The shimmering waters of Lake Victoria, a lifeline for thousands of cage fish farmers across East Africa, are currently hiding a silent, suffocating threat.
The Kenya Marine and Fisheries Research Institute (KMFRI) has officially sounded the alarm, warning of a potential mass “die-off” that could devastate the regional blue economy.
Following a week of relentless heavy rainfall, the lake’s delicate ecosystem has been thrown into turmoil.
Data captured by an advanced early warning system at Dunga Beach reveals a terrifying drop in dissolved oxygen levels.
According to KMFRI, oxygen has plummeted below $2\text{ mg/l}$ – a lethal threshold for popular cultured species like Tilapia.
The crisis is a perfect storm of environmental factors. Dr. Chrisphine Nyamweya, KMFRI Assistant Director, explained that the recent downpours triggered a “turnover” in the water column, bringing oxygen-depleted water to the surface.
“The dropping of oxygen levels below the minimum threshold is lethal for cultured fish species,” Dr. Nyamweya warned.
He further noted that fluctuating pH levels are currently compromising the fishes’ ability to breathe through their gills, making them more susceptible to disease and less likely to feed.
The stakes could not be higher. Between 2024 and 2025, cage farmers watched in horror as an estimated one billion shillings’ worth of fish perished due to similar suffocation events.
To prevent a repeat of this catastrophe, KMFRI is urging farmers in Kisumu, Siaya, Busia, Homa Bay, and Migori counties to take immediate, drastic action.
In a detailed advisory, the institute recommended that farmers:
Suspend or Reduce Feeding: Uneaten feed decomposes and consumes precious remaining oxygen.
Emergency Harvesting: Immediately harvest fish near marketable size to reduce “stocking density.”
Relocation: Move cages to areas with stronger water currents and better circulation.
“Uneaten feed and fish excretion consume dissolved oxygen during decomposition,” KMFRI stated, emphasizing that cutting back on feeding is a critical short-term sacrifice to ensure long-term survival.
As the rains continue, the fishing community remains on high alert, hoping that these proactive measures and a bit of help from nature will protect their livelihoods from the suffocating depths.
