Farmers’ outcry as Lake Victoria fish continue to die

Silvanus Juma was on his way to feed his fish one recent morning when he observed that something was fatally amiss. Hundreds of fish were floating on the shores of Lake Victoria, dead.

The farmer from Seme in Kisumu County was horrified. He was, however, able to row his boat to his cages where he kept fish 100 meters from the shore . Upon reaching there, his worst fear was confirmed.

“Hundreds of fish had died. Others were floating on water, their mouths wide open,” Juma narrates.

His first suspicion was foul play. Someone had definitely poisoned the fish, he feared. On inspection of adjacent cages, however, he found more dead fish.

Juma was disturbed by one more thing: a foul smell coming from the lake whose water was decolourised.

In total, the farmer had lost more than 500 fish in just a day. Fish that would have fetched him about Sh125,000 in revenue had drowned. For the next few days, a traumatised Juma watched helplessly as more fish died until all his cages had no living fish.

From an investment of Sh40,000, the farmer had been hoping to earn at least Sh1 million in sale of mature fish before disaster struck.

Yet Juma’s tribulations are not isolated. His neighbours too lost their investment in the tragedy. For some like George Ochieng, the catastrophe befell the sub-county one week before he could harvest from his cages. In one night from hell, he lost more than 10,000 fish. Like other farmers, he could do nothing to save his investment. For those that had not died, it was only a matter of time.

“I had put most of my savings in the fish cages. My first harvest was due in days,” a resigned Ochieng recounts.

Struggling to find his words, he adds: “We have never experienced such an occurrence in this area. We appeal to the responsible bodies to help us find answers.”

The farmers were forced to sell the dead fish at throwaway prices. But it is the prospect of an uncertain future they are dreading more. “We are unsure how to restock our cages.”

The tragedy had spread to other locales such as Usoma, Genge and Dunga Beach. Residents of Othany alone lost Sh40 million worth of investments according to the a report by Kisumu County.

In the neighbouring counties of Homa Bay and Migori, the situation has not been any different. For months now, farmers have been reporting death of tilapia in cages. This has resulted in a drastic reduction of fish in the market in a region where it is a staple food.

The deaths have disrupted business in the lake region. “Some of our customers are hesitant to buy our catch,  with fears that our fish may be contaminated by the dead fish,” laments Millicent Akinyi, a fishmonger.

Now Akinyi is worried about the fate of her business that she has run for 20 years. “This lake is a natural habitat for the fish. Why would they suddenly start to die?” She wonders, devastated.

This, though, is not the first time such deaths have happened in the world’s second largest freshwater lake. In February 2021, similar deaths were reported in the lake in what experts described as suffocation.

Kenya Marine and Fisheries Research Institute (KEMFRI) says the fish died from shock. This occurs when currents of de-oxygenated cold water move and replace the top warm and oxygenated lake water. The condition is called potted upwelling according to KEMFRI assistant director, Dr Christopher Aura.

“Our team sampled water from various points where factories discharge waste into the lake. We found out that the lake has recently been experiencing extreme cold and warm temperatures due to effects of climate change,” Dr Aura explains.

He shares that in some instances, the temperature would hit 28 degrees Celsius, causing the decomposition of algae and water hyacinth in a process that is oxygen-dependent.

“This decomposition reduces oxygen levels at the bottom of the lake,” explains Dr Aura, adding that when water currents move, the bottom cold water moves up to replace the top and warm oxygenated water.

“When the de-oxygenated water gets into the cages with minimal water circulation, the fish experience shock, leading to death,” he says.

Residents here are now having to put up with not just losses but a strong odour coming from the lake. Nyalenda estate resident Moses Odhiambo says even water from taps has the offensive smell. Odhiambo and his neighbours now fear the possibility of pollution. 

Meanwhile, Kisumu Water and Sanitation Company, the water supplier, has assured the residents that they have extended their abstraction points deeper into the lake to ensure clean water for consumers. 

Company managing director Thomas Odongo says they have introduced aeration in the treatment plants to reduce the odour. “There is no cause for alarm. We have put all control measures in place. We want to assure our customers that the water supplied to them is safe for consumption,” says Odongo.

The researcher notes that the water body has recently been experiencing high nutrient levels due to pollution from domestic and industrial discharges. These discharges in turn support aquatic primary productivity and, therefore, an algal bloom which, upon decomposition, results in the pungent smell.

Dr Aura says algae coverage in the lake is currently at 6,000 hectares while the hyacinth covers about 4,000 hectares.

He attributes the excessive growth of algae to either decomposition of hyacinth or pollution from human activities, adding that raw sewer finding its way into the lake can boost this growth.

“Sewerage companies located within the lake region should have hotlines so that residents can report sewage bursts to avoid the waste from spilling into the lake,” he says.

Dr Erick Ogello from the science department of animals and fisheries at Maseno University says cage fishing is one of the interventions that have been adopted to boost production to meet growing demand.

Dr Ogello says cage farming has thrived in the area since the fish are reared in the lake, which is their natural habitat. This promotes efficient management and faster maturity.

The departmental chair, however, notes that fish production in the freshwater lake had been on a downward trend in recent years owing to human activities (pollution), predation and siltation. Heavy siltation, he says, has made the lake shallower by up to 40 metres. 

He advises farmers to use larger cages in deeper waters to allow proper air circulation and limit cases of suffocation.

“Caging is an emerging frontier. Farmers should be careful not to exceed the lake capacity lest their investments are lost,” he warns.

[email protected]