Lakes of the Great Rift Valley in Africa

Along the eastern part of the Great Rift Valley in Africa is a series of lakes that are tainted with sodium carbonates. These chemicals have leached down from volcanic catchment areas or have entered the lakes through subterranean volcanic activity. Some lakes, such as Lake Turkana in northern Kenya, have a slight alkalinity. Surrounded by thousands of square miles of lonely desert bush, Lake Turkana sometimes takes on a beautiful jade-green color and is home to the largest crocodile population in the world. Lakes such as Lake Magadi of Kenya and Lake Natron in Tanzania are so saturated with salts that they form almost solid deposits of encrusted white soda. The cause? The absence of an outlet that would otherwise carry away the salts. Most of the water escapes through evaporation, leaving behind a high concentration of minerals. Few animals are able to survive in and around the bitter waters of the Rift Valley soda lakes. Notable exceptions, however, are the delicate pink flamingos that move from one soda lake to another, feeding on the microscopic algae that thrive in the caustic waters. Here flamingos congregate by the millions, forming a living sea of pink.

Another inhabitant that thrives in these otherwise deadly waters is a tiny fish called tilapia grahami. This alkaline-resistant fish is often found near underwater steam vents, where the water is so hot that it is uncomfortable to touch with the hand. Yet, there this tiny fish survives, feeding on the lake’s algae.

Only a few of the eastern rift lakes have fresh water. Lake Naivasha, in Kenya, is one. It sits 6,135 feet [1,870 m] above sea level, and its crystal waters provide shelter for varieties of fish as well as basking herds of hippos. All along the shores are lush green beds of papyrus and aquatic plant life, which accommodate over 400 different species of colorful birds. Set against the backdrop of yellow acacia trees and the surrounding mountain ranges, Lake Naivasha is most beautiful to behold.

Amid the rift-valley system lies the second-largest body of fresh water in the world, Lake Victoria. Its waters lap the shores of Kenya, Uganda, and Tanzania, and it is one of the sources of the Nile River. Farther south, the waters of Lake Tanganyika plunge to a depth of 4,710 feet [1,440 m]. This is the second-deepest lake in the world.