Geographic Information Systems as an Integration Tool for the Management of Mariculture in Paraty, Rio de Janeiro, Brazil

Abstract

Worldwide, the exhaustion of marine living resources, due to the degradation of the environmental quality and to overfishing has driving efforts to aquaculture as an alternative to the production of protein rich food. A FAO report of 2004 (Food and agricultural organization, 2004) has pointed out that for a total of 132 million tons of aquatic food in 2003, 31.7 % was produced from aquaculture, a rate that increased 22.8 % in the six preceding years (25.8 % in 1998). Although marine aquaculture contributes with only 12.6 % of the whole 2003 production, it experienced an increased production of 24.4 % since 1998. Furthermore, marine fish capture has reached peak values in the year 2000 (86.8 million tons), but afterwards it showed a consistent decrease (81.3 million tons in 2003; Food and agricultural organization, 2004). Although aquaculture has been seem as a major alternative for the threat of reducing stocks of fish worldwide, its insertion among the other coastal uses has shown to present significant environmental issues. Troell et al. (2003) analyzed peer-reviewed papers published in the literature of mariculture and identified a number of findings and techniques that provide new approaches for the sustainability of the activity. It is clear from Troell and colleagues’ article that integration of the activity within the coastal zone management is the only way that can lead to a long term sustainability. On the other hand, Focardi and Corsi (2005) observed that the techniques to manage mariculture are still complicated and demand adaptation for each environmental condition, and is unaffordable for coastal populations in developing countries. The lack of sound management techniques drive fish-farmers to use chemicals that improve production, or to work with fed cultures and exotic species that impact the water quality, and affect ecosystems. Among the 10 future actions reported in Troell et al. (2003), the last one concerns the transfer of technology from researchers to producers, constituting the most challenging task for the sustainability of the activity. Considering the complexity of uses in the coastal region and the possibility of conflicts that compromise the sustainability of the different activities, it is largely agreed that the application of geographic information system (GIS) modeling to determine the boundaries of the activities