The raw analytical results of this study have only very recently been generated. Therefore, in this article the objective is to provide a brief overview of the study and some examples of the early results. An estimate of warm water fish farming potential in Africa already has been made (Kapetsky, 1994) and the implications for food security have been examined (Kapetsky, 1995). However, no similar studies have yet been made for Latin America. The objective was to estimate the potential fish farming in the inland waters of continental Latin America to: (1) stimulate improved planning for aquaculture development at national levels (2) provide information to plan comprehensively for technical assistance activities by FAO and other national and international organisations
This study was carried out using a geographical information system (GIS) for the basic analyses. An overview of GIS applications in aquaculture is provided by Meaden and Kapetsky (1991) and a review of applications was made by Kapetsky and Travaglia (1995). This study estimates potential in three categories that relate well to the types of fish farming in Latin America described by Martinez-Espinosa (1994, 1995) : small-scale, with minimum inputs; and two levels of commercial farming distinguished by differing feeding levels and weights at harvest. This investigation is similar in many ways to a traditional site selection study. That is, the study quantifies how well sites satisfy the requirements of the culture system and how well four candidate species will perform at the sites. It differs only in that a GIS is used to quantify the potential and in that the study is synoptic for all of Latin America. Each site that is being evaluated is an approximately 9 km x 9 km (at the equator) grid cell of which there are nearly one-quarter million in Latin America. For the first time in so far as we are aware, a bioenergetics model was incorporated into a GIS to predict the number of fish crops possible per year over a large geographic area. Four representative species were included: Nile tilapia (Oreochromis niloticus), tambaqui (Colossoma macropomum), pacu (Piaractus mesopotamicus) and common carp (Cyprinus carpio). The bioenergetics model (adapted from Bolte et al., 1995) accounts for the effects of seasonal water temperature, photoperiod, size and feeding level on food consumption rates, and therefore fish growth. The number of crops per year for each of the our fish species was estimated from one year simulations with the energetics model. Daily water temperatures required for the growth model were obtained by the use of a water temperature model (Nath, 1996).
Models for commercial and small scale fish farming development and operation bring together the factors tabulated below according to their relative importance as established by FAO experts and the first author using a pair-wise comparison method (table 1).
|Commercial Model||Small-Scale Model|
|Farm Gate Sales||3%||6%|
|(a) Commercial Model||(b) Small-Scale Model|
The results (although as yet unverified) are encouraging: There are 9 countries that have more than 50% of their area in the Very Suitable (VS) category for commercial fish farming and 11 countries in the same category for small-scale farming.
The results from the bioenergetics model for each of the four species, in terms of numbers of crops per year possible, were analysed via the commercial and small scale models. For illustration, two outcomes are reported: The first, a best of the best outcome, is shown in Figure 4. It combines areas that have scored VS for commercial fish farming with those that provide an environment in which more than one crop/year of Nile tilapia can be realised . All of the countries that score highest for this combination are in Central America. The second outcome combines the small-scale model with the critical biomass approach in the bioenergetic model. There are nine countries in which 40% or more of the area could lend itself to such low-level small-scale farming of Nile tilapia (Figure 5).
Completion of the Study and Publication It is intended to publish this study in the COPESCAL (Committee for Inland Fisheries in Latin America) Technical Paper series in English and Spanish. Look for the English version in a few months and the Spanish version towards the end of the year.
Bolte, J.P., Nath, S.S. and D.H. Ernst. 1995. A decision support system for pond aquaculture. Twelfth Annual Administrative Report. PD/A CRSP. Corvallis, OR. Pp. 48-67.
Kapetsky, James McDaid. 1995. A first look at the potential contribution of warm water fish farming to food security in Africa. In: Symoens, J.-J. and J.-C. Micha (eds.). Proceedings of the Seminar on the Management of Integrated Freshwater Agro-Piscicultural Ecosystems in Tropical Areas, Brussels, 16-19 May, 1994. Technical Centre for Rural Co-operation (CTA), Wageningen, Netherlands. pp. 547-592.
Kapetsky, J.M. and C. Travaglia, 1995. Geographical information systems and remote sensing: An overview of their present andpotential applications in aquaculture. In: Nambiar, K.P.P. and T. Singh (eds). Aquaculture towards the 21st Century. INFOFISH, Kuala Lumpur. pp.187-208. Kapetsky, J. M. 1994. A strategic assessment of warm water fish farming potential in Africa. CIFA Technical Paper. No. 27. Rome, FAO. 67p.
Martinez-Espinosa, M. 1994. (ed.). Entre la acuicultura de los mas pobres y las de los menos pobres . Una propuesta methodologica para el desarrollo de la acuiculturea rural tipo II: Dos casos piloto en Venezuela y Colombia. Proyecto Aquila II. GCP/RLA102/ITA. Documento de Campo No. 21. 114p.
Martinez-Espinosa, M. 1994. Development of Type II rural aquaculutue in Latin America. FAO Aquaculture Newlsetter. (11): 6-10.
Meaden, G.J. and J.M. Kapetsky. 1991. Geographical Information Systems and Remote Sensing in Inland Fisheries and Aquaculture. FAO Fisheries Technical Paper 318. 262p.
Nath, S.S. 1996. POND: A decision support system for pond aquaculture.
Ph.D Dissertation, Department of Bioresource
Engineering, Oregon State University, Corvallis, OR. In preparation.