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‘Outstanding’ PhD thesis earns Chancellor’s Medal at graduation ceremony


Sharlene King
1 June 2018

Rachel Murray spent three years knee-deep in the mangrove and estuary systems of north Queensland measuring nitrous oxide. The insights the then PhD researcher gleaned using a new approach - continuous real time monitoring of this greenhouse gas – saw her awarded Southern Cross University’s highest accolade for an outstanding thesis, the Chancellor’s Medal, at today’s graduation ceremony.

“I think it’s great, I’m really excited. I feel really proud,” Dr Rachel Murray said of the honour she received from the University’s Chancellor Nick Burton Taylor AM for her thesis ‘N₂O cycling in vegetated estuaries: Insights from continuous, real time N₂O measurements and isotopomer analysis’.

Nitrous oxide is a powerful, long‐lived greenhouse gas, but little is known about the role of estuarine areas in the global N2O budget. Rachel’s research set out to change that.

“Estuaries are a source of nitrous oxide as a greenhouse gas but they can also be a sink for nitrous oxide,” said Dr Murray who spent time in the Johnston, Burdekin and Fitzroy river catchments, between the north Queensland towns of Innisfail, Ayr and Rockhampton.

“We were using a unique method of taking continuous samples of nitrous oxide along the length of an estuary. That gave us higher resolution data about nitrous oxide emissions. We got more data than we otherwise would have.

“The data told us exactly where the nitrous oxide was coming from: some was coming from sewerage treatment plants, some coming from the soil, some came from fertilisers upstream in the estuary.

“In the mangroves we found that nitrous oxide could actually be consumed which is uncommon to observe in coastal areas.”

Dr Murray worked with researchers from the University’s Centre for Coastal Biogeochemistry. Professor Bradley Eyre, the Centre’s Director, was one of her PhD supervisors.

“It’s an outstanding achievement for Rachel to receive this award. The examiners, all international experts, saw how difficult the topic was and what an outstanding job she did in handling the thesis,” said Professor Eyre.

Dr Murray already had two degrees under her belt - a Bachelor in geology and a Master’s in climate science - when she relocated to Australia from the USA to pursue postgraduate research at the Southern Cross University Lismore campus.

“In the future we may have taxes on greenhouse gases and credits for mitigation so my research is relevant for planning for the future. Land management and conservation efforts will have to account for both natural and man-made sources of greenhouse gases,” she said.

Six Doctors of Philosophy were awarded, along with two Doctors of Business Administration.

A University Medal was awarded to Kate Bradshaw in recognition of a very high standard of academic achievement in her Bachelor of Science with First Class Honours degree.

Around 165 students graduated at two ceremonies in the Whitebrook Theatre at the Lismore campus.