By Godfrey Ombogo

For close to six decades, fish from Lake Victoria has been Michael Nyaguti’s favorite dish.

However, now he is skeptical of the dish, even when it is served in his own house. This is because Lake Victoria, where Nyaguti has been a fisherman for years, is heavily contaminated and he is no longer sure if the fish are fit for human consumption.

“It saddens me to see what I love doing being threatened by wanton pollution and impunity,” says Nyaguti, who is the chairman of Magnam Environmental Network, a community-based organization campaigning against pollution of Lake Victoria.

In the recent past, Lake Victoria has seen mass deaths of fish, a phenomenon now called fish kills, leading to loss of millions of dollars in investments and threatening food security in the lake region.

In 2022 and early 2023, local fishers, who rear fish in cages inside the lake, lost up to 7 million dollars when thousands of fish died in the cages.

Dr Christopher Aura, the Director of Fresh Water Systems at the Kenya Marine and Fisheries Research Institute (KMFRI), blames the fish kills on upwelling of the lake.

“Fish die when there is upwelling – the process in which deep, cold water rises towards the surface. Displaced surface waters are replaced by cold, nutrient-rich water that wells up from below,” explained Dr Aura during a media science café organized by the Media for Environment, Science, Health and Agriculture (MESHA) at Dunga Beach.

The Kisumu County Government also attributes the fish kills and declining production to wrong placement of the fish cages and use of illegal nets by the fishers.

“The mass death of the fish last year was a lesson to us on the correct cage location. We now sensitize the fish farmers on this to ensure they don’t lose their investment,” says Susan Adhiambo, the Director of Fisheries in the Kisumu County Government.

Lake Victoria – Africa’s largest lake by area, and the world’s largest tropical and second-largest freshwater lake by surface area – is the main source of fish consumed in Kenya.

According to KMFRI, more than 60 percent of fish production in Kenya and one percent of captured fish globally comes from this lake.

However, fish production in the lake has declined from 200,000 tons in 2002 to 98,000 tons in 2022.

This decline in production is a threat to food security in Kenya, but more so in the lake region where fish is the staple food for most households.

According to the Kenya Demographic and Health Survey 2022, out of the six counties that recorded the highest proportions of households that reported lacking food, three are from the lake region. They include Vihiga (59 percent), Busia (57 percent) and Homa Bay (57 percent). The survey also shows that Kisumu is among counties with the highest percentage of stunted children at nine percent.

Contamination of the lake is making this decline in production worse, with Dr Aura saying it adversely affects the productivity or fertility of the fish.

“The lake has the potential to produce 300,000 metric tons annually, but the current annual production on average is about 115,000 tons valued at Ksh12 billion ($85 million) on a declining trend,” he says.

Dr Aura attributes the contamination to eutrophication, which is the gradual increase in concentration of phosphorus, nitrogen, and other plant nutrients in an aging aquatic ecosystem such as a lake, according to Encyclopedia Britanica.

Eutrophication, he says, is caused by fertilizers, untreated sewage, detergents containing phosphorus, and industrial discharge of waste.

As one moves deeper into the lake, the water changes color from clear to dark then green and at some point, it produces a pungent smell.

At the mouth of River Kisat, one of the many rivers draining into the lake, the contamination is apparent – plastic and other substances strewn on the smelly water.

According to Nyaguti, all this is a result of poor waste management that his network has been fighting for several years now. He blames it on factories, including some multinational corporations, operating in the lake region.

Nyaguti says the river also washes run-off water and waste from the informal settlements of Obunga, Bandani and Mamboleo in Kisumu city as it flows towards the lake. He disagrees with KMFRI that the color and smell of the water are only as a result of the algal bloom caused by rotting water hyacinth.

“This is where we differ with KMFRI. Water hyacinth moved from this area long time ago, so even if it was rotting, that should have stopped by now. Whatever little that was sedimented should have rotten long time ago,” says the environmental activist.

Adjacent to the lake at the mouth of River Kisat is a golf course. Nyaguti says the management of the course wanted to expand it towards the wetland area, but he went to court and stopped them.

However, the wetland is currently being cleared and the golf course seems to be expanding towards the lake after all.

“Our argument was that a large amount of the waste in this river is removed from the water by the wetland. So, the court ordered that any establishment must be at least 60 meters away from the riparian area,” says Nyaguti.

One of the companies he accuses of releasing effluent into the lake, ironically, is the Kisumu Water and Sanitation Company Limited (KIWASCO), a government water treatment plant.

But KIWASCO Managing Director Thomas Odongo says they only release treated water into the lake. He says the two main sources of phosphates in the lake are soaps used by residents around the lake and artificial fertilizers from surrounding farms.

He says KIWASCO’s two treatment plants next to River Kisat and Nyalenda Estate are able to handle both domestic and industrial waste to the required standards.

“They are not sewer treatment plants but water resource recovery centers where we recover the wastewater, treat it, make it environmentally friendly, and release it back to the water bodies,” Odongo says.

“Waste that comes from treatment plants is very minimal. We need to deal with the source of the phosphates. Everyone who is in the Lake Region Economic Bloc is responsible for the pollution in one way or another.”

The bloc consists of 14 counties that share the lake resource. The lake is also shared by three countries in the East African region, with Kenya occupying only six percent, Uganda (45 percent) and Tanzania (49 percent).

Odongo says KIWASCO is in the process of acquiring a compact waste management system to improve its capacity and better fight the contamination of the lake.

Despite all the assurance, Salim Abdala, a local fisherman and the vice chairperson of Kichinjio Beach Management Unit, says they often see dead fish washed to the shore of the lake, and are worried of what the future holds for their main source of livelihood and food.

In the meantime, Dr Aura says the contamination is continuously denying Kenya more than 280 million dollars in annual revenue.

For Nyagut, Abdala and other fisherfolk, their main source of living and nutrients is under threat and the only solution is to stop the contamination forthwith.