COUNTRY FILES (Contd.)

KENYA (Contd.)

LAKE NAIVASHA

(a) FAO/UNDP, 1966
(b) Statistical Bulletin, Fisheries Dept., Govt. of Kenya

Potential annual yield: 1 000 t (Welcomme, 1979a)
              3 000–4 000 t (FAO/UNDP, 1966)

LAKE NAKURU

LAKE NATRON
(International water)

LAKE OL BOLOSSAT

LAKE TURKANA (RUDOLF)
(International water)

Fisheries data
No. of fish species: 37 (Greenwood, 1964)
Total annual catch and effort: (in Kenya)

Source: 1967–1986: Stat. Bull., Fisheries Dept., Govt. of Kenya

Fig. 2. LAKE RUDOLF - TURKANA
(Welcomme, 1972)

LAKE VICTORIA
(International water)

Fisheries data
No. of fish species:
     177, of which 127 are cichlids (Greenwood, 1964), mostly Haplochromis species.
     Species introduced: in the 1950's: Oreochromis niloticus, O. leucostictus, Tilapia zillii, T. rendalli;

Species introduced: in the late 1950's, early 1960's: Lates niloticus

• In the 1960's and 1970's, Haplochromis species constituted an estimated 80% of the Lake's fish biomass (FAO, 1973).
• In the late 1970's and the 1980's, the Nile Perch (L.niloticus) population increased extremely, to the detriment mainly of the Haplochromis population. (See Table 6, underlined.)
• From data provided by the Fisheries Depart. of the Govt. of Uganda, the relative importance of Nile Perch increased as follows (cited in TDRI, 1983):

It is anticipated that the Nile Perch population will decrease as the Haplochromis stocks become seriously depleted (TDRI, 1983).

Main catches: See Table 5 (Kenya) and Table 6 (total Lake)

Table 5. MAIN CATCHES (KENYA) - LAKE VICTORIA
(after Reynolds & Greboval, 1988)

Sources: CIFA, 1981; DFK Statistical Bulletins; Bwathondi, 1988.

Total annual catch and effort: (in Kenya)

Source: 1967–1986: Stat.Bull, Fisheries Dept., Govt. of Kenya

Potential annual yield: (in Kenya)
25 000 t (Welcomme, 1972)
28 000–40 000 t (FAO/UNDP, 1966)
30 000–45 000 t (Coche & Balarin, 1982)
10 000–26 000 t (Zonneveld, 1983)

Fig. 3. LAKE VICTORIA
(Welcomme, 1972)

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

EWASO NGIRO RIVER

GANALE DORYA/JUBA RIVER
(International water)

MIGORI RIVER

NZOIA RIVER

Fisheries data

Total annual catch: 1 000 t in 1959 (Whitehead, 1959a,b), but in recent years this fishery for migratory Labeo victorianus from Lake Victoria has collapsed.

No. of fish species: 28 (Petr & Paperna, 1979)
Note: Other reference: Balirwa & Bugenyi, 1980

SABAKI (GALANA, ATHI) RIVER

TANA RIVER

TURKWEL RIVER
(International water)

