Part of an ongoing series of Gazette stories celebrating researchers who received support as part of a major investment by the federal government in science and research on May 29.
More than a garbage truck’s worth of plastic enters the ocean every minute.
So, understanding how plastic moves through the ocean and how quickly it sinks to the ocean floor is critical to understanding the harm it inflicts on wildlife and humans.
That’s according to Dr. Xia (Alice) Zhu, one of Memorial University’s newest Banting post-doctoral scholars.
She will begin her post-doctoral research at Memorial this fall, thanks to the $70,000 per year for two years that comes with the position.
Based in the Department of Ocean Sciences, Faculty of Science, Dr. Zhu’s research focuses on the bottom of the Atlantic Ocean to study the transport and fate of plastic pollution in our marine environment.
The impacts of plastic pollution, particularly on our oceans, are not well understood.
Critical environmental challenge
Dr. Zhu’s project, The Settling Flux of Plastic Pollution and its Influence on Carbon Sequestration in the Deep Ocean, is set to make significant strides in understanding the environmental impact of microplastics.
Her research focuses on the sedimentation process of microplastics (particles less than five millimetres in size) and their potential to disrupt the biological carbon pump — a key process through which the ocean sequesters carbon.
The ocean plays a major role in storing carbon, particularly anthropogenic carbon from burning fossil fuels, negatively impacting humans’ ability to survive on the planet due to its role in global climate change.
Marine snow and microplastics
A significant part of Dr. Zhu’s research will focus on documenting how microplastics interact with marine snow: organic matter left behind from decaying organisms that is an integral part of the carbon pump.
Dr. Zhu hypothesizes that as microplastics settle to the ocean floor, the plastic particles interact with the marine snow, which could impede the marine snow’s descent to the deep ocean and impair the ocean’s ability to permanently lock away carbon.
“I dispelled the myth that you cannot get paid to study trash.”
The interaction between marine snow and microplastics could result in less carbon absorbed by the ocean over time, contributing to the effects of climate change, she says.
Before Dr. Zhu’s earlier work, which proposed this link, the connection between plastic pollution and climate change was not widely acknowledged.
However, her research has brought this potential interference to the forefront of environmental science.
Dr. Zhu will collaborate with scientists from Canada, the U.K. and Germany to sample settling microplastics across the Atlantic Ocean and develop a model to explain the observed patterns.
Among these scientists is Memorial’s Dr. Uta Passow, Dr. Zhu’s supervisor, from the Department of Ocean Sciences.
A history of ocean conservation
When Dr. Zhu was in high school, she watched a news report about the discovery of the amount of plastic outweighing the amount of plankton in the Great Pacific Garbage Patch which was discovered in the late 1990s by Capt. Charles Moore.
The story inspired her to do something about it.
“I did an experiment in my parent’s basement and built a device to filter plastic out of sediment, and it got published in the peer-reviewed journal Marine Pollution Bulletin,” she said. “I dispelled the myth that you cannot get paid to study trash.”
She followed her passion during her undergraduate and master’s programs, which included working with Dr. Chelsea Rochman from the University of Toronto.
She has been working in the field of conservation and protecting the ocean ever since.
Recognition and future impact
The outcomes of Dr. Zhu’s Banting Fellowship research will have direct implications for global environmental policies and contribute to global efforts to combat climate change including Canada’s net-zero emissions target.
The Banting Fellowship, one of Canada’s most prestigious research awards, will not only support Dr. Zhu’s research, it will highlight the importance of conservation and climate change action.
“St. John’s and Memorial is the perfect place to conduct this research,” said Dr. Zhu. “Memorial is a rigorous and intensive university, and the oceanography program is filled with top-tier scientists. There is a lot of support, resources and collaboration possibilities.”
The most recent round of Banting Post-Doctoral Fellowships and Vanier Canada Graduate Scholarships was announced on June 14.
Dr. Zhu will also receive a Banting Post-Doctoral Research Grant, valued at a total of $30,000 over two years, to be jointly funded by Memorial’s Office of the Vice-president (Research) and the School of Graduate Studies.
