Mwanza. The National Environmental Management Council (NEMC) has stepped up its efforts to tackle the growing threat of an invasive aquatic weed that has been rapidly spreading across Lake Victoria.
The weed, which has disrupted transport, fishing, and fish farming, is posing a significant challenge to the livelihoods of millions of people in the region.
NEMC, in collaboration with government agencies, local authorities, and environmental experts, has implemented a series of measures to mitigate the crisis and prevent further environmental damage.
In response to the weed crisis, NEMC has conducted environmental impact inspections on more than 134 facilities within a week.
These facilities included industries, farms, mining sites, and households, all of which were scrutinized for their compliance with environmental regulations. The council is focusing on curbing pollution, a major contributing factor to the rapid spread of the invasive weed. NEMC officials have stressed the importance of adhering strictly to environmental laws and regulations. They have also issued stern warnings to investors who fail to conduct environmental impact assessments before commencing operations. Some investors have exceeded the permitted pollution limits, which is exacerbating the deteriorating condition of the lake’s ecosystem.
Jaome Ansgary Kayombo, the Lake Zone Manager, emphasized the gravity of the situation.
"Fishermen in Sengerema and Misungwi districts first noticed the floating vegetation in August 2024. Initially concentrated around fish landing sites such as Buyagu, Chole, Nyahiti, and Mbalika, the weed—tentatively identified as belonging to the Saravia species—spread rapidly due to wind currents and nutrient-rich waters," said Kayombo.
By January 2025, the weed had expanded dramatically, causing significant disruptions to ferry operations, fish cages, and fishing activities. Access to clean water also became increasingly difficult as the weed proliferated across the lake.
In response to the growing crisis, the regional government formed a task force made up of the Lake Victoria Basin Authority, NEMC, the Tanzania Fisheries Research Institute (TAFIRI), and local authorities. Non-governmental organizations (NGOs), rescue teams, and Beach Management Units (BMUs) have also been involved in the efforts.
The task force has made alarming findings, including the fact that the weed doubles or even triples in mass every eight days, making control efforts difficult.
High nutrient levels in the lake, primarily caused by agricultural runoff, waste disposal, and construction activities along the shoreline, have further accelerated the weed's growth.
Despite the removal of approximately 36 metric tons of the invasive weed over the course of four days, the impact was minimal due to the rapid rate of its spread.
Authorities have reiterated that human activities are exacerbating the problem, particularly the construction of structures and farming activities right up to the water’s edge.
This is a clear violation of the 60-meter buffer zone law, which aims to protect the lake’s ecosystem and prevent further damage from human encroachment.
The invasive weed crisis has had a substantial economic impact, increasing the costs of water purification and disrupting the fishing industry, which is a critical source of livelihood for many in the region.
Fish farmers in areas such as Chelele and Bukumbi have reported significant losses as the weed depletes oxygen levels in the water, threatening the survival of fish in the affected areas.
According to NEMC data, the Lake Zone is home to 1,602 fish cages operated by 125 fish farmers, with Mwanza accounting for 1,379 of those cages.
However, only about 10% of these fish farmers have conducted environmental impact assessments, which underscores the lack of compliance with regulations that are crucial for protecting the lake's health.
Authorities have stressed that addressing the invasive weed crisis requires collective action from all stakeholders, including local communities, government agencies, and international organizations.
NEMC has expressed sympathy for the affected fishermen, transport operators, investors, and residents, emphasizing the urgency of implementing short-, medium-, and long-term solutions to safeguard Lake Victoria.
As the world’s second-largest freshwater lake, Lake Victoria is essential to the livelihoods of millions of people in Tanzania, Kenya, and Uganda. However, the lake is facing increasing threats from pollution, illegal land use, and the effects of climate change, which continue to undermine its sustainability.
NEMC has called on local governments to enforce waste management laws more rigorously and encourage residents to dispose of waste in an environmentally responsible manner.
The invasive weed crisis serves as a stark reminder of the need for immediate and long-term action to protect the health of Lake Victoria and ensure that economic activities dependent on the lake’s resources can continue without further disruption.
Failure to address the problem could result in irreversible damage to the ecosystem, affecting not only the environment but also the economic well-being of millions of people who rely on the lake’s resources for survival.
The crisis surrounding the invasive aquatic weed in Lake Victoria underscores the urgent need for stronger environmental management practices and greater accountability from industries and individuals.
NEMC, along with its partners, is committed to fighting the spread of the weed and protecting the lake’s ecosystem.
However, success will only be achievable through collective efforts and a shared commitment to sustainability. As stakeholders come together to address this crisis, the hope remains that Lake Victoria can be saved from further degradation, ensuring its continued role as a vital resource for the region.
