COUNTRY FILES (Contd.)

NAMIBIA

1. GEOGRAPHY AND CLIMATE

Namibia has a surface area of 823 290 km². The country is largely semi-arid plateau and desert.

The climate is hot and dry with highly restricted rainfall. The economy is based on mineral extraction.

2. HYDROGRAPHY (see Fig. 1)

2.1 Lakes

There are no permanent freshwater lakes of any significant size. Non-permanent is Lake Liamberi, associated with Linyanti swamp.

2.2 Rivers, Floodplains and Swamps

Four large rivers flow along Namibia's borders: the Zambezi, Orange, Cunene and Okavango/Cubango.

2.3 Reservoirs

There are several impoundments: Hardop, Avis, Goreangab, Naute, Van Rhyn, Daan Viljoen, Ondangua, Okatana and Oshikango (the latter three are “saucer” dams located on the flat Ovambo tableland).

2.4 Coastal Lagoons

There is only one important lagoon at Sandwich Habour.

3. FISHERY PRODUCTION/POTENTIAL

3.1 Aquaculture

There is no aquaculture in Namibia (Vincke, 1989, pers.comm.)

3.2 Fish Production and per caput supply (see Table 1 on following page)

3.3 Inland catch range and potential yield

Total annual yield: No data available (except Table 1 and Lake Liamberi: 180 t in early 1980's).

Potential annual yield: No data available.

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

¹ Source: FAO
² Source: FAO Fisheries Department FISHDAB
Important note:
Inland capture: excluding export
Marine capture: export statistics not available.
The 1970–87 catch data for Namibia include most of the quantities caught by fishing craft flying the South African flag and landed in Lüderitz and Walvis Bay (Namibia). Most of these landings are utilized for reduction into fish meal, for export abroad and domestic use. No statistics are available to ascertain precisely what part of the marine capture is actually used for domestic consumption.
³ No aquaculture in Namibia
⁴ No data available
⁵ 1974–1987 rough estimates for inland capture

4. STATE OF THE FISHERY

4.1 Yield

No statistical data available except for Lake Liamberi, but it seems likely that catches are only a small fraction of the potential.

4.2 Factors influencing yield

Low rainfall and also, undoubtedly, the unstable security situation.

4.3 Future development possibilities

Development of inland fisheries is likely, once national sovereignty and stable internal security have been achieved.

Fig. 1. RIVERS AND LAKES OF SOUTHERN AFRICA
(Welcomme, 1972)

5. KEY BIBLIOGRAPHY (none)

6. WATER BODIES DIRECTORY

LAKE LIAMBERI/LINYANTI SWAMP
(International water)

CUNENE RIVER
(International water)

OKAVANGO/CUBANGO RIVER
(International water)

ORANGE RIVER
(International water)

ZAMBEZI RIVER
(International water)

Physical and chemical data above Lake Kariba (Coche, 1968)

Fisheries data
No. of fish species: Upper Zambezi: 49; Middle Zambezi: 50 (Jubb, 1961)

OVAMBO FLOODPLAIN
(International water)

HARDAP (= FISH RIVER) RESERVOIR

SANDWICH HARBOUR LAGOON

7. BIBLIOGRAPHY

Coche, 1968
Jubb, 1961
Keulder, 1970
NORAD, 1985
Welcomme, 1972

REUNION

1. GEOGRAPHY AND CLIMATE

Reunion (surface area of 2 500 km²) is a mountainous island of volcanic origin. Coastal areas are forested. There are numerous torrential rivers. Maximum elevation is 3 069 m asl. The climate is tropical, but varies with altitude. Cyclones occur. The economy is based on agriculture, mainly sugar and flower oil.

2. HYDROGRAPHY

2.1 Lakes

There are no natural lakes of significant size.

2.2 Rivers, Floodplains and Swamps

There are numerous short torrential mountainous rivers.

2.3 Reservoirs

There are no large impoundments.

2.4 Coastal Lagoons

There are no lagoons.

3. FISHERY PRODUCTION/POTENTIAL

3.1 Aquaculture

Inland and marine aquaculture are practised. (See Table 1)

Table 1. AQUACULTURE PRODUCTION BY SPECIES (t)

Source: Vincke, 1989 (pers.comm.)
* No data available for earlier years

3.2 Fish production and per caput supply (See Table 2)

Table 2. FISH PRODUCTION AND PER CAPUT SUPPLY - Reunion, 1970–1987

¹ Source: FAO
² Source: FAO Fisheries Department FISHDAB
³ Inland aquaculture only
⁴ - = data not available
⁵ Marine exports were as follows: 1980: 114 t; 1981: 569 t; 1982: 894 t; 1983: 1 308 t.
⁶ Vincke, 1989 (pers.comm.)

