Africa's rift lakes shelter more than 1,500 species of cichlid fish
Strung along the East African Rift, the African Great Lakes include Victoria, the world's second-largest freshwater lake by area, and Tanganyika, second-largest by volume and depth. Ten countries share the region, more than 50 million people lived there by 2020, and the western lakes hold over 1,500 cichlid species.
The lakes belong to the Rift Valley system in and around the East African Rift. Besides Victoria and Tanganyika, the group takes in Malawi, fourth-largest freshwater lake by volume, and Turkana, the world's largest permanent desert lake. Lists differ on exactly which lakes count; smaller rift lakes in the same drainage basins are sometimes added, and Lake Kyoga belongs to the system without being a great lake itself. Kenya, Uganda, Tanzania, Rwanda, Burundi, Ethiopia, Malawi, Mozambique, Zambia and the Democratic Republic of the Congo make up the region, sometimes called interlacustrine, meaning between the lakes.
The basin took its present shape about 12 million years ago. Before that, water from the equatorial plateau ran either west into the Congo or east to the Indian Ocean, until the rift, a weak seam where East Africa is pulling away from the rest of the continent, opened troughs where lakes could pool. Victoria itself sits outside the rift, in a depression between the Eastern and Western branches raised on either side. Turkana, larger and more fertile two to three million years ago, yielded Skull 1470 to Richard Leakey's team in 1972, a two-million-year-old fossil some assign to Homo rudolfensis.
The western rift lakes are freshwater and astonishingly rich in endemic life, with more than 1,500 cichlid species alongside amphibians and plentiful Nile crocodiles; elephants, gorillas and hippos live nearby. Flamingos wade in Turkana's shallows, and the rift acts as a flyway for migrating birds. Invasive water hyacinth has so far choked only Lake Victoria. Catching tilapia and Nile perch is the main livelihood, and Uganda, bordered by four of the lakes, ranks among the world's largest freshwater fish producers.
Dense settlement and farm surpluses once supported kingdoms such as Buganda, Bunyoro, Karagwe, Rwanda and Burundi. Europeans had long hunted here for the Nile's source, and the region is also where the Nile, Congo and Zambezi watersheds meet; missionaries arrived first, then colonisers, and wider contact brought devastating epidemics among people and cattle. Swahili is the most widely spoken language and holds national or official status in five countries. Conflict scarred roughly 1980 to 2020, though in 2022 the UN refugee agency praised Tanzania for sheltering refugees.
Source: African Great Lakes
