For decades, water hyacinth has been wreaking havoc on Lake Victoria in Kenya, covering vast swathes of its surface. The plant blocks out light, dramatically reducing the amount of oxygen in the lake and killing off fish. It also makes access to the open lake increasingly difficult for fishermen. But locals are looking at new ways to use the plant and make a profit from it. Our France 2 colleagues Marc de Chalvron and Baptiste Rimbert report, with FRANCE 24's Wassim Cornet.