Estudo da característica estrutural das praias de nidificação de Podocnemis expansa e dos impactos potenciais decorrentes da atividade antrópica em áreas ribeirinhas na Bacia do Araguaia- TO

Abstract

It is one of the most important representatives of the turtle fauna of the Amazon region Podocnemis expansa. This species has a tendency to spawn in groups of several turtles on the same night. Their nests are relatively deep and concentrated in a certain area of the beach. The nesting sites are crucially important to many animals of different species, in particular for turtles, since the choice of an environment can influence the phenotype, the survival of chicks and cost of the female reproduction, affecting maternal and adequacy of descendants. This study aimed to evaluate aspects related to the reproductive process of P. expansa and the impacts of anthropogenic interference in riverine areas surrounding the river Javaés and Formoso River in the Araguaia basin - TO. They were marked 75 nests of P. expansa in the two areas of study, 38 from the beaches of Javés River (Pium-TO) and 37 of the Formoso river beaches (Lagoa da Confusão - TO). Regarding the height of the beaches of the two study areas, the U test was not significant (U = 14125; p = 0.8237). In comparison relationship between areas, the heights of the P. expansa nests on the beaches of Javaés River differed from the heights of the nests of the Formoso river beaches, with significant results (U = 331.5, p <0.0001) .When analyzed data grain size, we obtained significant results p <0.000015 showing that there is a relationship between grain size samples of all the beaches. The location, marking and characterization of spawning environment in both reproductive areas showed us that the beaches of the Araguaia River basin, also have favorable properties for nesting P.expansa and can say that possess natural features and the height of the beaches not influences the granulometry of the same standard. The impacting activities in the areas studied in the show that there is need for increased oversight, since the beaches of the river Javaés and Formoso river, did not significantly differ by the amount of impacting activities, but the intensity of these activities in each area.