Assessment of availability and anthropogenic enrichment of metals, arsenic and hydrocarbons in marine sediments from Estuário de Caravelas (Southern Bahia)

Abstract

Nowadays, pollution of coastal environments has grown rapidly, becoming a serious threat for both, people and all local biodiversity, as a result of economic and industrial developments that are not sustainable. The southern region of Bahia hosts two major biomes which are rich in biodiversity and endemism: the Atlantic Forest and the Abrolhos Reef Complex. Previous studies found anomalous levels of As in sediments from Abrolhos Complex and the Caravelas Estuary. This fact may be associated with anthropogenic enrichment in these areas, which have been greatly affected by deforestation and activities from paper and cellulose industries. Accordingly, at Laboratório de Química Inorgânica Marinha (LAQIMAR) of Instituto Oceanográfico/Universidade de São Paulo (IO/USP), in the last years, several environmental projects have been developed. These works aim to quantify the levels of trace elements with great toxic potential to the marine organisms. Therefore, this proposal intends to assess the temporal enrichment of arsenic (As), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb) and zinc (Zn) in profiles and surface sediments that will be collected in the Caravelas Estuary, in southern Bahia. The study will focus on methods of partial, total and chemical fractionation digestions. Thus, the proposal will contribute to find the background levels and understanding the mobility of the studied elements. Furthermore, aliphatic and aromatic hydrocarbons will be evaluated as indicators of anthropogenic activities such as burning or other fossil fuel sources in the region. The behavior of chemical elements will be also assessed regarding the morphological evolution of the region based on numerical modeling in order to comprehend the sedimentary distribution and enabling the environmental characterization of that important region of the Brazilian Coast. (AU)