Lake Victoria is Africa’s largest lake by area, and it is the largest tropical lake in the world. Lake Victoria is the worlds 2nd largest freshwater lake by surface area; it is home to a large number of popular aquarium species, many of them endemic to the lake. Unfortunately, the native wildlife in Lake Victoria is under constant threat from invasive species, pollution, and over fishing.
The Water hyacinth has been a major invasive plant species in Lake Victoria. The release of large amounts of sewage, agricultural and industrial runoff directly into Lake Victoria over the past 30 years, has greatly increased the nutrient levels of nitrogen and phosphorus in the lake triggering massive growth of exotic Water hyacinth, which colonised the lake in the late 1990’s. Water hyacinth has covered as much as 680 square kilometres of the lake.
This invasive weed creates anoxic (total depletion of oxygen levels) conditions in the lake inhibiting decomposing plant material, raising toxicity and disease levels to both fish and people. Also, the plant’s mat creates a barrier for boats and ferries to maneuver, impedes access to the shoreline, interferes with hydroelectric power generation, and blocks the intake of water for industries.
The Nile perch (Lates niloticus) was also deliberately introduced in 1954, since it is an appreciated food fish. During the 1960s, introduction efforts intensified, but it wasn’t until the mid 1980s that the Nile perch population began to really dominate the fish community in Lake Victoria. The Nile perch is believed to be responsible for the extinction or severe decline of several hundred cichlid species in Lake Victoria, as well as native tilapia species, Negege (Oreochromis esculentus).
In response to the magnitude of problems facing the lake, the three riparian countries; Kenya, Uganda and Tanzania sought funding from Global Environment Facility (GEF) to address Lake Victoria’s ecosystem health. The project’s main objective is to restore the ecological health of the lake basin. One of the project components includes Water hyacinth control and management; which involves reducing the weed to manageable levels using both biological and manual methods.
In 2011, The Greene’s organization implemented a project aimed at helping local populations control the water hyacinths by turning them into an economic resource. The project proposed that locals could make fuel briquettes for cooking, fertilizer, woven furnishings and biodegradable sanitary napkins. This was based on the understanding that; as with most invasive plants, villagers on Lake Victoria’s shores may not be able to eliminate the hyacinth but by making use of it, they could control the plant’s invasion, and restore some of the lake’s health.
In August 2013, The Kenya Organic Research Centre for Excellence (KORCE) proposed to help environmentalists and fishermen rid lake waters of water hyacinth by using the plant as a raw material for generating electricity. The firm plans to generate power by harvesting the plants and feeding them into a bio-digester that will in turn produce gas to turn turbines that will produce electricity.