Honours and masters projects at IMAS

Project supervisor:

• Dr. Madeline Green

Brief project description:

The Daily Egg Production Method (DEPM) is a key technique used to estimate the spawning biomass of pelagic fish species. However, one of its major limitations is the difficulty of accurately identifying fish eggs to species level when multiple species spawn in the same area. Recent advances in in situ hybridization (ISH) offer a molecular solution, enabling researchers to develop species-specific DNA probes that bind to target genes within fish eggs, allowing microscopic visualization and reliable species identification.

This project will build on the approach established by Oxley et al. (2017) to design and validate species-specific DNA probes for an ecologically and commercially important small pelagic species: Blue Mackerel (Scomber australasicus). The student will use online genetic databases to source DNA reference sequences, align and compare target gene regions (e.g. 16S or COI), identify species-unique markers, design labelled probes, and optimize hybridization protocols using preserved egg material.

This project provides hands-on experience in molecular biology, microscopy, and fisheries ecology. The students will gain practical skills in bioinformatics, probe design, and visualization of hybridized tissue, contributing to improved identification accuracy in ichthyoplankton surveys. The resulting tools will support future DEPM surveys and enhance spawning biomass estimates for Blue Mackerel in Australian waters, ultimately improving the scientific foundation for stock assessments and the sustainable management of small pelagic fisheries.

Prerequisites: Students must have completed Molecular Marine Ecology (KSA714) or Aquatic Molecular Biology (JFA305), or an equivalent molecular biology unit, to be considered for this project.

Primary supervisor:

• Dr. Timothy Ward

Brief project description:

Batch fecundity is the average number of eggs released by a female during each spawning event. Relative fecundity is the average number of eggs released by a female during each spawning event relative to female weight (e.g. oocytes per gram). In previous studies of Jack Mackerel off eastern Australia, batch fecundity has been estimated from females with ovaries with hydrated oocytes using the traditional gravimetric method of Hunter and Goldberg (1980). This approach involves counting hydrated oocytes in weighed of sub-sections of the ovaries. The main disadvantage of this approach has been that few females with hydrated oocytes have been collected in trawls.

Recently, samples of containing spawning Jack Mackerel were collected from Bass Strait that are suitable for estimating batch fecundity using the traditional method. In this study, the student will also use two new methods to estimate the number of eggs in each batch. Firstly, whole mounts of ovaries will be analyzed using image analysis methodology and software as described by Thorsen and Kjesbu (2001). Using this method, batch fecundity will be estimated from both hydrated oocytes and the oocytes that will comprise the next batch to be spawned. Secondly, histological slides from studies will be analyzed using stereological approaches described by Weibel (1966), Kjesbu, et al. (2011) and Saber et al. 2016).

Using these three approaches will help to resolve current uncertainties associated with estimates of the relative fecundity of Jack Mackerel off eastern Australia.

Primary supervisor:

• Scott Hadley

Supervisory Team:

• Klaas Hartmann

Brief project description:

The Inland Fisheries Service (IFS) is responsible for the management of the recreational trout fishery in Tasmania. In discharging this responsibility, the IFS manages several inland waters as `assisted fisheries' that rely on stocking and regulation to maintain a desirable level of fishery performance. Some of these assisted fisheries have no natural recruitment, however some have limited or variable natural recruitment. Performance criteria for these assisted fisheries have been established and are listed in the Tasmanian Inland Recreational Fishery Management Plan 2018-2028.

This project aims to develop a mathematical stocking model to support the management of assisted trout fisheries in Tasmania. Once established, the model will be used to support the annual IFS Transfer and Stocking Plan. Estimates for the model parameters will be obtained from the literature and historical IFS records however a field work component may be required to fill any knowledge gaps and/or to ground-truth the model.

The student will have an opportunity to work closely with the Inland Fisheries Service staff and have access to historical data sets regarding fish stocking and fishery performance assessments. The student will also have the opportunity to participate in field work to collect additional information relevant to model development as required. Applicants should be enthusiastic about the Tasmanian inland fishery and in terms of learning modelling techniques and their application to fisheries management.

Primary supervisor:

• Jan Jaap Meijer

Supervisory team:

• Helen Phillips

Brief project description:

Southern Ocean currents are barriers to the oceanic transport of heat towards Antarctica. These barriers break down at key locations along their circumpolar path around Antarctica where poleward heat transport is enhanced. This enhanced heat transport across ocean fronts supplies the warming waters around Antarctica that are contributing to accelerated melting of Antarctic sea ice, ice sheets and Antarctic glaciers (Pritchard et al. 2012).

This research builds on observational evidence that the Antarctic Circumpolar Current (ACC) has only a handful of regions of strong poleward eddy heat flux (Foppert et al. 2017) that are crucial for balancing the heat loss to the atmosphere around Antarctica. South of Tasmania, near the Southeast Indian Ridge and Macquarie Ridge, is one such region where standing meanders in the ACC enable strong cross-frontal transfer of heat and other properties (Meijer et al. 2022, Meijer et al. 2025).

To understand how heat can reach Antarctica, we have to understand how cross-frontal transport works in these meander regions, and with our newly developed framework we finally are able to make observational estimates of poleward heat transport.

Primary supervisor:

• Elena Di Stefano

Supervisory team:

• Zanna Chase
• Andrew Smith (ANSTO)

Brief project description:

The Million Year Ice Core (MYIC) project aims to recover a continuous ice core spanning the mid-Pleistocene Transition (700–1,250 kyr), when global ice volume increased and glacial cycles shifted from 41-kyr to 100-kyr cycles. The climate and carbon-cycle dynamics driving this transition remain poorly understood. MYIC climate records will test hypotheses on the MPT and improve understanding of long-term climate stability. Critical to the success of the project is establishing an accurate depth-age chronology.

One key dating technique uses the ‘cosmogenic’ isotope beryllium-10, a rare long-lived radioisotope produced in the atmosphere by the nuclear spallation of oxygen and nitrogen nuclei by cosmic rays, transported to the Earth’s surface and incorporated into the ice sheet. Its production rate is modulated by the solar cycle and by changes in Earth's magnetic field, leaving imprints that can be used to tie the MYIC chronology to other polar ice core records and to identify geomagnetic events. ¹⁰Be concentrations in ice (10⁴ atoms per gram) are measured by accelerator mass spectrometry (AMS).

The student will work across two facilities. At IMAS, they will collect meltwater samples from the Continuous Flow Analysis (CFA) system as sections of the 153–400 m core are melted and help develop an automated sample collection system. Filters capturing micrometeorites and dust will be retained for synchrotron analysis.

At ANSTO, the student will carry out chemical separation of beryllium using an automated prepFAST column system, prepare targets for the accelerator and participate in the measurement of ¹⁰Be/⁹Be ratios by AMS on the 6-million-volt SIRIUS tandem accelerator.