New radiochemistry facility to reconstruct environmental histories

A new, cutting-edge analytical facility at Southern Cross University’s National Marine Science Centre (NMSC) in Coffs Harbour is enabling researchers to investigate the history of carbon sequestration and pollution during the past 150 years.

This world-class radioisotope laboratory includes four germanium gamma spectrometers and was funded by the Australian Research Council.

“This is an outstanding facility that puts SCU in a great competitive position. Some of the instruments we have at the NMSC are the first ones in Australia and enable us to measure a large number of natural and artificial radioactive chemicals,” Professor Isaac Santos said.

“We specialise in the use of natural radionuclides that can date soil and sediment samples. We are reconstructing environmental histories back 150 years which is exactly the time scale of many environmental issues currently being debated.”

Trace quantities of radioactivity are found in all natural substances and can be used to understand the behaviour of specific processes, such as the global carbon cycle. By looking at the quantities of some trace elements that include thorium, radium, lead and cesium isotopes, researchers can better understand these processes.

Dr Christian Sanders, Professor Santos and their team of researchers are conducting a large-scale project, using the technology to look at carbon sequestration in mangroves from Darwin to Melbourne, with funding also from the Australian Research Council.

“With the information from this project we are trying to resolve the carbon budget. Where does carbon come from and where does it go? With the climate changing, do we have an intensification of carbon sequestration?”

Dr Sanders said this project would have significant ramifications for the preservation of mangrove forests and other marine systems that sequester carbon. Sequestering carbon in marine ecosystems, also referred to as ’blue carbon‘, has the potential to become a major accounting tool in future carbon economies.

“Because mangroves lock up lots of carbon, we have good reasons for preserving them, not draining mangroves or building houses on top of them.
The radioisotope laboratory at the NMSC is also being used as a hub for research from other universities across Australia and overseas including USA, Brazil and India,” said Dr Sanders.

Photo: Dr Christian Sanders (left) and Professor Isaac Santos taking a sediment sample from mangroves in Coffs Creek.