Lake Victoria: Farmers count huge losses as fish die of suffocation

In the past month, cage fish farmers have been reeling in debt running into millions following the sudden death of fish in cages dotting Lake Victoria.

“This is the job I do every day to fend for my family. If the government can perhaps check to tell us how they will help us with food and how we can take our children to school then we will appreciate it,” says David Ogal, a fish harvester. 

According to Edward Oremo, chairman Homa Bay beach management unit, the losses incurred are costly because there are 90 fish cages affected. 

“Every cage has about 6000 fish you multiply on the lower side by 200 or 300 shillings per piece it can even get to Ksh.100 million,” says Oremo. 

According to the Kenya Marine and Fisheries Research Institute, the fish in sections of Lake Victoria have been dying due to suffocation. 

The low oxygen levels are caused by a natural phenomenon called potted upwelling, where changes in wind direction affect the currents in the lake causing the mixing of the deep waters with waters from the surface on sections of the lake. 

“The water which is on the surface is light and has high temperatures it is forced to move away and the water from below comes up and occupies that space therefore the fish the problem with the fish in the cage is that they are confined and so when there is that upwelling which will take about an hour or less the fish confined in the cages now lack that oxygen,” says Dr. Joseph Nyaundu, a researcher at KMFRI. 

With the fish dying, a heavy stench hovers over parts of Kisumu city for at least one month now. 

The pungent smell according to KMFRI, is caused by the 8000 acres of decomposed water hyacinth and other aquatic plants, that are also being swept from the lake floor and floating near the surface covering the town with a heavy stench especially in the afternoon when the sun is up. 

“People are not comfortable eating the fish. Even when you go to buy it you are not sure of what could be inside it,” says Emily Achieng’, a food vendor. 

According to Dr. Christopher Aura, the director of fresh water systems at KMFRI, the smell will last depending on the available organic matter. 

“The organic matter is the water hyacinth that has sunk and other aquatic plants that have sunk and of course the pungent smell will decline and go only if there is increased rainfall to cause precipitation and strong winds,” says Aura. 

Pouring cold water on claims of pollution, KMFRI has however called for more caution, warning that while pollution may not be responsible for the current situation, the continuous dumping of chemicals into the lake may cause accelerated growth of hyacinth and other weeds, worsening the emanating pungent smell during upwelling.

Until then, residents near the shoreline can only brave the smell and wait for the skies to open and not only clear the air but also offer a lifeline to the suffocating fish.