Kenyan fish cage farmers in Lake Victoria have suffered enormous losses following the death of their fish stock in early November, which experts have attributed to upwelling and pollution. Images circulating online and sent to us by our Observers show thousands of lifeless fish in cages in Lake Victoria. More than 364 million fish are believed to have died, with an estimated value of 1.4 billion Kenyan shillings (equivalent to 11 million euros).
Our Observer, Ian Omondi Otieno, is a fisherman in Kisumu, a city that borders Lake Victoria. He told us he had been saving to buy a fish cage for five years and finally bought one for 370,000 Kenyan shillings (3,000 euros) earlier this year. He had been hoping to make some profit. But all he has now is dead stock that has set him back the equivalent of thousands of euros.
'Fishing is the backbone of our economy'
At the beginning of November, I went out to the lake and found lots of fish floating on the surface, dead. Others had been washed up on the shores. It’s a tragedy. Thousands of fish have died, and that’s just on our side of the lake. For other communities around Lake Victoria, it has been even worse.
The situation is causing a huge amount of stress, thousands of livelihoods have been destroyed. I saw one fisherman crying uncontrollably after discovering the loss of all the fish in his cage. He tried to commit suicide.
Fishing is the main source of income in my town. Around 90 percent of our population depend on fish, it is the backbone of our economy.
In a bid to cut down on losses, the fishermen are now harvesting the dead fish to sell as a common variety of dried fish. On November 13, Kenya Marine Fisheries Research Institute (KMFRI) cautioned the fish farmers to check for signs of contamination before consumption.
Experts at the KMFRI said the fish died due to upwelling, a natural phenomenon that involves temperature changes and oxygen depletion. Upwelling usually takes about an hour, but during the process, fish confined in cages are often deprived of oxygen.
It is hypothesised that global warming enhances land–sea temperature gradients that in turn increase upwelling favourable winds. Climate change has been keenly felt in Africa’s largest lake, which would therefore explain the increase of upwelling trends.
Evaporation, lack of precipitation and changes in the tilt of the Earth’s axis mean the lake is now at risk of disappearing. One 2020 study analysed historical and geological data from the past 100,000 years and found that the entire body of water could disappear in the next 500 years.
Lake Victoria gets most of its water from rain (about 55 inches each year). But according to a study by the National Science Foundation, rainfall levels 35,000 to 100,000 years ago were about 28 inches, or almost half what they are today. Low amounts of rainfall have caused the lake to dry up at least three times in the past 100,000 years, and it could happen again.
KMFRI organisation also blamed heavy pollutants and discharge of raw sewage into Lake Victoria, which has caused algae and the ferocious waterweed hyacinth to grow.
'Industries have been treating the lake like a dustbin'
Ian Omondi Otieno also believes that pollution is to blame.
Lake Victoria used to be clean and a place where marine life thrived. But in the past few years, it has changed a lot. It has become brown or green and it smells really bad. It used to taste clean, but I don’t even want to try drinking it anymore. This year, the situation is worse than ever.
Lots of industries, including a number of hotels, are being built around the lake. They have been throwing plastic and other poisonous waste into the water. They have been treating it like a dustbin. So the fish have been consuming this pollution, it’s been killing them.
Communities around Lake Victoria, the world’s second largest lake, have relied on the body of water for food, energy, and water for generations. According to the World Bank, the lake supports over 40 million inhabitants, nearly 50 percent of them with less than $1.25/day. Lake Victoria has also historically been a source of important biodiversity and home to hundreds of species of fish.
However, over recent years, scientists have been warning that Lake Victoria is “dying”. They have blamed overfishing and pollution for severely damaged fish stocks.
