Insetos aquáticos da serra do Tepequém, Roraima, Brasil: taxonomia de Trichoptera e Ephemeroptera e efeitos das atividades do garimpo de diamante

Abstract

The aim of this work was to inventory the fauna of the Serra do Tepequém, Roraima state Brazil and to evaluate the effects of diamonds mining activities on this fauna. The thesis is divided into four chapters that together describe the importance of the Serra do Tepequém to preserve the diversity of aquatic insects of Roraima. The first chapter consists in an analysis of the diamonds mining effects on the immature aquatic insects fauna of the Serra do Tepequém, focused on a local scale. We evaluated 19 streams located high in the mountains, being eight preserved and eleven impacted streams (which were the subject of mining activity). We find that the activities related to the extraction of diamonds carried to reduction in the richness of taxa and a simplification of the community of aquatic insects. We don’t have differences in the abundance between the two streams group evaluated. The estimated richness taxa bigger in the preserved streams and related to the vegetation cover. The variables that best explained the community of aquatic insects consisted of two parameters: vegetation cover and dissolved oxygen. The removal of riparian vegetation in impacted streams led to a reduction of habitats, reduction of richness and modification of the aquatic insects communities. The second and third chapters composed respectively of a Trichoptera and Ephemeroptera species list of the Serra do Tepequém, a comparison with the fauna of other locations with registration of Trichoptera and Ephemeroptera species in the Roraima state and description of new species to Science. The survey revealed that the fauna of the Serra do Tepequém has a high diversity of aquatic insects, housing 50% of the Trichoptera fauna and 46% of the ephemeroptera fauna known to the Roraima state, indicating that this region should be considered a priority area for the biodiversity conservation in Roraima state. In the fourth chapter presents an identification key for some orders, families and genres of immature aquatic insects of the Serra do Tepequém, representing the first step towards the correct identification of Roraima aquatic insects. In general, the information generated in this work could be used as a basis in developing appropriate projects to exploit the natural potentialities of the serra do Tepequém, which range from activities related to eco-tourism to the farming and mining.