For Dr Sarah Carroll, co-founder and CEO of MariHealth Solutions and one of South Africa’s rising figures in the blue economy, the origins of her career can be traced to a library aisle.
“When I first could read, science became my first love,” she recalls. Her grandmother would take her to the library for hours, where she immersed herself in books on plants, animals, oceans, ancient civilizations, geology and even the stars. It was there that a lifelong affinity for the natural world took shape, reinforced by hours of documentary watching and a childhood admiration for David Attenborough.
“Growing up, I loved animals and looked up to people like David Attenborough, dreaming of a life where I could genuinely make a difference,” she recalls.
Her academic journey aligned closely with this early passion. She completed a PhD in molecular biology at the University of Cape Town (UCT), researching the impacts of climate change on farmed South African abalone. She then stayed on as a researcher until the COVID-19 pandemic reshaped global academic pathways.
About eighteen months later, the University Technology Fund stepped in, urging her team to commercialise their research.
“About a year and a half later, we were approached by the University Technology Fund, who encouraged us to spin out our research into a company. With their pre-seed investment and UCT’s support, MariHealth Solutions was born,” she says.
She credits much of her trajectory to her family.
“My parents played a crucial role in fostering my curiosity and love for science. They always encouraged my reading and exploration, supporting my education wholeheartedly to the best of their abilities. Their support laid the groundwork for the journey I am on today.”
Founding MariHealth Solutions: From Lab to Industry
Dr. Carroll never set out to build a startup. She never aspired to run a business. “Honestly… starting a company was never my dream – I love research and just wanted to help animals and contribute something meaningful to the world,” she notes.
But her work in UCT’s marine biotech lab revealed a structural gap in global aquaculture that is the absence of proactive, data-led animal health systems. MariHealth Solutions, now considered one of Africa’s promising blue-economy biotech ventures, targets that weakness. The global seafood sector is projected to reach nearly USD 900 billion by 2030. Yet health-management tools have lagged, particularly in emerging markets.
“We noticed a huge gap in the aquaculture industry around proactive animal health management and the limited availability of tools for data-driven decision-making,” she recalls.
She also holds a firm view on the role of African universities: “I strongly believe that universities shouldn’t just be places of learning, but powerful vehicles of human progress through ingenuity and commercialization.”
Co-founding the business with her former PhD supervisor, Vernon Coyne, was “honestly a no-brainer.” Their strong working relationship offered both trust and continuity.
“Knowing we’d navigate the ups and downs of entrepreneurship together… was reassuring and aligned with our values,” Dr Carrol reflects.
Although different from her childhood dreams of working hands-on with wildlife, she says the company is definitely adjacent enough to keep that passion alive.
Curiosity as a Compass: How Science Led to Entrepreneurship
Dr. Carroll frames entrepreneurship not as a departure from science but as a continuation of it.
“My early passion for science and biology set the foundation for my journey into entrepreneurship in a big way,” she says. As a child, she was endlessly curious about how things worked and just couldn’t stand boredom.
What excites her is not the commercial architecture of the startup world, but the opportunity to apply science in a way that changes behaviour across an entire industry.
“Believing that we can all do something meaningful… made the jump into startups pretty appealing.”
Startups offered the same intellectual challenge. “Entrepreneurship felt like another chapter in my educational life… another chance to challenge myself and keep learning,” she reflects.
Her worldview, shaped by childhood afternoons poring over science books with my granny, taught her that meaningful change is achievable at any scale. Entrepreneurship, she realised, is simply another mechanism for that impact.
Choosing the Ocean: The Moment Sustainable Aquaculture Became Her Path
Her affinity for animals extended naturally to the ocean. “When I was a kid, beach visits literally meant my parents having to nag me to get out of the water.”
The pivot to sustainable aquaculture was equally instinctive. “My love for nature and animals has always been pretty obvious,” she says. As climate impacts on ocean ecosystems intensified, her academic interests sharpened. Halfway through her studies at Rhodes University, she sought out a research opportunity merging climate change, molecular biology, and marine life.
“That’s when I found Vernon’s lab… It felt perfect for me.” Abalone, she jokes, are hardly “cute and cuddly,” but “all animals matter, right? Even the ones we eat.”
Her steep learning curve, “I hadn’t studied biochemistry,” only deepened her interest.
Navigating Bias: Being a Woman in the Blue Economy
Like many women in male-dominated sectors, she has faced assumptions and underestimation. “Oftentimes, we are underestimated or assumed to be the ‘assistant’ when walking into a meeting.” Establishing authority often required more effort.
But she learned to use bias strategically. “I let people underestimate me and then use that to my advantage… allowing the data to be the loudest thing in the room.”
