Fish kills linked to shortage of dissolved oxygen in water.
by Blue Africa News
Cage fish farmers along the shores of Lake Victoria in Kenya’s Kisumu County are counting losses after massive fish deaths, which is being attributed to an acute shortage of dissolved oxygen in the water, possibly caused by human-induced pollution.
According to some of the affected farmers, the losses affecting between 10-12 fish cages at Dunga Beach, are running into over Sh9.6 million (approximately US$74.3 million), with the affected farmers now pondering on how to pick themselves up, even as issues of pollution and climate change came to the forefront.
“Starting Sunday, we witnessed some fish kills and so far, it is confirmed that we have lost fish in 12 cages at Dunga Beach. The other day we saw fish struggling to breathe, so the most possible cause was the depletion of oxygen in water attributed to climate change,” said Nicholas Owiti Didi, cage fish farmer and Dunga Beach Management Unit (BMU) chairman.
The losses, he said, have thrown the affected farmers off balance economically, since investing in cage fish farming is not for the “faint hearted.”
“It is an investment that really requires a lot of money… Normally, we keep this fish stocked for a period of 9 months before harvesting and per harvest, it ranges between Sh500,000 to Sh800,000,” said Didi.
He denied reports that the dead fish were being picked up for sale, stating that, “All the dead fish are still intact in the cages,” assuring Kenyans that the affected fish will be carefully disposed to avoid a public health problem.
Kenneth Onyango, Kisumu County Executive Committee Member (CECM) for Agriculture, Fisheries, Livestock Development, and Irrigation urged farmers who have not been affected to harvest immediately to avert further loss.
“We have more than 100 cages, but so far only 10 have been affected. If there are those with live fish, we urge them to harvest immediately. Public health officers will guide this process to ensure safety,” said the county official.
The Kenya Marine and Fisheries Research Institute (KMFRI) and the National Environment Management Authority (NEMA), Onyango noted, are currently conducting investigations to ascertain the cause and how to prevent the occurrence in the future.
“Preliminary reports point to oxygen depletion possibly caused by pollutants from nearby factories. We are working with KMFRI and NEMA to finalize investigations and will make the report public once it’s complete.”
Cage fish farmers counting loses at Dunga Beach in Kisumu, Kenya. Photo/Blue Africa News
It is not the first time fish kills have been reported in Lake Victoria. Similar incidents occurred in 2022 and 2023, when cage fish farmers lost over Sh880 million.
According to a 2022 report by KMFRI and the Aquaculture Business Development Program (ABDP) titled “Sustainable Community-based cage Aquaculture in Lake Victoria, Kenya,” cage culture has emerged in recent years as a new livelihood in Lake Victoria, rapidly spreading to Lake Victoria’s five riparian counties of Busia, Siaya, Kisumu, Homa Bay, and Migori.
The report noted that installation of cages had expanded significantly from 1,663 in 2016 to 5,242 in 2022. “This has in turn spurred growth within the blue economy sector within the Lake Victoria region, and provided employment opportunities for the people,” the report said.
The production from cage culture in Lake Victoria, Kenya, the report noted, was 21,000 metric tons yet the estimated carrying capacity is 109,226 tons.
Generally, cage aquaculture is an economically viable business, with the profitability of the cages varying depending on the scale of operations.
Oliver Ochieng, Blue Africa News