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Malagarasi River

Malagarasi River
Location
CountryBurundi
CountryTanzania
Physical characteristics
Mouth 
 • coordinates
5°15′23″S 29°48′6″E / 5.25639°S 29.80167°E / -5.25639; 29.80167
Length475 km (295 mi)
Basin size130,000 km2 (50,000 sq mi)
Basin features
River systemCongo River

The Malagarasi River is a river in western Tanzania, flowing through Kigoma Region, although one of its tributaries comes from southeastern Burundi. The river also forms the western border of Tabora Region, the southern border of Kagera Region and the southwestern border of Geita Region. It is the second-longest river in Tanzania behind the Rufiji—Great Ruaha, and has the largest watershed of any river flowing into Lake Tanganyika.[1] The Malagarasi-Muyovozi Wetlands are a designated a Ramsar site. Local tribes have nicknamed the Malagarasi as "the river of bad spirits".

Geography

The Malagarasi is the second-longest river in Tanzania, at 475 kilometres (295 mi).[2][3]

The source of the river is near the Tanzania-Burundi border.[1] The first 80 kilometres (50 mi) of the river form the international boundary between Tanzania and Burundi. Several tributaries from the Burundi highlands join its right bank. After the confluence with the Lumpungu River, the Malagarasi enters Tanzania, makes a circle and empties into the eastern side of Lake Tanganyika about 25 miles (40 km) south of Kigoma, near Ilagala.[4] It is one of the lake's primary inflows. Moyowosi River is the principal tributary, along with its affluent the Nikongo River;[5] other tributaries include Ugalla River, Gombe River, Ruchugi River, Lumpungu River,[6] and Nguya River. It is characterized as a low stream river,[7] and its drainage includes four biotopes: swampy areas, river channels, a flowing river with a few moderate rapids, and a large double-branched delta.[8]

The flow of the river ranges dramatically between the annual cycle of wet and dry seasons, and at times may be susceptible to flooding or reduced to a small stream; flow is also affected by local agriculture and deforestation which increase the level of sediments within the river.[1] At Mberagule, the flow of the river has been gauged to be 6.9 cubic kilometers per year.[1] About 80 kilometres (50 mi) from the mouth, the river flows through the Moyowosi swamplands, an area of "extensive swamps and floodplains" and a "marshy labyrinth".[9][10] It passes through the Dodoma Belt, a geological area of Archaean and Proterozoic age Precambrian crystalline rocks.[1]

Watershed

With a basin area of 130,000 square kilometres (50,000 sq mi), the Malagarasi has the largest watershed of all of the rivers flowing into Lake Tanganyika.[1] The Malagarasi watershed constitutes 30% of the Lake Tanganyika's total watershed area.[11]

The Malagarasi watershed is bounded on the north by the watershed of Lake Victoria, on the east by the closed basin of the Southern Eastern Rift, to the south by the closed basin of Lake Rukwa, and to the east by Lake Tanganyika.[12]

Most of the basin is miombo woodland, with Brachystegia spiciformis and Julbernardia globiflora as the dominant trees.[13] There are extensive areas of flooded grassland in the central Malagarasi-Moyowosi basin, and along the middle Ugalla River to the southwest.[14]

History

According to ecologist Rosemary Lowe-McConnell, "the Malagarasi and the Rungwa River are assumed to be relict headwaters of the extended pre-rift Zaire system".[15] The Malagarasi pre-dates Lake Tanganyika and was in pre-rift times a tributary of the Congo River to its west. Lake Tanganyika has since said to have "undergone both transgression and regression, depositing new sediments, altering the delta, and changing the course of the river".[1] Over its history, the lake level has altered dramatically between 100 and 200 metres (330 and 660 ft); historical accounts from the late nineteenth century indicate that it was about 10 metres (33 ft) higher than it is today.[1]

Culture

Local tribes have nicknamed the Malagarasi as "the river of bad spirits".[16] In the late 19th century, the Wavinza people, who ran the river's ferry service from the left bank, avoided assimilation with the Wanyamwezi people because of the natural barrier formed by the Malagarasi.[17] Also on the other bank were the Wangoni (Watutu Zulus).[18] Henry Morton Stanley, who considered missionaries important to Africa's "civilizing process", stated that missionaries could follow the Malagarasi and participate in "conversion-tours to Uvinza, Uha, and Ugala".[19]

Flora and fauna

The tree species in the Malagarasi basin include Albizia gummifera, Bridelia micrantha, Cyperus papyrus, Diospyros mespiliformis, Ficus sycomorus, Ficus verruculosa, Isoberlinia spp., Khaya senegalensis, Parkia filicoidea, Phoenix reclinata, Syzygium cordatum, and Syzygium owariense.[5] The prominent grasses in the valley grasslands are species of Hyparrhenia, Themeda, and Echinochloa.[20]

