The lingering foul odor reported in parts of Lake Victoria has been linked to intensified algal blooms driven by rising pollution levels, the Ministry of Water and Environment has said.
According to the ministry, Lake Victoria and its basin support over 45 million people, providing drinking water, transport, fisheries, hydropower, and trade. However, the lake is increasingly under strain from pollution entering from surrounding catchments.
“The Inner Murchison Bay, one of the most heavily utilised sections of the lake in Uganda, has been identified as the most affected area due to its shallow depth of less than 10 metres and its sheltered nature,” the ministry said. Other bays facing similar challenges include Kitubulu and Nakiwogo in Entebbe, and Napoleon Gulf in Jinja.
Pollution comes from multiple sources: surface runoff carrying silt, human and plastic waste, untreated municipal wastewater, industrial effluent, and agricultural runoff. Wetland degradation has worsened the problem, removing natural filters that once absorbed excess nutrients and organic matter.
The ministry monitors water quality through 23 stations in Inner Murchison Bay and 10 stations in Entebbe Bay. Quarterly data shows a steady increase in nitrogen and phosphorus, nutrients that fuel algal blooms.
“Prolonged dry conditions and high temperatures experienced over the past month triggered mixing in the bays, accelerating algal blooms. When the algae die and decompose, they consume oxygen and release gases such as hydrogen sulphide and ammonia, which are responsible for the foul smell being reported, especially around Luzira and parts of Entebbe,” the ministry explained.
These conditions reduce oxygen levels in the water, threatening aquatic life and potentially leading to fish kills. Decomposing algae also release nutrients back into the lake, perpetuating repeated blooms.
To tackle the issue, the ministry is restoring degraded wetlands, enforcing the 200-metre lake buffer zone, and strengthening water quality monitoring to guide policy decisions. Industries are being encouraged to adopt cleaner production methods to limit wastewater discharge, while enforcement of effluent permits for industries and municipal treatment plants has been stepped up.
Community awareness campaigns are also being intensified to reduce pollution, though the ministry noted more work is needed. “Protecting the environment and saving our valued Lake Victoria requires the contribution of every Ugandan,” the ministry said.
Additional steps highlighted include improved solid waste management, environmentally friendly agricultural practices, stricter enforcement by urban authorities, and wider public sensitisation, all aimed at restoring and maintaining the ecological balance of the lake.
