LAKE TANGANYIKA , scientifical description

From the beach of a fishing village near Uvira, Zaire

Photo: S.Yamagishi

A. LOCATION

• Kigoma and Rukwa, Tanzania; Shaba and Kivu, Zaire; Northern, Zambia; and Burundi.
• 3:25-8:45S, 29:10-31:10E; 773 m above sea level.

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B. DESCRIPTION

Among the chain of lakes on the bottom of the Western Great Rift
Valley, Lake Tanganyika is outstanding for its extraordinary
north-south extension (670 km) and depth (1,470 m). It is the second
largest of African lakes, the second deepest (next to L. Baikal) and
the longest lake of the world. Its very ancient origin, only rivalled
by such old lakes as Baikal, and a long period of isolation resulted in
the evolution of a great number of indigenous organisms, including
brilliantly colored cichlid fishes, well-known gastropods with the
appearance of marine snails, and so on. Of the 214 species of native
fishes in the lake, 176 are endemic; the number of endemic genera
amounts to 30 in cichlids and 8 in non- cichlid fishes.

The surrounding areas are mostly mountainous with poorly developed
coastal plains except on part of the east side. Especially on the
western coast, steep side-walls of the Great Rift Valley reaching 2,000
m in relative height form the shoreline. The sole effluent river, the
Lukuga, starts from the middle part of western coast and flows westward
to join the Zaire River draining into the Atlantic.

Agriculture, livestock raising and the processing of these products
as well as the mining (tin, copper, coal, etc.) are the main industries
in the drainage basin of L. Tanganyika. Fishery products, the
"Tanganyika sardine" (Stolothrissa tanganikae, Herring Family) in
particular, are also important for local economy. Well-developed
regular ship lines connect Kigoma (Tanzania), Kalemie (Zaire) and other
coastal towns as essential part of the inland traffic system of east
Africa.

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C. PHYSICAL DIMENSIONS (7)

Surface area [km2]	32,000
Volume [km3]	17,800
Maximum depth [m]	1,471
Mean depth [m]	572
Water level	Unregulated
Length of shoreline [km]	1,900
Catchment area [km2]	263,000

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D. PHYSIOGRAPHIC FEATURES (1)

D1 GEOGRAPHICAL

• Bathymetric map: Fig. AFR-06-01.
• Number of outflowing rivers and channels (name): 1 (Lukuga R.).

Fig. AFR-06-01

Bathymetric map (1).

D2 CLIMATIC

• Climatic Data at Bujumbura (3)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Ann.
Mean temp. [deg C]*1	23.4	23.1	23.3	23.4	23.3	23.0	22.9	23.9	24.8	24.7	23.3	23.0	23.5
Precipitation [mm]*2	94	109	121	125	57	11	5	11	37	64	100	114	848

*1 10-year mean. *2 1931-1960.

• Number of hours of bright sunshine: 2,242 hr yr^-1*.
  * 9-year mean.
• Solar radiation: 18.31 MJ m^-2 day^-1*.
  * 2-year mean.
• Water temperature: Fig. AFR-06-02.

Fig. AFR-06-02

Vertical distribution of water temperature [deg C] at 7 stations around
the lake, October-November 1975 (place names refer to the nearest
port)(4).

• Notes on water mixing and thermocline formation

  A
  more or less stable thermocline is formed at about 50 m depth. Seasonal
  variation of water temperature is limited to the surface 80 m layer,
  while the temperature remains stable in the underlying hypolimnion at
  23.3-23.5deg C (1).

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E. LAKE WATER QUALITY

E1 TRANSPARENCY [m](4)

39 stations, April-May 1975: 14.5 (4.8-19.0).

44 stations, September-November 1975: 12.2 (5.5-16.0).

E2 pH

8.6-9.2

E5 COD (4)

• DOC [moles l^-1], October-November 1975

South Lake (10 stations)	323
Central Lake (12 stations)	245
North Lake (4 stations)	189

E6 CHLOROPHYLL CONCENTRATION (4)

• Chlorophyll a [micro g l^-1], October-November 1975

South Lake	0.7
Central Lake	4.6
North Lake	1.5

E7 NITROGEN CONCENTRATION [micro g l^-1](4)

• TDN

October-November 1975
South Lake	85
Central Lake	72
North Lake	50

E8 PHOSPHORUS CONCENTRATION [micro g l^-1](4)

• TDP

October-November 1975
South Lake	10
Central Lake	4
North Lake	7

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F. BIOLOGICAL FEATURES

F1 FLORA

• Emerged macrophytes:

  Cyperus papyrus, Thpha, Carex (5).

• Floating macrophytes:

  Nymphaea, Trapa, Azolla, Pistia (5).

• Submerged macrophytes:

  Potamogeton, Ceratophyllum, Utricularia (5).

