Sterols and fecal indicator microorganisms in sediments from Admiralty Bay, Antarctica

Sediments from the proximity of Ferraz station outfall, located in Admiralty Bay, Antarctica, were analyzed for fecal indicator microorganisms and sterols during the austral summer of 1999/2000 in order to assess human sewage input. Concentrations of total sterols and coprostanol ranged from 0.09 to...

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Bibliographic Details
Published in:Brazilian Journal of Oceanography
Main Authors: César de Castro Martins, Rosalinda Carmela Montone, Rosa Carvalho Gamba, Vivian Helena Pellizari
Format: Article in Journal/Newspaper
Language:English
Published: Universidade de São Paulo 2005
Subjects:
Online Access:https://doi.org/10.1590/S1679-87592005000100001
https://doaj.org/article/9ce818944cdf47889f3cc52fb852881e
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Summary:Sediments from the proximity of Ferraz station outfall, located in Admiralty Bay, Antarctica, were analyzed for fecal indicator microorganisms and sterols during the austral summer of 1999/2000 in order to assess human sewage input. Concentrations of total sterols and coprostanol ranged from 0.09 to 19.6 ¼g.g-1 and < 0.01 and 14.0 ¼g.g-1 dry weight (dw), respectively. Our analyses indicated that only sites within to 400m of the sewage outfall exhibited a sterol signal characteristic of human sewage input. Low levels of coprostanol and high levels of cholesterol in distant sites could be attributed to natural sources such as marine mammals and planktonic organisms. Fecal indicator microorganisms (E. coli, fecal streptococci and Clostridium perfringens) were non-detectable beyond 50m from outfall. Both indicators (sterols and fecal indicator microorganisms) produced consistent data and fecal sterol parameters have sho wn themselves to be efficient in the evaluation of trace amounts of fecal material. This study concluded that sewage contamination is limited to the immediate vicinity of the sewage outfall. In general, the concentration of fecal sterols and microbiological indicators were lower than in other Antarctic areas. Amostras de sedimento, coletadas nas proximidades da saída de esgoto da Estação Antártica Comandante Ferraz (Brasil), Antártica, foram medidos durante o verão de 1999/2000. As concentrações de esteróis totais e coprostanol variaram entre 0,09 e 19,6 ¼g.g-1 e < 0,01 e 14,0 ¼g.g-1 de sedimento seco. Nossas análises mostraram que apenas os pontos localizados até 400 m desde a saída de esgotos apresentaram contribuições provenientes do esgoto da estação brasileira. Baixos níveis de coprostanol e alta concentração de colesterol em pontos distantes puderam ser atribuídos a fontes naturais, como os mamíferos marinhos e organismos planctônicos. Indicadores microbiológicos (E. coli, streptococci fecais e Clostridium perfringens) não foram detectados até 50 m desde a saída de esgotos. Ambos ...