3.3 Inland catch range and potential yield

No data available for annual catch or potential yield for the main rivers: Bras de la Plaine, Langevin, Marsouins, Mat and Roches.

Total annual yield: Inland catch: 0 t; Inland aquaculture: 22 t (in 1987) (Vincke, 1989, pers.comm.).

4. STATE OF THE FISHERY

4.1 Yield

Capture fisheries are probably restricted to angling, but no catch data is available. There is some marine turtle and fish farming, as well as rainbow trout and Macrobrachium culturing. Production by species is given in Table 1.

4.2 Factors influencing yield

Generally, a lack of large surface water reserves. The high potential of marine fisheries does not encourage professional inland fisheries.

4.3 Future development possibilities

Undoubtedly some aquaculture development is possible; tilapia, trout and prawns have already been introduced to the island. Tilapia species in particular now occur in all river basins. The prospect for capture fisheries are, however, minimal.

5. KEY BIBLIOGRAPHY (none)

6. WATER BODIES DIRECTORY

BRAS DE LA PLAINE RIVER

LANGEVIN RIVER

MARSOUINS RIVER

MAT RIVER

ROCHES RIVER

RWANDA

1. GEOGRAPHY AND CLIMATE (Welcomme, 1979a)

Rwanda has a surface area of 24 950 km² and consists mainly of grassy uplands which form part of the watershed between the Zaire and Nile River systems. It slopes from a range of high volcanoes in the northwest to savanna plains in the east. To the west the hills descend abruptly into Lake Kivu.

The high elevation makes for a temperate climate and frost may even occur in the high mountains. There is a short dry season in January with the major rainy season occurring from February to May. The main dry season lasts from May to September and the short rains from September to December. The rainfall is far heavier on the mountainous areas to the north and northwest than on the eastern savannas.

The population of Rwanda is entirely rural with small holdings dispersed throughout most of the country. Cattle herding is also very important although limited to the highlands because of heavy Tsetse infestations in the plains. There is one extensive national park along the lower portion of the Kagera River which contains many of the more important lowland lakes.

2. HYDROGRAPHY (see Fig. 1)

2.1 Lakes

Rwandan lakes fall into four main groups and into two main river basins:

1. Lake Kivu, Zaire River Basin - very deep and rich in nutrients;

2. High altitude lakes in the north (i.e. Lakes Luhondo and Bulera, the latter being associated with the Rugezi Swamps), Nile River Basin. These two lakes are cold, deep and rather infertile;

3. Upper Akagera* Lakes Complex (i.e. Lakes Birira, Cyohoha South, Gaharwa, Gashanga, Kidogo, Kirimbi, Mirayi, Mugesera, Muhazi, Murago, Rugwero, Sake), Nile River Basin. Mean altitude: 1 360 m (except Muhazi; 1 450 m). These lakes are warm, shallow and fertile. They are interspaced among the flooded papyrus plain of the Akanyaru and the Nyabarongo Valleys. The combined surface area in Rwanda is 166.5 km²;

4. Lower Akagera Lakes Complex (i.e., Lakes Chuju, Hago, Ihema, Iwapibali (=Rwakibale), Kishanja, Kivumba, Mihindi, Nasho, Ngerenke, Muhari, Rwampanga, Rwanyakizinga, Rwehikama), Nile River Basin. Mean altitude: 1 200 m. These are warm, shallow and fertile. They are spread over the lateral floodplain of the Akagera River below the Rusumo Falls. The combined surface area is 178.4 km².

* Also called “Kagera”

2.2 Rivers, Floodplains and Swamps

The country is dominated by the Akanyaru-Nyabarongo-Akagera River, which drains the majority of the country. The river is encased in narrow valleys for much of its upper course, but forms broad papyrus-filled swamps in its middle reaches. In its lower course, below the Rusumo Falls, it expands over large areas of savanna into a swamp mostly included in the Akagera National Park. The combined surface area of the Akagera swamps is about 1 000 km² in Rwanda. A higher altitude swamp occurs in the north of the country: Rugezi Swamp, 80 km², tributary of Lake Bulera. One other short but important river is the Ruzizi, which flows out of Lake Kivu toward Lake Tanganyika.

2.3 Reservoirs

Two reservoirs have been built, but are not used for fish production: Shyogwe reservoir near Gitarama (8.5 ha), drinking water reserve; and Nyabisundu reservoir near Bukare (7 ha), irrigation water reserve (Reizer, 1975).

