1. GEOGRAPHY AND CLIMATE (after Welcomme, 1979a)
The country consists of the main Island of Madagascar and some smaller offshore islands. Total surface area is 581 540 km2. The main island consists of a central high plateau between 1 000 and 2 000 m in altitude which falls away steeply on all sides to a narrow coastal belt.
The central islands have a temperate climate with a single rainy season from November to April. The coastal regions have a tropical climate. On the north and west coast rains are light, whereas on the south and east rains are heavy and continuous throughout the year.
The country is wholly agricultural and bad land-use practices and deforestation have resulted in severe erosion problems which have led to many of the rivers being heavily charged with silt.
2. HYDROGRAPHY (see Fig. 1)
2.1 Lakes
There are hundreds of small and medium-sized lakes. Many are associated with the floodplains of westward flowing rivers. There are also many small mountain and crater lakes. Totalling the lakes, reservoirs and coastal lagoons, there are some 530 lacustrine water bodies with surface areas over 0.20 km2 in Madagascar.
The ten largest lakes are:
(km2) | |
Alaotra | 200 |
Kinkony | 139 |
Ihotry | 94.2 |
Itasy | 35 |
Tsimanampetsotsa (saline) | 29.88 |
Komanaomby | 18.1 |
Bemamba | 15.9 |
Hima | 15.5 |
Mandrozo | 14.4 |
Amparihibe-South | 12.5 |
The total lake area in Madagascar is probably over 600 km2.
2.2 Rivers, Floodplains and Swamps
Many rivers flow from the central highlands of Madagascar. The largest river basins drain to the west and floodplains are developed along the lower courses. Total floodplain area has been estimated at 918 km2 but the actual area may be greater than 2 000 km2. Swamps are associated with some lakes (i.e., Lake Alaotra).
2.3 Reservoirs
Two medium-sized reservoirs (Mantasoa and Tsiazompaniry) with surface areas of 18.0 and 31.0 km2, respectively, are situated near the capital (Tananarivo).
There are also several small reservoirs:
(km2) | |
Ivakoana | 2.88 |
Sahamaloto | 2.80 |
Ambilivily | 2.35 |
Antanifotsy | 1.99 |
Maromandia | 1.99 |
Maroala | 1.44 |
Andekaleka, Ivendrano and Mandraka |
2.4 Coastal Lagoons
Madagascar has significant brackishwater resources. These consist of lagoons on the east coast and mangrove swamps grouped around the mouths of the main rivers on the west coast.
Main Lagoons | (km2) | |
Loza | 156 | |
Pangalanes (East Complex) | 180 | |
Anony | 22.6 | |
Ampahana | 21.8 | |
Masianaha | 13.3 | |
Total | 393.7 | |
Main Mangrove Swamps | ||
Mahavary-Nord | 332 | |
Loza and Marinda | 180 | |
Mahajamba | 394 | |
Betsiboka | 460 | |
Mahavavy-Sud | 340 | |
Besalampy | 457 | |
Maintirano | 255 | |
Tsiribihira | 370 | |
Mangoky | 232 | |
Total | 3 020 |
3. FISHERY PRODUCTION/POTENTIAL
3.1 Aquaculture
The number of ponds in existence in Madagascar since 1938 are shown below:
Year | Ponds |
1938 | 800–1 100 |
1939–45 | - |
1946 | 1 100 |
1947–52 | - |
1953 | 1 500 |
1954 | 2 000 |
1955 | 3 000 |
1956 | 23 300 |
1957 | 42 000 |
1958 | 62 500 |
1959 | 75 000 |
1960 | 72 000 |
1961 | 75 600 |
1962 | 85 000 |
1963 | 82 450 |
1964 | 79 150 |
1965 | 72 820 |
1966 | 65 530 |
1967 | 58 980 |
1968 | 49 332 |
1969 | 50 856 |
1970 | 42 375 |
In 1982 fishponds totalled about 1 000 ha in area. In addition, about 250 km2 of rice fields were used for rice-cum-fish culture.
In 1985, the number of ponds had already decreased to about 6 000, with an estimated production of 284 t, mainly common carp and tilapias. Production of aquaculture by species is shown below:
Species | 1982 | 1983 | 1984 | 1985 | 1986 | 1987 |
Cyprinus carpio | 300 | 180 | 186 | 210 | 145 | 156 |
tilapias (Oreochromis spp.) | - | - | 4 | 74 | 36 | 38 |
Salmo gairdneri | - | - | - | 0.3 | 0.1 | - |
Total | 300 | 180 | 190 | 284 | 181 | 194 |
Source: Vincke, 1989 (pers.comm.)
3.2 Fish Production and per caput supply
Table 1. FISH PRODUCTION AND PER CAPUT SUPPLY - Madagascar, 1970–1987
Nominal Production (including exports) (t) 2 | Nominal Consumer Supply (including exports) (kg/person) | ||||||||
Year | Population '000 1 | Inland capture | Aquaculture 3 | Marine capture 6 | Total | Inland capture | Aquaculture 3 | Marine capture | Total |
