Strengthening Freshwater Food Webs for Climate Resilience and Invasive Species Management in Sub-Saharan Africa

Invasive species. Climate change. On their own, each poses a serious threat to Africa’s freshwater ecosystems. Together, they could be disastrous.

Dr Nompumelelo C. Baso-Mdiza is working to ensure that doesn’t happen. A freshwater ecologist and data scientist, her research explores how these twin pressures are disrupting the complex food webs in Africa’s rivers, lakes, and dams, and what can be done to restore balance before it’s too late.

“Freshwater ecosystems are under siege,” she says. “We need to understand how these pressures interact and act fast with the right tools to prevent collapse.”

Her research focuses on how invasive aquatic plants and animals – species that don’t belong -combine with the warming, drying, and flooding effects of climate change to unpick trophic cascades: the delicate, layered chains of who eats whom. By mapping these shifts and modelling future scenarios, her team hopes to identify which freshwater systems are most vulnerable, and where targeted interventions, like biological control, can help restore stability.

It’s science with very real-world stakes. “These systems provide drinking water, food, and livelihoods,” says Baso-Mdiza. “When they collapse, it’s not just nature that suffers, people do too.”

Her conviction is backed by experience. During her PhD, split between South Africa and New Zealand, she studied the rampant spread of Lagarosiphon major, an aquatic weed choking waterways abroad, but growing more slowly in its native African habitat. “We had to use two people to haul our sampling gear out of the water in New Zealand,” she recalls. The key difference? Natural enemies. The research helped bolster a case for introducing biocontrol agents to tame the weed, showing just how effective, and necessary, nature-based solutions can be.

With backing from the JWO grant, she would expand her work across several African countries. The project would combine ecological fieldwork with machine learning to build a continent-wide picture of risk and resilience. Crucially, it would involve local partners at every stage, from monitoring to decision-making, and help train the next generation of African conservation scientists.

But Baso-Mdiza is quick to point out that many threats remain under the radar. Chief among them: invasive species. “They spread slowly, often invisibly,” she says, “but they are eroding biodiversity and water security across the continent. We can’t afford to ignore them.”

Still, she’s not without hope. One recent breakthrough she’s excited about is environmental DNA, or eDNA, a technique that uses traces of genetic material left in water or soil to detect species without physically catching them. “It’s faster, cheaper, and far less invasive. It’s transforming how we monitor biodiversity and catch invasives early.”

As a scientist, a mother, and a self-confessed R-coding addict, Baso-Mdiza is driven by both data and legacy. “Now that I have my own child,” she says, “I’m more determined than ever to protect the natural world they’ll grow up in.”

Whether it’s running trails or running simulations, she’s in it for the long haul.