Preliminary Study of Trace Metals by Environmental Quality Criteria in Sediments from a Mangrove Forest in Saco do Mamangua (Ilha Grande Bay, Rio de Janeiro, Brazil)

Urban and industrial activities are major sources of pollution to mangrove forests. Mangrove sediments can act as sink and reservoir for a wide range of contaminants, including heavy metals. The aim of this study was to investigate the contents of trace metals (Cu, Ni, Pb and Zn) in sediment samples from a potentially unpolluted mangrove ecosystem in the south of Rio de Janeiro state, Brazil. Determination of pH, Eh, organic carbon, nitrogen, phosphorus and particle size were also performed. In accordance to the international criteria of quality of sediment, the results indicate anthropogenic influence since some metals reached excessive values, which can affect the balance of the ecosystem studied. According to the results, the area cannot be considered a trace metal non-polluted area. Despite not having a significant source of metals inside the Bay nowadays, Ilha Grande Bay harbors a shipyard, an oil terminal, and a commercial port, as well as two thermonuclear power plants, all of which indirectly influence the study area.