1970 | 6 716 | 35 100 | - 4 | 13 100 | 48 200 | 5.2 | - | 1.9 | 7.1 |
1971 | 6 885 | 36 900 | - | 13 800 | 50 700 | 5.4 | - | 2.0 | 7.4 |
1972 | 7 058 | 37 600 | - | 14 200 | 51 800 | 5.3 | - | 2.0 | 7.3 |
1973 | 7 236 | 39 100 | - | 21 200 | 60 300 | 5.4 | - | 2.9 | 8.3 |
1974 | 7 417 | 40 300 | - | 25 400 | 65 700 | 5.4 | - | 3.4 | 8.8 |
1975 | 7 604 | 41 500 | - | 14 500 | 56 000 | 5.4 | - | 1.9 | 7.3 |
1976 | 7 806 | 41 500 | - | 13 450 | 54 950 | 5.3 | - | 1.7 | 7.0 |
1977 | 8 018 | 41 500 | - | 14 540 | 56 040 | 5.2 | - | 1.8 | 7.0 |
1978 | 8 239 | 41 500 | - | 12 880 | 54 380 | 5.0 | - | 1.6 | 6.6 |
1979 | 8 468 | 41 500 | - | 11 875 | 53 375 | 4.9 | - | 1.4 | 6.3 |
1980 | 8 704 | 37 964 | - | 12 188 | 50 152 | 4.4 | - | 1.4 | 5.8 |
1981 | 8 948 | 38 500 | - | 11 675 | 50 175 | 4.3 | - | 1.3 | 5.6 |
1982 | 9 200 | 38 700 | 300 5 | 10 335 | 49 335 | 4.2 | 0.03 | 1.1 | 5.3 |
1983 | 9 461 | 42 020 | 180 5 | 12 558 | 54 758 | 4.4 | 0.02 | 1.3 | 5.7 |
1984 | 9 731 | 42 310 | 190 5 | 13 463 | 55 963 | 4.3 | 0.02 | 1.4 | 5.7 |
1985 | 10 012 | 45 716 | 284 5 | 17 589 | 63 589 | 4.6 | 0.03 | 1.7 | 6.3 |
1986 | 10 307 | 45 819 | 181 5 | 17 589 | 63 589 | 4.4 | 0.02 | 1.7 | 6.1 |
1987 | 10 610 | 45 806 | 194 5 | 17 589 | 63 589 | 4.3 | 0.02 | 1.7 | 6.0 |
1 Source: FAO
2 Source: FAO Fisheries Department FISHDAB
3 included in “Inland capture” if not specified
4 - = data not available
5 Vincke, 1989 (pers.comm.)
6 From 1980 to 1983, marine exports were as follows: 3 429 t (1980); 3 237 t (1981); 3 989 t (1982); 3 120 t (1983).
3.3 Inland catch range and potential yield
Table 2. INLAND CATCH RANGE AND POTENTIAL YIELD
Water body | Period | Annual catch range (t) | Potential annual yield (t) |
Lakes | |||
Alaotra | 1960–71;1974 | 2 250–4 000 | - |
Itasy | 1960–71;1975 | 273–1 400 | - |
Kinkony | 1960–71;1975 | 620–826 | - |
No information available for | |||
Lakes Anosy, Antsohaly-Fenoarivo, Bemamba, Ihotry, Mahazoarivo, Mandrozo, Namonty | |||
Rivers | |||
Betsiboka/Floodplain | 1960–71 | 1 800–2 600 | - |
No information available for | |||
Rivers Sofia, Tsiribihina | |||
Reservoirs | |||
Mantasoa | 1960;1964–71;1975 | 6–60 | - |
Tsiazompaniry | 1962;1965–71;1975 | 1–60 | - |
No information available for | |||
Reservoirs Ambilivily, Antanifotsy, Ivakoana, Maroala, Maromandia, Sahamaloto | |||
Lagoons | |||
Pangalanes-East Lagoon Complex | 1960–71;1975 | 320–398 | - |
No information available for | |||
Lagoons Ampahana, Anony, Loza, Masianaka |
Total annual yield: 5 300–9 300 t (partial total, Table 2)
40 000–45 000 t (current: 1983–1987) (see Table 1)
Potential annual yield:
77 000 t fresh and brackishwater fish catches
(Rabelahatra, 1988)
4. STATE OF THE FISHERY
4.1 Yield (mainly after Rabelahatra, 1988)
Inland fisheries take place mainly in lakes and lagoons; the rivers are less exploited. Among the most important lakes and lagoons, seven are heavily exploited (22 500 t for 630 km2 in 1984 = 357 kg/ha). Two lakes (Alaotra and Itasy) are already overfished.
In 1984 there were 17 740 fishermen specialized in inland fisheries. About 70% of the catches are thought to be self-consumed by the fishermen's relatives and by the local farmers.
The current production from aquaculture (200–300 t/yr) can be substantially increased through training and better manangement. Production from 1982 to 1987, by species, is given in section 3.1.
4.2 Factors influencing yield
The fishery has been developing at about 2% per year over the last 15 years. In some lakes (i.e., Lake Alaotra), accelerated fishery development occurred when better fishing materials were introduced. Lake Itasy was over-exploited between 1960 and 1965 and the stocks did not reconstitute themselves. Many of the other areas, such as the Pangalanes, are recorded to be unproductive and intensively exploited.
4.3 Future development possibilities
No great increases in natural fish production can be anticipated from the inland and brackish waters of Madagascar. They are at present intensively exploited and need rational management to maintain their present levels of productivity. Further growth of the inland fisheries sector could occur through fish culture and intensive management of inland water bodies by stocking and feeding.
5. KEY BIBLIOGRAPHY
Collart & Rabelahatra, 1977
Kiener, 1963
Rabelahatra, 1988
6. WATER BODIES DIRECTORY
Lakes | ||
Alaotra | Itasy | Montagne d'Ambre Lakes Complex |
Anosy | Kinkony | Namonty |
Antsohaly-Fenoarivo | Mahazoarivo | Noss Be Crater Lakes Complex |
Bemamba | Mandroseza | Tsimanampetsotsa |
Ihotry | Mandrozo | |
Rivers | ||
Betsiboka | Sofia | Tsiribihina |
Reservoirs | ||
Ambilivily | Mantasoa | Sahamaloto |
Antanifotsy | Maroala | Tsiazompaniry |
Ivakoana | Maromandia | |
Lagoons | ||
Ampahana | Loza | |
Anony | Masianaka | |
Fort-Dauphin Lagoon Complex | Pangalanes-East Lagoon Complex |
1 Alaotra | 7 Bemamba | 14 Andranomean N. | 21 Mitsinjo |
2 Kinkony | 8 Hima | 15 Ankitrokaka-Matsadio | 22 Katondra |
3 Ihotry | 9 Mandrozo | 16 Masiadolo | 23 Andranomena S. |
4 Tsimanampetsotsa | 10 Amparihibe S. | 17 Amboromalandy | 24 Bendrony-Matsabe |
5 Itasy | 11 Antsohaly | 18 Tseny | 25 Tsiompaniry |
6 Komanaomby | 12 Ambanja | 19 Namonty | 26 Mantasoa |
13 Amparihibe N. | 20 Antsomangana |
Fig. 1. RIVERS AND LAKES OF MADAGASCAR
(Welcomme, 1972)
LAKE ALAOTRA
Geographical data | |
Location: | Madagascar - 17° 19'–39'S; 48°27'–38'E |
Altitude: | 750 m |
Surface area: | 200 km2 in dry season; the lake extends over |
1 000 km2 of swamp during the wet season | |
Max. length: | 38 km |
Max. width: | 9.5 km |
Inflowing rivers: | Sahamaloto, Sahabe |
Outflowing river: | Maningory |
Physical and chemical data | |
pH: | 6.8–7 |
Fisheries data | |
Fish species: | (Rabelahatra, 1988) Oreochromis macrochir; O. niloticus; O. mossambicus; Tilapia rendalli; Cyprinus carpio; Micropterus salmoides; Carassius auratus; Anguilla sp. |
Total annual catch and effort:
Year | Total catch (t) | No.of fishermen | No.of boats |
1960 | 2 250 | - | - |
1961 | 2 300 | - | - |
1962 | 2 400 | - | 745 |
1963 | 3 000 | - | - |
1964 | 3 120 | - | - |
1965 | 3 200 | 1 500 | - |
1966 | 3 295 | - | - |
1967 | 3 395 | - | - |
1968 | 3 530 | - | - |
1969 | 3 672 | - | - |
1970 | 3 820 | 1 260 | - |
1971 | 3 896 | - | - |
1972–74 | - | - | - |
