A statistical survey of the artisanal fisheries of south-eastern Nigeria and the influence of hydroclimatic factors on catch and resource productivity

A statistical survey of the artisanal fisheries of south-eastern Nigeria conducted from September 1992 to August 1993 showed that the mean catch per canoe fishing unit per year was 6204 kg and well within the 95% confidence interval of existing earlier estimates. Bonga, Ethmalosa fimbriata, dominated the catch of the coastal/estuarine fisheries; in the freshwater sector, the catfish Chrysichthys nigrodigitatus was the dominant (albeit relatively seasonal) species in the landings. Regression/correlation analysis indicated positive linear relationships between the mean monthly catch ( Y (MA)) as well as the catch-per-unit effort (CPUE) ( Yf −1 (MA)) of the marine inshore fisheries and air and water temperatures ( θ A and θ W, respectively) and estuarine salinity (SAL). No such linear relationships were observed in the case of freshwater fish catch ( Y (FW)); however, the regression of CPUE (i.e., Yf −1 (FW)) on the river/floodplain water level gave a highly significant negative correlation reflecting the difficulty of catching fish in the very much expanded volume of water during floods.