Catherine Kim

School of Earth and Atmospheric Sciences (QUT)
Rubble vs Recovery: Predicting where too much rubble could hurt the Great Barrier Reef

Catherine Kim


The Great Barrier Reef is the most iconic Queensland landscape and is facing more threats than ever before. Coral rubble is created when coral dies and is broken down by wave action and storms. Rubble itself is a natural and important habitat on reefs; however, when impacts like coral bleaching and cyclones repeatedly affect reefs, they can transition to rubble-dominated environments. When too much rubble is constantly moving on reefs, it can damage newly settled corals and prevent reefs from recovering.
My research uses spatial data about different impacts across the Great Barrier Reef such as cyclones, in combination with modelling like machine learning, to figure out which of the 3,000 reefs are most likely to create rubble. If we can accurately predict which reefs will have too much rubble, then we can efficiently manage and apply solutions to stabilise rubble and restore coral reefs. 


Queensland is home to the iconic Great Barrier Reef, which is the most inspirational Australian landscape from the 2013 Social and Economic Long Term Monitoring Program (SELTMP). Unsurprisingly, Queenslanders have a strong positive association with the Great Barrier Reef, which is very much a part of the Queensland identity. The Reef contributes 3.9 billion AUD in economic value and 33,000 jobs to the state (Deloitte Access Economics, 2017). A quarter of Queenslanders in coastal communities rely on the Reef for some of their household income. Queenslanders are also intimately impacted by the growing threats to the Reef from bleaching to cyclones. Nearly 80% of residents in coastal communities would be personally affected if the health of the Reef declined (SELTMP, 2013). 

Globally, we have seen healthy coral reefs transition to coral rubble-dominated states. As a part of the natural cycle of reefs, the rock skeletons of dead corals break up into rubble pieces through physical processes such as waves and storms. Coral rubble is an important part of reef environments and serves as a significant habitat in its own right. However, when coral reefs go through repeated impacts such as coral bleaching, cyclones, and dynamite fishing, too much rubble can form on reefs. Coral rubble can move with large wave events which can damage newly settled corals and prevent reef recovery. 

With climate change causing more frequent mass coral bleaching events and intense cyclones, there is a greater risk of coral rubble reaching this transition point in the Great Barrier Reef. The Rubble Stabilisation subprogram of the Reef Restoration and Adaptation Program aims to apply novel solutions to prevent coral reefs from transitioning to rubble states in the Great Barrier Reef.

A central question in conservation is how and where to use limited resources. The Great Barrier Reef is a classic case stretching over 2,000 kilometres and with over 3,000 individual reefs. My work uses spatial data of coral rubble drivers and modelling to predict which reefs are most likely to become rubble dominated. 

I use statistical models and machine learning to assess how factors that cause coral death (coral bleaching and crown of thorns seastar predation) and physical drivers (waves, cyclones, currents, and shipping) contribute to the generation of coral rubble across the Reef. Interestingly, physical drivers were not necessarily the most important in generating rubble as we hypothesised. By assessing these cumulative impacts on rubble, we can inform managers and scientists where to monitor for increases in coral rubble and which rubble stabilisation methods to potentially use for restoration. 

Coral reefs will likely require active management and restoration in the face of climate change. My research contributes to this pressing need to maintain the health of the Reef. This in turn will provide significant benefits to Queenslanders who earn livelihoods from Reef industries, recreate in Queensland’s beautiful beaches, and are connected culturally with the Great Barrier Reef. 

Deloitte Access Economics (2017). At what price? The economic, social, and icon value of the Great Barrier Reef  

Role Model

I know firsthand what it feels like to not “see” myself in my field. Despite being privileged to an excellent education, I had no teachers that looked like me in terms of gender and ethnicity throughout my formal education. My experience motivates me to be a good role model for women and girls who aspire to work in STEM because I intimately understand the importance of representation in STEM pathways. I achieve this through actively using my influence to promote visibility of women and minorities in STEM as a lecturer, supervising women who aspire to be researchers, and communicating my science to diverse audiences.

