PPG - Análise Ambiental Integrada

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https://hdl.handle.net/11600/61106

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Navegando PPG - Análise Ambiental Integrada por Palavras-chave "Acidificação oceânica"

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    Avaliação da biodisponibilidade de metais em sedimentos acidificados através da infusão de CO2 empregando bivalves (Crassostrea casar)
    (Universidade Federal de São Paulo, 2017-11-29) Medeiros, Tierry Val de [UNIFESP]; Cesar, Augusto [UNIFESP]; http://lattes.cnpq.br/7526259441170335; Universidade Federal de São Paulo (UNIFESP)
    CO2 capture and storage activities are employed in oil exploration wells and their by-products through a CO2 injection system to reduce emissions and CO2 concentration in the atmosphere. The potential risks of CO2 leakage and ocean acidification scenarios were evaluated for their implications for mobility and bioavailability in sediments with different levels of metals by means of toxicity tests using oysters of the Crassostrea gasar species, where the stability of the lysosomal membrane and mortality. The results showed that there was mobility of metals in the sediments for Cr and Ni metals only with reference sediments. The organisms exerted a metal detoxification behavior in all pH treatments. The stability of the lysosomal membrane was significantly compromised at pH 7 and 6.5 with the reference sediments. The low occurrence of mortality (14.28% only at pH 6.5 with enriched sediments), together with the biological responses, show the adaptation of these organisms to acidification scenarios. Oysters were considered a useful bioindicator for studies in acidification scenarios.
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    Avaliação dos efeitos da acidificação em sedimentos: mobilidade de contaminantes e biodisponibilidade em mexilhões (Mytella charruana)
    (Universidade Federal de São Paulo, 2017-11-30) Brito, Bruna Alves de [UNIFESP]; Cesar, Augusto [UNIFESP]; http://lattes.cnpq.br/7526259441170335; Universidade Federal de São Paulo (UNIFESP)
    In marine ecosystems, sediments act as a sink for contaminants, such as metals. However, acidification processes caused by accidental CO2 leakage associated with Carbon Capture and Storage activities may cause the remobilization and bioavailability of metals from sediments to the water column, resulting in toxic effects on marine biota. Considering the urgent need to understand the environmental risks of this activity, this study aimed to investigate the effects of acidification on marine sediments using Mytella charruana mussel. Therefore, ecotoxicological assays were performed over 14 days using sediment matrices from a reference and a contaminated site at four pH treatments (7.6, 7.0, 6.5, 6.0) and the seawater pH control (8.1). Lethal and sublethal effects were evaluated through behavioral, cytotoxicity, histopathology and bioaccumulation analysis. After 14 days, mortality and sublethal responses of behavior, cytotoxicity and histopathology evidenced deleterious effects of acidification, especially at the lower pH (6.5 and 6.0), which showed an intensification of synergistic effects with contamination. Bioaccumulation did not present a linear relation with the pH reduction. The most sensitive sublethal response was histopathology, since effects were observed in all acidification scenarios. Based on the responses analyzed, it was possible to note an impact associated with ocean acidification, especially as a result of CO2 leakage from CCS activity.