La Trobe University geneticist Dr Jan Strugnell – whose ground-breaking research has helped explain the origin and global distribution of deep-sea marine life, providing critical insights into climate change.
About 250 local and international experts will meet at the Australian Academy of Science’s Shine Dome to discuss the state of Antarctic science since Sir Douglas Mawson led Australasia’s first Antarctic Expedition in 1911-1914. Dr Strugnell will speak about marine biodiversity in the Southern Ocean. A former Rhodes Scholar, she made world headlines with the results of her research into the evolution of deep-sea octopuses.
She says modern molecular studies have revealed that the Southern Ocean is teeming with a huge diversity of previously unknown marine life. Her study was part of the first Census of Marine Life, a ten year project involving more than 2,000 scientists from 82 nations. She was lead scientist of a team that studied marine life from ocean floors that had never been sampled before.
In addition, genetic material from marine life from the project was brought together and made available to Dr Strugnell for DNA studies, who were then working at Queen’s University Belfast. The work revealed that all octopuses found in deep oceans world-wide originated in the waters around the South Pole about 33 million years ago. They spread into other oceans around 15 million years ago, as the Antarctic cooled and eventually froze over.
As a result, there was an outflow from Antarctica of cold, nutrient-rich water with high levels of salt and oxygen, creating a north-bound freeway along which octopuses travelled to their new habitats.
“We think that if octopuses colonized the deep sea by this route, it’s very likely that other organisms did so as well,” says Dr Strugnell.
She says her research also demonstrates that climate change can have profound effects on biodiversity, with impacts extending into habitats as remote as our deep oceans. Originally from Swan Hill in Victoria, Dr Strugnell’s doctoral study at Oxford was the first to use molecular and fossil evidence to estimate dates of divergence for octopus, squids and cuttlefish.
Since joining La Trobe’s Department of Genetics in 2010, she is also investigating the molecular basis of stress and disease in abalone, shellfish whose export is worth more than $200 million annually to the Australian economy.
Dr Strugnell says mass mortality disease of farmed abalone during the summer, related to high water temperatures, is likely to increase with predicted global warming.
Her ARC funded research aims to develop an early warning test for stress and stress resilience for the abalone industry. She is also continuing her studies into population and molecular evolution of Antarctic and deep-sea marine animals in the context of past climatic and geological change.