Rift Valley lakes
The Rift Valley lakes are a series of lakes in the East African Rift valley that runs through eastern Africa from Ethiopia in the north to Malawi in the south, and includes the African Great Lakes in the south. These include some of the world's oldest lakes, deepest lakes, largest lakes by area, and largest lakes by volume. 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 are expected to be discovered. The World Wide Fund for Nature has designated these lakes as one of its Global 200 priority ecoregions for conservation. Geology Lake Malawi and Lake Tanganyika have formed in the various valleys of the East African Rift zone. Ecology Lake Kivu's "still waters ... hide another face: dissolved within are billions of cubic meters of flammable methane and more still of carbon dioxide, the result of volcanic gases seeping in." Ethiopian Rift Valley lakes national park The Ethiopian Rift Valley lakes are the northernmost of the African Rift Valley lakes. In central Ethiopia, the Main Ethiopian Rift, also known as 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 (areal extent , elevation , maximum depth ), the largest Ethiopian Rift Valley lake by surface area Lake Chamo (areal extent , elevation , maximum depth ) Lake Zway or Dambal (areal extent , elevation , maximum depth ) Lake Shala (areal extent , elevation , maximum depth ), the deepest Ethiopian Rift Valley lake and the largest by water volume Koka Reservoir (areal extent , elevation , maximum depth not listed) Lake Langano (areal extent , elevation , maximum depth ) Lake Abijatta (areal extent , elevation , maximum depth ) Lake Awasa (areal extent , elevation , maximum depth ) Lake Tana, the source of the Blue Nile, lies in the Ethiopian highlands north of the Rift Valley; however, it is not a Rift Valley lake. Eastern Rift Valley lakes South of the Ethiopian highlands, the rift valley splits into two major troughs. The Eastern Rift is home to the Kenyan Rift Valley lakes, while most of the Central African Rift Valley lakes lie in the Western Rift. This area includes the Gregory Rift in Kenya and Tanzania. Kenya The Kenyan section of the Rift Valley is home to eight lakes, of which three are freshwater and the rest alkaline. Of the latter,