1. GEOGRAPHY AND CLIMATE
Cape Verde (with a surface area of 4 030 km2) consists of ten islands and five islets, all of volcanic origin. Most are mountainous and support lush vegetation at higher elevations (watered by moisture condensation).
Rainfall is sparse and cyclical droughts occur. Temperatures are moderate the year round.
The economy is mainly agricultural, bananas being the chief produce.
2. HYDROGRAPHY
2.1 Lakes: There are no lakes of any size.
2.2 Rivers, Floodplains and Swamps:
Most islands possess short streams up to 15 km long, which can remain dry for
several years.
2.3 Reservoirs: There are no large reservoirs.
2.4 Coastal Lagoons: There are no coastal lagoons.
2.5 Aquaculture: No aquaculture in Cape Verde (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: none.
4. STATE OF THE FISHERY
4.1 Yield: No yield can be expected from present hydrological resources.
4.2 Factors influencing yield: Poor rainfall, no inland water body.
4.3 Future development possibilities: Unless artificial lentic systems are created, conditions simply do not exist for any inland fishery production whatsoever.
5. KEY BIBLIOGRAPHY: none.
6. WATER BODIES DIRECTORY: none.
7. BIBLIOGRAPHY: none.
Table 1. FISH PRODUCTION AND PER CAPUT SUPPLY - Cape Verde, 1970–1987
Nominal Production (including exports) (t) 2 | Nominal Consumer Supply (including exports) (kg/person) | ||||||||
Year | Population '000 1 | Inland capture | Aquaculture | Marine capture 3 | Total | Inland capture | Aquaculture | Marine capture | Total |
1970 | 271 | 5 100 | 5 100 | 18.8 | 18.8 | ||||
1971 | 273 | 4 500 | 4 500 | 16.5 | 16.5 | ||||
1972 | 276 | 4 800 | 4 800 | 17.4 | 17.4 | ||||
1973 | 278 | 4 400 | 4 400 | 15.8 | 15.8 | ||||
1974 | 281 | 4 400 | 4 400 | 15.6 | 15.6 | ||||
1975 | 283 | 3 902 | 3 901 | 13.8 | 13.8 | ||||
1976 | 286 | 2 024 | 2 024 | 7.1 | 7.1 | ||||
1977 | 288 | 8 331 | 8 331 | 28.9 | 28.9 | ||||
1978 | 291 | 8 331 | 8 331 | 28.6 | 28.6 | ||||
1979 | 293 | 7 476 | 7 476 | 25.5 | 25.5 | ||||
1980 | 296 | 8 837 | 8 837 | 29.8 | 29.8 | ||||
1981 | 302 | 14 730 | 14 730 | 48.8 | 48.8 | ||||
1982 | 308 | 12 453 | 12 453 | 40.4 | 40.4 | ||||
1983 | 314 | 11 864 | 11 864 | 37.8 | 37.8 | ||||
1984 | 320 | 10 730 | 10 730 | 33.5 | 33.5 | ||||
1985 | 326 | 10 190 | 10 190 | 31.2 | 31.2 | ||||
1986 | 334 | 6 641 | 6 641 | 19.9 | 19.9 | ||||
1987 | 342 | 8 200 | 8 200 | 24.0 | 24.0 |
1 Source: FAO
2 Source: FAO Fisheries Department FISHDAB
In the early 1980's there was some over-estimation of Cape Verde catches; 1983 data based on a study by Shimura (CVI/82/003/REL/TEC/1); data from 1984 the result of improved catch assessment survey.
3 From 1980 to 1983 marine exports were as follows: 1980: 1 142 t; 1981: 428 t; 1982: 1 455 t; 1983: 2 159 t.
Fig. 1. MAP OF CAPE VERDE
1. GEOGRAPHY AND CLIMATE (Welcomme, 1979)
Nearly the whole country (with a surface area of 322 000 km2) is low-lying and only in the northwest does the relief begin to rise toward the Guinea highlands. The southern half of the country is densely forested and the northern half consists of sparse scrub savanna growing on poor lateritic or sandy soils.
The south of the country has a typical tropical climate with warm, even temperatures and high humidity throughout the year. There is a heavy annual rainfall which is concentrated into two rainy seasons: March-July, and September-December. In the south the climate is more arid, with a tendency for the two rainy seasons to become amalgamated into a single season lasting from March to October.
Côte d'Ivoire has a predominantly agricultural economy based on a wide range of products.
2. HYDROGRAPHY (see Fig. 1)
2.1 Lakes
There are only a few small natural lakes in the northern part of the country.
2.2 Rivers, Floodplains and Swamps
Apart from two very short headwater tributaries of the Niger River, all the rivers in Côte d'Ivoire are south-flowing. There are two main basins which lie wholly within the country: the Sassandra River (650 km), and the Bandama River (1 050 km). Smaller intensified rivers are the Komoe, Cavally, Tano, Bia and Black Volta. There are no extensive swamps or floodplains.
2.3 Reservoirs
There is one major reservoir (Kossou), two large (Buyo and Ayame), and several smaller ones (Taobo, Ayane II, Bouake, Yaora, Zatta and Yabra). Other planned reservoirs are at Soubre, Atakro, Malamalasso and Tiboto-Nyaake. There are a number of minor agricultural and potable water supply reservoirs.
2.4 Coastal Lagoons (see Fig. 2 and Table 3)
There are three large lagoon complexes: Aby-Tend-Ehy, Tagba-Maki-Tdio (Grand-Lahou), and Ebrie. In addition there are several small lagoons scattered along the coast.