• Phytoplankton (1)

  Kirchneriella, Treubaria, Chroococcus limneticus, Chrysochromulina parva, Chromulina sp., Nitzschia, Anabaena, Stephanodiscus sp., Strombidium.

F2 FAUNA

• Zooplankton:

  Cyclops, Diaptomus simplex, Limnochida tanganika (1).

• Benthos (5)

  Mollusca (Grandideria burtoni, Brazzaea anceyi, Tiphobia horei, Bythoceras iridescens, Paramelania domoni), Crustacea (Platytelphusa armata).

• Fish (5)

  Stolothrissa tanganikae, Limnothrissa miodon, Lamprichthys tanganicus,
  Engraulicypris minutus, Bathybates minor, Bolengorochromis microlepis, Lates mariae, L. angustifrons, L. stappersi.

F3 PRIMARY PRODUCTION RATE [mg C m^-2 day^-1](l, 4)

April-May	600
October-November	1,400
Annual	1,000

F4 BIOMASS

• Phytoplankton and protozoan (1, 4)

1975
Station		Biomass [mg m-3]	Percent composition of phytoplankton biomass*
	Ph**	Pr***	Cy	Chl	Chr	Bac	Cry	Pyr
Kipanga (south station)	Apr-May	169	89	37	27	18	6	10	3
Kilipi (SE shore)	Apr-May	138	144	35	16	25	15	6	2
Oct-Nov	105	24	8	66	15	–	10	–
Malagarasi (NE river)	Apr-May	362	143	9	15	32	3	5	36
Oct-Nov	105	38	53	30	1	10	5	0
Rumonge (north station)	Apr-May	108	72	22	38	25	–	13	2
Oct-Nov	110	27	18	34	11	28	1	–

*Cy = Cyanophyta, Chl = Chlorophyta, Chr = Chrysophyta, Bac = Bacillariophyta, Cry = Cryptophyta, Pyr = Pyrrophyta.
**Ph = Phytoplankton: ***Pr = Protozoa

• Fish [kg (fresh wt.) ha^-1](6)

  Pelagic zone: 162 (40-875).

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G. SOCIO-ECONOMIC CONDITIONS

G1 LAND USE IN THE CATCHMENT AREA

• Levels of fertilizer application on crop fields: Light.

G2 INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE

• Main products or major industries.

  Agriculture: Maize, cotton, tobacco, rice, sugar-cane, sisal, coffee, beans, groundnut, cassava, cattle and goat.

  Manufacturing: Textile, leather, brewing, food and cement industry.

  Mining: Tin, copper and coal.

G3 POPULATION IN THE CATCHMENT AREA

• Total population: N.A.
• Major cities (population)

  Bujumbura (157,000), Kalemie, Kigoma (20,000), Mbala.

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H. LAKE UTILIZATION

H1 LAKE UTILIZATION

Fisheries and navigation.

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I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS

I1 ENHANCED SILTATION

• Extent of damage: No information.

I2 TOXIC CONTAMINATION: No information.

I4 ACIDIFICATION: No information.

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J. WASTEWATER TREATMENTS

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA

(b) No sources of significant pollution.

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M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS

M3 RESEARCH INSTITUTES ENGAGED IN THE LAKE ENVIRONMENT STUDIES

1. Tanzania Fisheries Research Institute, Kigoma Centre, Tanzania
2. Centre of Uvira, S. R. I. (Scientific Research Institute), Uvira, Zaire

N. SOURCES OF DATA

1. Serruya, C. & Pollinger, U. (1983) Lakes of the Warm Belt. 569 pp. Cambridge University Press, Cambridge.
2. Hutchinson,
   G. E. (1975) A Treatise on Limnology, Vol.1. Part 1, Geography and
   Physics of Lakes. 540 PP, Wiley-Interscience. New York.
3. Muller
   M. J. (1982) Selected Climatic Data for a Global Set of Standard
   Stations for Vegetation Science. 306 pp. Dr. W. Junk Publishers, The
   Hague.
4. Hecky, R. E., Fee, E. J., Kling. H. & Rudd J. W.
   M. (1978) Studies on the Planktonic Ecology of Lake Tanganyika. 51 pp.
   Western Region Fisheries and Marine Service, Department of Fisheries
   and the Environment, Winnipeg.
5. Readle, L. C. (1981) The Inland Waters of Tropical Africa (2nd ed.). 468 pp. Longman Inc., New York.
6. Ssentongo.
   G. W., Durand, J. R. & Harbott, B. (1981) The rational exploitation
   of African aquatic ecosystems. The Ecology and Utilization of African
   Inland Waters (ed. Symoens, J. J., Burgis, M. & Gaudet, J. J.), pp.
   167-175. United Nations Environment Programme, Nairobi.
7. Herdendorf, C. E. (1982) Large lakes of the world. J. Great Lakes Res., 8(3): 379-412.