To eat or not to eat? The science and politics of Lake Nakuru fish

The evening air at Area 41 beach in Mwariki carries a deceptive stillness, but the shoreline is alive with a tense, quiet adrenaline.

Here, where Lake Nakuru’s swollen waters swallowed homes and displaced families, a dangerous cat-and-mouse game has taken root.

Under the fading light, young men prepare for a night in the water.

They grease their skin with layers of petroleum jelly to shield against the biting chill of the water and the sting of who-knows-what in Lake Nakuru’s saline water.

For them, every plunge into the lake is a gamble with their lives because the water does not belong to the lake but to Lake Nakuru National Park, which is a protected area under the strict jurisdiction of the Kenya Wildlife Service (KWS).

To cross the invisible watery boundary is to risk arrest, harassment or worse, disappearance like Brian Odhiambo, a 31-year-old fisherman whose mysterious disappearance on January 18, 2025, sparked major protests and an ongoing high-profile court case.

Yet, night after night, they dangle on the edge of survival, choosing the perils of the lake over the certainty of hunger and what has been classified as climate displacement.

“Our homes are submerged, we have no jobs, and this is where we are surviving. The water took our land, but gave us fish,” Emmanuel Bosuben says.

Here, the residents can freely express their frustrations and concerns, but get wild when they spot cameras.

“We will be hunted down even if we are fishing on our farms, and we will disappear like Brian,” they say.

Just a few metres from the beach, a woman trader sits comfortably, waiting to amass the catch for the market. She is not worried because the fish are coming in large numbers.

Around her, young women with makeshift floaters still strapped tightly to their waists are hauling the evening’s catch.

The trader does not look at the lake; her eyes are on the money and the size of the catch. Her fresh fish are piled in a sack as her fingers rhythmically count out crisp notes to pay the daring divers.

“This catch is ready for transportation to other counties. This lake has a lot of fish that feed many people across the country,” she says.

The women nod because they can now cater for the needs of their families. “The work gets easy because the fish is there, the buyers are here, and that is all we need, money to feed our children and take them to school,” one of the young women says.

While the residents see the lake as a water-took-water-gave situation, the bigger debate lies in the new developments, the science and politics surrounding the lake’s changing chemistry and the emergence of fish.

Originally, Lake Nakuru only contained a salt-tolerant species of tilapia. Studies, however, reveal high fish populations in the lake.

Before the lake swelled in 2020, Mwariki was a neighbourhood of homes and farms that had title deeds. Every year, the lake keeps advancing and swallowing homes and properties.

Besides the displacements lies a larger debate surrounding the Lake Nakuru fish.

To eat, or not to eat.

Over the last few years, these fish have been the subject of various scientific studies.

The warning sirens first sounded in late 2021, following an investigation by a multi-agency task force of experts from the Kenya Wildlife Service (KWS), Nakuru County Government, and the Kenya Marine and Fisheries Research Institute (KMFRI).

They had been called in after hundreds of Nile tilapia had mysteriously washed-up dead near the Barut and Mwariki bridges.

The report showed that the sampled fish contained high levels of chromium and nickel beyond the safety limits set by the Food and Agriculture Organisation (FAO). The report blamed raw urban sewage and industrial runoff.

In December 2025, a team of researchers drawn from Egerton University, the University of Eldoret, and the Kenya Marine and Fisheries Research Institute (KMFRI) published an ecological assessment titled “From Saline to Freshwater Ecological Shifts: Emerging Fisheries and Health Risks in Lake Nakuru.”

The paper confirms that due to massive climate-driven flooding and catchment degradation, salinity has collapsed from its historical hypersaline levels.

Because the lake’s chemistry changed, the research explained that this created the perfect breeding ground for toxic blue-green algae.

The researchers found that the Nile tilapia within the lake are literally fattening themselves on toxic blooms.

They discovered that a toxic blue-green algae known to secrete liver-damaging toxins was the fish’s main diet.

Combined with high concentrations of arsenic and lead in the fish tissue, the paper warned of public health risks, especially for pregnant women and children, and explicitly recommended an immediate, total ban on harvesting.

Following intense public outcry and petitions by Tom Mboya of Gaplink International regarding mysterious disappearances and allegations of harassment of young fishermen within the national park, the Senate Standing Committee on National Security, Defence and Foreign Relations stepped in.

They ordered the Kenya Fisheries Service (KeFS) to conduct sampling in the petitioner’s presence.

Under pressure from the Senate, the research was finally conducted. The KeFS team visited Lake Nakuru on April 6, 2026, and collected samples, which were sent to labs in Mombasa.

The results, finalised on April 13, 2026, confirmed the findings of the previous studies. Lead levels exceeded international safety standards.

They also noted that the fish were infested with flatworms and zoonotic flukes that can cause severe intestinal illness. In their report, the fish were found to be entirely unfit for human consumption.

But instead of closing the case, the report blew it wide open.

To Mboya, the activist whose petition brought the Senate to Nakuru, and co-petitioner Dr Peter Mbae, the warnings in the report looked like a coordinated distraction.

Mboya told the Senate that he and independent researchers had been completely locked out of the sampling process.

“If they were transparent enough, why did they not involve the petitioner and other independent researchers, and we were ready to accompany them? It feels like the state is investigating itself behind closed doors to justify chasing poor youths away from the water,” Mboya said.

To the petitioners, the non-involvement of communities and interested parties is worrying and signals something bigger.

“While local youth are being shot at, harassed, and arrested by KWS officers for trying to feed their families, influential individuals and powerful cartels are carrying out massive, illegal commercial fishing completely unchecked,” Dr Mbae told the Senate committee.

The enforcement agencies, the petitioners claim, are using conservation to control and monopolise a lucrative, underground seafood trade for elite cartels, where he alleges that local leaders are involved.

Early this month, the Senate shelved the KeFS report and ordered a new investigation, demanding a transparent, multi-agency study that would involve the petitioners and independent scientists.

But as the tug-of-war over whether the Lake Nakuru fish is fit for consumption continues, residents say they know best about the lake’s fish.

“We have been eating the fish for almost seven years now, and everyone is okay,” they say.

“If the fish will kill us in the next 20 or 30 years, which one is better: dying of hunger while you are homeless or playing the cat-and-mouse game and surviving for another few years?” a fisherman posed.

As of 2025, 264 households had been displaced, up from 155 in 2020 under a similar scenario. Every month, the water keeps pushing its boundaries. While what is happening is yet to be fully defined, it is a raw symptom of climate change. In the international arena of climate talks, policymakers use the phrase “Loss and Damage” to describe the irreversible destruction caused by extreme weather, the moments when adaptation is no longer possible, and assets are simply erased.

David Kahoro, the deputy chair of the committee of people who have been displaced in Nakuru, said that while the headcount of those displaced and valuation of property have been finalised and handed over to the government, they have yet to receive any response.

“People are displaced; they have no source of livelihood, no help coming their way, yet they are being harassed,” Kahoro said.

The government had promised to compensate those who were displaced in 2020.

“All we need is a solution to this problem. We cannot lose homes, property and also children who are trying to survive within these waters,” Jane Ndirangu says.

Conspicuously absent from every single session, Nakuru Governor Susan Kihika has repeatedly snubbed the Senate hearings, ultimately forcing lawmakers to issue a formal summons to compel her appearance at the next sitting this month.