Cumulative influences of a small city and former mining activities on the sediment quality of a subtropical estuarine protected area

Abstract

This study aimed to evaluate the sediment quality in the estuarine protected area known as Cananéia-Iguape-Peruíbe (CIP-PA), located on the southeastern coast of Brazil. The study was designed considering possible negative effects induced by the city of Cananéia on the sediment quality of surrounding areas. This evaluation was performed using chemical and ecotoxicological analyses. Sediments were predominantly sandy, with low CaCO3 contents. Amounts of organic matter varied, but higher contents occurred closer to the city, as well as did Fe and Total Recoverable Oils and Greases (TROGs) concentrations. Contamination by Cd and Cu was revealed in some samples, while concentrations of Zn were considered low. Chronic toxicity was detected in all tested sediments and acute toxicity occurred only in sediments collected near the city. The principal component analysis (PCA) revealed an association among Cd, Cu, Fe, TROG, fines, organic matter, CaCO3, and chronic toxicity, whereas acute toxicity was found to be associated with Zn and mud. However, because Zn levels were low, acute toxicity was likely due to a contaminant that was not measured. Results show that there is a broad area within the CIP-PA that is under the influence of mining activities (chronic toxicity, moderate contamination by metals), whereas poorer conditions occur closer to Cananéia (acute toxicity); thus, the urban area seems to constitute a relevant source of contaminants for the estuarine complex. These results show that contamination is already capable of producing risks for the local aquatic biota, which suggests that the CIP-PA effectiveness in protecting estuarine biota may be threatened.

Assessing pollution in marine protected areas: the role of a multi-biomarker and multi-organ approach

“…Additionally, the seasons also sometimes play an important role in the bioaccumulation of metals, depending on the site studied. The current findings corroborate the study by Cruz et al (2014) in which the sediment quality of the APA-CIP was assessed using ecotoxicological tools. The study concluded that the contamination from both the RIR and urban areas (the city of Cananéia) are relevant sources of pollution in the APA-CIP.…”

“…High levels of metals (Pb, Zn, Cu, Cr, As) recorded in river waters, bottom sediments, and suspended sediments were largely linked to mining activities in the river headwaters (Eysink et al 1988;Corsi and Landim 2003;Moraes 2004;Guimarães and Sígolo 2008). In the estuary, metals in sediments have been generally found only at moderate levels (Mahiques et al 2009;Azevedo et al 2011;Cruz et al 2014); however, these values have increased substantially since the opening of the Valo Grande channel and even more so after industrial mining activities began (Mahiques et al 2009). These reports show that metals in the APA-CIP are largely from anthropogenic sources.…”

“…This finding strongly suggests that PAHs from urban sources, when combined with metals, lead to LPO increases and DNA damage in the liver of C. spixii specimens living in the APA-CIP. Sources of PAH in this area include nautical structures (marinas, decks, nautical garages, and small docks), ferry boat stations, a nautical gas station, municipal sewage discharges, and urban drainage (Cruz et al 2014). PAHs are of concern in MPAs since they are potentially carcinogenic (Shailaja and D'Silva 2003) and may induce hepatic lesions, physiological disorders, and biochemical disorders in fish (Oliveira Ribeiro et al 2005).…”

“…Still, pollution studies in MPAs usually focus on measuring contaminant levels in environmental matrices such as water, sediments, and organisms (e.g., Michel et al 2001;Conti and Cecchetti 2003;Chou et al 2004;Pozo et al 2009;Perra et al 2011;King et al 2013;García-Alvarez et al 2014) rather than the effects of pollutants on the biota that is supposed to be protected (e.g., Terlizzi et al 2004;Pinsino et al 2008;Rodrigues et al 2013;Araujo et al 2013;Cruz et al 2014).…”

Efeitos biológicos da contaminação sobre bivalves filtradores de regiões do litoral de São Paulo, com ênfase na Baixada Santista

“…Isso é corroborado pelo reportado por Gusso- Choueri et al (2015), que detectaram metabólitos de metais e HPAs em bile de peixes demersais (C. spixii) associada a respostas antioxidantes, estresse oxidativo, neurotoxicidade e genotoxicidade. Os autores identificaram que efluentes urbanos da cidade de Cananéia e a drenagem fluvial do Rio Ribeira de Iguape foram identificados como as principais fontes de poluição desta região (Cruz et al, 2014;Gusso-Choueri et al, 2015). O fato das respostas aparecerem majoritariamente durante a primavera-verão pode estar associada tanto à flutuabilidade da densidade demográfica em função do turismo, que acarreta em maior volume de esgotos descartados, quanto à sazonalidade, com a qual variam os índices pluviométricos da região (CETESB, 2017;Gusso-Choueri et al, 2015).…”