Biomonitoramento da Área de Proteção Ambiental Costa dos Corais (APACC) com o Bivalve Tivela mactroides (Born, 1778), após o derramamento de óleo

Abstract

The oil spill that occurred in 2019 on the Coast of Brazil affected several Marine Protected Areas, including the Costa dos Corais Environmental Protection Area (APACC), in the State of Alagoas.One of the components of the oil are Polycyclic Aromatic Hydrocarbons (PAH's), which can cause several deleterious effects on aquatic organisms, such as redox imbalance and neurotoxicity.Biomonitoring studies using biomarkers are an important tool to clarify the different contaminants and their effects on the biota, and also to support environmental conservation policies. Thus, this study aimed to evaluate the potential ecotoxicological effects on the bivalve Tivela mactroides (maçunim) from areas affected by the oil. Specimen sampling were carried out in the intermediate (September/2020), dry (December/2020) and rainy (April/2021) periods in three APACC locations, which represented a decreasing gradient in relation to the volume of oil removed: 1) Maragogi; 2) Japaratinga and 3) Paripueira. The quantification of PAH's present in the soft body of bivalves, the evaluation of biomarkers of redox balance and neurotoxicity in the gills and digestive gland, as well as the calculation of the Integrated Index of Biomarkers (IBR) were performed. Among the 16 PAH's evaluated, 13 types were detected, being Pyrene, Benzo (a) anthracene, Chrysene, Benzo (b) fluoranthene, Benzo (k) fluoranthene, Benzo (a) pyrene and Idene (1,2,3-cd) responsible for ~43% of the total PAH's concentration. An antioxidant response was observed in all locations for both organs investigated, but these were not sufficient to prevent oxidative damage to the digestive gland of bivalves from Maragogi in the dry season and from Paripueira in the rainy season. The highest values of IBR were observed for Japaratinga and Maragogi, however there was no correlation with the levels of PAHs in these locations. In general, T. mactroides proved to be sensitive to environmental variations, however it presented antioxidant responses that make it resilient to different environmental stressors. Together, these data denote the importance of including ecotoxicological studies within the APACC, aiming to monitor the long-term effects after the oil spill episode, as well as other pollutants arising from anthropic activity.