'Lake Bogoria' is a
saline,
alkaline lake that lies in a
volcanic region in a half-graben basin south of
Lake Baringo,
Kenya, a little north of the
equator. Lake Bogoria, like
Lake Nakuru,
Lake Elmenteita, and
Lake Magadi further south in the
Rift Valley, and
Lake Logipi to the north, is home at times to one of the world's largest populations of
lesser flamingoes. The lake is a
Ramsar site and has been a protected National Reserve since
November 29,
1973. Lake Bogoria is shallow (about 10 m depth), and is about 34 km long by 3.5 km wide, with a drainage basin of
700 km².
Local features include the Kesubo Swamp to the north and the Siracho Escarpment to the east, both within the National Reserve. The reserve is also famous for its
geysers and
hot springs.
The lake waters are of Na-HCO
3-CO
3 composition. They originate from inflow from the Sandai and Emsos rivers, and from about 200 alkaline hot springs that are present at three onshore sites: Loburu, Chemurkeu, and a southern group (Ng'wasis, Koibobei, Losaramat). Other springs discharge directly from the lake floor. Lake Bogoria also contains the highest concentration of true
geysers in Africa (at least 18 are known). The lake waters are alkaline (
pH:10.5) and saline (up to 100 g/L Total Dissolved Salts). The lake has no surface outlet so the water becomes saline mainly through evaporation, which is high in this semi-arid region. The lake itself is
meromictic (stratified) with less dense surface waters lying on a denser more saline bottom waters. Although hypersaline, the lake is highly productive with abundant
cyanobacteria (
Arthrospira fusiformis) that feed the flamingoes, but few other organisms inhabit the lake.
The lake has not always been saline. Sediment cores from the lake floor have shown that freshwater conditions existed for several periods during the past 10,000 years, and that lake level was up to about 9 m higher than its present level of about 990 m above sea-level. At times it might have overflowed northward towards
Lake Baringo. At times, during the late
Pleistocene it might have been united with a larger precursor of modern Lake Baringo, but this is still uncertain.
The lake area was the traditional home of the
Endorois people, who were forced to leave the area in the 1970s and are now challenging their removal at the
African Commission on Human and Peoples' Rights.
References
Tiercelin, J.J. and Vincens, A. (Eds) 1987. Le demi–graben de Baringo–Bogoria, Rift Gregory, Kenya: 30,000 ans d’histoire hydrologique et sédimentaire. ''Bulletin des Centres de Recherches Exploration-Production Elf-Aquitaine'', v. 11, p. 249–540.
Renaut, R.W. and Tiercelin, J.-J. 1993. Lake Bogoria, Kenya: soda, hot springs and about a million flamingoes. ''Geology Today'', v. 9, p. 56-61.
Renaut, R.W. and Tiercelin, J.-J. 1994. Lake Bogoria, Kenya Rift Valley: a sedimentological overview. In: Sedimentology and Geochemistry of Modern and Ancient Saline Lakes. (Eds R.W. Renaut and W.M. Last), ''SEPM Special Publication'', v. 50, p. 101–123.
North Lewis, M. 1998. ''A Guide to Lake Baringo and Lake Bogoria''. Horizon Books. (ISBN 9966-868-17-8)
Harper, D.M., Childress, R.B.. Harper, M.M., Boar, R.R., Hickley, P., Mills, S.C., Otieno, N., Drane, T., Vareschi, E., Nasirwa, O.1, Mwatha, W.E., Darlington, J.P.E.C., and Escuté-Gasulla, X. 2003. Aquatic biodiversity and saline lakes: Lake Bogoria National Reserve, Kenya. ''Hydrobiologia'', v. 500, p. 259-276.
Renaut, R.W. and Owen, R.B. 2005. The geysers of Lake Bogoria, Kenya Rift Valley, Africa. ''GOSA Transactions'', v. 9, 4–18.
See also
★
Lake Naivasha
★
Lake Nakuru
★
Lake Baringo
★
Lake Turkana
★
Rift Valley Lakes
★
Great Rift Valley
External links
★
Minority Rights Group on the Endorois and Lake Bogoria