Seasonal Variation of Heavy Metals in Phorcus ( Osilinus ) turbinatus (Gastropod, Trochidae) in the Eastern Algerian Coast

摘要

With the aim to evaluate seasonal changes in heavy metals using a mollusc Phorcus (Osilinus)turbinatus (Born, 1781) as a biomonitor of elemental pollution in the eastern coast of Algeria, more than onehundred individuals of the gastropod were sampled and then examined with respect to the accumulation of Cd,Cr, Cu, Ni, Pb and Zn. Collection was performed in tree strategic locations along 400 km of the coastal area(Collo Bay, Gulf of Skikda, Gulf of Annaba and a control station: Chetaibi Bay), sample during 13 months(January 2011-January 2012). The relationships in various heavy metal concentrations were compared accordingto station and seasons. Heavy metal content varied with type of metals, seasons and station. A discussioninvolving the comparison with other molluscs previously tested will be given. Several statisticalapproaches able to analyze data with environmental purposes were applied. Moreover, statistical analyses(ANOVA, multiple comparison tests, cluster analysis) showed, the maximum rate of Zn (318.10±38.20 μg.g 1),Pb (6.51±1.47 μg.g 1) were recorded at the (station 1). In contrast, the highest level of Cd (3.63±1.14 μg.g 1),Cu (32.70±2.90 μg.g 1) and Ni (24.80±20 μg.g 1) were determined at the station 2. On the other hand, Station3, show a low bioaccumulation of ETM and only the control station has the lowest metal concentrations, exceptCr in winter (0.89±0.20 μg.g 1). Statistical approaches such as (Kruskal-Wallis and Mann–Whitney, no shownin this work) were carried out to assess the changes of the metal concentrations with time (seasons) in eachstation. Multivariate methods (linear discriminant analysis LDA on PCA factors) were also applied to obtaina more reliable site classification.