Moluscos aquáticos atuais de ecossistemas costeiros em Imbituba, Imaruí e Laguna, Santa Catarina, Brasil: parâmetro de caracterização para paleoambientes/ Present aquatic molluscs from coastal ecosystems of Imbituba, Imaruí and Laguna counties, Santa Catarina, Brazil: caracterization parameters for paleoenvironments
Resumo em inglês This paper registers 16 species of aquatic molluscs, especially the limnic and estuarine species Heleobia davisi Silva & Thomé, 1985, Heleobia australis australis (Orbigny, 1835) and Erodona mactroides Bosc, 1802, from D'Una river and Mirim, Imaruí and Santo Antônio lagoons and Laguna Beach (Santa Catarina, Brazil). This parameter was very important for the paleoecological analysis conduced for that area, where oscillation of the sea level occurred during the Holocen Period. Heleobia davisi is registered for the first time to the Santa Catarina.
Resumo em inglês Heavy-metal concentration in sediment is an important parameter for identifying pollution sources and assessing pollution levels in aquatic ecosystems. In this context, the present study aimed at determining concentrations of heavy metals in sediments from the Vitória estuarine system, Brazil. Twenty nine stations were surveyed to assess the spatial distribution of heavy metals. The metals for silt-clay fractions ((mais) etry. A discriminant analysis segregated the stations in four groups representing four areas within the estuarine system. The Espírito Santo Bay showed the lowest metal concentrations, while the Vitória harbor canal showed the highest. We concluded that concentrations of heavy metals reflect natural conditions and the contribution of human activities from sewage and industrial effluents. It was not possible to directly associate metal concentrations to specific pollution sources.