1975 | 4 000 | - | - |
1980* | 3 700** | 2 872 | 2 478 |
* Rabelahatra, 1988
** = 168 kg/ha
LAKE ANOSY
Geographical data | |
Location: | Madagascar - 18° 55'S; 47° 31'E |
Surface area: | 0.1 km2 |
Max. length: | 0.5 km |
Max. width: | 0.4 km |
LAKE ANTSOHALY-FENOARIVO
Geographical data | |
Location: | Madagascar - 19° 6'S; 44° 36'E |
Altitude: | 15 m asl |
Surface area: | 9.3 km2 |
Max. length: | 6.5 km |
Max. width: | 3.5 km |
LAKE BEMAMBA
Geographical data | |
Location: | Madagascar - 18° 51'S; 44° 21'E |
Altitude: | 2 m asl |
Surface area: | 15.9 km2 |
Max. length: | 10 km |
Max. width: | 4.6 km |
Outflowing river: | lateral spillage from Soahanina River |
LAKE IHOTRY
Geographical data | |||
Location: | Madagascar - 21° 56'S; 43° 41'E | ||
Surface area: | max. 94.2 km2 rainy season, | ||
min. 8.7 km2 dry season | |||
Max. length: | 13 km | ||
Max. width: | 10 km | ||
Inflowing rivers: | Andranakanga, Iambinda | ||
Outflowing river: | none; internal basin | ||
Physical and chemical data | |||
Ionic composition: | |||
mg/l | |||
Na | 3.6 | ||
K | 0.20 | ||
Ca | 0.52 | ||
Mg | 0.38 | ||
Cl | 6.0 | ||
SO4 | 1.73 | ||
HCO3 | 0.18 |
LAKE ITASY
Geographical data | |
Location: | Madagascar - 19° 4'S; 46° 47'E |
Altitude: | 1 225 m |
Surface area: | 35 km2 |
Depth: | 6.5 m (max) |
Max. length: | 10 km |
Inflowing/outflowing river: | Sakay (Tsiribihina drainage basin) |
Annual fluctuation in level: 1.5 km | |
Physical and chemical data | |
Surface temperature: | 15.5–26°C |
pH: | 6.8–7.5 (Moreau, 1970) |
Fisheries data | |
Fish species: | (Rabelahatra, 1988) Oreochromis niloticus; Cyprinus carpio; Micropterus salmoides; Tilapia rendalli; Channa sp.; Paratilapia polleni; Anguilla mossambica; A. nebulosa labiata; A. marmorata; Gambusia holbrooki. |
Total annual catch and effort:
Year | Total catch (t) | No.of fishermen | No.of boats |
1960 | 1 240 | - | - |
1961 | 1 270 | - | - |
1962 | 1 300 | - | - |
1963 | 1 350 | - | - |
1964* | 1 400 | 700 | 200–300 |
1965 | 1 340 | - | - |
1966 | 1 286 | - | - |
1967 | 1 157 | - | - |
1968 | 1 040 | - | - |
1969* | 830 | 700 | 184 |
1970 | 444 | - | - |
1971 | 273 | - | - |
1972–74 | - | - | - |
1975 | 300 | - | - |
1984** | 625*** | 1 000 | - |
* Welcomme, 1972
** Rabelahatra, 1988
*** = 179 kg/ha
LAKE KINKONY
Geographical data | |||
Location: | Madagascar - 6° 9'S; 45° 50'E | ||
Surface area: | 139 km2 | ||
Depth: | 3–4 m | ||
Max. length: | 15 km | ||
Max. width: | 10.5 km | ||
Inflowing river: | lateral spillage from Mahavavy River | ||
Physical and chemical data | |||
Conductivity: | K20 3 379 μ S/cm | ||
pH: | 6.7–8.3 | ||
Ionic composition: | mg/l | ||
Na | 10.7 | ||
Ca | 11.0–30.0 | ||
Mg | 7.2–8.0 | ||
Cl | 17.0–42.0 |
Fisheries data | |
Fish species: | (Rabelahatra, 1988) Megalops cyprinoides; Arius madagascariensis; Oreochromis macrochir; Tilapia rendalli; Chanos chanos; Caranx sp.; Paretroplus petiti; Mugil robustus; Scatophazus tetracanthus; Ambassis sp. |
Total annual catch and effort:
Year | Total catch (t) | No.of fishermen |
1960 | 620 | - |
1961 | 635 | - |
1962 | 650 | - |
1963 | 740 | - |
1964 | 760 | - |
1965 | 780 | - |
1966 | 800 | - |
1967 | 780 | - |
1968 | 764 | - |
1969 | 787 | - |
1970 | 810 | 160 |
1971 | 826 | - |
1972–74 | - | - |
1975 | 800 | - |
LAKE MAHAZOARIVO
Geographical data | |
Location: | Madagascar - 18° 56'S; 47° 32'E |
Surface area: | 0.2 km2 |
Max. length: | 0.8 km |
Max. width: | 0.4 km |
LAKE MANDROSEZA
Geographical data | |
Location: | Madagascar - 18° 56'S; 47° 32'E |
LAKE MANDROZO
Geographical data | |
Location: | Madagascar - 17° 33'S; 44° 6'E |
Altitude: | 6 m asl |
Surface area: | 14.4 km2 |
Max. length: | 6.5 km |
Max. width: | 4.0 km |
MONTAGNE D'AMBRE LAKES COMPLEX
Geographical data | |
Location: | Madagascar - 12° 35'S; 49° 10'E |
Special features: | a group of nine small mountain lakes: |
Mahery (=Sakaramy): 0.35 km2, 350 m asl; | |
Texier, Grand, Petit, Maudi, Amparihy, | |
Tsivahiny, Fantany (=Ampatinambohitra): 0.34 km2, 600 m asl; | |
Tanavo (= Antanavo, Sacre d'Anivorano): 1.49 km2, 380 m asl |
LAKE NAMONTY
Geographical data | |
Location: | Madagascar - 22° 04'S; 43° 25'E |
Surface area: | 5.97 km2 |
Max. length: | 11 km |
Max. width: | 2.5 km |
NOSSI BE CRATER LAKES COMPLEX
Geographical data | |
Location: | Madagascar - 13° 20'S; 48° 13'E |
Special features: | a group of small crater lakes situated on Nossi Be Island: |
Lake Amparihibe: 1.38 km2, 60 m asl; | |
Lake Andjavibe: 0.31 km2, 7 m asl; | |
Lake Antsahamanavaka: 0.39 km2, 180 m asl; | |
Lakes Amparihimirahavavy & Antsidihy: 0.27 km2, 70 m asl; and Lakes Maintimasoa, Bempaza, Djabala and Ampombilova. |
LAKE TSIMANAMPETSOTSA
Geographical data | |
Location: | Madagascar - 24° 05'S; 43° 44'E |
Altitude: | 34 m asl |
Surface area: | 29.88 km2 |
Special features: | highly saline; no fish present |
BETSIBOKA RIVER
Geographical data | ||
Source: | Falaise de l'Angavo | |
Altitude: | 1 755 m | |
Total length: | 525 km | |
Drainage area: | 11 800 km2 | |
Countries traversed: | Madagascar | |
Major tributaries: | Mahajamba, Isandrano, Ikopa | |
Discharges to: | Indian Ocean (Bombetoka Bay) - 15° 55'S; 46° 25'E | |
Volume of discharge at mouth: 74.3–678 m3/sec (monthly mean range) | ||
12 000 m3/sec (max) | ||
Flood regime: | peak flows January to March; minimum in October | |
Special features: | floodplain (circa 805 km2) present in lower course with 150 lakes of varying size. The largest of these lakes are: | |
Amparihibe-South | 12.5 km2 | |
Ambanja | 9.1 km2 | |
Amboromalandy | 6.5 km2 | |
Bondrony and Matsiabe | 5.0 km2 | |
Total lakes area is 80 km2. Two reservoirs (Mantasoa and Tsiazompaniry) are present in the Ikopa tributary basin. |
Physical and chemical data | |||
Temperature: | 30°C | ||
pH: | 6.7 | ||
Ionic composition: | mg/l | ||
Na2O | 3.5 | ||
K2O | 2.2 | ||
CaCO | 1.0 | ||
Mg | 4.7 | ||
Cl | 2.8 | ||
SO4 | 0.1 | ||
SiO2 | 13.0 | ||
Fe2O2 | 3.5 | ||
Al2O3 | 0.2 |
Fisheries data
Total no. of fishermen: 1 250 (in 1970)
Total annual catch: (from floodplain lakes)
Year | Total catch (t) | ||
1960 | 1 800 | ||
1961 | 1 860 | ||
1962 | 1 900 | ||
1963 | 1 950 | ||
1964 | 2 000 | ||
1965 | 2 100 | ||
1966 | 2 142 | ||
1967 | 2 206 | ||
1968 | 2 275 | ||
1969 | 2 400 | ||
1970 | 2 520 | ||
1971 | 2 600 |
SOFIA RIVER
