Dead fish on the shores of Lake Victoria in Uganda and Kenya

Recent fish kills reported on Lake Kyoga and Lake Victoria, Uganda, raised concerns among both local authorities and scientists, who subsequently collected and analyzed fish and water samples. The results are illustrative of a much larger problem in the country — deteriorating water quality, impacting the ecosystem.

To tackle problems holistically and contribute to the sustainable management of water resources, the SWAQ-Uganda project officially kicked off in Uganda on Wednesday, 27 September 2023. It is implemented by the Department of Water Quality Management in the Directorate of Water Resources Management (DWRM) of the Ugandan Ministry of Water and Environment (MWE), and coordinated by IIASA in partnership with the University of Natural Resources and Life Sciences (BOKU), Vienna. The project is funded by the government of Austria through the Austrian Development Agency (ADA) and focuses on conducting a comprehensive national water quality assessment, compiling data from existing information and water quality monitoring, and enhancing institutional capacity at the national level.

Activities aim to raise awareness and create visibility for the project and water quality challenges in general, highlighting the need for engagement across different sectors to address them. Similar activities will be conducted systematically as part of the project, focusing on a wide range of technical topics (e.g., biomonitoring, data processing and analysis, data management, and water quality modeling). The project will also help to conduct a comprehensive national water quality assessment for the country, improving water quality monitoring and information sharing.

In addition, the project will foster the development of a water quality modeling framework. The framework will offer policy and planning insights, contributing to further water quality assessment and management in the country.

The Kenya Marine and Fisheries Research Institute (KMFRI) says the sudden death of fish in cages witnessed in Lake Victoria’s Dunga Beach is a result of a lack of enough oxygen in the water.
KMFRI boss Dr. Christopher Aura says the thick green color of algae that has formed in parts of the lake, which is a sign of increased water pollution, also made the situation worse.

Dr. Aura says researchers from KMFRI collected samples from the cages area and also away from the cages for testing, also dead fish were taken for tests.

He says the team also observed floating dead snail shells in the water an indication that there was low oxygen concentration at the site.

He says the nets in the cages were clogged, limiting water circulation which may have hindered the supply of sufficient dissolved oxygen.

Dr. Aura says changes in weather variants between cool and hot conditions in the lake due to pollution and climate change are encouraging existing excess algae growth to decompose faster, especially in low oxygen concentrations causing the foul smell encountered during windy spells.

Dr. Aura urged cage farmers to be cautious about cage locations by consulting relevant authorities and also ensure proper spacing and even the number of fish stocked in the cages.

Since the end of 2020, piles of dead fish have been dumped on the shores of Lake Victoria in Uganda and Kenya. In January, three fish deaths were recorded in Lake Nakuru during the month. Remarkably, only one fish species, the Nile perch, was affected.
The National Environmental Management Agency (NEMA) released a statement saying that a preliminary investigation ruled out poison as the cause of the fish deaths. The incident was attributed to a drop in oxygen levels. Nile perch is a fish species sensitive to low oxygen levels (below 2 mg).
NEMA added that as a result of the recent flooding and rising water levels, large areas of weeds were flooded and buried under the lake bed. These weeds consume oxygen as they rot in the lake, so oxygen levels are dropping.

Lake Victoria in East Africa, due to increasing pollution and climate change that is causing it to steadily dry up, may soon disappear altogether. Cities near the lake are dumping untreated waste into its waters. One million tons of fish are taken from it each year, and the pressure on its stocks is increasing due to poaching and overfishing.
Because of the current situation, governments must develop plans to preserve Lake Victoria, meeting the needs of the more than 30 million people whose livelihoods depend on its resources.

The water level in Lake Victoria in East Africa is declining at an alarming rate. This is the conclusion made by Kenyan ecologists who have studied the state of this lake. They warn that such a phenomenon may cause a severe ecological crisis in the whole region.
According to scientists, even taking into account seasonal fluctuations, the lake has shallowed by half a meter for the last 10 years. This, in turn, leads to the reduction of biological resources and fish stocks, which are the source of food for millions of people in coastal countries - Kenya, Tanzania, and Uganda. Kenyan experts cite two main reasons for this phenomenon. Firstly, it is the general climate change, which has led to a decrease in rainfall throughout the region. The most negative influence is also the human factor. The continuing practice of inefficient water use and uncontrolled deforestation in coastal areas leads to a decrease in water volumes in dozens of large and small rivers that feed the waters of Victoria.