2.5 Aquaculture
Vincke (1989, pers.comm.) gives the following composite estimate of aquaculture production units in 1985:
Breeding centres: | 14 (surface area: 7.5 ha) |
Family-type ponds: | 2 900 (surface area: 140 ha) |
Large fish farms: | 2 (surface area: 7.4 ha) |
Fig. 1. COTE D'IVOIRE
(U.S. Department of State, 1987)
Fig. 2. THE LAGOON SYSTEM OF COTE D'IVOIRE
(Weigel, 1985)
3. FISHERY PRODUCTION/POTENTIAL
3.1 Fish production and per caput supply
Table 1. FISH PRODUCTION AND PER CAPUT SUPPLY - Côte d'Ivoire, 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 4 | Total | Inland capture | Aquaculture 3 | Marine capture | Total |
1970 | 5 553 | 5 000 | -5 | 55 500 | 60 500 | 0.9 | - | 10.0 | 10.9 |
1971 | 5 777 | 5 500 | - | 59 600 | 65 100 | 0.9 | - | 10.3 | 11.2 |
1972 | 6 010 | 6 000 | - | 66 400 | 72 400 | 1.0 | - | 11.0 | 12.0 |
1973 | 6 252 | 6 000 | - | 59 500 | 65 500 | 1.0 | - | 9.5 | 10.5 |
1974 | 6 505 | 6 000 | - | 69 251 | 75 251 | 0.9 | - | 10.6 | 11.5 |
1975 | 6 767 | 6 000 | - | 62 470 | 68 470 | 0.9 | - | 9.2 | 10.1 |
1976 | 7 027 | 4 100 | - | 72 895 | 76 995 | 0.6 | - | 10.4 | 11.0 |
1977 | 7 297 | 4 100 | - | 79 307 | 83 407 | 0.6 | - | 10.8 | 11.4 |
1978 | 7 578 | 4 103 | - | 74 908 | 79 011 | 0.5 | - | 9.9 | 10.4 |
1979 | 7 869 | 15 000 | - | 71 613 | 86 613 | 1.9 | - | 9.1 | 11.0 |
1980 | 8 172 | 18 000 | - | 67 920 | 85 920 | 2.2 | - | 8.3 | 10.5 |
1981 | 8 476 | 20 000 | - | 71 996 | 91 996 | 2.4 | - | 8.5 | 10.9 |
1982 | 8 792 | 21 493 | 507 6 | 69 221 | 91 221 | 2.4 | 0.06 | 7.9 | 10.3 |
1983 | 9 119 | 21 868 | 532 6 | 72 227 | 94 627 | 2.4 | 0.06 | 7.9 | 10.3 |
1984 | 9 458 | 21 957 | 443 6 | 65 691 | 88 091 | 2.3 | 0.05 | 6.9 | 9.3 |
1985 | 9 810 | 25 794 | 606 6 | 84 204 | 110 604 | 2.6 | 0.06 | 8.6 | 11.2 |
1986 | 10 155 | 28 314 | 686 6 | 76 174 | 105 174 | 2.8 | 0.07 | 7.5 | 10.3 |
1987 | 10 511 | 27 353 | 847 6 | 74 253 | 102 453 | 2.6 | 0.08 | 7.1 | 9.7 |
1 Source: FAO
2 Source: FAO Fisheries Department FISHDAB
No catch assessment survey for marine and inland artisanal fisheries; reliable data only for industrial fisheries.
3 included in “Inland capture” if not specified.
4 from 1980 to 1983 marine exports were as follows: 1980: 26 970 t; 1981: 29 393 t; 1982: 29 652 t; 1983: 38 455 t
5 - = data not available.
6 Vincke, 1989, pers.comm.
3.2 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) | |
Ayame Reservoir | 1975 | 1 120 | ||
1979 | 843 | |||
Kossou Reservoir | 1973 | 4 905 | 11 000–16 000 2 | |
1980 | 7 500 | |||
Aby-Tendo-Ehy Lagoon | 1979–82 | 3 500–11 000 | 8 275–10 000 3 | |
Complex | recent | 4 250–6 375 | ||
Ebrie Lagoon | recent | 3 000–7 800 | 7 000–9 000 3 | |
Tagba-Make-Tadio Lagoon | - | 2 899 | ||
Complex | recent | 600–715 | 2 000–2 800 3 | |
Total Rivers | - | - | 20 000 4 | |
Total Large Reservoirs | - | - | 20 000 4 | |
Total Small Reservoirs | - | - | 2 000 4 | |
Total Lagoons | - | - | 20 000 4 | |
17 275–21 800 3 | ||||
No data available for | ||||
Rivers Agneby, Bagoe, Bandama, Bandam Rouge, Baoule, Bia, Black Volta, Cavally, Cestos, Komoe, Nzi, Sassandra and Tano; | ||||
Reservoirs Ayame II, Buyo, Taabo, Yabra, Yaora and Zatta; | ||||
Lagoons Aghien, Bakie, Hebe, Kodioboue, Ngni, Ono and Potou. | ||||
Total annual yield: in 1982 (Gosse, 1984): | ||||
12 500 t - total lagoons (fisheries + aquaculture) | ||||
24 000 t - total rivers, reservoirs, inland aquaculture | ||||
(see also Table 1) | ||||
Potential annual yield: 62 000 t (Lazard, 1975; 1977) |
1 Sources: see text
2 FAO/UNDP, 1976
3 see Table 3
4 Lazard, 1975; 1977
4. STATE OF THE FISHERY (after Welcomme, 1979; Gosse, 1984)
4.1 Yield
Gosse (1984) estimates the inland fish production in 1982 as about 36 500 t (lagoons fisheries and aquaculture: 12 500 t; other inland fisheries and aquaculture: 24 000 t); FAO's statistics for the same period give 22 000 t (Table 1). Lack of reliable data does not permit a precise production figure.
The brackishwater lagoon production is summarized in Table 3.
Production from aquaculture is estimated at 847 t in 1987, and has been increasing since the beginning of the 1980's (see Table 4).
4.2 Factors influencing yield
The main factor which has tended to keep the catch rates from Ivorian inland waters low is the lack of skilled fisherman within the country. As inland fishery is not a traditional activity in Côte d'Ivoire, the waters have been fished by Ghanian fisherman, but the policy of the Ivorian government to keep foreign fishermen out of the country has left a shortage of manpower. This has, to a certain extent, been overcome by the training of fishermen on Kossou Reservoir, and there is almost certainly a continued, if illicit, foreign presence on the various fishing grounds.
Although lagoon yield still seems to remain under the potential, increasing pollution in the lagoons may soon affect productivity.
