COUNTRY FILES (contd.)

NIGERIA (Contd.)

ANNEX I

A PRELIMINARY CHECKLIST OF INLAND WATER BODIES IN NIGERIA WITH SPECIAL REFERENCE TO LAKES AND RESERVOIRS

Extracted from: E.O. Ita, E.K. Sado, J.K. Balogun, A. Pandogari and B. Ibitoye, 1985

Kainji Lake Research Institute
Technical Report Series No. 14

WATER BODIES IN:

ANAMBRA STATE

BAUCHI STATE

BENDEL STATE

BENUE STATE

BORNO STATE

CROSS RIVER STATE

GONGOLA STATE

IMO STATE

KADUNA STATE

KANO STATE

KWARA STATE

NIGER STATE

OGUN STATE

ONDO STATE

OYO STATE

PLATEAU STATE

SOKOTO STATE

SAO TOME AND PRINCIPE

1. GEOGRAPHY AND CLIMATE

Sao Tome and Principe consists of two mountainous volcanic islands. Total surface area is 960 km².

The climate is tropical but varies with altitude. The coastal lowlands are some-what warmer than the central highlands. The economy is centered around plantation agriculture, principally cocoa and copra.

2. HYDROGRAPHY

2.1 Lakes

None of significant size.

2.2 Rivers, Floodplains and Swamps

Numerous short seasonal torrential rivers only.

2.3 Reservoirs

None of significant size.

2.4 Coastal Lagoons

None at present, but in the past the mouth of the Malanza River had been barred to form a lagoon varying in area from 0.16 km² during the dry season to 0.80 km² during the rainy season.

2.5 Aquaculture

At present there is no aquaculture in Sao Tome and Principe (Vincke, 1989, pers. comm.).

3. FISHERY PRODUCTION/POTENTIAL

3.1 Fish production and per caput supply

(See Table 1)

3.2 Inland catch range and potential yield

Total annual yield: 10 t in 1980 in main river estuaries (Robinson & Mundt, 1983).

4. STATE OF THE FISHERY

4.1 Yield

About 10 t in 1980 from capture fishery activity by marine fishermen at the mouths of the main rivers, mainly brackishwater fishes and crustaceans (Robinson & Mundt, 1983).

Table 1. FISH PRODUCTION AND PER CAPUT SUPPLY - Sao Tome and Principe, 1970–1987

¹ Source: FAO
² Source: FAO Fisheries Department FISHDAB
³ No aquaculture in Sao Tome and Principe (Vincke, 1989, pers.comm.)
⁴ From 1980 to 1983, Marine exports were as follows: 1980–1982: nil; 1983: 761 t

4.2 Factors influencing yield

Very limited hydrography, as well as depauperate ichthyofauna.

4.3 Future development possibilities

Only very limited capture fishery development is possible; aquaculture development is more feasible.

5. KEY BIBLIOGRAPHY

Robinson & Mundt, 1983

6. WATER BODIES DIRECTORY

Fig. 1. MAP OF SAO TOME AND PRINCIPE
(U.S. Department of State, 1983)

AGUA AMOREIRA RIVER

AGUA MADALENA RIVER

7. BIBLIOGRAPHY

FAO, 1983
Robinson & Mundt, 1983
U.S. Department of State, 1983

SENEGAL

1. GEOGRAPHY AND CLIMATE (Welcomme, 1979; Deceuninck, 1989b)

Most of Senegal (total surface area of 192 000 km²) is low-lying, rolling terrain covered with savanna. In the southeast the country rises to the foothills of the Fouta Djallon Mountains. Some rainforest and swamps are found in the south.

There are two well-defined seasons: the rains occur from June to October; December-February is cool and dry. Senegal is a very arid country over much of which marginal agriculture is practised. There is some pastoralism, especially in the eastern parts and in the Senegal River Valley. Much of the river valley is being converted to irrigated agriculture, a process which will be accelerated after the construction of the projected upstream dams.

Many small rivers go dry from February-March to July.

2. HYDROGRAPHY (Welcomme, 1979; Deceuninck, 1989b)

(See Fig. 1 and Table 1)

2.1 Lakes

One major lake, the Lac de Guiers, is connected to the Senegal River by a short channel, the Tawey. The lake area fluctuates between 120 km² at low water and 240 km² at high water.

2.2 Rivers, Floodplains and Swamps

The Senegal River and its tributary, the Falmèmè, form the northern and western frontiers of the country with Mali and Mauritania. The Senegal River has extensive floodplains, both fringing the main channel (5 000 km² at peak flood) and in the delta (7 970 km² at peak flood). Other rivers are the Saloum, Gambia and Casamance.

