Research spotlight: Alexandra Bastick (Charles Sturt University)

by Georgia Barrington-Smith, 11th October 2024

How Pipelines Impact the Marine Food Web

AINSE’s focus for October is Oceans Month, which we are kicking off by spotlighting Alexandra (Alex) Bastick: an Honours student from Charles Sturt University, AINSE Pathway Scholar, and emerging young voice in environmental research!

With our oceans facing increasing threats from pollution and toxic runoff, Alex’s work at ANSTO’s Lucas Heights campus investigates the impact of ionising radiation on the growth of tropical marine microalgae, Tisochrysis lutea, native to Australia. Her research aims to understand how decommissioned pipelines containing NORM — Naturally Occurring Radioactive Material — might impact marine organisms in the surrounding environment. This is of particular interest to seafood consumers, as toxic bioaccumulation in the marine food web can potentially have severe health implications down the line.

Simulating the ocean environment in the lab

Marine organisms will colonise the surface of decommissioned pipelines for shelter, habitat cover, and to set up in a suitable breeding location. Previous modelling in the northern hemisphere showed that terrestrial and aquatic colonising organisms were exposed to radiation exposure levels of 34µGy/hr — three times higher than the International Atomic Energy Agency’s (IAEA) screening level of 10µGy/hr.

Alex Bastick conducting an experiment in ANSTO’s Ecotoxicology Labs.

Alex was able to simulate these potential environmental threats in a laboratory setting using a sealed source of radioactive Ceasium-137, produced in ANSTO’s OPAL Multipurpose Reactor at Lucas Heights. In a series of 72-hour chronic toxicity assays, T. lutea culture were exposed to the radioactive isotope and daily growth metrics were monitored. The results revealed no significant impact on population growth at does rates up to 7.9 mGy/hr (or 7.9 thousand µGy/hr), considerably higher than what organisms will encounter in the wild!

These findings suggest that the growth of T. lutea is unlikely to be adversely impacted by the expected radiation doses encountered at NORM-contaminated pipelines. However, there may be other impacts on cellular processes, including photosynthesis and DNA replication, that cannot be deduced from growth measurements alone. In addition, species-specific radiation sensitivity needs to be considered in future studies, in order to assess the overall impacts of NORM-contaminated pipelines, and therefore ensure best and safe practices in their decommissioning.

From university studies to cutting-edge research

Alex was able to complete her Honours project at ANSTO facilities this year with the help of AINSE’s Pathway Scholarship, which “took some of the financial burden off”, enabling her to focus more on her research activities.

Alex’s nuclear science journey began after her involvement with AINSE’s 2021 Women in STEM and Entrepreneurship (WISE) School, which she recalls “…opened her eyes to the diverse range of sciences that benefit from nuclear research”, and where she realised that her interests in marine biology could find a natural partnership with ANSTO researchers and research capabilities.

Alex Bastick (5th from left) alongside other 2023 AINSE Winter School students at the Lucas Heights on-site visits in September 2023.

Following the WISE School, Alex returned to participate in AINSE’s 2023 Winter School to learn more about collaborative research opportunities at ANSTO. During her on-site visit to Lucas Heights, she connected with her current supervisor Dr. Tom Cresswell: an isotope ecologist and key figure in ANSTO’s environmental research team. For Alex, the “Winter School was particularly impactful,” giving her “the opportunity to network with both ANSTO scientists and fellow students.”  

Looking ahead, Alex plans to expand the scope of her research and apply for AINSE support in progressing her postgraduate studies through the PGRA Scholarship.

If you are also interested in financial support during your postgraduate or early-career research journey, or an undergraduate student interested in exploring possible connections to world-class facilities and incredible researchers, check out AINSE’s range of events and scholarships, and follow our social media channels for the latest news and announcement of new scholarship rounds! For further advice or assistance, please email the AINSE team at enquiries@ainse.edu.au.

AINSE are proud to support Alex’s research as she champions the use of nuclear science and technology techniques to understand and protect our marine environments.

Keep up to date with our regular research spotlights, including a highlight of Bohao Dong’s fascinating insight into ‘The environmental history of the Great Barrier Reef as told by a giant clam shell’!