Impactos das ações antrópicas sobre a distribuição da espécie de peixe Piaractus mesopotamicus na bacia hidrográfica Paraná-Paraguai

Abstract

The impacts caused by changes in land use and occupation affect species that depend on vegetation as a source of food, as is the case of the species Piaractus Mesopotamicus. The species is endemic to the Paraná-Paraguay river basin, and because of deforestation, it has increasingly lost sites suitable for its occurrence. Thus, the present study aimed to identify areas of high interest for the conservation of the species Piaractus mesopotamicus, taking into account climatic-environmental conditions and the current scenario of land use and occupation. In order to identify the most suitable areas for its occurrence in the basin, the ecological niche modeling tool was used.. However, this tool was not enough because it is based only on climatic and occurrence data. In order to increase accuracy, the vegetation rate was integrated, which is represented by the current use and occupation of the Earth in the basin. This integration of data gave rise to the index of environmental suitability, which is the association of climatic-environmental data, occurrence data and land use and occupation data. The results of the index were validated through a statistical analysis of spatial autocorrelation. In general, the most suitable sites for the species are concentrated in the upper and lower Paraguay River, which are the regions with the highest vegetation conservation rates, with a main focus in the rivers of the lower Paraguay River, which is the place the smaller amount of Conservation Units, and consequently the place that needs greater protection. The integration of climaticenvironmental data and occurrence data, with data on land use and occupation, has proved to be an efficient tool in the proposal of Conservation Units, since it has been able to identify in a precise way the real places that the species can occur, and who really need protection.