Table 3. PRODUCTION FROM LAGOONS (t)
(Doucet et al., 1985)
Surface (ha) | Present Production 1 | Prod. potential I 5 | Prod. potential II 8 | ||||
Estimate 2 | |||||||
low | mean | low | mean | low | mean | ||
Aby | 42 600 | 4 250 | 6 375 | 5 500 5 | 8 275 5 | 7 200 | 10 000 |
Ebrie | 56 600 | 6 800 3 (2 000) | 7 800 3 (3 000) | 5 000 6 | 7 000 6 | 7 000 | 9 000 |
Grand Lahon | 19 000 | 600 4 | 715 4 | 1 520 7 | 2 000 7 | 2 320 | 2 800 |
Total | 118 200 | 11 650 3 (6 850) | 14 890 3 (10 090) | 12 020 | 17 275 | 16 520 | 21 800 |
1 Calculated after data from: Charles-Dominique, Hiè Darè, Lae, Durand.
2 Minimum and mean estimates (there will always be some good and some bad years in lagoons).
3 With seine nets (without seine nets)
4 It is considered that Tadio is exploited by professionals, as is Ebriè (without Zone II); the rest of the lagoon is underexploited. (See Fig. 5)
5 Catch controls.
6 By improving fishing methods, by catch controls, and by fishing Ethmalosa with seine nets in Zone III.
7 By developing the fishery.
8 By exploiting migrant sea fishes, and by developing the “acadjas” in paddocks, in addition to 5, 6 and 7.
Table 4. AQUACULTURE PRODUCTION, BY SPECIES IN COTE D'IVOIRE (t)
Species | 1982 | 1983 | 1984 | 1985 | 1986 | 1987 |
Oreochromis niloticus | 207 | 232 | 282 | 549 | 478 | 618 |
Oreochromis, Sarotherodon spp. | 300 | 300 | 150 | 10 | 25 | 30 |
Chrysichthys spp. | - | - | 1 | 35 | 170 | 130 |
Clarias spp. | - | - | 10 | 12 | 13 | 69 |
Total | 507 | 532 | 443 | 606 | 686 | 847 |
Source: Vincke, 1989, pers.comm.
4.3 Future development possibilities
Côte d'Ivoire possesses a diverse inland capture fishery which could produce up to 62 000 t/yr (see Table 2). However, this optimistic estimate needs confirmation through a reliable and updated potential survey. Attempts to introduce aquaculture on a large scale have so far been unsuccessful, though there is no doubt that a potential exists for expansion of both fresh and brackishwater production of fish in ponds and cages.
5. KEY BIBLIOGRAPHY
Lagoons: Doucet et al., 1985; Dufour, 1987; Kapetsky, 1981a; Weigel, 1985.
Kossou Reservoir: Entz, 1984; FAO/UNDP, 1976.
6. WATER BODIES DIRECTORY
Lakes | |||
Dalaba | Dalandjougou | ||
Rivers | |||
Agneby | Baoule/Bagoue/Bani | Cavally | Niger |
Bandama | Bia | Cestos | Nzi |
Bandama Rouge | Black Volta | Comoe/Komoe | Sassandra |
Tano | |||
Reservoirs | |||
Ayame | Bouake | Kossou | Yabra |
Ayame II | Buyo | Taabo | Yaora |
Zatta | |||
Lagoons | |||
Aby-Tendo-Ehy Complex | Ebrie | Ngni | |
Aghien | Hebe | Ono | |
Bakre | Kodioboue | Potou | |
Tagba-Make-Tadio Complex (= Grand-Lahou) |
LAKE DALABA
Geographical data | |
Location: | Côte d'Ivoire - 9° 51'N: 6° 22'W |
Inflowing river: | Ba (= Bagoè) |
LAKE DALANDJOUGOU
Geographical data | |
Location: | Côte d'Ivoire - 9° 32'N: 4° 9'W |
Inflowing river: | Keleworo |
Outflowing river: | Bavè |
AGNEBY RIVER
Geographical data | |
Source: | Bougouanon, Côte d'Ivoire |
Total length: | 200 km |
Drainage area: | 8 700 km2 |
Countries traversed: | Côte d'Ivoire |
Discharges to: | Ebrie Lagoon |
Volume of discharge at mouth: 50 m3/sec (mean) | |
Special features: | four small impoundments |
Fisheries data | |
No. of fish species: | 29 |
BANDAMA RIVER
Geographical data | |
Source: | the Bandama is formed by the confluence of the Bandamas Rouge and Blanc. The source of the Bandama Blanc (main tributary) is 9° 20'N; 6° W, near the town of Korhogo. The Bandama Rouge rises slightly to the southwest of the Bandama Blanc. |
Altitude: | 400 m |
Total length: | 280 km (from White and Red Bandama confluence to sea) |
Drainage area: | 97 000 km2 |
Countries traversed: | entirely in Côte d'Ivoire |
Major tributaries: | Nzi |
Discharges to: | Tagba-Make-Tadio Lagoon Complex - 5° 8'N; 5° 0'W |
Volume of discharge at mouth: 700 m3/sec (mean) | |
Flood regime: | in flood from July to October |
Special features: | Taabo Reservoir; Kossou Reservoir on White Bandama |
Physical and chemical data | |
Conductivity: | 90–200 μ S/cm (Welcomme, 1972) |
pH: | 6.7–7.6 |
Ionic composition: | (Iltis & Leveque, 1982) |
Flood mg/l | Mean mg/l | Low water mg/l | ||
Na | 3.2 | 5.0 | 6.0 | |
K | 4.0 | 2.3 | 2.7 | |
Ca | 5.2 | 4.6 | 5.5 | |
Mg | 2.0 | 2.0 | 2.5 | |
HCO3 | 38.8 | 36.0 | 45.7 | |
Cl | 0.0 | 0.7 | 0.8 | |
SO4 | 10.1 | 4.5 | 1.7 | |
PO4 | 0.1 | 0.2 | 0.0 | |
Fisheries data | ||||
No. of fish species: 79 (Daget & Iltis, 1965) |
BANDAMA ROUGE RIVER
Geographical data | |
Source: | northern Côte d'Ivoire |
Altitude: | 840 m asl |
Total length: | 550 km |
Drainage area: | 24 300 km2 |
Countries traversed: | entirely in Côte d'Ivoire |
Major tributaries: | Yasaru; upper course of Bandama Rouge is called Marahouè |