The Malagarasi sardine (Mesobola spinifer) is endemic to the river.[21] The Malagarasi contains several fish species which occur in the Congo River Basin but not in Lake Tanganyika.[5] Giant freshwater Mbu pufferfish, however, occur in both the Central and Upper Zaire Basin and the Malagarasi River.[22]

Malagarasi-Muyovozi Wetlands

The Malagarasi-Muyovozi Wetlands lie in the middle of the basin, at 1200 meters elevation at the confluence of the Malagarasi with the Gombe, Muyovozi, Ugalla, and other tributary rivers. The wetland includes 250,000 hectares (620,000 acres) of dry-season lakes and open water including Sagara and Nyamagoma lakes, and 200,000 hectares (490,000 acres) of permanent papyrus swamp. Seasonally-flooded grasslands on the surrounding floodplain vary seasonally and with annual rainfall, and can cover up to 1.5 million hectares (3.7×10^6 acres).[23]

The papyrus swamps are dominated by the sedge Cyperus papyrus and the grass Oryza barthii. The seasonally-flooded grasslands include Hyparrhenia rufa and Echinochloa pyramidalis, with Hyparrhenia dominant in the least-flooded areas, Echinochloa in more frequently-flooded areas, and Vossia nearest the permanent wetlands.[24]

The middle and upper reaches of the Ugalla River include a seasonally-inundated floodplain 120 kilometres (75 mi) long and up to 50 kilometres (31 mi) wide. The floodplain supports extensive grasslands, dominated by the grasses Echinochloa haploclada, Themeda triandra, Setaria spp., Andropogon spp., Eragrostis spp., Digitaria spp., and Sporobolus spp. The floodplains include scattered trees including Combretum fragrans, C. obovatum and C. purpureiflorum, groves of the palm Borassus aethiopum, and small patches of closed-canopy forest on large termite mounds.[25]

Vulnerable and endangered animals in the wetland include Shoebill (Balaeniceps rex), Wattled crane (Bugeranus carunculatus), African bush elephant (Loxodonta africana), Sitatunga (Tragalephus spekii) and Central African slender-snouted crocodile (Mecistops leptorhynchus). The wetlands are home to 50 species of fish, including the Dark stonebasher (Pollimyrus nigricans) and various endangered, endemic, and food species.[26][27] Waterbuck (Kobus ellipsiprymnus) and hippopotamus (Hippopotamus amphibius) are common in the wetlands.[20] Concerns have been raised over hippo poaching in the river basin by the Wanyahosa people, who prefer the meat over fish.[28]

Protected areas

The Malagarasi-Muyovozi Wetlands became a designated a Ramsar site on April 13, 2000.[29] It is the country's first Ramsar Site. At 35,000 square kilometres (14,000 sq mi) it is the world's third-largest Ramsar Site.[27]

