Piles of dead Nile perch have been washing up on the shore of Lake Victoria in Uganda for no obvious reason, threatening the livelihoods of the surrounding communities, locals said.
Teddy Nagadya, a fishmonger in Kigungu, a shoreline village in Entebbe town, told Reuters the dead fish have induced panic.
"We do not know why Nile Perch are dying yet all the other fish are not dying," she said.
Uganda's ministry of agriculture and fisheries said on Sunday that hypoxia - "a usual phenomenon" - may have led to the fish deaths, although fishermen in the area told officials the numbers 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, threatening the livelihoods of nearby communities, said Amos Wemanya, Greenpeace's Africa Campaigner.
Poison or chemicals, especially agro-chemicals, that come from the farms and industry were also a problem, he told Reuters.
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 probing water from Lake Kyoga and the river Nile.
Nagadya feared pollution may have killed the fish and said she was scared for children who swim in the water.
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.
He remarked some people were eating the fish but feeling no side effects - which they would have done if the fish were poisoned.
(Reporting by Francis Musaka; Writing by Omar Mohammed; Editing by Alexandra Hudson)
