Piles of dead Nile perch have been washing up on the shore of Lake Victoria in Uganda for no obvious reason, locals said.
“We do not know why Nile perch are dying, yet all the other fish are not dying,” Teddy Nagadya, a fishmonger in Kigungu, a shoreline village in Entebbe town, told Reuters.
Uganda’s ministry of agriculture and fisheries said on Sunday that hypoxia, a condition in which the body gets no oxygon, may have led to the fish deaths.
Fish hypoxia has happened before in Uganda, but fishermen in the area told officials the number of fish dying was much higher than in the past.
Industries, farms and settlements near Lake Victoria have been a source of environmental stress for the lake over the last years, said Amos Wemanya, Greenpeace’s Africa campaigner.
Poison or chemicals, especially agrochemicals, that come from the farms and industry were also a problem, Wemanya said.
The government ruled out poisoning of the fish as only the Nile perch species of fish had been affected. “It is suspected that the recent storms on the lakes caused mixing of the different waters, thereby reducing the oxygen levels in the lake,” it said.
Further tests are being conducted to determine the definitive reason behind the deaths, the ministry said, adding it was also testing water from Lake Kyoga and the river Nile.
Fisherman Elias Ndayisaba had a different theory for the dead fish. “Some people say that the lake froze at the bottom, which is causing the fish to freeze to death,” he said.
