Levels and Probable Sources of Hydrocarbons in the Sediments of Jeddah Coast, Red Sea, Saudi Arabia

Aliphatic hydrocarbons including resolved aliphatics (C11-C30), isoprenoids (phytane and pristane) and unresolved complex mixture, as well as total aromatic hydrocarbons were analyzed in 25 surface sediment samples represented five sites along Jeddah coast, Red Sea. The descending order of total petroleum hydrocarbons in the different sites along the coast was found as following: Al-Arbaeen Lagoon (site 2) 481 ppm > Al-Shabab lagoon (site 3) 410 ppm > Southern Corniche (site 1) 205.3 ppm > Northern Corniche (site 4) 172.7 ppm > Sharm Obhur (site 5) 23.6 ppm. The concentrations of total aliphatic hydrocarbons were ranged between 2.18 and 492 ppm dry weights, while the range for the total poly aromatic hydrocarbons was from 2.67 to 160.6 ppm dry weight. The highest concentrations for hydrocarbons were recorded at site 2 (Al-Arbaeen lagoon, station 8). The indices used to evaluate the probable origin of hydrocarbons indicated petroleum origin with high degradation process in most stations as well as fresh oil inputs in few stations at sites 1 and 4. The levels of total aromatic hydrocarbons for 80% of studied stations were exceeding effects range-median value (ERM) for the sediment quality guideline (SQG).