2.4 Coastal Lagoons: None; Rwanda is landlocked.

3. FISHERY PRODUCTION/POTENTIAL

3.1 Aquaculture

In the late 1950's total pond area was circa 450 ha. There were 2 662 ponds in 1978 with a combined area of 77.64 ha, an estimated production of 18 891 kg and an average yield of 243 fish/ha/yr. (Source: Ministère de l'Agriculture et de l'Elevage, Annual Report, 1978).

3.2 Fish production and per caput supply

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

¹ Source: FAO
² Source: FAO Fisheries Department FISHDAB; see other sources data (bibliography) item 3.3.
³ included in “Inland capture” if not specified
⁴ - = data not available
⁵ Source: Ministère de l'Agriculture et de l'Elevage, 1978
⁶ Giudicelli et al., 1987: 1 800 t
⁷ Ministère de l'Agriculture et de l'Elevage, 1985: 1 256 t in 1984

Fig. 1. RWANDA, HYDROGRAPHIC NETWORK
(adapted from Mahy, 1977)

3.3 Inland catch range and potential yield

Table 2.

¹ Aubray, 1976
² Reizer, 1975
³ unaccessible; not in total
* Lakes located in Akagera National Park

4. STATE OF THE FISHERY

4.1 Yield

Present yield estimates vary from 1 630 t (Table 1) to 1 800 t (Giudicelli et al., 1987), and 3 000–3 950 t (see table 2). An average current estimate of 2 500 t/yr seems reasonable.

4.2 Factors influencing yield

A variety of factors influence the yield of Rwandan inland waters. Lake Kivu traditionally has been a poor lake for fishing and, as a consequence, only the narrow coastal fringe has been exploited in a desultory manner (about 300 t of cichlids per year) (Welcomme, 1979a).

Now that Limnothrissa miodon has become established in Lake Kivu (yield about 1 900 t in 1987), an average total yield of about 2 000 t can be expected from the Rwandese waters of Lake Kivu.

The high altitude lakes (i.e. Bulera and Luhondo) and Upper Akagera Lakes Complex are fairly intensely exploited, although with proper management they could possibly sustain higher levels of catch. The Lower Akagera Lakes Complex was barely exploited because most of it lies within the game reserve and because of the lack of transport facilities in Rwanda (fish was caught mainly by Tanzanian fishermen in Lake Ihema). More recently, a development project in Lake Ihema allows fish catching and marketing to be effective in Rwanda (186 t in 1983; 400 t in 1986).

4.3 Future development possibilities

The fish catch from Rwanda could be increased, depending mainly on fisheries management. Although some authors estimate that Lake Kivu could yield up to about 5 500 t/yr for the Rwandan waters, a recent study, based on acoustic stock assessment surveys, estimates that the catchable L. miodon stock does not exceed 945 t in Rwanda.

Overfishing and destructive fishing methods have already considerably decreased production in the Upper Akagera Lakes and in those Lower Akagera Lakes not located in the National Park. Proper fisheries management and respect of fisheries regulations would significantly increase production. Dunn (1974) simply proposes a limit of 5 fishermen/km² for each lake and a catch limit of 12.5 t/km²/yr.

The decision to officially open lakes located in the National Park to fishing activities must consider, on one hand, the estimated yield (1 730 t/yr) and, on the other hand, the damages that may arise in the National Park (Dunn, 1974).

No great increases can be anticipated for the high altitude lakes.

5. KEY BIBLIOGRAPHY

General: Aubray, 1976; Dunn, 1974; Mahy, 1977; Reizer, 1975
Lake Kivu: Hanek et al., 1988
Akagera Basin: Burgis, Mavuti, Moreau and Moreau, 1987; Frank et al., 1984; Kiss, 1977a, b

6. WATER BODIES DIRECTORY

* Mistakenly called “Murago” on some official maps (Dunn, 1974)
** Also called “Kagera”

LAKE BILINGA

Fisheries data
Potential annual yield: High altitude, isolated lake. Production, if any, must be very low. No data available.

LAKE BIRIRA

LAKE BULERA

* (for Lake Bulera+Lake Luhondo+Rugezi Swamp)

LAKE CHUJU

LAKE CYOHOHA NORTH

LAKE CYOHOHA SOUTH
(International water)

LAKE GAHARWA

LAKE GASHANGA

LAKE HAGO

LAKE IHEMA

LAKE IWAPIBALI (= RWAPIBALE = RWAKIBALE = RWAKIBARE)

LAKE KARAGO

LAKE KIDOGO
Mistakenly called “MURAGO” on some official maps (Dunn, 1974)

LAKE KIRIMBI

LAKE KISHANJA (= KISANJI)

LAKE KIVU
(International water)

see entry under country “ZAIRE”

LAKE KIVUMBA

LAKE LUHONDO

LAKE MIHINDI

LAKE MIRAYI