Methods Numerical data, maps and satellite images and were collected and categorised into environmental and economic factors of production. Each was given a physical score from 1 to 4. These were then processed to produce surrogate thematic maps using ArcView 3.2 at a scale 1:7,000,000 and projected geographically.

Results Twelve percent of the Nigeria’s area, 112,085 square kilometres has very sufficient water for fish farming and about 75 percent or 696,314 square kilometres have moderately sufficient water. 98 percent falls within very suitable and suitable areas for water temperature. Dissolved oxygen and pH were found to be most limiting environmental factors; areas that fall within the very suitable and suitable are 6.0 percent and about 5.0 percent respectively. Suitable soil covers 77 percent and 75 percent has adequate common and trace elements for good fish growth. Almost all of Nigeria has some farm residues that could be used either as feed or fertiliser; more than 50 percent is suitable. Fisheries manpower was of higher academic quality suited mostly for academic teaching. No correlation between availability of man power to availability of fish farms. About 30 percent of area has more than 200 individuals per square kilometre i.e. good market. Environmental considerations favour good potential. Favourable environmental considerations neutralises the negative effects of economic factors and the result is about 77 percent (709,305sq.km or 70 million hectares) of Nigeria’s area have very good potential outside February to May in the some northern parts. The remaining 23 percent is of moderate potential and the remaining 23 percent is of moderate potential. Economic factors were 70 percent unsuitable for fish farming. Trained manpower contributes most to this negative influence.

Abstract presented at the Fourth International Symposium on GIS/Spatial Analysis in Fishery and Aquatic Sciences in Rio de Janeiro, Brazil, from 25–29 August 2008.