Pond aquaculture spatial distribution, production and productivity determinants in Ghana
The choice of a suitable site for any aquaculture practice is a critical decision to make since it has a large impact on the economic profitability of the venture, considering the fact that location defines the amount of capital needed, production costs, yield and access to market. The limited public and private sector support for small-scale aquaculture can be optimized if farms are zoned into areas with relatively similar performance and needs. Considering the high rate at which aquaculture is increasing globally and its consequent impact on the environment, it is projected that improvements will be made in the practices employed in aquaculture. As these improvements are made, there is the need for the review of the location of aquaculture infrastructure and services in order to increase the productivity of the sector. Also, aquaculture statistics such as location of farms and production estimates are fundamental to policy making and development planning at both national and global levels. Aquaculture statistics are however chronically scanty or unreliable in developing countries such as Ghana. Thus, the goal of this study was to show the relative suitability of areas in Ghana for aquaculture and identify the key variables to be considered in the development (including improvement of existing farms) of the aquaculture sector of the country. I used satellite imagery and GIS data in combination with field observations and questionnaires, to develop a map of the feasibility of pond aquaculture in Ghana and provide a reliable estimate of the number of ponds, their areas, productivity and aggregate production in the country. The main factors that have influenced the current distribution of pond aquaculture in Ghana are population density (indicating the availability of markets, input and labor) and proximity to stream and road networks. My results show a gross underestimation of the number of fish ponds in the country and smaller sizes of ponds than existing records suggest. The average water depth of ponds in Ghana is only half of the recommended depth which explained over 80% of the variation in productivity among farms. I estimated the contribution of ponds to domestic fish production to be two to three times what has been previously reported, but still well below the potential. The results of this study will be vital to current national and international efforts to improve aquaculture enterprises in Ghana.