Dr. Adam Kessler Honours Projects

What do sands eat?

Supervisor: Adam Kessler
Field of Study: Biogeochemistry
Support Offered: Lab, field & technical costs
Collaborating Organisation: School of Chemistry; potential other universities

Nutrient cycling in near-coastal sediments (i.e. beach sands!) has been under studied. We have recently shown that the expected “redox cascade” of biogeochemical reactions does not happen in these environments, possibly due to their dynamic nature. Instead, it seems that fermentation is the dominant anaerobic metabolism.

In this project, you will measure the uptake of organic carbon by microbes in sands under a variety of conditions. Your goal will be to determine what biogeochemical reactions are important in these environments. You will use stable- and radio- isotope tracing techniques to determine processes, and measure metabolites using gas chromatography, spectrophotometry and microsensors.

Depending on the direction you take, this may involve field trips to local beaches, and lab work in collaboration with the Schools of Chemistry and Biological Sciences. This project is part of a wider collaboration with researchers from Deakin University, Southern Cross University and the University of Southern Denmark.

For more information – contact Adam Kessler

How do anoxia-tolerant worms change nutrient cycles?

Supervisor: Adam Kessler
Field of Study: Biogeochemistry
Support Offered: Lab, field & technical costs
Collaborating Organisation: School of Chemistry

Burrowing polychaetes (worms) pump overlying water into their burrows to keep them oxygenated, and pore water from in and around their deep burrows is flushed to the overlying water, termed ‘bioirrigation’. In doing so, they often transport large amounts of oxidised species – such as O2, nitrate, iron oxides – around the sediment. Recently, we have shown that many of these worm species are tolerant of very low oxygen concentrations, and can even survive for some time without any oxygen. This means that they are able to transport large amounts of reduced solutes – such as Fe2+ or ammonium.

This project will involve a combination of field work at Paynesville and Patterson Lakes, and laboratory incubation experiments where oxygen is carefully controlled and the underlying biogeochemistry is measured. You will use oxygen imaging techniques and a combination of micro-sensors and nutrient analysis to measure changes in sediment biogeochemistry. There is also some scope for computational modelling, if desired.

For more information – contact Adam Kessler

What controls the balance of denitrification and DNRA in Port Phillip Bay?

Supervisor: Adam Kessler
Field of Study: Biogeochemistry
Support Offered: Lab, field & technical costs
Collaborating Organisation: potential collaboration with Schools of Chemistry and Biological Sciences, EPA, Melbourne Water, DELWP

The balance of the two processes which remove or recycle nitrate from aquatic sediments is an important topic, both scientifically and from the perspective of waterway management.

This project aims to understand the physical, chemical, microbial and/or land-use factors which control the fate of nitrate Port Phillip Bay and its receiving estuaries. This project could involve a combination of field, lab, and/or modelling activities.

For more information – contact Adam Kessler