The Rift Valley lakes are a group of lakes in the East African Rift which runs through the whole eastern side of the African continent from north to south. These lakes include some of the oldest, largest and deepest lakes in the world, and many are freshwater ecoregions of great biodiversity, while others are alkaline "soda lakes" supporting highly specialised organisms.
The Rift Valley lakes are well known for the evolution of at least 800 cichlid fish species that live in their waters. More species will be discovered.
The World Wildlife Fund has designated the African Rift Valley lakes one of its Global 200 priority ecoregions for conservation.
In this article, the major lakes are listed, generally in order from north to south, and more detailed articles on each lake can be accessed through the linked names.
The East African Rift came into being approximately 40 million years ago as the African tectonic plate began to split. Lakes such as Lake Malawi and Lake Tanganyika have formed in the various valleys of the rift zone, including the huge Lake Victoria.
Although the East African Rift lakes contribute comparatively little greenhouse gas emission, nonetheless there is a need to reduce the deforestation rate of surrounding areas and restore cleared areas. These forests provide carbon sinks for greenhouse gases and therefore mitigate climatic changes.
Ethiopian Rift Valley lakes
The Ethiopian Rift Valley lakes are the northernmost of the African Rift Valley lakes. In central Ethiopia the Great Rift Valley splits the Ethiopian highlands into northern and southern halves, and the Ethiopian Rift Valley lakes occupy the floor of the rift valley between the two highlands. Most of the Ethiopian Rift Valley lakes do not have an outlet, and most are alkaline. Although the Ethiopian Rift Valley lakes are of great importance to Ethiopia's economy, as well as being essential to the survival of the local people, there were no intensive and extensive limnological studies undertaken of these lakes until recently.
The major ones are
Lake Abaya (1162 km2, elevation 1285 m), the largest Ethiopian Rift Valley lake
Lake Chamo (551 km2, elevation 1235 m)
Lake Zway or Dambal (485 km2, elevation 1636 m)
Lake Shala (329 km2, elevation 1558 m), the deepest Ethiopian Rift Valley lake
Lake Koka (250 km2, elevation 1590 m)
Lake Langano (230 km2, elevation 1585 m)
Lake Abijatta (205 km2, elevation 1573 m)
Lake Hawasa (129 km2, elevation 1708 m)
Lake Tana, the source of the Blue Nile, lies in the Ethiopian highlands north of the Rift Valley; it is not a Rift Valley lake.