Discharges to: | unites with Bandama Blanc to form the Bandama |
Physical and chemical data | |
Conductivity: | 71–92 μ S/cm |
Ionic composition: | (Iltis & Leveque, 1982) |
mg/l | ||
Na | 5.8 | |
K | 3.8 | |
Ca | 5.7 | |
Mg | 2.3 | |
HCO3 | 43.5 | |
Cl | 1.6 | |
SO4 | 3.8 | |
PO4-P | 0.7 |
BAOULE/BAGOUE/BANI RIVER
(International water)
Geographical data | ||||
Source: | northwestern Côte d'Ivoire (Baoulè tributary) | |||
Altitude: | 806 m | |||
Total length: | 1 050 km (Baoulè and Bani). Bani formed by confluence of Baoulè and Bagoè tributaries. Channel lengths (km) as follows: | |||
Mali | Côte d'Ivoire | |||
Bani | 430 | - | ||
Baoulè | 480 | 140 | ||
Bagoè | 340 | 225 | ||
Countries traversed: | Mali, Côte d'Ivoire | |||
Major tributaries: | Degou and Banifing are tributaries of Baoulè; Yankèlaba and Bafini are tributaries of Bagoè. | |||
Discharges to: | Bani discharges to Niger River at Mopti (14° 30'N; 4° 12'W) | |||
Special features: | floodplain with numerous small lakes along Bani; smaller floodplain along lower course of Bagoè. There are three small impoundments in Côte d'Ivoire. | |||
Physical and chemical data | ||||
Conductivity: | 51.4 μ S/cm (mean) |
BIA RIVER
Geographical data | |
Source: | Ghana |
Altitude: | 306 m |
Total length: | 300 km (200 km within Ghana) |
Drainage area: | 9 500 km2 (6 500 km2 within Ghana) |
Countries traversed: | Ghana, Côte d'Ivoire |
Discharges to: | Abi Lagoon, Côte d'Ivoire - 5° N; 3° W |
Volume of discharge at mouth: 83 m3/sec | |
Special features: | two impoundments (Ayame and Ayame II Reservoirs) |
Physical and chemical data | |
pH: | 6.5–7.5 |
Fisheries data | |
No. of fish species: | 32 (Daget & Iltis, 1965) |
BLACK VOLTA RIVER
(International water)
Geographical data | |
Source: | Burkina Faso (70 km southwest of Bazo) |
Altitude: | 300 m asl |
Total length: | 1 300 km (650 km in Burkina Faso) |
Drainage area: | 149 600 km2 |
Countries traversed: | Burkina Faso, Côte d'Ivoire (circa 100 km along border with Ghana), Ghana |
Major tributaries: | Bougouriba, Tui |
Discharges to: | Volta Reservoir |
Volume of discharge at mouth: 243 m3/sec (mean annual) | |
Flood regime: | unimodal flood peak in September-October |
Special features: | the Black Volta has several floodplains fringing its upper course where some 75 000 ha are liable to flooding each year. A particular feature of this is the Sourou Depression in Burkina Faso, with 25 000 ha of flooded lowland, and the “Mare aux Hippopotames” (1 200 ha in extent). |
Physical and chemical data | |
Conductivity: | K20 41–124 μ S/cm (Welcomme, 1972) |
pH: | 6.5–7.3 (Welcomme, 1972) |
6.4 (Blanc and Daget, 1957) | |
Ionic composition: | (Blanc and Daget, 1957) |
mg/l | ||
Na | 3.9 | |
K | 0.25 | |
Ca | 380* | |
Mg | 11.86 | |
CO2 | 11.3 | |
Cl | 17.5 | |
SO3 | 72* | |
SiO2 | 125.5 |
* Ca and SO3 figures seem aberrently high and should be taken with care.
Fisheries data
No. of fish species: 96 (Daget and Iltis, 1965)
CAVALLY RIVER
(International water)
Geographical data | |
Source: | Nimba Mountains, Guinea |
Total length: | 700 km |
Drainage area: | 22 400 km2 |
Countries traversed: | Guinea, Côte d'Ivoire, Liberia |
Major tributaries: | Duobe, Hana |
Discharges to: | Atlantic Ocean, Côte d'Ivoire - 4° 20'N; 7° 30'W |
Fisheries data | |
No. of fish species: | 28 (Daget & Iltis, 1965) |
CESTOS RIVER
(International water)
Geographical data | |
Source: | near Mt. Nimba |
Total length: | 380 km (60 km in Côte d'Ivoire; 110 km along Côte d'Ivoire/Liberia frontier; 210 km in Liberia) |
Countries traversed: | Côte d'Ivoire, Liberia |
Major tributaries: | Nuon |
Discharges to: | Atlantic Ocean - 5° 27'N; 9° 35'W |
COMOE/KOMOE RIVER
(International water)
Geographical data | ||
Source: | Burkina Faso, 5 km north of Karfiguela | |
Altitude: | 420 m | |
Total length: | 1 160 km (150 km in Burkina Faso) | |
Drainage area: | 78 000 km2 | |
Countries traversed: | Côte d'Ivoire, Burkina Faso | |
Discharges to: | Atlantic Ocean at Grand Bassam, Côte d'Ivoire - 5° 8'N; 3° 43'W | |
Volume of discharge: | (at Aniassue, Côte d'Ivoire) | |
September: | 1 040 m3/sec | |
February: | 13.1 m3/sec | |
Maximum: | 2 340 m3/sec | |
Overall annual mean: | 430 m3/sec | |
Flood regime: | floods last from July to October | |
Special features: | there are three minor impoundments (Ouangolodongou, Tanda and Abengourou). | |
Physical and chemical data | ||
Conductivity: | 51.4 μ S/cm (mean) | |
Ionic composition: (Iltis & Leveque, 1982) |
Flood mg/l | Mean mg/l | Low water mg/l | |
Na | 1.2 | 3.3 | 2.4 |
K | 3.2 | 2.5 | 2.8 |
Ca | 3.2 | 4.4 | 5.8 |
Mg | 1.4 | 1.8 | 3.5 |
HCO3 | 19.8 | 30.9 | 41.5 |
Cl | 0.0 | 1.5 | 0.7 |
SO4 | 6.6 | 5.3 | 3.0 |
PO4 | 1.4 | 0.2 | 0.1 |
