Nereis diversicolor: an Unreliable Biomonitor of Metal Contamination in the 'Ría de Bilbao' (Spain) |
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| Authors: | J I Saiz-Salinas G Francés-Zubillaga |
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| Institution: | Departamento de Biología Animal y Genética, Facultad de Ciencias, Universidad del Pais Vasco, Aptdo. 644, E-48080 Bilbao, Spain. |
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| Abstract: | Abstract. Samples of the polychaete Nereis diversicolor O.F. M üller and surficial sediments from a clean and a polluted estuary were taken during a year at monthly intervals to determine, by comparison, the range of temporal fluctuations in trace metal concentrations. Whereas metal variations in surficial sediments were more pronounced in the polluted estuary, concentrations in N. diversicolor in both estuaries showed a wide range of temporal variation that surpassed that of surficial sediments. A clear decline in all metals studied (except Mn) from polluted sediments was noted after episodes of strong rainfall. In the reference estuary the fluctuations were less pronounced. Metal body burdens in N. diversicolor from the two estuaries were usually quite similar even though total levels in sediments differed considerably, indicating a lack of worm-sediment relationship. The low level of Cu, Cr and Pb in the tissues of N. diversicolor suggest a mechanism which prevents the polychaete from being exposed to these metals in highly polluted sediments. Therefore, it is concluded that N. diversicolor cannot be considered to be an ideal biomonitor of metal contamination in the polluted Bilbao Estuary. |
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| Keywords: | Nereis diversicolor biomonitor trace metals Bilbao Estuary temporal variations sediments |
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