FORAMINIFERAL ASSEMBLAGES AND TEXTURAL COMPOSITION OF AREA NEAR CIGARRAS DOMESTIC SEWAGE SUBMARINE OUTFALL, SÃO SEBASTIÃO CHANNEL, SÃO PAULO STATE, BRAZIL

Abstract

The goal of this study was to integrate grain size analysis with foraminiferal assemblages to obtain a preliminary characterization of area near Cigarras domestic sewage submarine outfall, located in the São Sebastião Channel, São Paulo State, Brazil. The sampling grid with ten superficial bottom samples was positioned surrounding submarine outfall diffusers. Analysis of grain size, organic matter contents and foraminiferal assemblages were performed. Thanacoenosis (taphonomic and morphometric analysis) and grain size revealed that study area is a low hydrodynamic environment, what permit high concentration of organic matter deposition. The low richness, specific diversity and equitability observed on biocoenosis are indicative of environmental stress, which can be associated to organic enrichment that there is in the study area. Ammonia tepida is the predominant specie in all stations analyzed.