Fisheries data | |
No. of fish species: | 35 species in Burkina Faso (Blanc & Daget, 1957); |
56 species in Côte d'Ivoire (Daget & Iltis, 1965) | |
No. of fishermen: | 151 (1971) in Côte d'Ivoire |
Total annual catch: | 12 t in Burkina Faso |
NIGER RIVER AND FLOODPLAIN
(International water)
Geographical data | (Welcomme, 1972, 1985) |
Source: | Fouta Djallon, Guinea |
Altitude: | 1 000 m |
Total length: | 4 183 km |
Drainage area: | 1 125 000 km2, including the Benue |
Area of water: |
Floodplain (Niger River) | At peak flood (km2) | At low water (km2) | Floodplain area (km2) | Authority | |
Central delta (Mali) | 20 000 | 3 877 | 16 123 | Raimondo, 1975 | |
Fringing plains | |||||
Niger | 907 | 270 | 637 | FAO/UN, 1971 | |
Benin | 274 | 32 | 242 | FAO/UN, 1970 | |
Nigeria | 4 800 | 1 800 | 3 000 | FAO/UN, 1970 |
Countries traversed: | Niger River: Benin, Guinea, Mali, Niger, Nigeria Tributaries: Burkina Faso, Côte d'Ivoire |
Major tributaries: | Bani (Mali); Alibori, Mekrou, Sota (Benin); Beni (Burkina Faso); Bagoue (Côte d'Ivoire); Sokoto, Banue/Benouè (Nigeria) |
Discharges to: | Atlantic Ocean - 4° 22'N; 5°27'–7°14'E |
Volume of discharge at mouth: 6 100 m3/sec Suspended silt load: 5 050 000 t/yr | |
Flood regime: | At the Nigerian border there are two floods, one with a peak in January-February, originating from Guinea; the other in August-October, originating locally. |
Special features: | Internal delta and lakes (Mali), Kainji dam and reservoir (Nigeria). Delta at mouth. Several floodplains. |
Physical and chemical data | |
Conductivity: | K20: 31 μ S/cm (upper course) (Daget, 1957) |
Temperature: | 19–30° C (upper course) (Daget, 1957) |
pH: | 7.2 (upper course) (Daget, 1957) |
6.7–6.8 (middle course) (FAO/UN, 1962) | |
Ionic composition: |
At level of central delta (Daget, 1957) | |
mg/l | |
Na | 2.99 |
K | 1.96 |
Ca | 4.01 |
Mg | - |
Cl | 1.07 |
SO4 | - |
At level of Kainji dam (White, 1965) | |
mg/l | |
Ca | 3.45–5.98 |
Mg | 1.18–2.69 |
Na | 2.25–5.80 |
HCO3 | 24.64–38.67 |
SO4 | 0–1.73 |
Cl | trace-1.28 |
μ g/l | |
NO3 | 1.43–6.29 |
PO4 | 0.483–3.102 |
Fisheries data
No. of fish species: 135 (Daget, 1954)
Total annual catch:
Niger River in 1966, inland waters (excluding Niger Delta) | ||
Benin | 1 000 t | (FAO/UN, 1971) |
Mali | 90 000 t | |
Niger | 9 696 t | (FAO/UN, 1971) |
Nigeria | 13 450 t | (FAO/UN, 1970) in river |
Total | 114 146 t |
NZI RIVER
Geographical data | ||
Source: | northern Côte d'Ivoire | |
Total length: | 725 km | |
Catchment area: | 35 500 km2 | |
Countries traversed: | Côte d'Ivoire | |
Discharges to: | Bandama River | |
Volume of discharge: | (at Zienoa) | |
Maximum: | 768 m3/sec; | |
October mean: | 317 m3/sec; | |
February mean: | 3.30 m3/sec. | |
Physical and chemical data (Iltis & Leveque, 1982) | ||
Conductivity: | 71 (mean) μ S/cm (at Katiola); | |
106 (mean) μ S/cm (at Bouakè) | ||
Ionic composition: |
at Katiola mg/l | at Bouakè mg/l | ||
Na | 6.4 | 12.0 | |
K | 4.3 | 5.0 | |
Ca | 5.7 | 8.4 | |
Mg | 2.2 | 3.2 | |
HCO3 | 32.0 | 61.7 | |
Cl | 2.7 | 6.3 | |
SO4 | 5.7 | 6.0 | |
PO4-P | 0.7 | 1.3 |
SASSANDRA RIVER
Geographical data | |
Source: | Côte d'Ivoire (Odiensè) |
Total length: | 840 km |
Drainage area: | 66 000 km2 |
Countries traversed: | Côte d'Ivoire |
Major tributaries: | Nzo |
Discharges to: | Atlantic Ocean at Sassandra - 4°48'N; 6°5'W |
Volume of discharge at mouth: 425 m3/sec | |
Flood regime: | from July to November; maximum in September |
Special features: | one major (Buyo) and three minor impoundments (Daloa, Duekue and Gagnoa - the latter on the Daro tributary) |
Physical and chemical data (Molinier, 1976) | |
Ionic composition: |
mg/l | ||
Na | 5.1 | |
K | 2.4 | |
Ca | 4.2 | |
Mg | 2.3 | |
HCO3 | 34.1 | |
Cl | 2.6 | |
SO4 | n.d. | |
PO4-P | n.d. |
TANO RIVER
(International water)
Geographical data | |
Source: | Ghana |
Altitude: | 430 m |
Total length: | 625 km |
Drainage area: | 16 000 km2 |
Countries traversed: | Ghana, Côte d'Ivoire |
Discharges to: | Abi Lagoon |
Volume of discharge: | 129 m3/sec |
Physical and chemical data | |
pH: | 6.9–9.0 |
AYAME RESERVOIR
Geographical data | |
Location: | Côte d'Ivoire - 5°37'N; 3° 10'W |
Altitude: | 91 m at USL |
Date closed: | August 1959 (Ayame I dam) |
Surface area: | 197 km2 (at USL); 84 km2 (min) |
Depth: | 20 m (max) |
Max. length: | 40 km |
Max. width: | 6 km |
Major inflowing river: | Bia |
Outflowing river: | Bia |
Catchment area: | 9 300 km2 |
Physical and chemical data | |
Surface temperature: | 24–32° C |
Conductivity: | 60–270 μ S/cm |
pH: | 6–7 |
Fisheries data
No. of fish species: 37. Two species have been introduced: Heterotis niloticus;
and Oreochromis niloticus (which makes up 50% of the catch).
