{{Short description|Crater lake in Tanzania and Kenya}} {{Infobox lake | name = Lake Chala | type = Crater lake | other_name = Lake Challa | location = Straddles the border between Tanzania and Kenya in east Africa | image = Lake Chala.jpg | image_bathymetry = | caption_bathymetry = | coords = {{Coord|3|19|S|37|42|E|type:waterbody_scale:3000000|display=inline,title}} | outflow = Subsurface | inflow = Subsurface | catchment = {{convert|1.38 to 1.43|km2}}<ref name="BIT">{{cite journal | url=https://pure.qub.ac.uk/portal/files/43901012/lake.pdf | title=Interannual and (multi-)decadal variability in the sedimentary BIT index of Lake Challa, East Africa, over the past 2200 years: assessment of the precipitation proxy | author1=L. K. Buckles | author2=D. Verschuren | author3=J. W. H. Weijers | author4=C. Cocquyt | author5=M. Blaauw | author6=J. S. S. Damste | journal=Climate of the Past | year=2016 | volume=12 | issue=5 | page=1244 | accessdate=27 June 2018|doi=10.5194/cp-12-1243-2016| doi-access=free }}</ref> | basin_countries =Rombo, Tanzania<br>Kenya | length = | width = | area = {{convert|4.2|km2}}<ref name="BIT"/><ref name="Seismic"/>{{rp|215}}<br>{{convert|4.5|km2}}<ref name="Seasonality"/> | depth = | max-depth = {{convert|98|m}}<ref name="Seasonality"/> | volume = | shore = | elevation = {{convert|880|m}}<ref name="Seismic"/>{{rp|215}}<ref name="Seasonality"/> | residence_time = | islands = | islands_category = | cities = <!-- Map --> | pushpin_map = Tanzania#Africa | pushpin_label_position = | pushpin_map_alt = Location of Lake Chala in Tanzania. | pushpin_map_caption = <!-- Below --> | website = | reference = }}
'''Lake Chala''', also known as ''' Lake Challa''', is a crater lake<ref>{{cite web | url=http://www.go2africa.com/tanzania/lake-chala | title=Tanzania » Places Of Interest » Lake Chala | website=go2africa.com | accessdate=12 June 2010 | archive-date=22 April 2023 | archive-url=https://web.archive.org/web/20230422024256/https://www.go2africa.com/destinations/tanzania/why-go | url-status=dead }}</ref> that straddles the border between Kenya and Tanzania. The lake formed approximately 250,000 years ago.<ref>{{cite journal | url=http://www.aqua.iee.unibe.ch/unibe/portal/fak_naturwis/d_dbio/b_ioekev/abt_ae/content/e60752/e339757/e376721/files681202/Dieleman_Muschicketal.2018_Hydrobio_LakeChala_eng.pdf | title=Species integrity and origin of ''Oreochromis hunteri'' (Pisces: Cichlidae), endemic to crater Lake Chala (Tanzania-Kenya) | author1=Jorunn Dieleman | author2=Moritz Muschick | author3=Wanja Dorothy Nyingi | author4=Dirk Verschuren | journal=Hydrobiologia | volume=832 | doi=10.1007/s10750-018-3570-7 | series=Advances in Cichlid Research III | date=4 April 2018 | page=12 | s2cid=4591524 | accessdate=27 June 2018 | archive-date=27 June 2018 | archive-url=https://web.archive.org/web/20180627173649/http://www.aqua.iee.unibe.ch/unibe/portal/fak_naturwis/d_dbio/b_ioekev/abt_ae/content/e60752/e339757/e376721/files681202/Dieleman_Muschicketal.2018_Hydrobio_LakeChala_eng.pdf | url-status=dead }}</ref> The lake is east of Mount Kilimanjaro, {{convert|8|km}} north of Taveta, Kenya, and {{convert|55|km}} east of Rombo District. The lake is surrounded by a steep crater rim with a maximum height of {{convert|170|m}}.<ref name="Seasonality">{{cite journal | url= https://epic.awi.de/id/eprint/36193/1/Wolff_LO_2014.pdf| title=Modern seasonality in Lake Challa (Kenya/Tanzania) and its sedimentary documentation in recent lake sediments | author1=Christian Wolff | author2=Iris Kristen-Jenny | author3=Georg Schettler | author4=Birgit Plessen | author5=Hanno Meyer | author6=Peter Dulski | author7=Rudolf Naumann | author8=Achim Brauer | author9=Dirk Verschuren | author10=Gerald H. Haug | journal=Limnology and Oceanography | year=2014 | volume=59 | number=5 | page=1621 |doi=10.4319/lo.2014.59.5.1621 | doi-access=free }}</ref>
