The demersal resources of the Central Gulf of Guinea division (34.3.5) are exploited by the artisanal fisheries of Cameroon, Nigeria, Equatorial Guinea and Sao Tomé and Principe, as well as by industrial vessels of these coastal countries. Other countries like Ivory Coast, Togo, Benin, Spain and USSR have occasionally fished in the area. This chapter describes the data on these fisheries as available to the Working Group.
Table 1 summarizes the information available on the surface areas of the fishing grounds by country in division 34.3.5. These data were taken from the report of the Working Group on the evaluation of the demersal stocks of the Ivory Coast-zaire sector (FAO, 1979b). The Working Groupregretted that no further detailed estimates were available and that therefore confusion continues to exist over the extent of the pink shrimp grounds (30–50 m deep muddy grounds) in Nigeria and Cameroon. Raitt and Niven (1969) indicate that the exploitable area would be 2,500 mi2 in Nigeria, whereas Burukowski and Bulanenkov (1969) give values of 1,300 mi2 and 190 mi2 respectively for Nigeria and Cameroon shrimp grounds. SCET (1980a) repeats these estimates taking the value of Raitt and Niven for Nigeria (9000 km2) and the one of Burukowski and Bulanenkov for Cameroon (700 km2).
The demersal fish and shrimp stocks of Cameroon are exploited since 1951 by the industrial fleet (Laure 1969, 1972). Table 2 shows the numbers of trawlers in the years 1951–1971. Their numbers increased from 1 in 1951 to 39 in 1971. The fleet composition since 1970 is presented in Table 3 (Njock, in press). The industrial trawlers belong to several fishing companies which fish for shrimp or finfish. The distribution of the shrimp and finfish trawlers per fishing company is presented in Table 4 (1979–1984). The actual fleet consists of trawlers of 20–31 m length, 345–650 HP and 85–177 GRT. The mesh size (codend) used by the shrimp trawlers is in the range of 32–40 mm (stretched mesh) and that of the finfish trawlers of the order of 36–41 mm.
During the year the finfish landings may vary considerably. Landings tend to decrease at the end of the dry season (March to June) and to increase during the rainy season (July to October). From November to February the catches stay more or less stable. The average monthly landings over the period 1980–1983 are presented in Figure 1. The seasonal variation of the shrimp landings is synchronous to the rainfall. Maximal catches are taken in the wet season (April-September). From October to March the shrimp catches are rather feeble (Figure 2).
The Cameroonian shrimp trawlers which fish for pink shrimp (Penaeus notialis) operate mainly in the area between the estuary of the Cameroon River and the mouth of the New Calabar River (Nigeria). From time to time the estuary of the Sanaga River is frequented. The pink shrimp is fished between 30 and 60 meters depth. The Guinea shrimp (Parapenaeopsis atlantica) is sought in the inshore zone between 10 and 30 meters depth. The main fishing grounds for this species are found between the Sanaga River and the Ambas Bay. Interruptions of unknown duration have occurred in 1979 and 1981 and since 1983 the Nigerian waters have not been visited by Cameroonian vessels (Njock, in press).
The traditional fishing grounds for the finfish trawlers are found in the estuaries and in the inshore zones off the mouths of the Rivers Rio del Rey, Sanaga and Bibundi between 6 to 20 meters depth (Figure 3).
The fishing company COTONNEC which exploits the finfish resources since 1953, operates off the river mouths. In Table 5 the numbers of fishing trips per area are presented for the period 1977–1978.
The catches consist principally of sciaenids or croakers (Pseudotolithus elongatus, P. typus), polynemids or threadfins (Galeoides decadactylus, Pentanemus quinquarius) and ariids or catfish (Arius spp.).
In 1977, a socio-economic survey in the artisanal fishery was undertaken by the Panafrican Institute for Development based at Douala (Dikoume, 1976 and 1977). This survey identified the major problems with which the artisanal fishermen are confronted. About 95 % of the artisanal fishermen are of Nigerian origin. Further nationalities recorded beside Cameroonian are Benin, Central African Republic, Ghana, Equatorial Guinea, Chad and Togo. A total of 15 000 – 17 000 fishermen was recorded, operating 2 300 fishing units. The percentages of motorized canoes were rather low, and of the order of 3 %. Gears used were mostly passive, beach and purse seines being of recent introduction.
