What began as a question about algae in a koi pond soon grew into a project with wider environmental relevance.
Nurturing young talent
"My project is to see if lactic acid can be a cost-effective way to help with excessive algae growth in my koi pond at home, thereby treating eutrophication. I monitored what would happen to the chlorophyll-a concentration, turbidity, and dissolved oxygen concentrations," explains Denica.
Although inspired by conditions in her family's pond, the research explored a challenge affecting water bodies far beyond her backyard. Testing different concentrations of lactic acid, Denica found that while it reduced algal biomass, it also created pH levels that were unsuitable for koi survival.
Her interest in science can be traced back to a simple moment. "When I saw a video on social media about chemistry, the lab work in the chemistry field excited me the most," she says.
That curiosity was encouraged for years by her father, who first persuaded her to enter the Welkom Regional Science Fair when she was in Grade 4. Since then, science fairs have become a regular part of her life.
Prof Vasu Reddy, Deputy Vice-Chancellor: Research, Innovation and Postgraduate Studies, remarked, “The outstanding achievement of Denica is a powerful reminder of what becomes possible when young talent is nurtured through access to world-class research expertise, infrastructure, and mentorship. Her success exemplifies the value of partnerships between schools, communities, and the University to build a strong pipeline of future researchers and knowledge leaders. It is clear that as a university we are demonstrating that investing in young people is an investment in innovation and societal progress, inspired by discovery and enquiry.”
But curiosity alone was not enough to complete a project that required laboratory testing and scientific methods that stretched beyond the school curriculum. "Getting someone to assist me in the lab was one of the most challenging parts," she explains. "I then had to learn new terminology and understand concepts beyond what I am currently learning at school."
That challenge led her to the University of the Free State (UFS).
According to Denica,
Prof Ernie Langer, Associate Professor in the UFS Department of Chemistry – well-known to many science fair participants through the annual Science Show presented at the regional expo – became the first point of contact after her father reached out for advice. Through him, the family was introduced to
Dr Lore-Mari Deysel, Principal Scientific Officer in the Faculty of Natural and Agricultural Sciences, who in turn connected Denica with
Dr Tascha Vos from the UFS Centre for Environmental Management.
"I received mentorship from these UFS scientists, and they helped me to do the necessary lab tests under controlled conditions," says Denica. "After the regional science fair in Bloemfontein, they also assisted in checking all my documents before I participated in the International Science Fair."
Dr Deysel says supporting young scientists remains important to those who have experienced the wonder of science and nature and want to pass that experience on to the next generation of researchers, medical professionals, and scientists. “It was a great privilege to guide this very enthusiastic young lady and to introduce her to some UFS laboratory facilities. I trust this investment played a part in shaping Denica for the future. Our children are our future.”
Dr Vos worked closely with Denica during the laboratory phase of the project, guiding her through the analyses required for the research. This included water-quality and chlorophyll-a testing, as well as helping her understand the significance of the results and how they would inform her discussion of the findings. In addition, Dr Vos prepared and identified the preserved algae samples, providing technical support that strengthened the scientific foundation of the project. "We are here to teach and pass on knowledge, and to inspire the next generation, no matter how young they are, to do great things," says Dr Vos.
Transformative role of university
The exposure seems to have strengthened Denica’s ambitions. After school, she hopes to study either medicine or chemical engineering. While she dreams of exploring opportunities beyond her hometown, she says the UFS remains ‘an obvious first choice’.
"Besides innovating in the field of medicine or chemistry, I would like to see more learners exposed to the opportunities that science competitions offer. I would like more young women to take part in these expos or do more things in STEMI."
Away from the laboratory, Denica enjoys modern and contemporary dance, listening to music, and spending time with her cat, Paprika, who technically belongs to the neighbours but has quietly adopted her family.
What began as a question about algae in a koi pond ended up on one of the country's biggest science stages. With support from scientists at the UFS, Denica Swartz turned that question into award-winning research and a place among South Africa's brightest young scientists. If her curiosity is anything to go by, there is plenty more to come.
“Denica’s accomplishment affirms the transformative role of our university as anchored in the community to unlock potential, creating conditions and opportunities that advance scientific literacy to foster innovation. It is in fact about investing in talent that will shape our collective responsible societal futures,” remarked Prof Reddy.