Geographical data | |
Source: | Massif du Tsaratanana |
Altitude: | 1 784 m asl |
Total length: | 350 km |
Countries traversed: | Madagascar |
Major tributaries: | Bemarivo, Anjobony |
Discharges to: | Indian Ocean (Mahajamba Bay) - 15° 26'S; 47° 13'E |
Special features: | floodplain (circa 500 km2) on lower section with over 29 lakes. Largest lakes are Amparihibe-North (8.2 km2); Tserry (6.4 km2); and Marovario (3.2 km2). Total lakes area is 37.0 km2. |
TSIRIBIHINA RIVER
Geographical data | |||
Source: | near Fandriana (Mania tributary) | ||
Altitude: | 1 676 m | ||
Total length: | 465 km | ||
Countries traversed: | Madagascar | ||
Major tributaries: | Mahajilo, Sakay, Kitsamby, Mania, Sakeny | ||
Discharges to: | Indian Ocean - 19° 40'S; 44° 26'E | ||
Special features: | Lake Itasy on Sakay tributary. Large floodplain (circa 700 km2) on lower reach with over 70 lakes. Total lakes area is 116 km2. Largest lakes are: | ||
Komanaomby: | 18.1 km2; | ||
Hima: | 15.5 km2; | ||
Andranomena-South: | 7.7 km2 | ||
Andranomena-North: | 5.4 km2; | ||
Sariaka: | 4.3 km2. |
AMBILIVILY RESERVOIR
Geographical data | |
Location: | Madagascar |
Surface area: | 2.35 km2 |
ANTANIFOTSY RESERVOIR
Geographical data | |
Location: | Madagascar |
Surface area: | 1.99 km2 |
IVAKOANA RESERVOIR
Geographical data | |
Location: | Madagascar |
Surface area: | 2.88 km2 |
MANTASOA RESERVOIR
Geographical data | |
Location: | Madagascar - 19° 1'S; 47° 52'E |
Altitude: | 1 385.50 m USL |
Date closed: | 1935 |
Surface area: | 18 km2 at USL; 11.50 km2 (min); 13.75 km2 (mean) |
Depth: | 17 m (max); 6.7 m (mean) |
Volume: | 0.12 km3 |
Annual fluctuation level: | 7.0 m |
Major inflowing river: | Varahina |
Outflowing river: | Varahina |
Physical and chemical data | |
Surface temperature: | 0–30°C |
pH: | 6.6–6.8 |
Fisheries data | |
Fish species: | (Rabelahatra, 1988) Tilapia rendalli; Cyprinus carpio; Micropterus salmoides; Carassius auratus |
No. of fishermen: | 20 in 1970 |
Total annual catch:
Year | Total catch (t) |
1960 | 6 |
1961–63 | - |
1964 | 8 |
1965 | 6 |
1966 | 11 |
1967 | 12 |
1968 | 14 |
1969 | 35 |
1970 | 55 |
1971 | 57 |
1972–74 | - |
1975 | 60 |
MAROALA RESERVOIR
Geographical data | |
Location: | Madagascar |
Surface area: | 1.44 km2 |
MAROMANDIA RESERVOIR
Geographical data | |
Location: | Madagascar |
Surface area: | 1.99 km2 |
SAHAMALOTO RESERVOIR
Geographical data | |
Location: | Madagascar |
Surface area: | 2.80 km2 |
TSIAZOMPANIRY RESERVOIR
Geographical data | |
Location: | Madagascar - 19° 16'S; 47° 53'E |
Altitude: | 1 490 m asl |
Date closed: | 1956 |
Surface area: | 31 km2 at USL; 18 km2 (min) |
Annual fluctuation level: | 9 m |
Max. length: | 20 km |
Max. width: | 5 km |
Major inflowing river: | Varahina-South |
Outflowing river: | Varahina-South |
Fisheries data | |
Fish species: | (Rabelahatra, 1988) Tilapia rendalli; Cyprinus carpio; Micropterus salmoides; Carassius auratus |
Total annual catch and effort:
Year | Total catch (t) | No.of fishermen | No.of boats |
1962 | 1 | - | - |
1963–64 | - | - | - |
1965 | 2 | - | - |
1966 | 7 | - | - |
1967 | 9 | - | - |
1968 | 10 | - | 15 |
1969 | 45 | - | - |
1970* | 52 | 68 | 42 canoes |
1971 | 54 | - | - |
1972–74 | - | - | - |
1975 | 60 | - | - |
AMPAHANA LAGOON
Geographical data | |
Location: | Madagascar - 14° 46'S; 50° 13'E |
Surface area: | 21.8 km2 |
Max. length: | 5.6 km |
Max. width: | 1 km |
Major inflowing rivers: | Andamasina, Bedinta |
Outflow: | channel to Indian Ocean |
Physical and chemical data | |
pH: | 6.6 |
ANONY LAGOON
Geographical data | |
Location: | Madagascar - 25° 8'S; 46° 29'E |
Surface area: | 22.6 km2 |
Max. length: | 12 km |
Max. width: | 3 km |
FORT DAUPHIN LAGOON COMPLEX
Geographical data | |
Location: | Madagascar - 24° 47'– 25° 9'S; 46° 42' – 47° 11'E A series of 11 lagoons, not all interconnected. The main lagoons are: Mananivo, Ambavarano, Lanirano, Andriambe, Andranany, Andratoloharano and Ranofotsy. |
LOZA LAGOON
Geographical data | ||
Location: | Madagascar - 14° 37'S; 47° 54'E | |
Surface area: | 156 km2 | |
Major inflowing rivers: | Doroa, Maevarano | |
Outflow: | channel to Indian Ocean | |
Physical and chemical data | ||
Ionic composition: | ||
Cl | 0.042–0.181 meq/l | |
SiO4-Si | 0.8–11.2 mg/l | |
PO4-P | 0–172.8 μ g/l | |
NO3-N | 0–252 μ g/l |
MASIANAKA LAGOON
Geographical data | |
Location: | Madagascar - 23° 35'S; 47° 36'E |
Surface area: | 13.3 km2 |
Max. length: | 8 km |
Max. width: | 3.2 |
Major inflowing rivers: | Masianaka, Mahasakoho |
Outflow: | channel to Indian Ocean |
PANGALANES-EAST LAGOON COMPLEX
Geographical data | |
Location: | Madagascar - 18° 10'–22° 49'S; 47° 49'–49° 24'E Consists of a chain of more than 18 lagoons connected by the Pangalanes canal. |
Surface area: | 180 km2 combined. Largest lagoons are Nosive (36 km2), Ampitabe, Rasoamasay, Rasoabe, Ihosy, Alanampolsy, Rangazavaka, Morongary and Tampolo. |
Major inflowing rivers: | Ivondro, Rianila, Sakanila, Mangoro, Masora, Mananjary, Faraony, Matitanana, Manampatrana |
Physical and chemical data | |
Conductivity: | K20 437–1 325 μ S/cm |
pH: | 5.9–7.3 |
Salinity: | 128–1 686 mh/l |
Fisheries data | |
Fish species: | (Rabelahatra, 1988) Caranx melampygus; Ptychochromis oligacanthus; Eleotris fusca; Tilapia rendalli; Mugil robustus; Liza macrolepis; Paretroplus polyactis; Oreochromis mossambicus; Ambassis commersoni; Leognatus equila; Cyprinus carpio. |
Total annual catch and effort:
Year | Total catch (t) | No.of fishermen | No.of boats |
1960 | 320 | - | - |
1961 | 330 | - | - |
1962 | 340 | - | - |
1963 | 350 | - | - |
1964 | 358 | - | - |
1965 | 365 | - | - |
1966 | 381 | - | - |
1967 | 390 | 600 | 350 |
1968 | 398 | - | - |
1969 | 390 | - | - |
1970* | 381 | 600 | 350 canoes |
1971 | 343 | - | - |
1972–74 | - | - | - |
1975 | 320 | - | - |
7. BIBLIOGRAPHY
Collart & Rabelahatra, 1977
Kiener, 1963
Moreau, 1970
Rabelahatra, 1988
Welcomme, 1972; 1979a
1. GEOGRAPHY AND CLIMATE
Malawi has an area of 94 080 km2, about 20% of which is occupied by Lake Malawi, in the Great Rift Valley. The Great Rift continues from the south end of the lake past the southern borders of the country. East and west of the valley the land rises to form high plateaus, generally between 1 000 and 1 300 m, although the Nyika uplands rise as high as 2 800 m.
