Ripples of Change: Dr Baso-Mdiza on Climate, Invasive Aliens, and Africa’s Rivers

"The thing is," Dr Nompumelelo Baso-Mdiza, a Botanist, freshwater ecologist, and founder of Baso R-Analytics, points out, "much of the research often studies climate change and invasive species separately."

This observation has led her to a profound question, "What happens when these two threats interact to reshape Africa’s freshwater ecosystems?"

Dr Nompumelelo Baso-Mdiza in her element – knee-deep in the rivers she’s working to protect.

Freshwater ecosystems are a crucial resource for livelihoods and form the backbone for some of the most marginalised communities globally. They provide essential water for drinking, agriculture, sanitation, and even vital food sources like fish. However, these vital and often vulnerable ecosystems are under increasing threat from two big pressures, such as invasive species and climate change.

Dr Baso-Mdiza is currently studying how invasive species, especially water (aquatic) plants and climate change, together affect freshwater ecosystems. She likens this intricate process to a web, "when you pull one threat," she explains, "like introducing a new species, the entire web can shift in unintended ways."

This often happens because these new species tend to dominate their new environments, lacking natural enemies such as insects and diseases. Going deeper, her work examines how these shifts affect biodiversity, food webs, and water quality. She uses ecological modelling tools to predict how these effects might unfold under future climate scenarios.

Fieldwork in progress: Sampling water in a changing river system, where climate stress meets plant invasion.

Untangling Freshwater’s Complex Web

Just how complex is this web? It's not easy to explain with just "words," so Nompumelelo paints a compelling picture based on a real-life, two-week expedition. She was part of this intensive field survey, working alongside a large team of ecologists from the UK and other African institutes. They were out in the rivers running through the Kruger National Park, down in the Limpopo/Mpumalanga region, studying the very base of the food web.

This meant really zooming in on the animal and plant species in these rivers – everything from tiny algae and water plants to macro-invertebrates like insects, and even invasive crayfish, all the way up to the diverse fish communities. They didn't stop there, also looking at the river's physical structure and water quality "to help connect the ecological dots," as she puts it. The goal was to truly understand how invasive species affect the entire ecosystem in a profoundly holistic way.

At the river’s edge, a team of ecologists, including Dr Baso-Mdiza, work together to untangle the complex web of freshwater ecosystems.

So, why does this all matter? Freshwater is incredibly scarce, making up just 3% of our planet's water, yet we all depend on it for survival. That's why studying the combined effects of these threats is so crucial. As Nompumelelo emphasises, "It helps us better understand and, hopefully, manage the ripple effects they have on local biodiversity, livelihoods, and the overall health of these vital ecosystems."

Biological Control Ignites Hope

Invasive alien species are a persistent global challenge, and even some of our own South African species cause problems elsewhere. However, despite their continued spread, biological control (natural enemies) offers a powerful beacon of hope.

"For instance," Nompumelelo points out, "our native South African Oxygen weed is anticipated to spread further in New Zealand under future climate conditions, according to a recently published paper. Yet, through proposed biological agents, there's real, tangible hope to manage its impact in all affected regions."

Even more encouraging news comes from Dr Baso-Mdiza's own MSc research. Her findings showed that the biological control agents we use in South Africa, and across many other parts of the world, to control some of the worst invasive plants in our rivers and lakes, like Salvinia, Water lettuce, and Parrot’s feather, will still be effective in the future, even as carbon dioxide levels are expected to rise.

"This provides us with promising, innovative, and environmentally friendly solutions in our critical ongoing quest to conserve the precious ecosystem services derived from these vital freshwater habitats," she notes.

Finding Purpose in Nature's Challenges

We asked Dr Baso-Mdiza how she got into this research, and she takes us fondly back to her childhood. "My journey was one of layered curiosity," she explains. "I've always felt connected to nature, fascinated by how living things interact for harmony in a seemingly chaotic system."

Growing up in the rural Eastern Cape, nature was her unfettered playground. She constantly asked questions, realising over time they "needed scientific vigour." She was especially inspired by research that could have a tangible, real-world impact, not just "secluded fieldwork and data analysis that never gets to see the light of the day. This is where I found my niche!" she emphasises.

Her doctoral visit to New Zealand starkly revealed the harsh, undeniable realities of biological invasions. She witnessed firsthand choked waterways and degraded freshwater quality, sparking her deep interest in how introduced species unleash devastating, unexpected consequences.

"I saw the full extent of how invasive water plants had completely choked the inlet to Clutha River (the longest river in the South Islands), hindering access to the water for fishing and recreation.  It wasn't just a scientific observation; it was an emotional realisation. I remember thinking, 'This is why my work matters.'"

This powerful, transformative moment led her to a PhD in Botany, focusing on nature-based solutions for aggressive invaders like our very own notorious Oxygen weed (Lagarosiphon major).

Now a Postdoc fellow at the South African Institute for Aquatic Biodiversity, Nompumelelo passionately examines how invasive species and climate change jointly impact freshwater food webs. She's also passionate about using data and statistical models to unravel these complex interactions, offering her expertise to students, researchers and businesses through her consultancy.

Balancing Life, Academic Deadlines and Business

Balancing motherhood, academic deadlines, and consulting during her PhD was incredibly tough for Dr Baso-Mdiza. She often found herself "coding with one hand and holding a baby with the other," all while heartbreakingly grieving her grandmother, "uMama", and courageously navigating the unprecedented challenges of the pandemic. She candidly shares that she overcame these hurdles by "leaning into my husband and our community, asking for help, and staying disciplined." A strong support system and a deep sense of purpose were absolutely key to pushing through.

From coding with one hand to crossing the stage in cap and gown, Dr Baso-Mdiza’s PhD journey was nothing short of extraordinary.

Away from her demanding work, she finds true joy and grounding in quiet garden evenings or cycling with her husband and "not so toddler anymore." She also enjoys self-development podcasts and admits to being "a bit obsessed" with learning new statistical and programming skills. If not a scientist, she imagines being a full-time entrepreneur, teaching data skills and financial literacy, or perhaps a singer, though she jokes that might "only end in the shower."

Her Lesson: "Science is often seen as cold or distant, but I believe it’s deeply human. Every fieldtrip, every dataset, every paper: there’s a story behind it. My journey has taught me that vulnerability and curiosity are just as important as rigor."

Her Message to Scientists: "Start messy, but start, and stay the course! Progress isn’t linear, and no one knows everything at the beginning. I still get imposter syndrome too sometimes. Stay curious, ask questions, and surround yourself with people who challenge and support you."

Dr Baso-Mdiza hopes her research empowers better decision-making for managing invasive species and preserving biodiversity. More profoundly, she aims "to show that African science, led by African scientists, has the power to solve global challenges."

Every fieldtrip, every dataset, every paper: there’s a story behind it. Here’s one of Dr Baso-Mdiza’s!

In many ways, Dr Baso-Mdiza’s work brings her back to that first profound question: "What happens when these two threats interact to reshape Africa’s freshwater ecosystems?"  With every model, every field survey, and every shared insight, she’s helping Africa better understand, and ultimately adapt to, these ripples of change.

Connect with Dr Nompumelelo Baso-Mdiza on LinkedIn.

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