Controlling an Invasive aquatic plant for improved biodiversity and livelihood on the Lukanga swamp IBA.
BirdWatch Zambia’s Salvinia molesta biocontrol project in the Lukanga swamps IBA is funded by the UK government’s Darwin Initiative through BirdLife International. This multi-year project “Controlling an invasive aquatic plant for improved biodiversity and livelihoods” will control the Salvinia molesta (Kariba weed) by introducing a very effective and host specific weevil, Cyrtobagous salviniae, a known natural enemy that exclusively feeds on the Kariba weed. Weevil damage causes the plants to turn brown and eventually sink and rot. Depending on climate and extent of Salvinia infestation, mats sink within 1-3 years. This is expected to improve habitat conditions for waterbirds, other biodiversity as well as the livelihoods of >2500 fishermen households.
2100 Cyrtobagous salviniae (weevils) were successfully released into the Lukanga swamp in October 2018. These weevils where released in 11 points within a 5km radius from Waya harbour. Monitoring activities currently indicate extent of weevil spread at an average of 9m from the points of release. Additionally, 3/11 points have undergone disturbance from both humans and animals due to a reduction in the water level on the swamp that caused a shift in the grazing and harbour points inwardly. The weevils are adapting very well in the swamp
5 non-weevil release points have been selected in the swamp. These will be used to compare between weevil release sites and non-release sites and will undergo the same monitoring.
Weevil mass rearing is currently going on at 3 locations; in two troughs at the BWZ office, two troughs in Chilwa and two other ponds in Waya. These facilities serve as nurturing and breeding grounds for the weevils prior to release into additional points in the swamp.
Extensive education and awareness raising about the biocontrol control process and weevil management has been conducted targeting fishermen, fish traders, health workers, pupils and the general community living in and around the Lukanga swamp. So far, awareness has been raised to 521 people since project inception.