She also confronts the “Confidence Gap.”
“I sometimes battle with the ‘Confidence Gap’- the tendency to only speak up when I am 110% sure of the outcome, whereas many peers in the startup world are comfortable selling a vision that doesn’t exist yet,” she says. “I naturally ‘undersell’ because I value integrity over hype.”
For many women in deep-tech fields, the challenge is not competence but self-positioning. Dr. Carroll is learning to advocate for her company without compromising her principles
“I may doubt myself, but never the data and that’s what’s crucial,” she declares.
Science as an Early Warning System: Data Analytics and Proteomics
MariHealth Solutions’ work sits at the intersection of marine biology and high-resolution analytics, a field experiencing global momentum.
“For us at MariHealth, data analytics and proteomics aren’t just buzzwords; they are the tools that allow us to listen to what is happening biologically underwater,” Dr. Carrol reveals.
The industry has historically relied on reactive indicators: sick fish, appetite loss, and water-quality crashes. Dr. Carroll’s team flips that model. Proteomics allows early detection of stress biomarkers, giving producers days or weeks of warning. It is a shift from treatment to prevention, echoing wider global trends in personalised health, regenerative farming and precision agriculture.
“This shifts the industry from a reactive approach (often involving antibiotics or chemical treatments) to a proactive one.” Early detection reduces waste, optimises nutrition and cuts reliance on antibiotics and chemicals, an alignment of ecological and commercial logic.
Dr. Carroll rejects the idea that technology and environmental stewardship need to be balanced. “I don’t view innovation and sustainability as opposing forces,” she argues. “In aquaculture, the most biologically efficient farm is also the most sustainable one.”
For her, the equation is simple, healthier fish mean cleaner oceans, stable yields and profitable farms. “We want to make environmental stewardship the most logical, economic choice for the industry,” she says.
Trends to Watch: Biotech Rising Across African Aquaculture
Dr. Carroll has long argued that biotechnology will shape aquaculture’s future. She sees the shift accelerating.
“We are moving from traditional farming methods to science-led innovation.”
Her current work underscores this philosophy. MariHealth is developing diagnostics and therapeutics for a pathogen affecting rainbow trout farmers in Southern Africa.
“We are gearing up for in-field trials next year.”
This wave of biotech-driven aquaculture aligns with global forecasts. By 2035, food systems analysts expect marine biotechnology to be one of the fastest-growing verticals in the ocean economy.
The momentum is also reflected in recognition. MariHealth recently became a finalist in The Big Pitch competition hosted by Startup Club ZA and has won the SA Startup Awards in the Deep Tech category. These accolades align with the continent-wide rise in climate-tech, food-tech and ocean-economy startups.
“It feels like the market is finally catching up to the science we’ve been championing,” she says, a welcome force multiplier as the company enters a new fundraising cycle.
Advice to Entrepreneurs: Especially Women in Deep Tech
Her guidance is pragmatic and grounded in lived experience. It is grounded in realism rather than rhetoric.
“Don’t wait until you feel 100% ‘ready’ to start.” Entrepreneurship, she stresses, is iterative.
“You don’t need to be the loudest voice in the room… If you have the evidence, you belong at the table.”
Her final counsel centres on emotional resilience:
“Build your support system early. This journey can be incredibly lonely… You don’t have to carry the weight of it all on your own,” she says.
2035 and Beyond: How Biotechnology Will Redefine Aquaculture
She believes biotechnology will fundamentally reshape food systems over the next decade.
“I believe the next decade will define the shift from treating disease to engineering resilience.”
Instead of reacting to illness, producers will use proteomics and genetics to tailor nutrition, strengthen immunity and design interventions before problems arise.
“By 2035, I see us routinely using tools like proteomics and genetics not just to cure sick fish, but to understand exactly what they need to thrive before problems ever arise. This will allow us to tailor nutrition and health solutions so precisely that the need for antibiotics or harsh chemicals is drastically reduced, if not mitigated entirely,” Dr. Carrol adds.
This, she argues, is central to global food security. If aquaculture is to scale sustainably enough to feed a growing population, the industry must operate proactively and scientifically.
“Ultimately, this revolution isn’t just about better technology; it’s about food security… without compromising the health of our oceans.”
Dr Sarah Carroll represents a generation of African scientists transforming academic research into globally relevant, commercially viable impact. She did not intend to become an entrepreneur but her lifelong scientific curiosity has positioned her to help shape the future of sustainable aquaculture.
From a child in a library discovering the natural world to a scientist using proteomics to change an industry, her journey speaks to a broader continental shift, African ingenuity moving from the laboratory to the global market, powered by data, deep science and a drive to build solutions that matter.