Total annual catch and effort:
Year | Total catch (t) | No.of fishermen |
1964 | 160 | 320 |
1965 | - | - |
1966 | 555 | - |
1967 | 908 | - |
1968 | 871 | - |
1969 | 1 089 | - |
1970 | 685 est. | 600 |
1971 | 620 | - |
1972 | 672 | - |
1973 | 540 est. | - |
1974 | 750 est. | - |
1975 | 1 120 | - |
1976 | 1 000 | - |
1977 | - | - |
1978 | 547 | 1 058 |
1979 | 843 | - |
Potential annual yield: 100 kg/ha/yr (Welcomme, 1972)
AYAME II RESERVOIR
Geographical data | |
Location: | Côte d'Ivoire - 5° 34'N; 3° 9'W |
Date closed: | 1964 (Ayame I dam) |
Surface area: | 7 km2 |
Max. length: | 5 km |
Max. width: | 2 km |
Major inflowing river: | Bia (outflow from Ayame I dam/reservoir) |
Outflowing river: | Bia |
Special features: | Ayame II Reservoir is situated immediately downstream from Ayame I dam/reservoir. It is heavily infested with floating macrophytes (Pistia). |
BOUAKE RESERVOIR
Geographical data | ||
Location: | Côte d'Ivoire - 7° 41'N; 5° 2'W | |
Depth: | 10 m (max) | |
Physical and chemical data | ||
Surface temperature: | 26.3–27.1° C | |
Conductivity: | 73.8–75.4 μ S/cm | |
pH: | 8.2 | |
Ionic composition: | ||
PO4 | 17–29 μ g/l | |
Total N | 0.24–0.56 mg/l |
BUYO RESERVOIR
Geographical data | |
Location: | Côte d'Ivoire on the White Bandama - 6° 16'–7° 4'N; 6° 54'–7° 30'W |
Altitude: | 200 m at USL; 186.5 m at min. level |
Surface area: | 900 km2 at USL; 200 km2 at min. level |
Date closed: | March 1980 |
Max. length: | 89 km |
Max. width: | 23 km |
Major inflowing rivers: | Sassandra, Nzi |
Outflowing river: | Sassandra |
Fisheries data | |
No. of fishermen: | 238 (1983) |
KOSSOU RESERVOIR
Geographical data | |
Location: | Côte d'Ivoire on the White Bandama - 7–8° N; 5° 30'W (see Fig. 3) |
Altitude: | 204 m when full |
Surface area: | 1 600 km2 |
Date closed: | February 1971 |
Depth: | 60 m (max); 14.3 m (mean) |
Volume: | 20.5 km3 |
Max. length: | 170 km |
Shoreline: | 3 500 km |
Annual fluctuation in level: 2.82 m (mean) | |
Major inflowing river: | White Bandama |
Catchment area: | 33 000 km2 |
Physical and chemical data | |
Temperature: | 25.0–27.0°C |
Conductivity: | K20 70–180 μ S/cm |
pH: | 7.7–9.0 |
Fisheries data | |
No. of fish species: | 84 |
Total annual catch and effort: |
Year | Total catch (t) | No.of fishermen | No.of boats |
1972 | 5 640 | 1 371 | - |
1973 | 4 905 | 2 022 | 1 762 |
1974 | 7 355 | 2 970 | - |
1975 | - | 3 200 | - |
1976–79 | - | - | - |
1980 | 7 500 | - | - |
Potential annual yield: 11 000–16 000 t (FAO/UNDP, 1976)
Specific references: Entz, 1984; FAO/UNDP, 1976.
TAABO RESERVOIR
Geographical data | |
Location: | southern Côte d'Ivoire - 6° 13'N; 5°2'W |
Date closed: | 1978 |
Surface area: | 80 km2 at USL |
Max. length: | 19 km |
Max. width: | 7 km |
Major inflowing river: | Bandama (discharge regulated by Kossou dam upstream) |
Outflowing river: | Bandama |
YABRA RESERVOIR
Geographical data | |
Location: | southern Côte d'Ivoire (near Zatta) |
Surface area: | 3.65 km2 |
Date closed: | February 1974 |
Depth: | 3.7 m (mean); 7 m (max) |
Physical and chemical data | |
Temperature: | 24.3–24.8° C |
Conductivity: | K20 259–282 μ S/cm |
Fig. 3. LAKE KOSSOU/RESERVOIR
(Welcomme, 1972)
YAORA RESERVOIR
Geographical data | |
Location: | southern Côte d'Ivoire (near Zatta) |
Surface area: | 1.70 km2 |
Date closed: | May 1973 |
Depth: | 2.3 m (mean); 6 m (max) |
Physical and chemical data | |
Temperature: | 25.3–25.7° C |
Conductivity: | K20 220–234 μ S/cm |
ZATTA RESERVOIR
Geographical data | |
Location: | southern Côte d'Ivoire (near Zatta) |
Surface area: | 0.81 km2 |
Date closed: | 1970 |
Depth: | 1.6 m (mean); 4 m (max) |
Physical and chemical data | |
Temperature: | 25.0–26.6° C |
Conductivity: | K20 217–279 μ S/cm |
ABY-TENDO-EHY LAGOON COMPLEX
(International water)
Geographical data | |
Location: | Côte d'Ivoire, Ghana - 5°5'–23'N; 2° 51'–3°21'W (Ghana has about 25 km of shoreline along the Tendo-Ehyportia but no actual lagoon surface area) (see Fig. 4) |
Surface area: | 410 km2 |
Depth: | 14.9 m (max); 5.0 m (mean) |
Max. length: | 52 km |
Max. width: | 30 km |
Annual fluctuation in level: 0.3–0.5 m | |
Major inflowing rivers: Bia, Tano | |
Outflow: | channel to Atlantic Ocean; also a short canal to Juen Lagoon in Ghana. |
Physical and chemical data
Surface temperature: 24–30° C
Fisheries data
Total annual catch and effort: in Côte d'Ivoire
Year | Total catch (t) | No. of fishermen | No. of boats |
unspecified | - | 1 654 | 614 |
1979 | 11 000 | - | - |
1980 | 7 200 | - | - |
1981 | 5 000 | - | - |
1982 | 3 500 | - | - |
recent* | 4 250–6 375 |
Potential annual yield: 8 275–10 000 t (Doucet et al., 1985)
Fig. 4. THE ABY LAGOON
(Weigel, 1985)
AGHIEN LAGOON
Geographical data | |
Location: | Côte d'Ivoire - 5° 25'N; 3° 53'W |
Surface area: | 25 km2 |
Max. length: | 12 km |