LORIAN SWAMP

ARUBA RESERVOIR

GTARU RESERVOIR

KAMBURU RESERVOIR

KINDARUMA RESERVOIR

LESSOS RESERVOIR

MASINGA RESERVOIR

SASUMUA RESERVOIR

WANJII RESERVOIR

7. BIBLIOGRAPHY

Balarin, 1985a
Balirwa & Bugenyi, 1980
Beadle, 1932
Bell & Canterbery, 1976
Burgis & Mavuti, 1987
Bhushan, 1982
Bwathondi, 1988
CIFA, 1981
Coche & Balarin, 1982
Coe, 1966
EAFRO, 1952a,b; 1953
FAO, 1973; 1980a
FAO/UNDP, 1966
Fisheries Department, 1977
Government of Kenya, 1970; 1979a,b,c
Graham, 1929
Greenwood, 1964
Guest & Stevens, 1951
Hecky & Kilham, 1973
Kagai, 1975
Kilham, 1971
KMFRI, 1981
Lincer et al, 1981
Litterick, 1981
Melack, 1976
Melack & Kilham, 1974
NORAD, 1980; 1983a, b
Ongwenyi, 1979
Petr, 1977
Petr & Paperna, 1979
Reynolds & Greboval, 1988
Talling Talling, 1965
TDRI, 1983
Tuite, 1981
Vareschi, 1979, 1982
Vareschi & Jacobs, 1984
Welcomme, 1972; 1979a
Whitehead, 1959a, b; 1960
Zonneveld, 1983

LESOTHO

1. GEOGRAPHY AND CLIMATE

Lesotho (with a surface area of 30 350 km²) is primarily a highland plateau (headwaters of the Orange (= Senqu) River) with some lowlands in the south.

Lowland temperatures are generally high while upland regions are cool. Rainfall is moderate and droughts are common.

The economy is mainly subsistence in nature, based on livestock and farming. Soil erosion is severe, especially in the eastern uplands.

2. HYDROGRAPHY (after Chondoma, 1988a)

2.1 Lakes: There are no natural lakes.

2.2 Rivers, Floodplains and Swamps

All rivers in Lesotho belong to the Orange River system. There are three river systems: the Senqu, Makhaleng and Caledon (Fig. 1).

The Senqu River system, which is the largest, starts north of Cathedral Dome Peak at an altitude of 3 050 m and runs south. When flowing out of Lesotho into Orange Free State at the southwestern border of Lesotho, the Senqu River has a catchment area of about 2 100 000 ha and an average flow rate of 100 m³/s.

The Makhaleng, which starts in the Maluti ranges, runs south through the middle of the country. It joins the Senqu at the point where the Senqu leaves Lesotho into Orange Free State. At this point Makhaleng River has a catchment area of about 300 000 ha and an average flow of about 15 m³/s. The total length of Senqu and Makhaleng and their main tributaries in Lesotho is over 1 600 km.

The Caledon River forms the western border of Lesotho and drains the lowland part of the country. At the point where the Caledon flows into the Orange Free State it has an average flow rate of about 36 m³/s and a catchment area of about 1 300 000 ha, of which 700 000 ha are in Lesotho and 600 000 ha are in South Africa. The total length of the Caledon and its main tributaries in Lesotho is about 560 km.

The flow rates of the rivers fluctuates considerably between and within years, depending on the rainfall. It is common for the Caledon to run dry in dry years. Table 1 gives the catchment areas and mean annual runoff (MAR) of the three major river systems.

The rivers in Lesotho are in the upper reaches of the mountain zone where the flow is swift and there are no floodplains.

2.3 Reservoirs

There are a number of medium- and small-sized reservoirs which were constructed for water and soil conservation purposes. A small number of these reservoirs have been washed away and a fair number have silted up. There is no up-to-date information on the condition of the reservoirs in the country. However, a preliminary survey by Fisheries Section in the lowlands has revealed that over 100 ha of small reservoirs could be used for intensive aquaculture with minor improvements; another 50–100 ha of medium-sized reservoirs could be developed for capture fishery and cage culture.

Fig. 1. LESOTHO RIVER SYSTEMS AND THEIR CATCHMENTS
(SWECO, 1975)

Table 1. TOTAL SURFACE WATER RESOURCES OF LESOTHO BY CATCHMENT

* Sources: see Chondoma, 1988a

The Lesotho Highland Water Project plans to build 4 dams which will develop the highland water resources of the Senqu River for hydroelectricity generation, irrigation, fisheries and water for sale to South Africa. No estimates are available on the surface area of the dams after flooding, but other statistics of the dams to be constructed have been published (LHWP, 1986). The dams will be constructed in three phases, with the first phase expected to start in 1988 and the completion of the final phase planned for 2025.