In the Rift Valley the climate is hot and humid, especially during the November-April wet season. Elsewhere the climate varies with altitude and can be seasonally very cool.
Malawi is a predominantly rural country. The only major modification to the natural conditions is the barrage across the Shire River below Lake Malombe. This has changed the water regime of the river to a certain degree.
2. HYDROGRAPHY (see Fig. 1)
2.1 Lakes (Welcomme, 1979a)
There are four main lakes in Malawi:
Lake Malawi itself covers an area of 30 800 km2, over half of which is effectively controlled by Malawi. Lake Malawi is a deep Rift Valley lake with a maximum depth of 758 m, the richer shallow southern areas of the lake both lie within Malawi;
Lake Malombe is a 390 km2 lake to the south of Lake Malawi. It is a shallow lateral expansion of the Shire River, whose regime has been stabilized by a flood-control dam downstream;
Lake Chilwa is an endorheic lake showing extreme variations in level. It dries out almost completely in some years, but may extend over 2 590 km2 at highest water when it is surrounded by 1 000 km2 of marshland. Its mean area is about 750 km2;
Lake Chiuta is a smaller lake of the same type as Lake Chilwa and covers about 200 km2 when full.
2.2 Rivers, Floodplains and Swamps (Welcomme, 1979a)
The Shire River (520 km) flows from Lake Malawi into the Zambezi. Most of its length is in Malawi, where it floods over large areas to form the Elephant and Ndinde marshes. The total system covers about 1 030 km2 at peak floods, but reduces in area to 480 km2 at low water.
2.3 Reservoirs
No important reservoirs as yet, but several are planned for the Shire River. There is one small reservoir on the Zomba Plateau.
FAO/UNDP (1981b), in an appraisal of irrigation, also described numerous reservoirs in the Central Regions, constructed in the 1960's for irrigation. Their present use is mainly for stock watering but, due to poor maintenance, most are in disrepair. These structures represent valuable assets which could be revived. They include not only scope for irrigation but also for fish farming development. Landell Mills Associates (1983) quote inventory records of the Department of Lands, Valuation and Water, showing 700–800 such reservoirs totalling 420–960 ha of water. The average size is 1–2 ha but only 80% are active and the dry season drawdown represents 50% of the potential capacity (Balarin, 1987).
2.4 Coastal Lagoons
None; Malawi is landlocked.
3. FISHERY PRODUCTION/POTENTIAL
3.1 Aquaculture
The status of aquaculture in Malawi has recently been the subject of an EEC-financed study by Landell Mills Associates (1983). In the past it has also been studied by Pruginin (1971, et seql)* and Vincke (1981), as well as by local experts such as Msiska (1981, et seql)*. Balarin (1987) summarized these studies as follows:
"The most recent statistics reported by SADCC (1984) report 70 t/yr as the total aquaculture production. Landell Mills Associates (1983) however arrived at 93.6 t/yr from 319 rural small-holder ponds and 26 ha of estate ponds. From data presented in the text of this report as well as Vincke (1981) and Msiska (1982), it is possible to arrive at a better composite picture. From 370 to 500 ponds are implicated, an area approaching 72 ha, with production estimates of 96–104 t/yr. In addition, there are about 700–800 reservoirs totàlling nearly 1 000 ha and producing at least 105–192 t/yr. It is possible, therefore, that the total fish farming production may reach 300 t/yr. Landell Mills Associations (1983) recommend a project capable of producing additional 695 t/yr. Meecham (1976) has indicated that over 20 000 ha in the marsh land of the Lower Shire Valley might be suitable for fish farming.
"The main indigenous fish species present in fish ponds are the tilapias (Oreochromis shiranus chilwae, O. mossambicus, Tilapia rendalli) and Clarias gariepinus.
"Malawi has been very cautious about fish species introduction for fear of affecting Lake Malawi fishery.
"The first introductions of exotic fish species were of trout, both Salmo gairdneri and Salmo trutta imported from Wales in 1906. Micropterus salmoides were introduced from Zimbabwe as a sport fish in the 1920's. Apart from reservoir stocking and tilapia control trials, this fish has never been cultured in ponds.
"The common carp was introduced from Israel in 1975/76. Yields of C. carpio have been higher than tilapia and the species is highly favoured as a polyculture candidate at Domasi and Kasinthula, finding ready market acceptability (Msiska, 1982).
“One exotic species worthy of mention if Macrobrachium rosenbergii. This freshwater prawn was introduced in 1976 and cultured at Domasi. Results suggest yields of 300 kg/ha, but maintenance of the hatchery was problematic. In 1984 the Dwangwa Sugar Estate has imported post larvae from Mauritius for starting a commercial growout operation.”
* see detailed bibliography in Balarin, 1987.
For a total aquaculture production of 103 t in 1987, Vincke (1989, pers. comm.) estimates a production of 83 t of tilapias, 9 t of Clarias gariepinus, 3 t of Cyprinus carpio, and 8 t of Macrobrachium rosenbergii.
For further information on aquaculture, see Balarin, 1987.