Max. width: | 3 km |
Outflow: | canal to Poton Lagoon |
BAKRE LAGOON
Geographical data | |
Location: | Côte d'Ivoire - 5° 15'N 4° 05'W |
Surface area: | 8.4 km2 |
Max. length: | 8 km |
Max. width: | 1.5 km |
EBRIE LAGOON
Geographical data | (see Fig. 5) |
Location: | Abidjan, Côte d'Ivoire - 5° 10'–21'N; 3° 43'–4° 48'W |
Surface area: | 560 km2 |
Depth: | 20 m (max); 4.8 m (mean) |
Max. length: | 130 km |
Max. width: | 7 km |
Annual fluctuation in level: 0.3–0.7 m | |
Major inflowing rivers: Komoe, Me, Agnebi | |
Physical and chemical data | |
Surface temperature: 25–32° C | |
pH: | 6.5–8.0 |
Salinity: | 0 to 35 ‰ |
Fisheries data | |
No. of fishermen: | 7 246 |
No. of boats: | 3 938 |
Total annual catch: | 2 000–3 000 t - without seine nets |
6 800–7 800 t - with seine nets (recent) (Doucet et al., 1985) | |
Potential annual yield: 7 000–9 000 t (Doucet et al., 1985) |
HEBE LAGOON
Geographical data | |
Location: | Côte d'Ivoire - 5° 12'N; 3° 33'W |
Surface area: | 2.5 km2 |
Max. length: | 3.5 km |
Max. width: | 1 km |
individual fishing | Treichville market | From CRO document 1983 | ||
beach seine fishing | Dabou market | |||
purse seine fishing | Vidri | |||
shrimp fishing |
Fig. 5. PRINCIPAL FISHING ZONES ON THE EBRIE LAGOON
(Weigel, 1985)
KODIOBOUE LAGOON
Geographical data | |
Location: | Côte d'Ivoire - 5° 14'N; 3° 35'W |
Surface area: | 8 km2 |
Max. length: | 7.5 km |
Max. width: | 1.5 km |
NGNI LAGOON
Geographical data | |
Location: | Côte d'Ivoire - 5° 11'N; 5° 35'W |
Surface area: | 6.3 km2 |
Max. length: | 9 km |
Max. width: | 1 km |
Major inflowing river: Bolo |
ONO LAGOON
Geographical data | |
Location: | Côte d'Ivoire - 5°22'N; 3° 34'W |
Surface area: | 12.6 km2 |
Max. length: | 9 km |
Max. width: | 2 km |
POTOU LAGOON
Geographical data | |
Location: | Côte d'Ivoire - 5° 22'N; 3° 47'W |
Surface area: | 29.4 km2 |
Max. length: | 14 km |
Max. width: | 3 km |
Major inflowing rivers: Mè River and outflow from Aghien Lagoon | |
Outflow: | short canal which joins outflow from Ebrie Lagoon and the Komoe River and then discharges to the Atlantic Ocean |
TAGBA-MAKE-TADIO LAGOON COMPLEX (= GRAND-LAHOU LAGOON)
Geographical data (see Fig. 6) | |
Location: | Côte d'Ivoire - 5° 7'-14'N; 4° 59–5° 25'W |
Surface area: | 250 km2 |
Depth: | 8 m (max); 2 m (mean) |
Annual fluctuation in level: 0.3–0.5 m | |
Major inflowing rivers: Boubo, Go, Bandam | |
Outflow: | Atlantic Ocean |
Fisheries data | |
No. of fishermen: | 2 995 (date unspecified) |
No. of boats: | 1 448 (date unspecified) |
Total annual catch: | 2 899 t (date unspecified) |
600–715 t (recent) (Doucet et al., 1985) | |
Potential annual yield: 2 000–2 800 t (Doucet et al., 1985) |
Fig. 6. THE GRAND-LAHOU LAGOONS
(Weigel, 1985)
7. BIBLIOGRAPHY
Blanc & Daget, 1957
Daget, 1954; 1957
Daget & Iltis, 1965
Doucet et al., 1985
Dufour, 1987
Entz, 1984
FAO/UN, 1962; 1970; 1971
FAO/UNDP, 1976
Gosse, 1984
Iltis & Leveque, 1982
Kapetsky, 1981a
Lazard, 1975; 1977
Molinier, 1976
Raimondo, 1975
U.S. Department of State, 1987
Weigel, 1985
Welcomme, 1972; 1979; 1985
White, 1965
1. GEOGRAPHY AND CLIMATE
The country consists of two parts: (a) a mainland enclave (Rio Muni) and 3 small nearby islands (combined area of 25 952 km2); and (b) the large island Bioko and another smaller island (combined area of 2 020 km2). Rio Muni is mainly a fluvial mainland plateau. The islands are of volcanic origin. Most of the country is covered by tropical rainforest. (See Fig. 1.)
The climate is tropical, alternating wet and dry seasons.
Equatorial Guinea is an almost entirely agricultural economy.
2. HYDROGRAPHY (mainly after Matthes, 1980)
2.1 Lakes
There are three small volcanic crater lakes on Bioko Island.
2.2 Rivers, Floodplains and Swamps
There are no large rivers in the country. The biggest river, Rio Benito (about 230 km long) traverses the middle of the mainland province of Rio Muni and has an average width of some 150 m. It is not navigable, being cut by frequent rapids, waterfalls and also obstructed by tree trunks. Other rivers have similar physiography and all typically have acid, fairly clean, “black” waters of low pH (4.0–6.5), low in nutrient salts and dissolved oxygen, high in humic acids, resulting in low productivity, certainly no more than 25 kg/ha/yr for fish.
2.3 Reservoirs
There are no significant impoundments.
A hydroelectric project at Bikoma (18 km from Bata) on this river will create a small reservoir of 7–10 ha, but fishing will be difficult there as no bush clearing will be carried out.
2.4 Coastal Lagoons
There are three large estuaries (Rio Campo, Rio Benito and Rio Munior Utamboni) with brackish, also acidic, water and fairly extensive mangroves (especially in Rio Muni). These appear to be nursery grounds for many marine fish species, as well as crustacea (prawns).
