Large scale fish deaths on Lake Victoria not linked to poisoning – NEMA

Large scale fish deaths on Lake Victoria not linked to poisoning - NEMA
Large scale fish deaths on Lake Victoria not linked to poisoning - NEMA

Africa-PressUganda. A sudden episode of mass death of fish on Lake Victoria has triggered panic and anxiety in the country, threatening livelihoods, and a multi-million export sector.

For the third consecutive week, residents and fishermen report an unusual phenomenon of dead fish floating on water or being washed ashore. Residents of Gerenge Landing Site in Entebbe, Wakiso District, told Daily Monitor last week that the most endangered species are Nile Perch and Tilapia.

“The water changes according to the temperature and algae [level]. The fish dies and floats on top of the water. But this time, the volume of fish dying is too much,” said 38-year-old Florence Mbabazi, a mother of eight.

Our journalists during a visit last Tuesday witnessed a number of residents harvesting the decaying fish and either deep-frying or drying them in the sun before sale.

The reason for the mass deaths of seemingly healthy fish remains unclear, leading to speculation of possible poisoning, limited oxygen or adverse temperatures on Lake Victoria.

“We do not know what is happening. We have taken samples to the laboratory … to analyse and find out what is happening (to the fish in the lake). It could be a natural occurrence, but we also suspect poisoning,” Mr Tom Bukenya, the commissioner for Fisheries in the Ministry of Agriculture, Animal Industry and Fisheries, said.

The impact of the consumption of such fish on human life also remains unknown.The rising mid-morning sun cast stretched shadows of returning fishermen. The group of fishermen had spent Monday night on the waters, but were not as lucky. After retrieving loads of nets, they counted only seven Nile Perch. A kilogramme of Nile Perch is at Shs10, 000. One of the seven fish was visibly rotten but because it was big, the fishermen sold it at a discounted rate.

At another landing site, about one kilometre away, a middle-aged man, was salting, drying and smoking dead fish. He hung some on his shack house made of polythene and tarpaulins.Another woman fanned wood fire to smoke fish placed on rusty iron sheets above the logs.

“If you are not buying [fish], then leave us alone,” a resident said as he straddled to join colleagues at a drinking joint in a nearby banana garden.Mr Fred Lutalo, 54, who has been a fishman for four decades, said the trend of fish dying in the lake is “seasonal”.

“When [the] hot season begins, many (fish) die. This is not the first time it is happening,” he said.Ms Anosiyata Namudu, a fisher at Kigungu Landing Site in Entebbe, last Tuesday said: “This time even the young fish (fry) are dying. We are wondering what is causing it.”

She added:“As a result, we only remove the maw sometimes and throw away the flesh”.An average maw costs between $450 (Shs1.6m) to $1,000 (Shs3.7m), depending on its quality and strength of the market internationally. Uganda’s fish is sold in mainly European Union markets including Italy and Germany, according to Fisheries commissioner Tom Bukenya, who disclosed plans to expand the market to Saudi Arabia.

Whereas government reported increase in fish stock since the Uganda People’s Defence Forces began the clampdown on illegal fishing, alongside growing cage fish farming, Bank of Uganda statistics released in September 2020 showed Uganda’s exports had declined by more than 5,000 tonnes. This resulted in Shs124b fish export revenue shortfall.

“I do not think the issue is with the temperatures because the survival rate of the fish in the water cannot be related to the temperature in the water,” Mr George William Omony, a senior meteorologist at the Uganda National Meteorological Authority, said.He added that fish did not die in masses when Uganda registered the highest temperatures of 38 degrees Celsius in 2019 on Lake Victoria.

Lake Victoria is a fresh water body shared by Uganda, Kenya and Tanzania. In Kenya’s Homa Bay County at the shores of the lake, the Beach Management Unit chairperson, Mr Edward Oremo, confirmed on Wednesday last week that they had received reports from fishermen that they had seen some dead fish on the lake. He added that some of the affected areas were in Kiwa and Nyandiwa beaches in Suba Sub-county, Homa Bay County. He could not confirm whether more are still dying.

Nation Media Group’s Mgongo Kaitira in Mwanza region, Tanzania, said the fishermen at the landing sites had not reported any fish dying in the water. Mr James Rukas, a fisherman in Philomena Landing Site in Mwanza, told journalist Kaitira that the fish become many and float close to the water surface in January, but do not die.

Water and fisheries experts, the line ministries and Makerere University were unable to verify the cause of the mass death of fish, although they in a previous report highlighted pollution.Mr Suja Goswami, the chairman of Uganda Fish Processors and Exporters Association, said they were not aware of mass fish deaths on Lake Victoria.“Maybe it is at the landing site level of which we are not aware,” he said, adding that the incident could damage Uganda’s fish export prospects.

In July 2019, Uganda National Bureau of Standards and Directorate of Fisheries issued simplified quality standards guidelines in local languages to provide basic information on the laws, regulations, procedures and principles for addressing safety and quality of fish products. The guidelines were also to be applied during handling, preparation (such as drying), processing, packaging, storage, transport and marketing of fish.

NEMA explainsLarge scale fish deaths on Lake Victoria not linked to poisoning

Communities living in and around the shores of Lake Victoria have recently been concerned by the growing number of dead fish, especially Nile Perch, being washed ashore.

The dead fish are not only an eyesore but also emit an offensive odor as the decomposition occurs. However, preliminary investigations have ruled out the possibility of poison as the cause of the deaths of the fish.

The occurrence has been attributed to a drop in oxygen levels. Nile perch is species of fish known to be sensitive to low oxygen levels- (below 2mgl). As a result of the recent flooding and rising water levels, large masses of weeds were submerged and sunk into the lake bed. These weeds use up oxygen as they rot from within the lake hence a drop in the oxygen levels.

Also, the recent strong winds around the lake Victoria basin have heightened lake overturn; a phenomenon that causes water from the bottom of the lake that is low in oxygen, to come up and mix with upper layers, where fish live; leading to a reduction in oxygen, hence the death of fish. This is not the first time large scale fish deaths are occurring on Lake Victoria; Fishing communities have always referred to this situation as “Kaliro” and it occurs periodically.

Communities living around the lake are advised to bury the dead fish to contain the pungent smell; as further research and studies are undertaken by all stakeholders including, NEMA, MAAIF, Communities, developers etc


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