As a newly minted lecturer for the Geospatial Information Science class of 70, I developed interviews of various professionals who use geospatial science for my class. Part of my mission was to showcase a diverse cohort of professionals and I consciously reached out to both men and women. Ultimately, six out of ten interviews featured women. I also get the opportunity to embed Indigenous perspectives every class session. After the acknowledgement of country, I share spatial work that includes Indigenous perspectives such as Dr. Bill Pascoe’s Bunya Festival map displaying songlines of Indigenous Peoples who traveled for the Bunya nut harvest. As I have graduated from being a student, I have direct control in some spheres like my classroom and use this platform to promote women and minorities in STEM.

As a supervisor, I directly influence my students, tutors, and research assistants. At my PhD student’s recent confirmation panel, paperwork restricted my ability to be an official panelist despite being an associate supervisor. The three panelists were senior white men. Afterward, I discussed how I could be incorporated into the existing “manel” for future milestones with my student and the primary supervisor. I aim to get to know all my supervisees, including women, minorities, and queer individuals, as people, discussing their interests and aspirations in informal settings like over coffee. This way, I gain a better understanding of how I can support them as unique individuals and help them achieve their goals such as obtaining postgraduate scholarships. This also applies to all the female members in my network. For example, I used my recent QUT ECR symposium award funds to invite 6 female postgraduate students in my school for a coffee for International Women’s Day.

I have been engaged in STEM outreach and communication for nearly 10 years. Last year, I experienced firsthand the impact I am having with these efforts. At the QWiSP 2022 awards, I was approached by three female secondary students and their teacher who said I had visited their class in 2018 at Pomona State School. They are now pursuing marine science and STEM at university and seeing the impact I have had was truly rewarding. I rarely saw people who looked like me in STEM growing up and I am a good role model because I strive to let women and girls know that they belong in STEM.


Being an active role model for girls in STEM has been a priority for my career. I have engaged in STEM outreach throughout Queensland, communicated my research internationally, and organised community groups such as R-Ladies Brisbane.

I have been involved in the Wonder of Science (WoS) program as a Young Science Ambassador fostering a culture of STEM across Queensland for eight years. I have interacted with 800+ primary and secondary students at school visits in the Brisbane area and rural regions such as Dalby, Dysart, and Moranbah. During classroom visits, I share my STEM journey in research and assist with curriculum-aligned challenge tasks. I have participated in specific programs promoting girls in STEM through WoS such as Girls in STEM with Foxwell State School (2021, 2022) and the Coolumboola Environmental Education Centre’s STEM Girls Camp (2020). I have been a judge at over 10 WoS conferences where students present their challenge task projects. I also held a virtual coral bleaching workshop at a state conference (2021).

I also communicate to non-scientific audiences through events such as the Flying Scientist Airlie Beach public lecture (2019) and Northside Metropolitan Teacher’s Colloquium (2017, 2018). I am also a mentor for the Future Makers STEM Inventors Challenge (2023) and was 1 of 25 featured in Australian Data Science Network’s “Meet Australia’s Rising Women in Data Science Rising Stars” event (2023). My STEM engagement extends beyond Australia. I have participated in a Skype a Scientist program with students in the UK (2014) and spoken at the Pennsylvania State University Science-U camps (2016) and kindergarten classes in Washington DC (2017). My thesis research was based in Timor-Leste and outreach and dissemination of my results in-country was essential. I presented a summary of my PhD thesis results to the Timor-Leste Ministry of Agriculture and Fisheries, the National University of Timor-Leste, and industry stakeholders such as tourism operators, non-governmental organisations, and international aid groups (2019). Gender equity is a pressing issue in-country and speaking to marine science students at the National University as a female role model was a highlight.

I am passionate about promoting women in coding. I became a Certified Instructor (2019) for the Carpentries non-profit with a mission to build global capacity in essential data skills for researchers and taught 2-day Carpentries workshops for the Queensland Cyber Infrastructure Foundation. This led to teaching R classes at The University of Queensland Library as a Technology Trainer, where I taught 500+ people over 50 classes and 3 workshops in 6 months. As the only female trainer out of 4, I realised there is still a strong need to encourage girls that coding is for them. In this vein, I became a co-organiser for the R-Ladies Brisbane Chapter (2020) promoting women who use R and the Geospatial Community (2021). I have also contributed workshops at the Research Bazaar Queensland (2021, 2022). Through being active, visible, and engaging in STEM and outreach spaces, I endeavour to demonstrate the importance of STEM to women, girls, and the greater public.


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