Petroleum Hydrocarbons and Trace Metals in Mollusca (Tivela ponderosa) from the Gulf of Aden الهيدروكربونات النفطية والمعادن النزرة ( الثقيلة ) في النواعم (الرخويات) Tivela ponderosa من خليج عدن

The present investigation represent an assessment of contaminants level including petroleum hydrocarbons and heavy metals in mollusca Tivela ponderosa from the Gulf of Aden-Arabian Sea aiming to establish their background concentrations. The study revealed comparable levels of petroleum hydrocarbons and heavy metals in this region to that reported from other part of the world. The concentrations of petroleum hydrocarbons in the mussels range from 9.5 µg/g at (station 4) to 40.38 µg/g dry weight at Al- Zyiot port (station 1) expressed as Marib crude oil equivalent. Fat content in the mussels ranged from 0.2 to 0.7 % at station 9 and 8 respectively. It was suggested that mollusca is subjected to oil pollution from the following resources: Tanker discharging of oily ballast water, effluent from the petroleum refineries located on the coastal areas, and loading facilities and transportation activities. On the other hand, the heavy metals were found in comparable concentration to unpolluted marine environments. Level of Cd, Cu, Pb, and Zn in the study mussels were generally within the range of values reported for other parts of the world. The result shows low degree of petroleum hydrocarbons and some trace metals pollution in the Gulf of Aden mussels. Hydrocarbons pollution may be due to transportation and other sources of oil pollution. The concentrations of trace metals may be attributed to natural rather than anthropogenic origin. Thus, it was concluded that the investigated heavy metals don?t present environmental hazards for the present time. However, it is recommended to carry out continuous monitoring programs for the Gulf of Aden and that the concentration of petroleum hydrocarbons and heavy metals must remain within the prescribed worldwide ratio. أظهرت الدراسات الحالية تقديرا لمستوى التلوث بالهيدروكربونات النفطية والمعادن الثقيلة في النواعم (Tivela ponderosa) من سواحل خليج عدن ـ البحر العربي وذلك لمعرفة المستوى الأساسي لهذه التراكيز في النواعم.