Data on total demersal fish landings by the industrial fleet are available since 1951 (Table 2). These also include catches from freezer trawlers fishing outside Cameroonian waters. Catch and effort statistics for the industrial fleet fishing in Cameroonian/Nigerian waters exist since 1970. In Table 10 the total fish and shrimp catches are summarized by species. Since 1979 detailed catch data are available for the fishing companies operating in Cameroonian waters (Tables 11a-f). The efforts for the shrimp and finfish trawlers were standardized for a 400 HP vessel by Njock (in press). The effort data are given in number of days fishing (Table 12). The fishing strategy of one of the companies changed in 1980 when shrimpers started fishing for finfish in the period unfavourable for good shrimp catches. The raw effort data for the several companies are presented in Table 13.
Catch per unit of effort data for the Cameroonian fleet (fish and shrimp trawlers), for the finfish trawlers of COTONNEC and for the shrimp trawlers of CRECAM are summarized in Table 14.
Total fresh fish landings of the industrial fleet in the period 1970–1982 fluctuated between 15736 tons (1974) and 20397 tons (1976). In 1983 and 1984 catch levels (14230 t and 12457 t respectively) are much lower than in the preceding years as Cameroonian trawlers have no longer fished in Nigerian waters. The CPUE follows more or less the same trend.
Shrimp landings increased from 942 t. (1970) to 2360 t. (1972), and then decreased again to 1696 t. in 1975. Catches went up to 2438 t. in 1977. After 1977, total shrimp landings dropped to 268 t. in 1980 to increase again to the present level of 859 tons.
The Working Group noted some gaps in the available statistical data and observed that more data were needed to enable management of artisanal and industrial fisheries.
The Working Group also focused attention to the difficulties encountered in collecting and estimating landings in the remote extensive Niger Delta area with estuaries, mangroves and creeks.
The total demersal finfisn and shrimp catch by artisanal and industrial fleets account for about 70% of the total national catch from brackish waters and sea. The croakers (Pseudotolithus), threadfins (Polynemidae), soles (Cynoglossidae), grunters (Pomadasyidae) are the dominant finfish species landed.
Although sampling coverage in some coastal sectors (particularly the Niger delta area) is incomplete, the total catch of demersal fish species by the artisanal fishing units was reported to increase from 143 700 t. in 1971 to about 259 000 t. in 1983 and suddenly dropped to about 159 400 t. in 1984 due to certain economic factors encountered by the fishing industry. The catch trends are given in Table 15.
Similarly the demersal finfish catch of inshore fish trawlers increased from 5 700 t. in 1974 to 12 400 t. in 1981 and then to 22 300 t. in 1984 as shown in Table 15.
The total annual shrimp catch by shrimpers increased during the period 1970–1983 (i.e., 1 200 t. in 1972 ; 1 700 t. in 1976; 1 900 t. in 1979 ; and 3 500 t. in 1982) as shown in Table 15.
There are at present insufficient data to enable reliable assessment of the shrimp and prawn resource accessible to the artisanal coastal inshore fishermen. Shrimps and prawns occur in an inshore strip along the entire Nigerian coast. The total exploitable area is put at 6 475 km2 (2 500 mi2). The most important stock is located in the Niger Delta area. Exact catches by fishing grounds of penaeid shrimp species, even those of Penaeus notialis are unknown. There are no separate data available on the exact catch of Palaemon.
The species composition and catch magnitudes of the demersal stocks exploited by Nigerian artisanal and industrial fleets are given in Table 16. The catch trends of the inshore trawlers based at Lagos are shown in Table 17.
Information on fishing effort expended to obtain a certain quantity of catch is scanty. In most instances the weight of the catch and the value of fish are recorded. Information on numbers of gillnets, castnets, hooks, beach seines, etc., used is still missing. There are no data on rates of discards from shrimp trawlers or other major gears operated by the industrial fishermen but these are likely to be considerable. Reliable data on separate effort in the creeks, estuaries, coastal lagoons and inshore waters are still lacking. However, general trends in fishing effort exerted by the artisanal fishery are given in Table 18.
Available data also indicate an increase in number of inshore fish trawlers and shrimpers operating on the Nigerian continental shelf during the period 1971–1984 (see Table 18). The rapid expansion of the industrial fleet in the early 1980's is due to the Government supplying Polish inshore trawlers to artisanal fishermen cooperatives under the 50 % subsidy scheme.
The Working Group examined effort data of the artisanal fishing units and noted that the information was not adequate to enable determination of CPUE for the entire national artisanal canoe fleet.
Past trends in the industrial fisheries (trawlers/shrimpers) are given in Table 19. Since there is no information on numbers of days fished for the entire national industrial fleet, the determination of equilibrium yield could not be attempted. Available data from two of the Nigerian national fishing and shrimping companies (shown in Table 20) however indicate a decline in total catch and CPUE between 1982 and 1984.
Reliable statistics on shrimp catches in Nigerian waters are only available for 1973. The total catch in this year was about 142 tons as shown in Annex 5.
Annex 4 summarizes catch data for industrial vessels based at Cotonou for the period 1981–1984. It is not known to what extent catches were made in Nigerian waters.
Industrial fisheries statistics are limited. In 1967, the total catch was of the order of 877 tons of demersals, of which 20–25 % was shrimp. No data are available on USSR catches, except that they landed annually 4,000–6,000 tons of fish in the period 1973–1979. These quantities were not necessarily caught in Statistical division 34.3.5.
The artisanal fishery caught an annual 1500 t. (FAO 1970) or 2000 t. (Lagoin and Salmon 1967a) prior to 1970. Present catch levels are thought to be closer to 1000 t.
The industrial fleet composed of 6 liners and 2 lamparos caugnt 320 t. of fish in Sao Tomé waters. The artisanal catch is of the order of 1880 t. in 1967 and 1500 t. in 1979 (SCET 1980c) but consists mainly of pelagics.
Annex 8 summarizes the available data on Togolese fish landings. Like for Benin, it is not known what part of the catch, if any, was taken in statistical division 34.3.5.
