Nakuru is a small, shallow, alkaline-saline lake located in a closed basin without outlets in the Eastern Rift Valley of equatorial East Africa. B eing in the Rift Valley where tectonic and volcanic activities as well as climatic changes have been very remarkable, the lake underwent drastic changes during the recent geological ages.
Main ions are sodium and bicarbonate-carbonate.
The biota in the lake is very simple as in other saline lakes, consisting of phytoplankters dominated by blue-green algae and very poor planktonic and benthic fauna originally lacking fish. However, the lake is highly eutrophic owing to the vigorous growth of a planktonic blue-green alga, Spirulina platensis, which supports an immense number of alga.grazing lesser flamingo and an increasing population of the introduced fish, Sarotherodon alcalicum grahami, though, in the last several years since 1974, the planktonic productivity and the flamingo population decreased abruptly. The city of Nakuru on the northernmost shore of the lake is a rapidly growing local centre of industry and agriculture. Effluents from the city's two sewage treatment plants are discharged into the lake. With little seasonal variation.