Lake Tanganyika is one of Africa's Great Lakes. It is an aquatic biodiversity hotspot, containing species that are not found anywhere else in the world. But years of pollution and overfishing have left it degraded, and the lake has been ranked among the most threatened in the world.
This week, Africa Science Focus reveals fears that eating contaminated fish caught in Lake Tanganyika may be damaging people's eyesight. Journalist Njenje Chizu reports from the lakeside district of Mpulungu, in Zambia.