Análise multibloco de contaminantes em diferentes matrizes ambientais da baía da Babitonga - SC

Abstract

The discharge of different types of pollutants into marine waters, including pollutants such as metallic species and Polycyclic Aromatic Hydrocarbons (PAHs), causes damage to the marine habitat as well as to humans. In this context, both bioaccumulation and biomagnification in marine organisms can be harmful to humans, since many of these animals are part of their diet, and the ingestion of certain metals, depending on their quantity and toxicity, poses serious health risks. In addition, the presence of these contaminants in aquatic organisms consumed by the population represents an additional risk to public health. Therefore, proving the correlation between the contamination of aquatic organisms by water pollution is extremely relevant, as these are species consumed by humans and may lead to public health problems. Fish and oysters, for example, can be good indicators of the type of pollution present and the general health status of the estuary in which they live. Thus, this study aims to verify and evaluate the results of contaminant concentrations and possible correlations in different environmental matrices of Babitonga Bay – Santa Catarina, Brazil. The work was developed based on data previously obtained by the research group from samples collected in Babitonga Bay (BB) on the northern coast of Santa Catarina State. The sampling points were defined in order to obtain more representative samples of the environment as a whole, namely at Mandijituba Island, Flores Island, and Redonda Island, during January, February, and March of 2015 and 2016. After collection, physical and chemical parameters of the water were quantified: temperature, pH, NaCl concentration, dissolved oxygen, total dissolved solids, redox potential, conductivity, and turbidity. The oysters used in the study were collected in natura, with about 30 oysters taken from each chosen point. The analyses performed on the oysters included moisture content, ash content, and quantification of metallic species. Sediment sampling was conducted to ensure that the spatial distribution of the samples would be representative of the area’s dimension and the volume to be dredged. In the sediments, moisture content and concentrations of metallic species were determined, as well as the concentration of Polycyclic Aromatic Hydrocarbons (PAHs). With the dataset obtained from the different environmental matrices (water, sediment, and oysters), a multiblock analysis was performed using the Common Dimensions Analysis (ComDim) method, aiming to identify common patterns among physical, chemical, and biological variables, enabling the correlation between contamination levels and the effects observed in aquatic organisms. The evaluation of the data collected for the different environmental matrices of BB demonstrated that the existing pollution in the region directly affects aquatic organisms, evidenced by the presence of heavy metals and PAHs in sediments, in water, and by the bioaccumulation of these substances in oysters.It was possible to correlate the experimental results obtained in oysters, sediments, and water, showing the presence of contaminants in all the environmental matrices analyzed. The multiblock analysis evidenced that sediments presented the highest concentrations of heavy metals, especially lead (Pb), cadmium (Cd), and zinc (Zn), as well as high molecular weight Polycyclic Aromatic Hydrocarbons (PAHs), such as benzo[a]pyrene. In oysters, bioaccumulation of cadmium and lead was particularly evident, confirming the role of these organisms as bioindicators of contamination. These results demonstrate the direct relationship between sediment pollution and aquatic organisms consumed by the population, reinforcing the need for continuous monitoring of Babitonga Bay and supporting environmental management actions.