3.2 Fish production and per caput supply
Table 1. FISH PRODUCTION AND PER CAPUT SUPPLY - Malawi, 1970–1987
Nominal Domestic Production (excluding exports) (t) 2 | Nominal Consumer Supply (excluding imports and exports)* (kg/person) | ||||||
Year | Population '000 1 | Inland capture | Aquaculture 3 | Total | Inland capture | Aquaculture 3 | Total |
1970 | 4 518 | 66 300 6 | - 4 | 66 300 | 14.7 | - | 14.7 |
1971 | 4 641 | 73 200 6 | - | 73 200 | 15.7 | - | 15.7 |
1972 | 4 767 | 84 100 6 | - | 84 100 | 17.6 | - | 17.6 |
1973 | 4 897 | 69 300 | - | 69 300 | 14.1 | - | 14.1 |
1974 | 5 030 | 70 277 | - | 70 277 | 14.0 | - | 14.0 |
1975 | 5 167 | 70 992 | - | 70 992 | 13.7 | - | 13.7 |
1976 | 5 315 | 74 900 | - | 74 900 | 14.1 | . | 14.1 |
1977 | 5 467 | 68 200 | - | 68 200 | 12.5 | - | 12.5 |
1978 | 5 623 | 67 800 | - | 67 800 | 12.0 | - | 12.0 |
1979 | 5 784 | 60 000 | - | 60 000 | 10.3 | - | 10.3 |
1980 | 5 950 | 65 757 | - | 65 757 | 11.0 | - | 11.0 |
1981 | 6 137 | 51 392 | - | 51 392 | 8.4 | - | 8.4 |
1982 | 6 329 | 58 347 | 69 5 | 58 416 | 9.2 | 0.01 | 9.2 |
1983 | 6 528 | 66 917 | 76 5 | 66 993 | 10.2 | 0.01 | 10.2 |
1984 | 6 733 | 64 991 | 73 5 | 65 064 | 9.6 | 0.01 | 9.6 |
1985 | 6 944 | 61 987 | 80 5 | 62 067 | 8.9 | 0.01 | 8.9 |
1986 | 7 178 | 72 762 | 90 5 | 72 852 | 10.1 | 0.01 | 10.1 |
1987 | 7 421 | 88 485 | 103 5 | 88 588 | 11.9 | 0.01 | 11.9 |
1 Source: FAO
2 Source: FAO Fisheries Department FISHDAB
3 included in “Inland capture” if not specified
4 - = data not available
5 Vincke, 1989 (pers. comm.)
6 cited in Balarin, 1987
* Inland exports were: 1980: 2 522 t; 1981: 1 500 t; 1982: 1 456 t; 1983: 1 500 t.
3.3 Inland catch range and potential yield
Table 2. INLAND CATCH RANGE AND POTENTIAL YIELD
Water body | Period | Annual catch range (t) 1 | Potential annual yield (t) 1 |
Lake Chia | - | - | - |
Lake Chilwa | 1982 | 15 500 | 20 000 |
Lake Chikukutu | - | - | - |
Lake Chiuta | 1982 | 1 400 | - |
Lake Malawi | 1982 | 24 200 | 73 200–97 600 |
Lake Malombe | 1980–82 | 6 500–12 100 | 2 000 |
Shire River and Elephant Marsh | 1982 | 5 200 | 4 000–17 000 |
Rivers Bua, Dwangwa, Lilongwe, Lufira, North Rukuru, Songwe, South Rukuru | 1970–82 | 4 000–17 000 2 | 15 000 3 |
1 Sources: see text
2 NSO, 1984
3 Welcomme, 1979a
Total annual yield: | 56 800–75 400 t (totals, Table 2) |
31 000–113 500 t: 1970–1982 production range (NSO, 1984) | |
Potential annual yield: | 114 200–151 600 t (totals, Table 2) |
80 000 t (Welcomme, 1979a) | |
150 000 t (SADCC, 1984) |
4. STATE OF THE FISHERY
(adapted from Balarin, 1987; Welcomme, 1979a; and Marshall, 1984a)
4.1 Yield
Malawi fisheries can be classified into three categories: ornamental, commercial and traditional. The ornamental fishery concerns tropical aquarium fish for export and is not considered here.
The statistics of national fishery catches are summarized in Tables 1 and 2. Catch data show a rise in annual landings to a peak of 84 000 t in 1972. At this point, Lake Malawi provided 67.8% of the national catch; it subsequently declined to less than 41% in 1982. Production from other sources has also fluctuated: Lake Chilwa yielded 25 800 t in 1979 but was below 3 000 t in 1975; Lake Malombe yielded 12 100 t in 1982 but prior to this landings were never over 8 000 t/yr; the Lower Shire floodplains produced 17 000 t in 1972 but have in recent years remained at 4 000–5 000 t/yr.
4.2 Factors influencing yield
One of the critical factors about Malawi's inland waters is the extent to which they fluctuate, due to climatic changes and variations in lake levels. In 1980, Lake Malawi reached its highest water level in history.
The fishery on Lake Malawi is poorly developed, except in the south, but studies suggest that an annual yield of 30–40 kg/ha may be possible (FAO, 1982a). In inshore waters most of this would be Haplochromis spp. but Engraulicypris sardella would be most abundant in open waters.
Both Lake Chilwa and Shire Floodplain fisheries are sensitive to climatic variability and can give greatly reduced catches in bad years.
4.3 Future development possibilities
The estimates of potential fish yields for Malawi range from 80 000 t/yr (Welcomme, 1979a) to 150 000 t/yr (SADCC, 1984), whereas the range of maximum/minimum catches since 1970 (Table 1) suggests a potential MSY of 31 000–113 500 t/yr. Catch data indicate a relatively stabilized catch of 55 000–75 000 t/yr since 1970. Welcomme's (1979a) estimate of 80 000 t/yr has been adopted as the average national MSY, pending new data establishing the actual potential yield of Lake Malawi.
There are, however, excellent opportunities for fish culture in the country, which contributed about 103 t to the total yield in 1987; production may be expanded in this manner.
