Metals impact into the Paranaguá Estuarine Complex (Brazil) during the exceptional flood of 2011

Abstract

Particulate and dissolved metal concentrations were determined after the largest flood in the last 30 years on the east-west axis of the Paranaguá Estuarine Complex (PEC) and compared to the those of the dry period at two stations. Results confirmed that the flood greatly affected riverine outflows and the behavior of metals in the PEC. In particular, a sharp decrease in salinity was followed by extremely high SPM concentrations leading to a decrease in DO concentrations at both stations. For the dissolved phase, ANOSIM analysis showed a significant dissimilarity at each station between the sampled periods, whereas for the particulate phase this dissimilarity was found only for the samplings taken at the Antonina Station. KD values suggested dissolved Cu behavior was related to the presence of organic complexes and dissolved Mn had sediment resuspension of redox sediments and or/pore water injection as sources. Metal concentrations were lower than in polluted estuaries, though high enrichment factors found after the flood pointed to the influence of anthropogenic sources. In conclusion, the flood's influence was more evident at the Antonina Station, due to its location in the upper estuary, whereas in Paranaguá a high SPM content with low metal concentration was found, following the common pattern generally found in other marine systems subject to heavy rainfall events. Com o objetivo de avaliar a influência do maior evento de enchente dos últimos 30 anos no Complexo Estuarino de Paranaguá (CEP), ocorrido em 2010, concentrações de metais na fase particulada e dissolvida foram medidas em duas estações amostrais, e comparadas ao período seco. Os resultados confirmaram a influência desse evento no aumento do fluxo dos rios e no comportamento dos metais no CEP. Uma acentuada diminuição na salinidade, concomitante ao aumento de material particulado em suspensão, gerou a diminuição das concentrações de oxigênio dissolvido nas duas estações amostradas. A análise de ANOSIM indicou ausência de similaridade entre ambas as estações e períodos amostrados, enquanto que para a fase particulada essa diferença foi evidente apenas para a estação de Antonina. Os valores do coeficiente de partição (KD) sugeriram um input de manganês dissolvido por meio de processos de oxi-redução. As concentrações de metais registradas foram menores do que as encontradas em estuários poluídos; no entanto, o aumento do Fator de Enriquecimento após o evento de inundação sugeriu a influência de fontes antrópicas. Como conclusão geral, a influência do evento de inundação foi mais evidente na estação de Antonina, principalmente devido a sua localização na parte superior do estuário, enquanto que em Paranaguá o aumento do SPM foi acompanhado de uma diminuição na concentração de metais, seguindo o comportamento de metais registrados em outros estuários após eventos de inundação. AbstrAct Marilia Lopes da Rocha resumoDescritores: Metais na fase dissolvida, Metais no particulado, eventos de inundação, coeficiente de partição.

Spatial environmental variability of natural markers and habitat use ofCathorops spixiiin a neotropical estuary from otolith chemistry

“…The Ba/Ca pattern found in this study has also been reported in other estuaries such as Chesapeake Bay (Dorval & Jones, 2005), French West Indies in the Caribbean Sea (Tabouret et al ., 2010) and La Plata River Estuary (Avigliano & Volpedo, 2013; Avigliano et al ., 2019). The negative relationship between Mn and salinity was previously reported for the PEC (Rocha et al ., 2017). The oxy-redox sensitivity of Mn can cause spatio-temporal variations in estuaries (Walther & Nims, 2015), while precipitation can be favoured in well-oxygenated environments (Du Laing et al ., 2009).…”

“…In the present study, we analysed the west–east axis, which is responsible for 82% of the fluvial discharge in the PEC (Rocha et al ., 2017). The largest contributors of fresh water are the Cachoeira and Nhundiaquara rivers.…”

Statistical assessment of background levels for metal contamination from a subtropical estuarine system in the SW Atlantic (Paranaguá Estuarine System, Brazil)

“…The maximum turbidity zone (MTZ), lying between Teixeira's Island and the Port of Paranaguá cross section (Rocha et al 2017), features an important role in the processes of deposition, erosion and resuspension of fine particles, once the increased concentration of suspended particulate material as well as regular mixture between continental and marine waters (Noernberg 2001;Cattani and Lamour 2016) lead to intensive physical, chemical and biological reactions between dissolved and particulate species (Gebhardt et al 2005).…”

“…Around the Port of Paranaguá cross-section, at the transition between riverine and proper estuarine zones, the increases in Sc contents and consequently other metals indicates resuspension/deposition processes associated with the maximum turbidity zone (MTZ) (Rocha et al 2017), that apparently is acting as a barrier for the transport of fine particles towards the coast (Cattani and Lamour 2016).…”

“…Higher Fe/Ca values were found in the inner and middle sector of the estuary. The first is characterized by the presence of the Cachoeira and the Nhudiaquara rivers, which together, according to Rocha et al (2017), contribute 82% Fig. 2 Concentrations of Sc as a particle-size proxy along the PES, South Atlantic of the total discharge of continental water into the estuarine system.…”