References

  1. ^ a b c d e f g h Shick, Kate; Flaccus, Kathy. "Malagarasi River Delta Sedimentology: Evidence of Lake Level Changes in Lake Tanganyika" (PDF). Geology Department of the University of Arizona. Retrieved 30 May 2012.
  2. ^ Kisangani, Emizet F.; Bobb, F. Scott (2010). Historical Dictionary of the Democratic Republic of the Congo. Scarecrow Press. p. 299. ISBN 978-0-8108-5761-2. Retrieved 30 May 2012.
  3. ^ Elf-Aquitaine (Company) (1992). Bulletin des centres de recherches exploration-production Elf-Aquitaine. Société nationale Elf-Aquitaine (Production). Retrieved 30 May 2012.
  4. ^ Maps (Map). Google Maps.
  5. ^ a b c Hughes, R. H.; Hughes, J. S. (1992). A Directory of African Wetlands. IUCN. pp. 244–. ISBN 978-2-88032-949-5. Retrieved 28 May 2012.
  6. ^ Brownlie, Ian; Burns, Ian R. (1979). African Boundaries: A Legal and Diplomatic Encyclopaedia. C. Hurst. p. 748. ISBN 978-0-903983-87-7. Retrieved 30 May 2012.
  7. ^ Klerkx, J.; Imanackunov, Beishen (1 January 2003). Lake Issyk-Kul: Its Natural Environment. Springer. pp. 231–. ISBN 978-1-4020-0900-6. Retrieved 28 May 2012.
  8. ^ Thieme, Michele L. (5 April 2005). Freshwater Ecoregions of Africa and Madagascar: A Conservation Assessment. Island Press. pp. 197–. ISBN 978-1-55963-365-9. Retrieved 28 May 2012.
  9. ^ Kamukala, G. L.; Crafter, S. A. (1993). Wetlands of Tanzania: Proceedings of a Seminar on the Wetlands of Tanzania, Morogoro, Tanzania, 27-29 November, 1991. IUCN Wetlands Programme. p. 34. ISBN 978-2-8317-0185-1. Retrieved 30 May 2012.
  10. ^ Lambrecht, Frank L. (1991). In the Shade of an Acacia Tree: Memoirs of a Health Officer in Africa, 1945-1959. American Philosophical Society. p. 217. ISBN 978-0-87169-194-1. Retrieved 30 May 2012.
  11. ^ Director of Wildlife, Wildlife Division of the United Republic of Tanzania (1999). "The Malagarasi-Muyovozi Wetlands". Information Sheet on Ramsar Wetlands, 21-08-1999. Accessed 18 September 2019. [1]
  12. ^ "Malagarasi-Moyowosi". Freshwater Ecoregions of the World (FEOW). Accessed 18 September 2019. [2]
  13. ^ "Malagarasi-Moyowosi". Freshwater Ecoregions of the World (FEOW). Accessed 18 September 2019. [3]
  14. ^ "Zambezian Flooded Grasslands". WWF ecoregion profile, accessed 18 September 2019. [4]
  15. ^ Lévêque, C. (13 May 1997). Biodiversity Dynamics and Conservation: The Freshwater Fish of Tropical Africa. Cambridge University Press. pp. 107–. ISBN 978-0-521-57033-6. Retrieved 28 May 2012.
  16. ^ Grant, Richard (25 October 2011). Crazy River: Exploration and Folly in East Africa. Simon and Schuster. pp. 339–. ISBN 978-1-4391-5414-4. Retrieved 4 June 2012.
  17. ^ The Journal of the Anthropological Institute of Great Britain and Ireland (Public domain ed.). Anthropological Institute of Great Britain and Ireland. 1883. pp. 8–. Retrieved 4 June 2012.
  18. ^ Newman, James L. (2010). Paths Without Glory: Richard Francis Burton in Africa. Potomac Books, Inc. pp. 105–. ISBN 978-1-59797-287-1. Retrieved 4 June 2012.
  19. ^ Newman, James L. (1 November 2004). Imperial Footprints: Henry Morton Stanley's African Journeys. Potomac Books, Inc. pp. 81–. ISBN 978-1-57488-597-2. Retrieved 4 June 2012.
  20. ^ a b Tanzania Society (1980). Tanzania notes and records. Tanzania Society. pp. 96–100. Retrieved 30 May 2012.
  21. ^ Seegers, L. (November 15, 2011). "Mesobola spinifer (Bailey & Matthes, 1971) Malagarasi sardine". FishBase. Retrieved 29 May 2012.
  22. ^ Davies, Bryan Robert (31 July 1986). The Ecology of River Systems. Springer. p. 218. ISBN 978-90-6193-540-7. Retrieved 30 May 2012.
  23. ^ Director of Wildlife, Wildlife Division of the United Republic of Tanzania (1999). "The Malagarasi-Muyovozi Wetlands". Information Sheet on Ramsar Wetlands, 21-08-1999. Accessed 18 September 2019. [5]
  24. ^ Director of Wildlife, Wildlife Division of the United Republic of Tanzania (1999). "The Malagarasi-Muyovozi Wetlands". Information Sheet on Ramsar Wetlands, 21-08-1999. Accessed 18 September 2019. [6]
  25. ^ Director of Wildlife, Wildlife Division of the United Republic of Tanzania (1999). "The Malagarasi-Muyovozi Wetlands". Information Sheet on Ramsar Wetlands, 21-08-1999. Accessed 18 September 2019. [7]
  26. ^ Director of Wildlife, Wildlife Division of the United Republic of Tanzania (1999). "The Malagarasi-Muyovozi Wetlands". Information Sheet on Ramsar Wetlands, 21-08-1999. Accessed 18 September 2019. [8]
  27. ^ a b "The Project for Sustainable and Integrated Management of the Malagarasi-Muyovozi Ramsar Site (SIMMORS)". Ramsar. March 2007. Retrieved 2 June 2012.
  28. ^ Tanganyika Society (1963). Tanganyika notes and records. Tanganyika Society. p. 210. Retrieved 30 May 2012.
  29. ^ "TANZANIA, UNITED REPUBLIC OF Ramsar Site 1024;(WI Site 1TZ001)". Wetlands International. Archived from the original on 16 April 2013. Retrieved 2 June 2012.
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