Ugandan authorities have launched an investigation into the cause of the large-scale death of fish on Africa’s largest freshwater reservoir, Lake Victoria.
Residents had posted photos of several dead fish washed ashore Lake Victoria, as well as Lake Kyoga and River Nile on social media. There were suggestions the fish were poisoned.
But Pius Wakabi Kasajja, the Permanent Secretary of the Ugandan Ministry of Agriculture, Animal Industry and Fisheries, has dismissed as untrue rumours that the fish died from poisoning.
“Preliminary investigations have ruled out fish poisoning,” he said in a statement from the ministry.
“It is suspected that the recent storms on the lakes caused mixing of the different waters thereby reducing the oxygen levels in the lake.”
The ministry, however, warned the public not to eat the dead fish and to instead bury them.
The ministry also added that samples – including the dead fish and water samples – have been taken and will be tested for further analysis at three labs namely: Directorate of Government Analytical Laboratory (DGAL) – (for toxicology); National Fisheries Resources Research Institute Laboratory – (for Algae analysis); and National Animal Disease Diagnostics and Epidemiology Centre (NADDEC) – (for Pesticide Residue Analysis).
The ministry says the only affected species are the Nile perch, a staple in many Ugandan households. The Nile perch is believed to be sensitive to oxygen levels below two milligrams per litre of water.
The ministry further warned the public “to disregard the audio circulating on social media calling upon people to stop eating fish as the fish from the regular catches can easily be distinguished from the floating dead fish”.