This fishery resource assessment was undertaken between August 1980 and April 1985 at the request of the FAO/UNDP Project for Artisanal and Inshore Fisheries Development (NIR/77/001) and the Federal Department of Fisheries (FDF) of Nigeria. The purpose of the study was to estimate the potential yield of exploitable fish stocks available to the artisanal and coastal inshore fishermen. The study also evaluates the present level of exploitation of both the artisanal canoe fleets and the industrial fleets exploiting the same or contiguous fishing grounds. Focous is given to present-day catch magnitudes and catch rates as well as to the optimum and extra catch that could result from various fishery development activities.
The Federal Government of Nigeria has had a vigorous programme for accelerating development of the artisanal and coastal inshore fisheries and fishermen's cooperatives. In these circumstances, it is vital to determine the magnitude of the available resources and their potential yield compared to present levels of harvest in order to be able to ascertain the long-lasting economic benefits that can accrue from various fishery development activities and management policies.
Fishery statistical data of the Federal Department of Fisheries (Lagos) show that the inshore and brackishwater artisanal fisheries contributed about 323 900 t and about 227 700 t of marine fish landings in 1981 and 1984 respectively. But national coastal industrial fisheries (shrimp and finfish) only landed about 14 400 t and 24 600 t in 1981 and 1984 respectively. Hence, the artisanal sector has thus consistently provided over 90% of the total declared national fish landings.
Long historical catch records and catch per unit effort data (cpue) which would give indices of effort, biomass and potential yield are not available. Hence, it is not possible to apply general production models to evaluate long-term cyclic variations. A more meaningful interpretation of possible species interaction and fishing trends would require continuous collection of catch and effort data of various fishing fleets.
The inshore multiple stock fishery of Nigeria is exploited by a variety of gears (gillnets, castnets, beach seines, trawls, purse seiners, ringnets, traps, hooks and handlines and hooks on longlines); and unfortunately any attempt to use realistic mathematical models in assessing the status and potential of the resources would introduce complexities that would require more and more basic data. But in Nigeria fishery development is already in full swing and there are indications that some of the exploited fish species are declining and require prompt management measures. In these circumstances, we have adopted a general ecological approach through the study of fish communities to assess possible stock potentials. Hence, this study focuses on the magnitudes of the demersal and pelagic stocks, assesses the composition of exploitable stocks, compares the productivity and catch rates in the different coastal States and geographical sectors (creeks, estuaries and open coastal inshore waters), and describes the interaction between various fisheries. Additionally, this report examines the results of various acoustic and fishing surveys conducted in Nigerian waters.
