Using a tiered approach based on ecotoxicological techniques to assess the ecological risks of contamination in a subtropical estuarine protected area

Abstract

This study sought to assess the ecological risks of sediments from the northern portion of an estuarine protected area (Cananéia-Iguape-Peruíbe Protected Area--CIP-PA). The CIP-PA is located on the southern coast of São Paulo State, Brazil and is influenced by former mining activities along the Ribeira de Iguape River (RIR). We used a tiered approach based on multiple lines of evidence (geochemical analyses, toxicity tests, and whole sediment toxicity identification and evaluation) in order to assess environmental quality. The sediments presented a heterogeneous composition, but the samples collected close to the RIR exhibited higher concentrations of metals (Cd, Cr, Cu, Pb) and toxicity. Multivariate analysis showed that toxicity was associated with metals, mud, organic matter, and CaCO3 quantities. The whole-sediment toxicity identification evaluation approach indicated that ammonia and metals were responsible for sediment toxicity. Overall, we concluded that the sediments collected at depositional areas from the northern portion of the CIP-PA presented high levels of metals, which originated from former mining areas located in the upper RIR basin, and that this contamination had toxic effects on aquatic invertebrates. The tiered approach was useful for identifying the degradation of sediment quality and also for indicating the causes of toxicity. Because the CIP-PA is an important estuarine protected area that is ecologically at risk, large-scale measures are required to control the sources of contamination.

Is the microcosm approach using meiofauna community descriptors a suitable tool for ecotoxicological studies?

“…Toxicity was already reported as a result from environmental relevant concentrations of pharmaceutical compounds (Bila and Dezotti, 2003;Shareef et al, 2008;Maranho et al, 2015), personal care products (Cortez et al, 2012) and hydrocarbons (Jensen and Sverdrup, 2002), for example, among other sewage components. In addition, interactive effects between metals (Hagopian-Schlekat et al, 2001), and metals and other potentially toxic substances in sediment, such as ammonia (Campos et al, 2016), can not be ruled out.…”

Trace metal bioavailability in sediments from a reference site, Ribeira Bay, Brazil

“…Cadmium concentrations were below the analytical detection limit (b0.002 μmol g −1 ) in all samples, while Ni was below detection limit (b 0.05 μmol g −1 ) at station J1 (Table 2). For the same suite of metals, non-contaminated and low-contaminated coastal sediments on a regional scale (southeastern Brazil) presented ΣSEM values ranging from 0.02 to 0.47 μmol g −1 (Nizoli and Luiz-Silva, 2012;Campos et al, 2016). In heavily polluted sites from this region, such values were values up to 6.6 μmol g − 1 in the Morrão River estuary (Nizoli and Luiz-Silva, 2012) and up to 18 μmol g −1 in Guanabara Bay (Machado et al, 2010).…”

Bioacumulação e biomagnificação de metais pesados em teias tróficas de estuários do sul-sudeste do Brasil

“…Além disso, os sedimentos são substrato para espécies bentônicas e área de alimentação para espécies bentívoras, sendo um compartimento ecológico importante, e que pode ser utilizado como um indicador da saúde do ecossistema (Abessa et al, 2006). (Campos et al,2016).…”

“…Ni não foi detectado no SELCI nos estudos pretéritos (Amorim et al, 2008;Campos et al, 2016), mas no presente estudo foi quantificado em todas as amostras.…”

“…Chumbo apresentou menores valores no presente estudo com relação aos estudos pretéritos no CEP (Choueri et al, 2009) e no SELCI (Campos et al, 2016). No CESSV, Pb apresentou oscilação ao longo do tempo, com concentrações elevadas em 1998 a 2000 (Hortellani et al, 2008), em 2007 apresentou níveis anômalos e elevados (Buruaem et al, 2012), em 2014 diminuição (Kim et al, 2016), e os menores valores foram obtidos no presente estudo.…”