Eradicate water hyacinth in Lake Victoria

Residents join in on a clean-up exercise during the launch of a 10-day Lake Victoria

Residents join in on a clean-up exercise during the launch of a 10-day Lake Victoria clean-up exercise at River Kisat at Nyanza Golf club in Kisumu on March 3, 2020. 


Photo credit: File | Nation Media Group

Water hyacinth has become a major invasive plant species in Lake Victoria. While it is native to South America, human activity has introduced the weed to the lake region, where it has negatively affected the local ecosystems.

As its flowers are reputed for their beauty, it might have been brought over as an ornamental plant for garden ponds by the Belgian colonialists in Rwanda and Burundi. The consensus is that water hyacinth entered Lake Victoria from Rwanda via River Kagera, probably in the 1980s.

Since its emergence in Kenyan waters, the hyacinth has completely covered some sections of Lake Victoria with serious repercussions like hindering the work of fishermen by blocking waterways, hence limiting boat traffic by producing a dense canopy on the water's surface. Fishermen from the lake region have complained about this many times but their pleas fall on deaf ears.

Recently, a news agency reported that 364 million fish died in Lake Victoria while the total loss was estimated to be more than Sh1.4 billion. That was a result of low oxygen in the lake, which is mainly caused by the growth and thriving of water hyacinth.

Oxygen reduction

Water hyacinth is fatal to fish species as it leads to the reduction of dissolved oxygen in the aquatic environment by growing very fast and forming a thick mat on the surface of water bodies.

Due to its vegetative propagation and extremely high growth rate, water hyacinth clogs drainage, irrigation canals and waterways. The flow of water, also referred to as water turbulence, is reduced by 40-95 per cent in irrigation channels and that may cause flooding and affect agricultural activities carried out through irrigation.

Lake Victoria is valued not only for its economic but also transport and recreational importance to the East and Central African region. Economically, it has made a tremendous contribution to the fisheries industry by providing Kenya, and the entire region, with export earnings and a base for industrial commercial growth.

This sector also provides employment to Kenyans. A large population near Lake Victoria that partly or wholly depends on the lake for a livelihood is affected by the infestation of the lake by the water hyacinth.

The government should come up with proper criteria to help curb the further growth of the weed in Lake Victoria. For instance, the Chinese now use both mechanical and biological controls to help in prohibiting the growth of the water hyacinth in various water bodies in their country.

The government should emulate China by collaborating with Beijing to eradicate the weed. For a long time, Kenya and China have had good ties. Through this, the water menace in our water bodies will be solved.

Tobias Osano, Kisumu