Principal Research Scientist Freshwater Aquaculture Research Aquaculture Nutrition & Fish Health Fish Nutrition • Probiotics • Sustainable Aquafeeds • Genetic Improvement Work Email: mopiyo@kmfri.go.ke Location Kisumu Years of Experience 2009-Present (16 years at KMFRI) Research Interests Fish nutrition and Fish health management; Climate Smart Aquaculture technologies; Cage Aquaculture; Farming systems; Microalgae; Genetic improvement of farmed fish for quality seed production | Research Focus: Advancing sustainable aquaculture through research on cage culture, alternative protein sources for fish feed, fish health management, and genetic improvement of African catfish and Nile tilapia through hybridization and selective breeding. Dr. Mary A. Opiyo is a Principal Research Scientist in Aquaculture and a 2023 African Food Fellow with 16 years of research experience. Her current work focuses on cage culture in Lake Victoria, alternative protein sources for sustainable fish feed production, fish health management, and improving the quality of African catfish and Nile tilapia seed through hybridization and selective breeding. She has published 67 peer-reviewed papers in SCI-indexed journals, 16 books and book chapters, and 35 conference proceedings. Her research has been conducted in collaboration with international and regional partners including NORAD, LIDC, ICIPE, VLIR-UOS, BBSRC, STFC, KCSAP, WIOMSA, ASARECA, VicRes-IUCEA, Wageningen University & Research, EU-Horizon, and KAPAP, with funding from DANIDA, DfID, the European Union, SIDA, UKRI, and the World Bank. Dr. Opiyo has worked as the National Coordinator of Seed Quality Assessment for both private and public fish hatcheries, monitors and evaluates hatchery performance, coordinates the development of tilapia and catfish seed standards, and authenticates new hatcheries, work that has helped meet national demand for quality fish seed. She is also a member of the national technical team that developed the Manual of Standard Operating Procedures for Fish Inspection and Quality Assurance for Fish Business Operators in Kenya, the East African Community technical committee for fish seed standards and certification, the LVFO Aquaculture Research taskforce, and the AU-IBAR Taskforce on African Ornamental Fisheries. She has carried out 21 research projects, including climate-smart aquaculture technologies; Black Soldier Fly larvae as a sustainable protein source; addressing livestock-derived antimicrobial resistance in the Nairobi River basin; enhancing omega-3 fatty acids in farmed fish; probiotics applications; selective breeding of Nile tilapia; Strategic framework for aquaculture education in Kenya; commercialization of fish feed production; and enhancing aquaculture productivity, competitiveness, and market linkages. As a resource person, she has trained fish farmers, hatchery managers, processors, traders, students, and government extension officers in good aquaculture practices, sanitary and phytosanitary requirements, ornamental fishery, seed production and hatchery management, aquaculture entrepreneurship, economics, nutrition, fish health management, and fish welfare. Research & Administrative Responsibility
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Awards and Honours African Food Fellow – 2024 Women Achiever – Sustainable Aquaculture - East Africa Selected Publications Opiyo, M. A., Muendo, P., Mbogo, K., Maranga, B., Ngugi, C. C., Charo-Karisa, H., Nseve, J., Leschen, W., Glencross, B.D. and Tocher, D. R. (2026). Dietary sea lettuce (Ulva lactuca) enhances the levels of omega-3 long-chain polyunsaturated fatty acids in the muscle of juvenile Nile tilapia (Oreochromis niloticus). Aquaculture Research. https://doi.org/10.1155/are/7984665 Mutai, I.J., Nyanswi, B., Omwenga, E.O., Apopo, A.A., Lweikiza, I.K., Mwangi, V.I., Mugo, M., Mwai, F., Opiyo, M.A., Gichana, Z. and Opondo, J.N., Obiero J. A., Nyoike, T.W., Mwangi, J., Ochieng, A., Nyachieo A. (2025). Bacterial pathogens in fish and aquaculture systems in Kenya. Academia Biology, 3(4): 1-14. https://doi.org/10.20935/AcadBiol8049 Magondu, E., Njogu, L., Ouko, K., Mboya, J.B., Muthoka, M., Yossa, R., Munguti, J., Opiyo, M.A., Meenakshisundaram, M., Tanga, C.M. and Obiero, K. (2025). A PESTEL-SWOT Matrix Analysis of Sustainable Aquafeed Sector: A Case of Kenya's Fish Feed Sector. Reviews in Aquaculture, 17(4), p.e70081. https://doi.org/10.1111/raq.70081 Kwikiriza, G., Muthoka, M., Omara, T., Abaho, I., Tibihika, P.D., Curto, M., Opiyo, M.A., Munguti, J., Abwao, J., Orina, P. and Meimberg, H. (2025). Nile tilapia (Oreochromis niloticus L.) Cage aquaculture in africa: potential threats to congeneric fish species and advances to detect escapes. Aquaculture Fish & Fisheries, 5: e70090. https://doi.org/10.1002/aff2.70090 Opiyo, M.A., Mbogo, K., Orina, P. (2024). Potential of Freshwater Macrophytes for Aquafeed in Kenya. In: Gabriel, N.N., Abasubong, K.P., Erasmus, V.N., Kamble, M.T. (eds) Sustainable Feed Ingredients and Additives for Aquaculture Farming. Sustainability Sciences in Asia and Africa, pp. 29-42. Springer, Singapore. https://doi.org/10.1007/978-981-97-4279-0_2 Kaminski, A. M., Pounds, A. M., McAdam, B., Bostock, J., Opiyo, M. A., & Little, D. C. (2024). Growing smaller fish for inclusive markets? Increasing stocking density and shortening the production cycle of Nile tilapia in cages on Lake Victoria. Aquaculture, 581, 740319. https://doi.org/10.1016/j.aquaculture.2023.740319 Nzeve, J., Muendo, P., Opiyo, M., Odede, R., & Leschen, W. (2024). Fish health knowledge, management practices and prophylactic health products usage in aquaculture systems in Kenya. Journal of Applied Aquaculture, 36:1, 215-227. https://doi.org/10.1080/10454438.2022.2155500 Opiyo, M. A., Muendo, P., Mbogo, K., Ngugi, C. C., Charo-Karisa, H., Orina, P., Leschen, W., Glencross, B.D. Tocher, D. R. (2022). Inclusion of duckweed (Lemna minor) in the diet improves flesh omega-3 long-chain polyunsaturated fatty acid profiles but not the growth of farmed Nile tilapia (Oreochromis niloticus). Animal Feed Science and Technology 292, 115442. https://doi.org/10.1016/j.anifeedsci.2022.115442 Opiyo, M. A., Jumbe J., Ngugi C.C., Charo-Karisa H. (2019). Different levels of probiotics affect growth, survival and body composition of Nile tilapia (Oreochromis niloticus) cultured in low input ponds. Scientific African 4: July 2019, e00103. https://doi.org/10.1016/j.sciaf.2019.e00103 Opiyo, M. A., Jumbe, J., Ngugi, C.C. and Charo-Karisa, H. (2019). Dietary administration of probiotics modulates non-specific immunity and gut microbiota of Nile tilapia (Oreochromis niloticus) cultured in low input ponds. International Journal of Veterinary Science and Medicine 7 (1): 1-9. https://doi.org/10.1080/23144599.2019.1624299 Links |