2.5 Aquaculture
There is no aquaculture in Equatorial Guinea (Vincke, 1989, pers. comm.).
3. FISHERY PRODUCTION/POTENTIAL
3.1 Fish production and per caput supply
Table 1. FISH PRODUCTION AND PER CAPUT SUPPLY - Equatorial Guinea, 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 | Total | Inland capture | Aquaculture 3 | Marine capture | Total |
1970 | 291 | - 4 | 4 000 | 4 000 | - | 13.7 | 13.7 | ||
1971 | 297 | - | 4 000 | 4 000 | - | 13.4 | 13.4 | ||
1972 | 302 | - | 4 000 | 4 000 | - | 13.2 | 13.2 | ||
1973 | 307 | - | 4 000 | 4 000 | - | 13.0 | 13.0 | ||
1974 | 313 | - | 4 000 | 4 000 | - | 12.8 | 12.8 | ||
1975 | 319 | - | 4 000 | 4 000 | - | 12.5 | 12.5 | ||
1976 | 325 | - | 4 000 | 4 000 | - | 12.3 | 12.3 | ||
1977 | 331 | - | 4 000 | 4 000 | - | 12.1 | 12.1 | ||
1978 | 338 | - | 4 000 | 4 000 | - | 11.8 | 11.8 | ||
1979 | 345 | 300 5 | 4 000 | 4 300 | 0.9 | 11.6 | 12.5 | ||
1980 | 352 | - | 2 500 | 2 500 | - | 7.1 | 7.1 | ||
1981 | 359 | - | 2 500 | 2 500 | - | 7.0 | 7.0 | ||
1982 | 367 | - | 2 019 | 2 019 | - | 5.5 | 5.5 | ||
1983 | 375 | - | 2 341 | 2 341 | - | 6.2 | 6.2 | ||
1984 | 383 | 400 | 3 600 | 4 000 | 1.0 | 9.4 | 10.4 | ||
1985 | 392 | 400 | 3 200 | 3 600 | 1.0 | 8.2 | 9.2 | ||
1986 | 401 | 450 | 3 950 | 4 400 | 1.1 | 9.8 | 10.9 | ||
1987 | 411 | 400 | 3 600 | 4 000 | 1.0 | 8.7 | 9.7 |
1 Source: FAO
2 Source: FAO Fisheries Department FISHDAB (includes Rio Muni, Bioko, Annobon, Corisco, Elobey Chico and Elobey Grande)
3 No aquaculture in Equatorial Guinea (Vincke, 1989, pers. comm.)
4 - = data not available
5 FAO, 1980; Matthes, 1980
3.2 Inland catch range and potential yield
Water body | Period | Annual catch range (t) | Potential annual yield (t) |
3 crater lakes on Bioko Island | 1979 | 300 1, 2 | 1 000 1 |
Benito River, Other Rivers/Lakes | 1987 | 400 3 |
1 Matthes, 1980
2 FAO, 1980
3 FAO Fisheries Statistics
Total annual yield: | 300 t in 1979 (Matthes, 1980; FAO, 1980) |
400 t in 1984–1987 (FAO Fisheries Statistics) | |
Potential annual yield: 1 000 t (Matthes, 1980) |
Fig. 1. MAP OF EQUATORIAL GUINEA
(U.S. Department of State, 1984)
4. STATE OF THE FISHERY (after Matthes, 1980)
4.1 Yield
The rivers of Rio Muni and some small volcanic crater lakes on the islands provide limited supplies of freshwater fish (about 300 t/yr) (FAO, 1980).
The total number of inland artisanal fisherman, operating professionally, is around 400 for the whole country (there is no inland fishery on the islands). There are several thousand occasional fishermen, mainly young boys linefishing for small fish and trapping river crayfish or crabs.
Present production/fishermen is unlikely to exceed 0.5 t/yr.
Probably half of the present fish production is being exported in order to buy gear.
4.2 Factors influencing catch
Inland fishery is in an extremely depressed condition; lack of equipment is so acute that each fisherman has only one type of gear left, and that is in poor condition; he is reduced to subsistence fishing, trying to make his equipment last.
Only on Rio Campo and Rio Muni (Cameroon and Gabon borders) do they have access to fishing gear materials, as they sell their catches across the border in order to acquire CFA francs and buy gear.
4.3 Future development possibilities
Given the required equipment, the fishermen can increase their per caput production to around 2 t/yr, i.e., the inland waters could then produce about 1 000 t annually, which is probably all these waters can produce without depleting the stocks.
As the country has abundant hydroelectric potential, the small reservoirs which will be created in relation to this development should be planned with an eye to their fishery potential and should, as a first step, be completely bush cleared.
On Annobon island there is a small crater lake (Lake Mazofin, circa 24 ha), which apparently has an outlet to the sea. The feasibility of stocking this lake with suitable fish (a Tilapia/Clarias combination, for instance) should be investigated.
Owing to the physico-chemical characteristics of the inland waters, there appears to be little potential for aquaculture, considering the costs involved; an equivalent investment in the marine field (particularly in its infrastructures for distribution) would give considerably higher returns.
Marine fisheries are likely to remain the dominant sector of the nation's fishing industry.
5. KEY BIBLIOGRAPHY
Matthes, 1980
6. WATER BODIES DIRECTORY
Lakes |
Bioko Crater Lakes |
Rivers |
Benito River |
BIOKO CRATER LAKES
Geographical data | |
Location: | Equatorial Guinea, Bioko Isdland |
Special features: | 3 crater lakes. |
Fisheries data | |
Total annual catch: | 300 t in 1979 (Matthes, 1980; FAO, 1980) |
BENITO RIVER
(International water)
Geographical data | |
Source: | northern Gabon |
Altitude: | 700 m asl |
Total length: | 365 km (245 km in Equatorial Guinea) |
Countries traversed: | Equatorial Guinea (Rio Muni), Gabon |
Discharges to: | Atlantic Ocean - 1° 35'N; 9° 37'E |
Fisheries data | |
Total annual catch: | 300 t in 1979 (including all inland catches in Equatorial Guinea) |
7. BIBLIOGRAPHY
FAO, 1980
Matthes, 1980
U.S. Department of State, 1984