COUNTRY FILES (Contd.)

UGANDA (Contd.)

LAKE VICTORIA
(International water)

Total annual catch:

Potential annual yield: in Uganda: 45 000 t (14.5 kg/ha; TDRI, 1983)

Table 5. MAIN FISH CATCHES IN UGANDA, 1975, 1979
(after Reynolds & Greboval, 1988)

Sources: CIFA, 1981; DFK Statistical Bulletins; Bwathondi, 1988.
Note: No figures are available for Uganda for 1985.

Table 6. LAKE VICTORIA - TOTAL FISH PRODUCTION (t), 1975, 1979, 1985
(after Reynolds & Greboval, 1988)

Sources: CIFA, 1981; DFK Statistical Bulletins; Bwathondi, 1988.
* Figures for 1985 combine Kenya and Tanzania only.
** Tanzania combines Rastrineobola with “Other small mixed”.

Fig. 9. LAKE VICTORIA
(Welcomme, 1972)

LAKE WAMALA

VOLCANIC CRATER LAKES OF WESTERN UGANDA

In the Rift Valley and on the neighboring uplands in western Uganda there are four clusters of volcanic craters containing a total of 89 lakes.

Melack (1978) reported the results of a limnological survey of 16 of these volcanic crater lakes. The following data are taken from Melack, 1978.

"The lakes range in latitude from 0° 42'N to 0° 19'S and vary in altitude from 1 520 to 895 m above sea level.

"Based on the concentration of dissolved salts in the surface waters the lakes can be divided into a concentrated saline group (electrical conductivity >15 000 μ S/cm at 20° C) and a dilute group (electrical conductivity <1 000 μ S/cm at 20° C). All the lakes were alkaline, and the pH of their surface waters ranged from about 7.5 to about 10.2.

Table 7. MAIN FEATURES OF SOME CRATER LAKES, UGANDA
(after Melack, 1978)

¹ Bundibugyo, Uganda, 1:50 000. (Series Y732, sheet 56/3. Uganda Government 1964)
² Kahunge, Uganda. 1:50 000. (Series Y732, sheet 66/2, edition 3-U.S.D. Uganda Government 1969)
³ Katanguru, Uganda. 1:50 000 (Series Y732, sheet 76/1, edition 4-U.S.D. Uganda Government 1965)
⁴ Katwe, Uganda. 1:50 000. (Series Y732, sheet 75/2, edition 3-U.S.D. Uganda Government 1965)
⁵ Rubirizi, Uganda. 1:50 000. (Series Y732, sheet 76/3, edition 3-U.S.D. Uganda Government 1965)

The midday temperatures of the surface waters ranged from 22.5 to 26.65° C in the dilute lakes and from 26 to 33° C in the saline lakes. In the lakes with persistent thermoclines the temperatures of the water near the bottom varied from 20.9° C (Lake Kanyangeye) to 24.75° C (Lake Chibwera) and tended to be higher in lakes at lower altitudes. In the lakes over 5 m deep both transient, superficial and persistent, deep-seated thermoclines existed.

“The hypolimnia were anoxic in all the lakes over 5 m deep, and the depth at which the deoxygenated water began coincided with the persistent thermoclines but varied more than was expected.”

Table 7 summarizes the main features of the 16 lakes. Fisheries data are not available.

See Lakes Nyamusingire, Saka and Katwe for more details on their characteristics.

KAGERA RIVER
(International Water)

KAZINGA CHANNEL (RIVER)

Fisheries data
Total annual catch:

* includes Lakes George and Edward

SEMLIKI RIVER
(International water)

TURKWEL RIVER
(International water)

WHITE NILE RIVER
(International water)

Physical and chemical data (after Talling, 1957)

Total annual catch: Albert Nile in Uganda

Potential annual yield: 6 000 t - Albert Nile (TDRI, 1983)

