Environmentalists in southwestern Uganda are alarmed at the re-emergence of water hyacinth on River Kagera in Isingiro district.
John Bagambe, a Senior Environmental Officer in Isingiro, says the water hyacinth is flowing downstream into Lake Victoria from Rwanda. He says if urgent measures aren't taken to stop the spread of the water weed, it will cause wide-scale silting and will suffocate marine life along the river and in Lake Victoria.
The invasion of water hyacinth on Lake Victoria was one of the biggest environmental emergencies of the late 1980s and 1990s. Various management activities were implemented by the governments of Uganda, Kenya and Tanzania to develop a Regional Water Hyacinth Management Plan that stopped the spread of the weed.
Rwanda implemented a biological management program, introducing the rearing of the Neochetina weevil species that feed on the destructive water hyacinth.
Bagambe attributes the new spread of the hyacinth to farmers along River Kagera, who uproot the weed from their dams and watering holes and dump it in the river. He warns that the hyacinth is threatening the success of a 17 million-dollar hydropower dam to be built at Kaseketi Falls in Isingiro by Shan Sheng, a Chinese power company.
Water hyacinth is an alien biological species, whose origin in Africa is unknown. Popular science attributes its introduction into Africa's waterways to Christian missionaries, particularly Catholic missionaries, who brought to the continent their long-standing tradition of collecting and carrying with them exotic plans and growing them in mission stations they established in foreign lands.
It is alleged that around 1900, the White Fathers introduced water hyacinth in Rwanda, at the headwaters or the Kagera River, which drains into Lake Victoria.