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The occurrence of n-alkanes and biomarkers (hopane and sterane) in surface sediments from Southwestern coasts of Caspian Sea and 28 rivers arriving to this lake, determined with a gas chromatography-mass spectrometry method, was used to assess the impacts of anthropogenic activities in the studied area. The concentrations of total n-alkanes (Σ21 n-alkane) in costal and riverine sediments varied from 249.2 to 3899.5 and 56 to 1622.4 μg g(-1), respectively. An evaluation of the source diagnostic indices indicated that petroleum related sources (petrogenic) were mainly contributed to n-alkanes in costal and most riverine sediments. Only the hydrocarbons in sediment of 3 rivers were found to be mainly of biogenic origin. Principal component analysis using hopane diagnostic ratios in costal and riverine sediments, and Anzali, Turkmenistan, and Azerbaijan oils were used to identify the sources of hydrocarbons in sediments. It was indicated that the anthropogenic contributions in most of the costal sediment samples are dominated with inputs of oil spills from Turkmenistan and Azerbaijan countries.

The relationships are evaluated between the heavy metal species in sediments and the accumulation by the soft tissues of Saccostrea cucullata collected from the northern and southern coasts of Qeshm Island, Persian Gulf. The sequential extraction technique was employed to fractionate the sediment into non resistant and resistant fractions. Data from sequential extractions indicated that the metals were mainly associated with the residual fraction at the north coast and with non residual fractions at the south coast. The results showed that the best correlations were observed between heavy metals concentrations in soft tissues and the fractions in the southern sediment. Note that the bioavailability of trace metals is influenced by the chemical characteristics and properties of the sediment. Therefore, the present results generally supported the use of soft tissues of S. cucullata as a more accurate biomonitoring organism for Cu, Pb and Cd in sediments from the southern coast of Qeshm Island, Persian Gulf.

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A study was conducted to determine the bioaccumulation and relationships of some essential and non essential metals in the different tissues of Saccostera cucullata to sediments by calculating their biota-sediment accumulation factor (BSAF) values and the correlation analysis. For this study, 53 rocky oysters (Saccostrea cucullata) and 15 surface sediment samples were collected from four stations in May 2010 of the intertidal zones of Qeshm Island, Persian Gulf, Iran. The results indicate that the highest BSAF values for Cu, Pb and Zn were found in the soft tissue. For Pb, the highest concentrations were obtained in the shell. The correlation results showed that there were correlations between concentrations of Cu and Cd in soft tissues with some fractions in sediment and concentrations of Pb in the shell with some fractions in the sediment. However, it was found that soft tissue of S. cucullata has the potential to be used as a biomonitoring agent for the contamination of Cu and Cd in sediments, as indicated by the high BSAF levels, the lower coefficient of variation (CV) values in soft tissue than in shell, and the significant positive correlation between concentrations of Cu and Cd in the soft tissue of oyster and in the sediment. In contrast, for Pb, higher BSAF values and lower CV values are found in the shell than in the soft tissue, and the significant positive correlation between Pb concentrations in the shell of oyster and sediment can be used as a biomonitoring material.