Lake Victoria, East Africa – A groundbreaking study has shed light on the health challenges facing cage-based fish farming in Lake Victoria, where rapid growth in the aquaculture industry has been accompanied by rising cases of disease-related fish deaths.
The research—led by Cornell University in partnership with the Kenya Marine and Fisheries Research Institute (KMFRI) and the International Livestock Research Institute (ILRI)—highlights critical gaps in disease surveillance, biosecurity, and antimicrobial resistance (AMR) monitoring among fish farmers, particularly in Kenya’s Busia County.
A Wake-Up Call for the Industry
Between 2020 and 2023, over 1.8 million tilapia were lost in more than 80 large-scale mortality events in the Kenyan portion of Lake Victoria. Yet, less than 40% of these incidents were reported to authorities, and only 17% of farmers attempted treatment—mostly without veterinary input or lab testing.
“This lack of early detection and diagnosis creates a major vulnerability for fish farmers and the entire aquaculture ecosystem,” said Eric Teplitz, lead author of the study and a veterinarian at Cornell University.
Understanding the Disease Drivers
The study combined farmer surveys, on-site investigations, disease surveillance, and laboratory testing of bacterial samples. Researchers found that bacterial pathogens—often worsened by poor water quality and stress—were common across affected farms. Several strains even showed resistance to commonly used antibiotics, raising concerns about the broader threat of AMR in aquatic environments.
“We’re seeing that antimicrobial resistance isn’t just a hospital issue—it’s a food systems issue,” said Dr. Ekta Patel, a scientist at ILRI. “Aquatic environments like Lake Victoria can act as silent reservoirs for resistant bacteria. Stronger surveillance is urgently needed.”
Solutions: Training, Biosecurity & Early Action
To help turn the tide, Cornell, KMFRI, and ILRI have led farmer training workshops across western Kenya, promoting better fish health and water management practices:
- Proper disposal of dead fish (e.g., burning or composting instead of dumping in the lake)
- Wider cage spacing in deeper waters to improve oxygen flow
- Cleaning and maintaining nets to ensure proper water circulation
- Timely disease reporting to national veterinary and fisheries authorities
“These best practices not only reduce disease outbreaks but also improve farm productivity,” said Christopher Aura, Director of Freshwater Systems Research at KMFRI. “We need stronger data-sharing systems between farmers, researchers, and regulators to scale these efforts.”
A Call for Policy Change
The study is the first in Lake Victoria to isolate bacterial pathogens during a tilapia mortality event and test their antibiotic resistance. Its findings align with ongoing regional efforts to tackle AMR through more evidence-based policy, responsible antibiotic use, and One Health approaches that connect human, animal, and environmental health.
Kathryn Fiorella, the study’s principal investigator at Cornell, summed up the broader impact:
“Aquaculture can provide jobs, income, and nutrition across East Africa, but only if we build resilient systems that can respond to disease risks. That means investing in biosecurity, diagnostics, and farmer education.”
Moving Forward
The authors urge policymakers to support integrated aquaculture strategies that prioritize early disease detection, coordinated surveillance, and responsible antibiotic stewardship. With Lake Victoria central to East Africa’s food security, the stakes have never been higher.