Chancellor’s Medal recipients recognised for innovative environmental research

The Chancellor’s Medal is the University’s highest accolade for an outstanding thesis.

Dr Jeffrey said he felt privileged and honoured to receive the award. “It’s a testament to many years of hard work, not just for me but also for my supervisors and the support I had from others during my PhD,” he said.

Dr Jeffrey’s PhD research aimed to close the knowledge gap surrounding coastal wetland greenhouse gas emissions and drivers, an important contribution to global carbon budgets from previously understudied southern hemisphere systems.

By conducting research at a number of estuaries including Caboolture River and Gulf of Carpentaria in Queensland, and Coffs Creek and Mid-Coast wetlands in New South Wales, Dr Jeffrey uncovered a number of drivers of carbon dioxide and methane emissions including groundwater discharge, soil geochemistry and catastrophic mangrove dieback events.

“Research from my PhD found that land use change can enhance river and wetland greenhouse gas emissions but healthy groundwater and river flow, and nutrient reduction via good land use practices, can help reduce these emissions,” Dr Jeffrey said.

His research has been cited in the United Nations' Intergovernmental Panel on Climate Change AR6 Report.

Dr Jeffrey is currently working as a Research Fellow at Southern Cross University. His postdoctoral position is supported by an Australian Research Council Discovery Grant and his current research aims to quantify the methane emissions from trees and forests nationally.

Dr Laura Stoltenberg also received a Chancellor’s Medal and said she felt surprised and honoured to have received such a prestigious award. “It is great to see a spotlight shone on some of the important research into coral reef biochemistry that goes on here at Southern Cross University,” Dr Stoltenberg said.

Dr Stoltenberg’s PhD research involved a field study of coral reefs at Heron Island at the southern end of the Great Barrier Reef, and assessed the temporal viability of organic and inorganic calcium carbonate sediment metabolic rates under ambient and elevated carbon dioxide levels, the temporal viability in net ecosystem calcification of a coral reef flat and its drivers, and the relative contribution of sediment community calcification to reef ecosystem calcification.

The results of the field study concluded that ocean acidification will be a significant driver in the response of shallow reef sediment dissolution within this century but seasonal variability could shape the response to ocean acidification. Changes in light and temperature were shown to affect sediment metabolism rates.

Dr Stoltenberg’s research revealed that sediment processes can play an important role in coral reef ecosystem metabolism and need to be taken into account when predicting the effects of climate change on net ecosystem processes.

Her research has been published in two scientific journals.

Dr Stoltenberg said for an ocean-obsessed person such as herself, studying coral reefs was ideal. “It is an incredibly complex and exciting ecosystem to study. The biogeochemical processes are multifaceted and intertwined. It is exciting to come up with new questions and see trends emerge in the data.”

Dr Stoltenberg currently works as Program Manager for Aquaculture at not-for-profit OceanWatch Australia. The organisation works with the Australian seafood industry to advance sustainability in the sector through improved environmental practices and community-based coastal habitat restoration programs.

Dr Jeffrey and Dr Stoltenberg graduated with a Doctor of Philosophy at Southern Cross University’s Lismore graduation ceremony on 5 November 2022.