A frame survey conducted in 1982–1983 by the Station de Recherches Halieutiques (SRH), Limbe, gave the following results (see Annex 3) : at the 57 landing sites visited, 6011 canoes were present (4–12 m long), and 18 615 fishermen of which 91% were immigrants. 33% of the canoes were motorized. The artisanal fishery mostly concentrates on the capture of pelagic species (Ethmalosa and Sardinella maderensis), which make up about 80 % of the total catch. Gears used are currently beach seines, hook and line, longlines and bottom nets for fish and traps for shrimps. The artisanal fishery usually operates in estuaries and the zone up to 2 miles offshore. Main species caught are Polydactylus quadrifilis, Pseudotolithus typus, P. senegalensis, P. elongatus and Arius spp. The fishing season is mainly the period April-October for finfish and October-December for shrimp.
No data are as yet available on the quantities caught, but SRH, Limbe, will start a catch assessment survey in July 1985.
The industrial fishing fleets exploiting the demersal resources of Nigeria consist of the inshore ice trawlers, freezer trawlers and shrimpers. The industrial fleet underwent rapid expansion since the early 1970's.
Numbers of inshore trawlers increased from 13 in 1971 to 29 in 1976 and to 52 in 1983. The Polish ice trawlers with an average length of about 13 m make short trips of about 6 days.
The Nigerian industrial fleet includes several freezer trawlers of private companies with an average length of 24 m. These make longer fishing trips of up to 25 days.
The ice trawlers and freezer trawlers operate on the sector of the continental shelf between Benin and Cameroon. They frequent areas with muddy sand, sandy muds, muds and sands of depths of more than 20 m. The total estimated continental shelf area possibly fished by artisanal fleets and inshore trawlers is shown in Table 6.
The Nigerian shrimpers mainly operate in the coastal sector extending from the mouth of Benin River, to the Cross River estuary. The shrimp trawlers appear to make higher catches around estuaries with greater flows. The sector of the continental shelf mainly frequented by shrimpers is given in Table 7.
The Shrimp catch is dominated by pink shrimp (Penaeus notialis). The Guinea shrimp (Parapenaeopsis atlantica) ranks second and the caramonete shrimp or tiger shrimp (Penaeus kerathurus) is of less importance. It should be noted that the estuarine white shrimp (Palaemon hastatus) does not appear in the shrimpers' catches made outside the estuaries.
There are differences in depth distribution of various shrimp species caught. The estuarine white shrimp (Palaemon hastatus) occurs in more shallow waters possibly less than 10 m deep. The pink shrimp (Penaeus notialis) extends to deeper waters on the continental shelf whereas the Guinea shrimp (Parapenaeopsis atlantica) occurs at intermediate depths.
The artisanal fishermen operate in the brackish water sector (that is the creeks, estuaries, intertidal mangrove swamps) and in the coastal inshore water up to a depth of about 40 m.
There are two principal types of artisanal fishing units:
the small dugout canoes in estuaries, lagoons and creeks, and,
the large motorized “Ghana-type” canoes mostly operating in waters up to 40 m depth.
The available data indicate that, at present about 19% of the total national coastal inshore canoes are motorized. During the dry season (October-May) the small dug-out canoes operate inside the estuaries and creeks whereas motorized canoes fish in the open sea. The rainy season with storms extends from May to September and the rough sea conditions restrict fishing operations of the open-sea fishermen. Hence a number of motorized canoes resort to fishing in the coastal lagoons, creeks, and also in the bar-built, lagoon-like estuaries.
The evolution of the Nigerian artisanal inshore canoe fishery based on the work of Ssentongo, Ajayi and Ukpe (1983) is given in Table 8.
The Nigerian multispecies demersal stocks are exploited with a wide variety of artisanal gears : set gillnets, beach seines, large, meshed shark drift nets, longlines/handlines and various traps.
The demersal target species exploited by artisanal fishing units are : croakers (Pseudotolithus), threadfins (Galeoides, Pentanemus and Polydactylus), soles (Cynoglossidae), marine catfish (Arius), brackishwater catfish (Chrisichthys), snapper (Lutjanus), grunters (Pomadasyidae), groupers (Epinephelus), and the estuarine white shrimp (Palaemon).
The 40 m contour is considered a fairly reliable boundary of the thermocline separating upper layer oceanic currents from the lower oceanic currents. It has been noted that the thermocline tends to limit the extent of the distribution of demersal fish stocks on the continental shelf. The Nigerian artisanal fishermen do not appear to extend beyond the 40 m depth. Their fishing is confined to the estuaries, creeks and offshore waters above the thermocline.
On the basis of records of the Federal Department of Fisheries (Lagos), the artisanal fishery accounts for more than 70% of the total national marine fish production. A list of the main demersal fish species exploited by artisanal and industrial fleets is given in Table 9.