2.3 Reservoirs

There are no major reservoirs at present although there are proposals to install a flood-control dam in the Senegal River delta at Diama. Other dams are planned at Kekreti and Sambangalou (on the Gambia River) and at Guidel, Baile and Anambè (on the Casamance River). Surface areas for two of the reservoirs would vary as follows:

2.4 Coastal Lagoons

The Casamance River has an estuarine zone which extends far inland. There are also estuarine lagoons around the mouth of the Saloum River, and the Senegal River has an extensive delta which is deeply penetrated by salt water. There are a few small lagoons to the north of Dakar.

2.5 Aquaculture

Vincke (1989, pers.comm.) gives the following composite estimate of aquaculture production units in 1985:

Table 1. RIVER BASINS OF SENEGAL
(Numbers refer to Figure 1)

3. FISHERY PRODUCTION/POTENTIAL

3.1 Fish production and per caput supply

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

¹ Source: FAO
² Source: FAO Fisheries Department FISHDAB
Catch data covers: the artisanal Senegalese fishery; the industrial Senegalese tuna fishery; the industrial Senegalese and French trawler fishery; and the industrial Senegalese sardine fishery.
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: 1980: 49 326 t; 1981: 46 017 t; 1982: 61 914 t; 1983: 60 420 t.

Fig. 1. HYDROGRAPHIC NETWORK AND BASINS
(adapted from M.D.R., 1988)

3.2 Inland catch range and potential yield

Table 3.

Sources: see text

4. STATE OF THE FISHERY

4.1 Yield

The catches from the Senegal River fell to 12 000 t/yr during the Sahelian drought, but rose again to their pre-flood levels once normal flood patterns were re-established. The estimates of inland catch are based mainly on the catches from the Senegal River, but national catches are presumably higher, as a fair but unreported quantity must also be caught in the Casamance, Gambia and Saloum systems. (Welcomme, 1979)

However, Frenoux (1988) gives higher estimates. 37 000 t (14 000 t freshwater fish and 23 000 t brackishwater fish) in 1987; 60 000 t before the drought (see tables 3 and 4).

In general, the Senegal fishery appears to be exploited. The swiftness of the collapse of the fishery during the drought bears witness to the intensity of fishing; however, the equally swift re-establishment of previous catch levels would indicate that the fishery is not severely over-exploited.

The main freshwater fishes are: Lates niloticus, Citharinus citharus, Mormyrus macrophthalmus, Hemichromis fasciatus, Gymnarchus niloticus, Clarias anguillaris, Hydrocynus, Alestes, Distichodus, Labeo, Schilbe, Synodontis, Polypterus, Heterotis. The main brackishwater fishes are: Elops, Liza, Mugil, Tilapia heudelotti, Ethmalosa, Ilisha, Cynoglossus, Polydactylus, Pellonula. (Reizer, et al., 1972)

Aquaculture production (t), by species, from 1982 to 1987 is reported by Vincke (1989, pers.comm.) as follows:

4.2 Factors influencing yield

Climatic factors have a very strong influence on the catches within the country (see figures from 1970 to 1987). The Senegal is a Sahelian river, and its fisheries suffer from the periodic droughts which beset this region.

Table 4 gives estimates of inland fisheries production before and after the drought.

Table 4. INLAND FISHERIES PRODUCTION BEFORE (NORMAL YEAR) AND AFTER (1987) THE DROUGHT

Source: Frenoux, 1988

4.3 Future development possibilities

As well as fuller exploitation of the capture fisheries of the river, other increases in production could result from an extensive, or semi-intensive use of the floodplain lagoons for aquaculture. Any plans for development of this type would depend greatly on the various types of hydro-agricultural management proposed. Three major upstream dams are being considered: Galoupo, Manantali and Gourbessi. There is also a proposal to install a dam in the delta (Diama) which would change its salinity characteristics. None of the upstream dams would be in Senegal, so the country would not benefit from the fisheries of the reservoirs they impound, and there would be a considerable loss in the fishery of the Senegal River floodplains. The long-term prospects for the Senegal River fishery are poor. It would thus be desirable to develop aquaculture to compensate for the loss in capture fishery yield.

5. KEY BIBLIOGRAPHY

Deceuninck, 1989b

6. WATER BODIES DIRECTORY

LAKE GUIERS and TAOUEY/TAWEY CHANNEL

Fisheries data
Total annual catch and effort:

Sources: * Welcomme, 1972
** Frenoux, 1988

Potential yield: approx. 2 500 t (Welcomme, 1972)

CASAMANCE RIVER

GAMBIA RIVER
(International water)

GEBA/KAYANGA RIVER
(International water)

SENEGAL RIVER
(International water)

* (Livingston, 1963)
** (Reizer, 1971)

Fisheries data
No. of fish species: 54 in Baoulè and Bakoyo Rivers (Daget, 1961)
Total annual catch and effort:

See also Table 4.

SINE - SALOUM RIVER

7. BIBLIOGRAPHY

Daget, 1961
Deceuninck, 1989b
Frenoux, 1988
Livingston, 1963
M.D.R., 1988
Reizer, 1971
Reizer, et al., 1972
Welcomme, 1972; 1979