Dr Mahlatse Mashaphu’s PhD in Biological Sciences is expected to contribute to the conservation of a native Tilapia species that is important to freshwater aquaculture but is under threat from hybridisation with introduced Tilapia species, resulting in a “vulnerable” rating on the International Union for Conservation of Nature (IUCN) lists.
Mashaphu explored the conservation genetics of Mozambique tilapia (Oreochromis mossambicus) across several provinces in South Africa. These fish are increasingly being hybridised with the invasive introduced Oreochromis niloticus, or Nile tilapia. She assessed the genetic diversity and population structure of O. mossambicus to inform conservation and management strategies.
Mashaphu identified populations affected by hybridisation and investigated human-related threats to wild populations, developing management recommendations to protect genetically pure populations. This could also serve as a potential brood stock for sustainable aquaculture.
She also applied the innovative environmental DNA (eDNA) metabarcoding tool to detect and monitor both native and invasive freshwater fish species, which has the potential to enhance biodiversity conservation globally.
Mashaphu completed her undergraduate and honours studies at the University of Limpopo and worked as an environmental officer intern at the then Department of Agriculture, Forestry, and Fisheries. She enrolled for her master’s studies at UKZN owing to her strong interest in sustainable management and conservation of freshwater fisheries resources, and a master’s programme that closely matched her interests.
Mashaphu found moving to the University rewarding due to its diverse research and supportive academic environment, particularly within the collaborative Willows-Munro Conservation Genetics Lab and the Downs Research Lab, where she experienced strong mentorship, community and opportunities for growth.
Providing technical support to marine and freshwater aquaculture farms during her internship sparked Mashaphu’s academic interest, especially given the importance of aquaculture for food security and livelihoods in South Africa. Drawn to conserve freshwater fish genetic resources for the preservation of biodiversity and the success of aquaculture, Mashaphu finds that contributing to the protection of vital ecosystems and natural resources is fulfilling through her work at the intersection of ecology, genetics, and fisheries management. Her master’s research was upgraded to a PhD, expanding the scope of her work.
Several river systems still contain genetically pure O. mossambicus populations, contrary to assumptions of widespread contamination by the invasive Nile Tilapia. This highlights the need to protect these rivers and restrict permits for farming the faster-maturing invasive species.
Mashaphu also successfully developed and applied an eDNA metabarcoding protocol to detect native and invasive species, a tool that will be useful for future monitoring and conservation.
In her postdoctoral research, supervised by Professor Sandi Willows-Munro and Professor Colleen Downs, Mashaphu is expanding this eDNA metabarcoding work to include other threatened and native species, refining the protocol to apply to monitoring freshwater fish species in KwaZulu-Natal’s river systems and other South African systems.
During her PhD, beginning in 2020 amid the COVID-19 pandemic, with no funding for a year, Mashaphu also faced the devastating loss of her older brother, Mr Oupa Mashaphu which deeply affected her. With the support she received from her supervisors, she could take time off to grieve and support her family. Accessing UKZN’s Student Support Services helped Mashaphu manage her grief.
Drawing strength from her brother’s pride in her academic journey, being the first in her family to attend university, Mashaphu found the strength to complete her studies, relying on her family, faith and wider community.
She regularly visited her family, attended church services and choir rehearsals, and participated in game nights with friends that helped her maintain emotional, physical and spiritual wellbeing. She enjoyed singing, taking long walks, and trying new recipes to unwind.
Mashaphu is passionate about continuing her research career, with academia a possible pathway, and she is building her profile as an emerging researcher to contribute to conservation genetics and freshwater ecology.
Mashaphu credited God for strength and protection during her studies and was grateful for the guidance and mentorship she received in abundance from her supervisors: Willows-Munro, Downs and Professor Gordon O’Brien.
Mashaphu thanked her friends, lab mates and church family for their encouragement; her parents and sister, Mr Matome, Mrs Moloko and Ms Mannyana Mashaphu, for their sacrifices, belief and support; her late brother for his faith in her and the financial support he provided for her studies; and her fiancé Dr Lehlohonolo Adams for being her anchor.
Mashaphu’s research was supported by the National Research Foundation, the Department of Forestry, Fisheries and the Environment, the South African Institute for Aquatic Biodiversity, Rivers of Life, the Agribusiness Development Agency, IUCN Save Our Species, Fondation Segré, Ford Wildlife Foundation, and IDEAWILD. She thanked the relevant authorities for providing the necessary permits and ethical approvals.
Words: Christine Cuénod
Photograph: Sethu Dlamini
