Assessment of Cd, Cr and Ni concentrations in macrobenthos communities of Khor Musa and correlation with metals accumulation in sediments
Document Type : Research Paper
Abstract
Heavy metals are discharged into the marine environment through natural process and anthropogenic activities. They can remain in solution or in suspension in the water column, precipitate to the bottom, or be taken up by various marine organisms. Thus, metals can accumulate to toxic concentrations causing ecological damage, and subsequently be transferred to humans and terrestrial animals through the food and feed chains. Therefore this study was conducted for evaluation of Cd, Cr and Ni concentrations in macrobenthos communities of Khor Musa and correlation with metals accumulation in sediments in 2012. For sediments sampling, cores of 40 cm length were collected with the help of a PVC tube by gently intruding it into the sediment and protruding it out, capping, and freezing it upon return to the laboratory. After digesting the sediments with Aqua Regia solution 3/1 (v/v) HCl/HNO3 in microwave device and identifying the macrobenthos species, concentrations of heavy metals sediments and macrobenthos samples were measured using ICP-AES. All statistical analyses were performed using the SPSS 18.0 statistical package. The results showed that maximum mean concentrations of Cd, Cr and Ni in sediment samples were 0.17±0.10, 46.50±2.0 and 41.43±2.0 ppm respectively, and maximum mean concentrations of these elements in macrobenthos samples were 0.21±010, 64.10±1.0 and 41.40±1.0 ppm respectively belonged to Bivalvia. Also the mean concentrations of metals were significantly lower than permissible limits recommended by WHO (P<0.05). Although currently the sediments of study area aren't polluted with heavy metals, but the establishment of the petroleum industries, the oil spill from drilling rigs and tankers discharging ballast water can cause a threat to sediments pollution and consequently aquatic animals of this area.
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