2.4 Coastal Lagoons

None; Lesotho is landlocked.

3. FISHERY PRODUCTION/POTENTIAL

3.1 Aquaculture

Annual average fish production in Lesotho is about 20 tons. In good production years yields as high as 30 tons have been realized. However, during the recent severe drought experienced in the region, stocked pond area fell from 20 ha to 8.0 ha and fish production fell to 8.8 tons in 1985 (Fisheries Section, Ministry of Agriculture) (see Table 2; updated estimates are given in Table 3).

Table 2. STOCKED POND AREA - Lesotho, 1979–1985
(after Chondoma, 1988a)

Fish species currently cultured in Lesotho fall into two main categories:
indigenous: Clarias gariepinus;
introduced: Cyprinus carpio, Hypophthalmichthys molitrix, Salmo gairdneri, Ctenopharyngodon idella.

Aquaculture production by species from 1982 to 1987 is given below (Vincke, pers.comm., 1989).

In light of the recent drought the water security situation, and land use trends, an area of 500 ha of intensive commercial fish farms, with current production levels of 1 000–1 500 kg/ha, Chondoma (1988a) estimates potential annual yields of 500–750 tons.

3.2 Fish production and per caput supply

Table 3. FISH PRODUCTION AND PER CAPUT SUPPLY - Lesotho, 1970–1987

¹ Source: FAO
² Source: FAO Fisheries Department FISHDAB
³ - = data not available
⁴ SADCC, 1984
⁵ Vincke, 1989 (pers.comm.)

3.3 Inland catch range and potential yield

Table 4. INLAND CATCH RANGE AND POTENTIAL YIELD

(Sources: see text)

4. STATE OF THE FISHERY (adapted from Chondoma, 1988a)

4.1 Yield

The diversity of fish species in Lesotho is very limited; only 9 indigenous species in 5 genera occur. There are 8 introduced species, 5 of which have acclimatized well in the rivers and reservoirs; 2 are exclusively used in ponds for aquaculture.

There is no capture fishery of any significance in Lesotho. The only existing capture fishery is the sport fishery, mainly for trout and yellowfish in the mountain streams and bass in the lowland reservoirs. There is, however, a seasonal interest in catching yellowfish during the spawning migrations upstream, when they are caught by shepherds using very primitive gear such as stones, sharp sticks and stone traps.

The current estimated catch from the rivers is between 1 and 2 tons, mainly of trout and yellowfish.

The only significant fish production comes from aquaculture (see section 3.1).

4.2 Factors influencing yield

Unpredictable rainfall in dry years may cause the drying up of rivers, reservoirs and ponds. Cool temperatures also slow down growth rates and therefore production. Constraints on aquaculture include low market value of fish and high feed costs.

4.3 Future development possibilities

Information on potential fish production is not available. The only estimate is that done by Maar (1965), which gives riverine annual production from indigenous stocks as 100 tons and 20 tons from trout, if the rivers are regularly restocked with trout fingerlings.

At the 1983 production level of 18 tons and an import of 1 030 tons, an annual increase in production of over 1 000 tons is needed to substitute the imported fish. It is recognized that, at the present rate of aquaculture development and potential (500–750 t) and riverine fishery potential (120 t), Lesotho is unlikely to meet its national fish production requirement in the near future. The greatest potential for fisheries development in Lesotho lies in the realization of the Lesotho Highland Water Project, scheduled to start in 1988 and to be completed in 2025.

5. KEY BIBLIOGRAPHY

Chondoma, 1988a

6. WATER BODIES DIRECTORY

ORANGE RIVER (= SENQU RIVER)
(International water)

SCOTT RESERVOIR

ZACHOLO RESERVOIR

7. BIBLIOGRAPHY

Chondoma, 1988a
Keulder, 1970
LHWP, 1986
Maar, 1965
SADCC, 1984
SWECO, 1975
Welcomme, 1972