Recent efforts in biological control of water hyacinth in the Kagera River headwaters of Rwanda.

Abstract

As part of regional water hyacinth management activities in the Lake Victoria Basin that also involve Kenya, Tanzania, Uganda and several international partners, Rwanda is currently implementing efforts to rear and release the two Neochetina weevil species as biological control agents through coordination of training activities and training visits made to Uganda and Tanzania. Weevils for release in Rwanda have come from stocks maintained in Uganda. The implementation of the biological control program within the Kagera River system of Rwanda is expected to further support the long-term control of water hyacinth in the Lake Victoria Basin by reducing water hyacinth biomass in source waters. Funding and technical support for the implementation of the biological control program for water hyacinth in Rwanda are being provided by Clean Lakes, Inc. through a two-year cooperative agreement with the United States Agency for International Development Greater Horn of Africa Initiative through the Regional Lake Victoria Water Hyacinth Management Program. APPROXIMATELY 13 years ago water hyacinth was officially recognised as having invaded the world’s second largest lake, East Africa’s Lake Victoria. During the ensuing years various management activities have been implemented by Kenya, Tanzania and Uganda with support from several international partners and donor organisations. Recently, these countries and Rwanda have begun to coordinate management efforts through regional organisations such as East African Cooperation (EAC), the Lake Victoria Fisheries Organization, the Lake Victoria Environment Management Program, or through bilateral memoranda of understanding. Biological control efforts using the weevils Neochetina eichhorniae and N. bruchi began in late 1995 through release efforts initiated by Uganda that continue to date. Rwanda is currently implementing water hyacinth control through rearing and release efforts assisted by Clean Lakes, Inc. (CLI), under cooperative agreement funding from the United States Agency for International Development (USAID), and through coordination of training activities and visits carried out in Uganda and Tanzania. Weevil stocks maintained in Uganda are the source of weevils imported into Rwanda. The Lake Victoria Basin water hyacinth infestation extends to its uppermost point within the Kagera River system to the headwaters of Mukungwa River tributary, located approximately 50 km northwest of Kigali, Rwanda (F. Orach Meza, pers. comm.). The Mukungwa River is joined by the Nyaborongo River, keeping the latter’s name, until it merges with the * Clean Lakes, Inc. – Uganda, Nile International Conference Center, Room 235, PO Box 7057, Kampala, Uganda. Email: [e-mail] † Clean Lakes, Inc., P.O. Box 3186, Martinez, CA 94553, USA. Email: [e-mail], or [e-mail].