of mineral dissolution products. Gigatons of alkalinity, silicate, and dissolved metals would end up in the oceans, and these large-scale perturbations of seawater chemistry could substantially disrupt marine ecosystems – potentially more than climate change itself.

The Southern Ocean has recently been identified as a hot spot for Alkalinity Enhancement, due to its unique chemical and physical conditions that make increasing CO2 absorption at least twice as efficient as in the polar North Atlantic, for example. Furthermore, biological productivity in the Southern Ocean is limited by iron, and potentially other trace metals, so that large-scale trace metal perturbations associated with ocean alkalinity enhancement would likely affect productivity and ecosystem structure.

This project aims to identify the vulnerability of Southern Ocean plankton communities to perturbations associated with ocean alkalinity enhancement. These are mainly carbonate chemistry perturbations (increasing pH), trace metal enrichment and potentially silicate fertilization.

The overarching goal is to understand how these perturbations individually and/or combined will (i) change the physiological performance of key Southern Ocean phytoplankton species, (ii) affect higher trophic levels such as krill or copepods who feed on phytoplankton, and (iii) change the composition of Southern Ocean phytoplankton communities.

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; and
  • 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 (e.g. environmental microbiology). Preferably experience with phytoplankton
  • Strong abilities to work in teams and collaborative environments
  • Ability and willingness to spend extended periods in the field (e.g. research voyage)
  • 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:

  • Experience with computational software such as R, Python, or Matlab
  • 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 2 x 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