As Benin waters form part of CECAF Statistical Division 34.3.4, and the artisanal fishery is entirely limited to this division, only the industrial fishery which also partly fishes in Nigerian waters (34.3.5) is dealt with here. Annex 4 describes the demersal fishery in Benin. Before 1972 a fleet of foreign trawlers (French, Italian, Greek) was based at Cotonou, from where fishing trips were made in Benin and Nigerian waters. No details were available to the Working group on their sizes, or activity patterns (*). Since 1973, only one or two local trawlers were active, partly in division 34.3.5. Between 1981 and 1983, the number of vessels further declined from three to one and in 1984 three vessels joined the fleet of which two for the joint Benin-Lybian fishing company (*). Recent private applications for licenses indicate that the number of vessels may further increase in the near future.
Annex 5 describes the Ivorian shrimp fishing activities in Nigerian waters, which were limited to the period 1970–1974. Six vessels (120–400 HP) were active in 1970, 11 in 1971, 8 in 1972, 6 in 1973 and 2 in 1974. After the collapse of the Ivorian shrimp stock in 1980–81, some vessels may again have fished in Nigerian waters.
Due to the absence of a Togolese scientist, no data were available to the Group on possible Togolese fishing activities in statistical division 34.3.5. A national report on the Togolese fishing activities was submitted after the meeting and included as Annex 8. It describes the total Togolese fishery, and it is not known if and to what extent fishing took place in Nigeria waters.
In 1967, 10 small Spanish trawlers were based at the island of Fernando Poo, from where fishing operations were made in the 30–60 m depth zone of the Nigerian, Cameroonian and Gabonese shelf (Lagoin and Salmon 1967a). of these vessels, 7 measured 16 m (180 HP) and 3 20 m (200 HP). The seven smaller vessels fished mainly for shrimp which represented up to 20% of the catch. High value bottom fish was the main target of the three larger vessels (SCET, 1980b).
In 1973, this local industrial fleet had practically disappeared and joint Soviet-Guinean venture ECOPESA was created, using 3 vessels (1 freezer SRTM, 1 trawler SRT, 1 shrimper MRTR). Few details are known about the fishing operations, the only data available being the numbers of vessels which landed fish:
| 1974: | 4 |
| 1975: | 5 |
| 1976: | 8 |
| 1977: | 8 |
| 1978: | 11 |
These Soviet vessels caught demersal fish as well as shrimp in Equatorial Guinea, Nigerian and Angolan waters. Shrimp catches were probably sold to Spain according to their joint SOVHISPAN agreements. Soviet operations in Guinean waters ceased after 1979 when the fishing agreement was not renewed.
In 1979 a French shrimping Company based at Libreville, Gabon, obtained a licence for 2 shrimpers to fish off Rio Muni. After some exploratory fishing trips, during which the fishing gears were seriously damaged due to the uneven structure of the bottom, this company withdrew and in 1980, no more industrial fishing activities took place in Equatorial Guinea (SCET, 1980b). The present situation (1985) is unknown but in the framework of mutual fishing agreement between Cameroon and Equatorial Guinea, some foreign trawlers based in Equatorial Guinea are thought to fish in Cameroonian waters.
FAO (1970) made a frame survey of the traditional artisanal fishery and found that there existed about 1000 dug out canoes and 2800 fishermen catching annually 2000 tons of fish. The demersal species exploited by handlines only make up a small percentage of this total.
SCET (1980b) reports, on the basis of a mission in January 1980 to some landing sites that the numbers of canoes were greatly reduced in the period 1973–1979, most being destroyed for political reasons. The present numbers of canoes is about 400 (Juhl, 1982).
These volcanic islands have a very limited continental shelf area, and the waters are clear and transparent, indicating little productivity. Besides, the bottom structure does not allow any industrial trawling. In 1979, there were 6 liners catching demersal fish. The artisanal fishery mostly catches pelagic species, although some handlining is done. 1500 canoes were present in 1967 and 1979, of which 300 were motorized (Lagoin and Salmon 1967b, SCET 1980c).
The Working Group noted that in both Cameroon and Nigeria conflicts occur between the artisanal and industrial demersal fleets when fishing on the same grounds. In order to protect the artisanal fishery, the authorities have adopted the following regulations. In Cameroon, the first two miles from the shoreline are reserved for the artisanal fishery. In Nigeria, the inshore trawlers are not allowed to fish at depths shallower than 20 meters (or less than two miles from the shoreline). It was noted that the regulations are not always respected and that artisanal fishing gear is occasionally damaged by industrial trawlers operating too close inshore.
Since the inshore areas of the continental shelf are spawning grounds for a number of demersal species, the Working Group felt that the competent authorities should take the necessary actions to regularize the situation.