5. KEY BIBLIOGRAPHY
Fisheries situation, general: Balarin (1987); Dunn & Smith (1988)
Lake Malawi: FAO, 1982
Limnology of Malawi: Tweddle & Mkoko, 1986
6. WATER BODIES DIRECTORY
Lakes | ||
Chia | Chikukutu | Malawi/Nyasa |
Chilwa | Chiuta | Malombe |
Rivers | ||
Bua | Lufira | Songwe |
Dwangwa | North Rukuru | South Rukuru |
Lilongwe | Shire (and Floodplain) |
LAKE CHIA
Geographical data | |
Location: | Malawi - 13° 8'S; 34° 19'E |
Altitude: | 471 m |
Surface area: | circa 11.2 km2 |
Max. length: | 8 km |
Max. width: | 2 km |
Outflowing river: | short channel to Lake Malawi/Nyasa |
Special features: | Lake Chia, also called Chia Lagoon, is a lagoon-like lake outflowing into Lake Malawi. |
Fig. 1. MAJOR RIVER CATCHMENTS OF MALAWI
(Smith-Carington & Chilton, 1983)
LAKE CHILWA
(International water)
Geographical data | |
Location: | Malawi, Mozambique - 15° 15'S; 35° 45'E |
Altitude: | 654 m |
Surface area: | very variable: 259–2 590 km2; mean: 750 km2 with a surrounding swampy area of 1 000 km2. Only a minute portion of the lake is situated in Mozambique (29 km2 max.). |
Depth: | 5 m (max); 2 m (mean) |
Max. length: | 45 km |
Max. width: | 32 km |
Major inflowing rivers: | Thondwe, Likangala, Sombani |
Outflowing river: | none; internal basin |
Annual fluctuation in level: 1.3 m (the lake may dry up completely on occasions) | |
Physical and chemical data | |
Surface temperature: | 21–37°C (Kalk, 1969) |
Surface water characteristics in the open water of Lake Chilwa in a ‘normal’ year (1970) (Source: Mepham, 1987a)
February | July | December | ||
Depth: (m) | 2.05 | 1.55 | 1.0 | |
Conductivity: (μS/cm) | 800 | 1 500 | 2 500 | |
pH: | 8.2 | 8.6 | 8.8 | |
Total alkalinity: (meq/l) | 7.15 | 8.7 | 19.0 | |
Oxygen: (mg/l) | 5.6 | 10.0 | 6.7 | |
Transparency: (Secchi) (cm) | 7.5 | 8.5 | 11.0 | |
Ionic composition: | mg/l | mg/l | mg/l | |
Na+ | 189 | 350 | 780 | |
K+ | 14.0 | 10.5 | 23.1 | |
Ca2+ | 10.8 | 13.4 | 13.2 | |
Mg2+ | 6.4 | 6.3 | 8.6 | |
Cl- | 182 | 277 | 515 | |
μg/l | μg/l | μg/l | ||
PO4-P | 1 240 | 1 214 | 2 000 | |
NO3-N | n.d. | n.d. | 59 |
Fisheries data | |
No. of fish species: | 28 (cited in Balarin, 1987) |
Main catches: | Orechromis shiranus; Barbus paludinosus; Clarias gariepinus. (Mepham, 1987a) |
No. of fishermen: | 700 (Chaika, 1982) |
Total annual catch and effort: in Malawi (varies with water level and area):
Year | Total catch (t) |
1962 | 3 500 |
1963 | 3 262 |
1964 | 5 255 |
1965 | 8 820 |
1966 | 7 100 |
1967 | 3 139 |
1968 | 97 |
1969 | 3 326 |
1970 | 4 166 |
1971 | 3 595 |
1972 | 5 246 |
1973 | 1 903 |
1974 | 3 171 |
1975 | 2 808 |
1976 | 21 200 |
1977 | 20 800 |
1978 | 17 800 |
1979 | 25 800 |
1980 | 19 400 |
1981 | 8 600 |
1982 | 15 500 |
Potential annual yield: 20 000 t in Malawi (for max area) (Chaika, 1982)
Specific reference: detailed data and bibliography in Mepham, 1987a.
LAKE CHIKUKUTU
Geographical data | |
Location: | Malawi - 12°56'S; 34° 13'E |
Surface area: | 2.5 km2 |
Max. length: | 3.5 km |
Max. width: | 1 km |
Major Inflowing river: | lateral spillage from Kaombe River |
LAKE CHIUTA
(International water)
Geographical data | |||
Location: | Malawi, Mozambique - 14°45'S; 35°50'E | ||
Altitude: | 620 m | ||
Surface area: | total: 200 km2 (40 km2 in Mozambique) | ||
Depth: | 5 m | ||
Max. length: | 21 km | ||
Max. width: | 8 km | ||
Catchment area: | 2 000 km2 | ||
Outflowing river: | Lugenda | ||
Special features: | a sandbar only 25 m higher than the floodplain separates Lake Chiuta from Lake Chilwa (Mepham, 1987a) | ||
Physical and chemical data (Welcomme, 1972) | |||
Surface temperature: | 21–37°C | ||
Conductivity: | K20 150 μ S/cm | ||
pH: | 7.0–8.0 | ||
Dissolved solids: | 0.10–0.15 g/l | ||
Fisheries data | |||
No. of fish species: | 40 (cited in Balarin, 1987) | ||
No. of fishermen: | 200 (Chaika, 1982, Welcomme, 1972) | ||
Total annual catch: | in Malawi | ||
Year | Total catch (t) | ||
1965 | 181 | ||
1971 | 900 | ||
1972 | 1 400 | ||
1973 | 800 | ||
1974 | 900 | ||
1975 | 700 | ||
1976 | 1 800 | ||
1977 | 1 500 | ||
1978 | 1 700 | ||
1979 | 1 600 | ||
1980 | 800 | ||
1981 | 900 | ||
1982 | 1 400 |
LAKE MALAWI/NYASA
(International water)
Geographical data (Welcomme, 1972) | |
Location: | Malawi, Mozambique, Tanzania |
Altitude: | 471 m |
Surface area: | 30 800 km2 (24 400 km2 in Malawi; 6 400 km2 in Mozambique) Tanzania claims 5 569 km2 of Malawian waters (see Fig. 2) |
Depth: | 758 (max); 426 (mean) |
Volume: | 8 400 km3 |
Max. length: | 603 km |
Max. width: | 87 km |
Shoreline: | 1 500 km (total lake); 300 km in Tanzania |
Catchment area: | 65 000 km2 |
Annual fluctuation in level: 6 m | |
Major inflowing rivers: | Ruhuhu, Songwe |
Outflowing river: | Shire |
Special features: | Although Tanzania has some 300 km of shoreline on the lake, the Nyasa area is remote from major centres of population, development activity has been minimal over the years, and the evolution of the fisheries has not been well documented. It is not known to what extent the development of the Nyasa fisheries is complicated by the question of territorial jurisdiction. Around the time of independence it was reported that the formal border between Malawi and Tanzania coincided with the Tanzanian shoreline so that, in theory, all the waters of the lake belonged to Malawi (Dibbs, 1964). |
Physical and chemical data (Jackson et al., 1963) | ||||
Surface temperature: | 23–25°C | |||
Conductivity: | K20 220 μ S/cm | |||
pH: | 7.7–8.6 | |||
Alkalinity: | N × 10-4: 20.0–25.9 | |||
Ionic composition: | (Jackson et al., 1963) (Talling & Talling, 1965) | |||
mg/l | mg/l | |||
Na | - | 21.0 | ||
K | - | 6.4 | ||
Ca | 15.1–20.2 | 19.8 | ||
CaCO3 | 100.0–129.0 | - | ||
HCO3 + Co3 | - | 144.0 | ||
Mg | 6–9 | 4.7 | ||
Cl | - | 4.3 | ||
SO4 | - | <5.0–5.5 | ||
SiO2 | 1.5–7.0 | 1.1 | ||
NO3-N | 0.02 | - | ||
PO4-P | 0.1–0.2 | - |
Fisheries data | ||
No. of fish species: | 245 described species, of which 193 are cichlids (Greenwood, 1964) | |
