Profile: The isotope fingerprint expert

“It’s always difficult to describe to people what I do because I work on so many different projects,” says Bernadette Proemse. The University of Tasmania researcher specialises in a technique called isotope fingerprinting, which means she literally has a finger in all the scientific pies.

Recently, a colleague asked for her expertise to study the water chemistry at a remote Tasmanian site. She agreed immediately.  “It was a free helicopter ride through the wild!” she laughs.  She and her colleagues unexpectedly discovered stromatolites – layered rock formations produced by the activity of microbes and considered the earliest evidence for life on Earth. They are mainly found in hypersaline waters in a select few locations around the world.

“The only big ones known in Australia are in Shark Bay in WA,” Proemse says. “Ours are really different because they’re freshwater stromatolites – and they’re still alive!”

Currently in the Freshwater Ecology Group at the University of Tasmania, Proemse’s work branches out beyond ancient organisms.

“All of my research uses a method called isotope geochemistry,” she explains. “If you’ve never heard of an isotope before, it’s basically like a fingerprint. For example, oxygen has a mass of 16, but depending on the number of neutrons, it can also have a mass of 17 or 18.”

By studying the different ratios of masses occurring in a sample, Proemse can assign a “fingerprint” to a source and therefore track down the origin of a material. This specific method has diverse applications across chemistry, physics and biology – one of the main reasons she was drawn to isotope geochemistry. 

Growing up in a family of scientists in Cologne, Germany, she always knew she wanted to be one too, but couldn’t decide on a field. When her mother saw a newspaper advert for a multidisciplinary hydrology degree in Freiburg, Proemse packed her bags. 

It’s a field that’s taken her to extreme places across the world. During her master’s degree, she jetted to California to work at the United States Geological Survey, and then moved to Calgary in Alberta, Canada, for her PhD. 

Her research focused on the Athabasca oil sands, the third largest oil reserve in the world. A decade ago, high oil prices meant that oil exploration was in full swing – but without the environmental monitoring in place to determine the impact of development. Proemse tracked the industrial emissions from bitumen-upgrading and open-pit mining to determine the how they affected the environment.

The fieldwork was so remote that she had to fly in and out to all her sites. “When you fly over these oil sands, the footprint is outstanding,” she reflects. “That in itself is the biggest environmental impact, because you’re in a remote boreal forest and just changing that landscape to open-pit mines is that biggest damage you’re going to do.”

During her PhD, Proemse also found herself on an Arctic expedition to study the northernmost hot spring on Earth. “The remarkable thing about it is that it forms gullies that are identical to the ones on Mars, from their morphology,” she says enthusiastically.

One of the best parts of her work, she says, is working in such extraordinary locations.

“I just love the solitude and the peacefulness when you’re out in the field in such a remote place,” she reflects. “I still remember in the Arctic it was just so nice to be away for four weeks from the internet, your mobile, from people you know … All you hear at night is the icebergs rolling over in the fjord.”

After five years in Canada studying wild and inaccessible sites, Proemse moved to Curtin University in Western Australia on a six-month Endeavour Fellowship.

“The last two weeks of my fellowship, I met my husband in Tasmania,” she says, laughing – and so she stayed.

She’s still using her skills in isotope fingerprinting to solve a diverse range of puzzles about the natural world.

“I probably have the perfect ratio of fieldwork, lab work and desk work,” she says.{%recommended 4835%}

Outside of research, her hands are full: “I have a beautiful 14-month-old daughter that I love spending time with, and my other passion is artwork. I love anything that has to do with printing techniques, from silkscreening to linocuts to etching.”

This year Proemse is moving into a new role at the Institute for Marine and Arctic Studies, also at the University of Tasmania. She will be studying samples from Heard and McDonald Islands – the sites of Australia’s only active volcanoes, along with several hotspots on the ocean floor that create hydrothermal plumes.

These plumes, Proemse explains, are thought to spout iron into the Southern Ocean, which may be feeding phytoplankton and creating higher bio-productivity. “I’ll be doing the isotopic fingerprints of the iron to figure out if it’s actually coming from the hydrothermal plume, or if it’s coming instead from glacial run-off from the islands or from sediments on the ocean floor.”

“Working on these bizarre geochemically-different places is what fascinates and excites me,” she says. She’s keen to study even more remote places: “I haven’t been to the Antarctic yet, so that’s on my list!”

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