KANYANYA RESERVOIR

KIGABAGABA RESERVOIR

KIZIRAMERE RESERVOIR

RUGONGI RESERVOIR

RUSHOZI RESERVOIR

7. BIBLIOGRAPHY

Balarin, 1985c
Beadle, 1932; 1981
Beauchamp, 1956
Burgis, 1987
Burgis, Mavuti, Moreau & Moreau, 1987
Bwathondi, 1988
CIFA, 1981
Dunn, 1989
Dunn, et al., 1969
EAFRO, 1952a, b; 1954
FAO, 1973; 1982b
Giudicelli et al., 1987
Graham, 1929
Greenwood, 1964; 1965
Hurst, 1925
HYDROMET, 1974
Jensen et al., 1983
Kerr, 1966
Kiss, 1977a
Marriott, et al., 1988
Melack, 1978
Okaronen, 1975a,b
Proude, 1984
Reynolds & Greboval, 1988
Statistisches Bundesamt, 1988
Talling, 1957
Talling & Talling, 1965
TDRI, 1983
Vakily, 1989
Van Der Ben, 1959
Viner, 1969
Visser, 1962
Welcomme, 1972; 1979a
Worthington, 1929; 1932

ZAIRE

1. GEOGRAPHY AND CLIMATE (Welcomme, 1979a)

Zaire (surface area of 2 364 200 km² consists mainly of a low-lying central basin covered by tropical rain forest. The basin is surrounded by mountainous terraces in the west, elevated plateaus covered with savanna in the south and southeast, and dense grasslands in the north. The eastern region is crossed by high mountains.

Zaire lies astride the Equator, about one-third to the north and two-thirds to the south. The climate, therefore, is equatorial and especially hot and humid in the forested central areas. North of the Equator there is a single rainy season from April to November; south of it a rainy season lasts from October to May. In the central region rainfall is distributed evenly throughout the year.

Zaire is densely forested, and much of the central basin is occupied by tribes using primitive ‘slash and burn’ agriculture. In the western highlands cash crops such as coffee and cotton are common; in the south, in Shaba province, the considerable mineral resources have given rise to intensive mining development.

2. HYDROGRAPHY (adapted from Welcomme, 1979a) (See Fig. 1)

2.1 Lakes

The major lakes within Zaire are those of the Rift Valley and are found in the extreme east of the country (Tanganyika, Mweru, Kivu, Edward and Albert). In addition to these lakes, there are two major water bodies attached to the lower reaches of the river system: Lake Tumba and Lake Maji Ndombe (2 300 km²). The Kamulondo Depression (Lualaba floodplain) contains some 50 lakes, of which Lake Upemba is by far the largest. Numerous small lakes are scattered throughout the country. The combined lake surface area is circa 28 000 km².

2.2 Rivers, Floodplains and Swamps

With the exception of parts of the Ubangi system and the upper reaches of some of the southern tributaries, almost the whole of the Zaire River basin lies within the country. The main channel of the Zaire is joined by such major tributaries as the Ubangi, Lualaba, Luapula, Lulonga, Tshuapa. There is a total of some 33 000 km of major river channel and their area (circa 34 000 km²) is increased by intensive floodplains, particularly in the Kamulondo Depression and in the Mbandaka region of confluence between the Ubangi and the Zaire streams. In total, the floodplains are thought to cover about 50 000 km² during high water, but such a figure can only be approximate due to the difficulties in measuring such areas.

2.3 Reservoirs

Two major reservoirs have been installed in the southeast of the country: Mwadingusha on the Lufira, and Nzilo on the Lualaba.

2.4 Coastal Lagoons

None of significant size.

3. FISHERY PRODUCTION/POTENTIAL

3.1 Aquaculture

In 1956 there were 94 761 ponds with a combined surface area of 3 863 ha. By 1960 this had increased to 120 000 ponds with an area of 4 200 ha.

In 1987, aquaculture production was estimated at about 700 t/yr (mainly Oreochromis niloticus) with possibilities of further development (Giudicelli et al., 1987).

