INTRODUCTION 
Aquaculture according to FAO (1997) is defined as ‘the farming of aquatic organisms including fish, molluscs, crustaceans and aquatic plants in selected or controlled environments’. Aquaculture production may have arisen as an intervention mechanism to enhance food production. It is currently one of the fastest growing food producing sectors in the world. Its global importance is related to its contribution in the reduction of the supply – demand gap of fish products. Production statistics indicate that between 1984 and 1996, there was a three fold increase in aquaculture products (FAO, 1997). The rapid growth in the aquaculture sector contrasts with the decline or near stagnation in the growth of supplies from capture fisheries. The implication is that aquaculture will continue to play an increasing role in fish supplies.