Foraminíferos atuais em um manguezal impactado por petróleo 20 anos atrás: o Rio Iriri, canal de Bertioga, Santos-SP

Pós-graduação em Geociências e Meio Ambiente - IGCE

Distribuição dos foraminíferos recentes associados à vegetação na faixa estuarina do Rio Itapanhaú, Bertioga, São Paulo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Foraminíferos em testemunho do manguezal do Canal de Bertioga (SP): padrões de estrutura de comunidades aplicáveis em reconstruções paleoambientais

Nowadays, there is a search for knowledgment that could be applied in the solution of the problems caused by petrolific activities involving the environment, like the biodiversity preservation and the ecosystems monitoring and management. Foraminifera (Protista) are used as an important tool to the environment characterizarion, because they answer quickly to the fisic-quimic variations and indicate local alterations. The goal of this job is to create models of foraminiferal communities composition through the screening of subsuperficial samples obtained from a core collect from Bertioga Channel, Baixada Santista (SP), trying to understand the influence of the environmental variations along the time upon the indicator species presence, as well as making paleoenvironmentals reconstructions of the area. A 80 cm-core was removed in the outer edge of marsh adjacent to Bertioga Channel, not far from the confluence with the Itapanhaú River. There are presented in abundance, equitability, diversity and species richness obtained in nine samples along the sediment. The lower part of the core is compound by calcareous species (rotalideos and miliolideos) with domain Ammonia (Biofacies 1) and the intermediate and upper parts contain mainly agglutinated species (Biofacies 2 and 3, which is dominated by species of Ammotium). The qualitative and quantitative study of the microfauna of foraminifera present in the core reveals that in recent decades the sampling area passed from a condition of infra-marginal strip under significant coastal marine influence for the condition of inter-coastal swamp covered with mangrove vegetation. This change indicates that the site has undergone a process of sediment progradation, a phenomenon that may have been timely, localized, or a reflection of a relative fall in sea level at the regional level