3.2 Fish production and per caput supply

Table 1. FISH PRODUCTION AND PER CAPUT SUPPLY - Zaire, 1970–1987

¹ Source: FAO
² Source: FAO Fisheries Department FISHDAB
³ included in “Inland capture” if not specified
⁴ - = data not available
⁵ Giudicelli, et al., 1987

Fig. 1. RIVERS AND LAKES OF THE CONGO/ZAIRE SYSTEM
(Welcomme, 1972)

3.3 Inland catch range and potential yield

Table 2. INLAND CATCH RANGE AND POTENTIAL YIELD

¹ rough estimate based on several authors
² Sources: see text.

4. STATE OF THE FISHERY (adapted from Welcomme, 1979a)

4.1 Yield

Up to the early 1960's the catch from the inland waters of Zaire underwent a growth phase. During the early post-independence period many fisheries collapsed, recovered in the late 1960's and early 1970's, declined a second time, and increased again in the 1980's. The potential catch from all water bodies is between 380 000 and 510 000 t/yr.

4.2 Factors influencing yield

A considerable demand for fish in Zaire shows that the present low level exploitation is due to constraints on the marketing and distribution of fish. Many of the water bodies are isolated or inaccessible, and adequate fisheries will only be developed as infrastructures are built up.

4.3 Future development possibilities

It seems highly probable that the total catch of inland fish in Zaire will rise steadily over the next decade and that establishment of two specialized fisheries, in particular, will eventually exceed these levels. The two fisheries are those of Lake Tanganyika, where there is a considerable unexploited stock of Stolothrissa and Limnothrissa, and Lake Kivu, where a new resource has been established following the introduction of Limnothrissa into that lake. One further area remains unexploited: that of Mbandaka Floodplains which, by reason of their inaccessibility and extremely low population density, will probably not be exploited for several decades.

5. KEY BIBLIOGRAPHY

General fisheries in Zaire: Aubray, 1976
Zaire Basin: Compere & Symoens, 1987

6. WATER BODIES DIRECTORY

LAKE ALBERT (= MOBUTU)
(International water)

Fisheries data
No. of fish species: 46 (Greenwood, 1964)
Main catches: 75–85% of catches are:
              Characidae: Alestes baremose; Hydrocynus forskahli;
              Centropomidae: Lates niloticus albertianus (Proude, 1984)
Annual production, entire lake: 15 000 t in 1982 (Giudicelli et al., 1987)
Total annual catch and effort: in Zaire

* industrial catches only
** Total catch: industrial + small scale (cited by Proude, 1984)
Note: Due to the variety of sources and methods used, these estimates do not necessarily reflect the actual catches.

Fig. 2. LAKE ALBERT (MOBUTU)
(after Welcomme, 1972)

Fig. 3. LAKE EDWARD/IDI AMIN
(after Welcomme, 1972)

LAKE BOYA

LAKE EDWARD (= IDI AMIN)
(International water)

Note: Due to the variety of sources and methods used, these estimates do not necessarily reflect the actual catches.

LAKE KAFAKUMBA

LAKE KASUKU

LAKE KATANIA

LAKE KIVU
(International water)

^a Fish: tilapia + Haplochromis
^b Fish: Limnothrissa miodon
Sources :
* (Aubray, 1976)
** (cited by Hanek et al., 1988)
*** (Hanek et al., 1988)

in Rwanda
Catches obtained by Project “Dèvelop. de la pêche au Lac Kivu” (RWA/87/012):

In addition, 55 private fishing units are estimated to produce two times more Limnothrissa miodon than the Project (Hanek et al., 1988).

Estimated total annual catch in Rwanda (1987): 1 900 t; (1 575 t Limnothrissa + 325 t tilapia/Haplochromis)

LIMNOTHRISSA MIODON FISHERIES SITUATION
in 1987 (Reusens, 1987) and in 1989 (Johannesson & Lamboeuf, 1989)

Potential annual yield:

Key reference for Lake Kivu: Hanek et al., 1988

Fig. 4. LAKE KIVU

LAKE LIBANDA

Fig. 5. LAKES OF THE KAMOLONDO DEPRESSION
(Welcomme, 1972)