Lake Chala's average annual rainfall is about {{convert|565|mm}}.<ref name="Seismic">{{cite journal | url=http://www.vliz.be/imisdocs/publications/ocrd/229981.pdf | title=The seismic-stratigraphic record of lake-level fluctuations in Lake Challa: Hydrological stability and change in equatorial East Africa over the last 140 kyr | author1=J. Moemaut | author2=D. Verschuren | author3=F. Charlet | author4=I. Kristen | author5=M. Fagot | author6=M. De Batist | journal=Earth and Planetary Science Letters | date=13 January 2010 | volume=290 | issue=1–2 | pages=214–223 | accessdate=27 June 2018|doi= 10.1016/j.epsl.2009.12.023}}</ref>{{rp|215}} The lake surface has an average annual evaporation of near {{convert|1735|mm}}.<ref name="Seismic"/> Approximately 80 percent of the lake's inflow comes from groundwater, which is derived mostly from rainfall in the montane forest zone of Mount Kilimanjaro at an elevation of {{convert|1800 to 2800|m}}.<ref name="BIT"/> It takes about three months for groundwater to reach the lake.<ref name="Seismic"/>{{rp|221}} The groundwater flowed into the lake at an estimated annual volume of {{convert|8390000|m3}} from 1964 through 1977.<ref>{{cite journal | url=https://pdfs.semanticscholar.org/0eb4/3f2932b390a81d7a1e15ae178f59dabd2520.pdf | archive-url=https://web.archive.org/web/20180625161058/https://pdfs.semanticscholar.org/0eb4/3f2932b390a81d7a1e15ae178f59dabd2520.pdf | url-status=dead | archive-date=25 June 2018 | title=Radioisotopes for the Estimation of the Water Balance of Lakes and Reservoirs | author=B. R. Payne | journal=Tracer Methods in Isotope Hydrology | publisher=International Atomic Energy Agency | year=1982 | page=161 | accessdate=25 June 2018}}</ref>
==Ecology== thumb|Aerial photo of Lake Chala
The only native fish in this lake is the Lake Chala tilapia (''Oreochromis hunteri''), which is found nowhere else in the world.<ref>{{cite web | url=http://www.fishbase.org/summary/speciessummary.php?id=2032 | title=''Oreochromis hunteri'' | website=fishbase.org | accessdate=25 June 2018}}</ref><ref name=Dieleman2019>{{cite journal| author1=Dieleman, J. | author2=M. Muschick | author3=W.D. Nyingi | author4=D. Verschuren | year=2019 | title=Species integrity and origin of Oreochromis hunteri (Pisces: Cichlidae), endemic to crater Lake Chala (Kenya–Tanzania) | journal=Hydrobiologia | volume=832 | issue=1 | pages=269–282 | doi=10.1007/s10750-018-3570-7 | s2cid=4591524 | url=https://boris.unibe.ch/116496/ }}</ref> It is considered critically endangered by the IUCN,<ref>{{cite web | url=http://www.iucnredlist.org/apps/redlist/details/60634/0 | title=The IUCN Red List of Threatened Species: Oreochromis hunteri | publisher=International Union for Conservation of Nature | year=2006 | accessdate=25 June 2018}}</ref> and now greatly outnumbered by other tilapia species that have been introduced to Lake Chala.<ref name=Moser2019>{{cite journal| author1=Moser, F.N. | author2=J.C. van Rijssel | author3=B. Ngatunga | author4=S. Mwaiko | author5=O. Seehausen | year=2019 | title=The origin and future of an endangered crater lake endemic; phylogeography and ecology of Oreochromis hunteri and its invasive relatives | journal=Hydrobiologia | volume=832 | issue=1 | pages=283–296 | doi=10.1007/s10750-018-3780-z | s2cid=52944759 | url=https://boris.unibe.ch/120465/7/Moser%20et%20al.%202018%20Hydrobiologia%20Lake%20Chala_accepted%20version.pdf }}</ref><ref>{{Citation|last1=Volkman|first1=John K.|title=Lipid Biomarkers as Organic Geochemical Proxies for the Paleoenvironmental Reconstruction of Estuarine Environments|date=2017|work=Applications of Paleoenvironmental Techniques in Estuarine Studies|pages=173–212|publisher=Springer Netherlands|isbn=978-94-024-0988-8|last2=Smittenberg|first2=Rienk H.|doi=10.1007/978-94-024-0990-1_8}}</ref>
An 18-year-old British woman was killed in 2002 by a relatively small Nile crocodile while swimming at night in the lake.<ref>{{cite news | url=https://www.telegraph.co.uk/news/worldnews/africaandindianocean/kenya/1387739/British-girl-killed-by-rare-dwarf-crocodile.html | location=London | newspaper=The Daily Telegraph | author=Adrian Blomfield | title=British girl 'killed by rare dwarf crocodile' | date=14 March 2002 | accessdate=25 June 2018}}</ref><ref>{{cite news | url=https://www.theguardian.com/uk/2002/mar/12/world.education | title=Girl's body found in crocodile lake | author=James Astill | newspaper=The Guardian | location=London | date=12 March 2002 | accessdate=25 June 2018}}</ref> A few days later, the Kenya Police Service said that the lake was "infested" with crocodiles, while the Kenya Wildlife Service said, "Crocodiles are found in Lake Chala and it is not regarded as safe to swim at all."{{cn|date=September 2020}}
==See also== {{Commons category|Lake Chala}} *Chaga people *List of lakes of Kenya *List of lakes of Tanzania *Rombo District
==References== {{reflist}}
{{Lakes of Tanzania}} {{Lakes of Kenya}} {{DEFAULTSORT:Chala}} Category:Geography of Kilimanjaro Region Category:Kenya–Tanzania border Category:Lakes of Kenya Category:Lakes of Tanzania Category:Volcanic crater lakes Category:Volcanoes of Kenya Category:Volcanoes of Tanzania