Main catches: | inshore waters: Haplochromis spp. open waters: Engraulicypris sardella (Marshall, 1984a) | |
No. of fishermen: | in Malawi: | 6 500 (Welcomme, 1972) |
7 200 (Chaika, 1982) | ||
in Tanzania: | 3 654 (Welcomme, 1972) | |
No. of boats: | in Malawi: | 1 125 total (1 000 canoes; 100 dinghies; 25 boats) |
(Welcomme, 1972) | ||
4 000 (Chaika, 1982) | ||
in Tanzania: | 1 898 canoes (Welcomme, 1972) |
Total annual catch: in Malawi
Year | Total catch (t) |
1962 | 7 938 |
1965 | 6 441 |
1970 | 44 000 |
1971 | 54 000 |
1972 | 57 000 |
1973 | 54 800 |
1974 | 52 200 |
1975 | 47 200 |
1976 | 36 500 |
1977 | 33 900 |
1978 | 33 600 |
1979 | 22 400 |
1980 | 30 200 |
1981 | 25 300 |
1982 | 24 200 |
1986 | 36 400 |
Potential annual yield: 73 200 – 97 600 t in Malawi (productivity 30–40 kg/ha/yr: FAO, 1982a)
Specific reference: FAO, 1982a
Fig. 2. LAKES MALAWI AND MALOMBE
(Welcomme, 1972)
LAKE MALOMBE
Geographical data | |||
Location: | Malawi - 14° 40'S; 35° 15'E (see Fig. 2) | ||
Altitude: | 470 m | ||
Surface area: | 390 km2 | ||
Depth: | 6 m (max); 4 m (mean) | ||
Max. length: | 29 km | ||
Max. width: | 17 km | ||
Major inflowing river: | Shire | ||
Outflowing river: | Shire (Lake Malombe represents a lateral extension of the Shire River to form a permanent floodplain). | ||
Physical and chemical data (Jackson et al., 1963) | |||
Conductivity: | K20 225 μ S/cm | ||
Alkalinity: | N × 10-4 25.3 | ||
Ionic composition: | mg/l | ||
Ca | 18.4 | ||
Mg | 8.3 | ||
CaCO3 | 126.5 | ||
SiO2 | 2 | ||
Fisheries data | |||
No. of fish species: | 90 (cited in Balarin, 1987) | ||
No. of fishermen: | 780 (1962) (includes the Shire River) | ||
900 (Chaika, 1982) | |||
No. of boats: | 500 (300 canoes, 200 dinghies) (Welcomme, 1972) | ||
360 (Chaika, 1982) |
Total annual catch:
Year | Total catch (t) |
1962 | 1 361 (includes upper Shire River) |
1965 | 1 542 (includes upper Shire River) |
1971 | 5 000 |
1972 | 3 100 |
1973 | 2 100 |
1974 | 4 200 |
1975 | 8 100 |
1976 | 6 100 |
1977 | 6 400 |
1978 | 6 100 |
1979 | 3 600 |
1980 | 6 500 |
1981 | 8 500 |
1982 | 12 100 |
Potential annual yield: 2 000 t (Chaika, 1982)
BUA RIVER
Geographical data | |
Source: | Dzalanyama Mountains |
Total length: | 255 km |
Countries traversed: | Malawi |
Major tributaries: | Rusa, Namitete |
Discharges to: | Lake Malawi/Nyasa - 12° 45'S; 34° 17'E |
Volume of discharge at mouth: 184 m3/sec (max); 0.141 m3/sec (min) |
DWANGWA RIVER
Geographical data | |
Source: | Kasungu National Park |
Altitude: | 1 338 m |
Total length: | 175 km |
Countries traversed: | Malawi |
Major tributaries: | Mapasazi, Lingadzi, Chitete |
Discharges to: | Lake Malawi - 12° 31'S; 34° 12'E |
Special features: | Bana Swamp near mouth |
LILONGWE RIVER
Geographical data | |
Source: | Dzalanyama Mountains |
Altitude: | 1 713 m |
Total length: | 190 km |
Countries traversed: | Malawi |
Major tributaries: | Linthipe |
Discharges to: | Lake Malawi - 13° 55'S; 34° 34'E |
Volume of discharge at mouth: 963 m3/sec (max) | |
Special features: | Kamuzu dam on upper course |
LUFIRA RIVER
Geographical data | |
Source: | near Wenya |
Total length: | 90 km |
Countries traversed: | Malawi |
Major tributaries: | Mbalisi |
Discharges to: | Lake Malawi/Nyasa - 9° 49'S; 33° 55'E |
Volume of discharge at mouth: 113 m3/sec (max); 0.057 – 0.141 m3/sec (min) |
NORTH RUKURU RIVER
Geographical data | |
Source: | Nyika Plateau |
Altitude: | 2 340 m |
Total length: | 125 km |
Countries traversed: | Malawi |
Discharges to: | Lake Malawi/Nyasa - 9° 54'S; 33° 57'E |
Volume of discharge at mouth: 680 m3/sec (max); 0.085–1.13 m3/sec (min) |
SHIRE RIVER AND FLOODPLAIN
(International water)
Geographical data | |
Source: | Lake Malawi/Nyasa (see Figs. 1 and 2) |
Altitude: | 470 m |
Total length: | 520 km (375 km in Malawi; 75 km along Malawi-Mozambique frontier; |
70 km in Mozambique) | |
Countries traversed: | Malawi, Mozambique |
Discharges to: | Zambezi River - 17° 42'S; 35° 19'E |
Volume of discharge at mouth: 283–566 m3/sec | |
Flood regime: | Floods between January and April |
Special features: | in Malawi: Lake Malombe in upper course and Elephant Marsh floodplain/swamp in lower course (500 km2 flooded permanently and up to circa 1 000 km2 flooded during rainy season) |
Physical and chemical data (Welcomme, 1972)
Upper course | Middle course | Lower course | |
Conductivity: K20 μ S/cm | 220 | - | 225 |
Temperature: °C | 10–25 | 20–31 | 20–35 |
pH: | 7.5–8.2 | - | - |
Fisheries data
No. of fishermen: 4 000 (Welcomme, 1972)
Total annual catch: in Malawi (excluding Lake Malombe)
Year | Total catch (t) | |
1965 | 1 814 | (lower Shire River only) |
1969 | 6 944 | |
1970 | 8 267 | |
1971 | 9 700 | |
1972 | 17 300 | |
1973 | 9 800 | |
1974 | 9 700 | |
1975 | 12 100 | |
1976 | 9 300 | |
1977 | 5 600 | |
1978 | 8 600 | |
1979 | 6 400 | |
1980 | 3 900 | |
1981 | 4 000 | |
1982 | 5 200 |
Potential annual yield: 4 000–17 000 t, including floodplain (FAO, 1983)
SONGWE RIVER
(International water)
Geographical data | |
Source: | near Vwawa, Tanzania |
Altitude: | 1 877 m |
Total length: | 165 km (140 km along Tanzania-Malawi frontier; 25 km in Tanzania only) |
Countries traversed: | Tanzania, Malawi |
Discharges to: | Lake Malawi/Nyasa - 9° 43'S; 33° 57'E |
SOUTH RUKURU RIVER
Geographical data | |
Source: | Viphya Mountains |
Altitude: | 1 809 m |
Total length: | 295 km |
Drainage area: | 11 482 km2 |
Countries traversed: | Malawi |
Major tributaries: | Kasitu, Luwewya, Mzimba |
Discharges to: | Lake Malawi/Nyasa - 10° 45'S; 34° 13'E |
7. BIBLIOGRAPHY
Balarin, 1987
Chaika, 1982
Dibbs, 1964
Dunn & Smith, 1988
FAO, 1982a; 1983a
FAO/UNDP, 1981b
Greenwood, 1964
Jackson et al., 1963
Kalk, 1969
Landell Mills Associates, 1983
Marshall, 1984a
Meecham, 1976
Mepham, 1987a
Msiska, 1981a,b; 1982
NSO, 1984
Pruginin, 1971
SADCC, 1984
Smith-Carington & Chilton, 1983
Talling & Talling, 1965
Tweddle & Mkoko, 1986
Vincke, 1981
Welcomme, 1972; 1979a