Petroleum hydrocarbons and trace metals in nearshore Gulf sediments and biota before and after the 1991 war: An assessment of temporal and spatial trends

Immediately following the 1991 Gulf War, a survey was organized to determine the extent and degree of contamination by petroleum hydrocarbons and trace metals that entered the Gulf from the massive oil spill and oil field fires in Kuwait. Between June-October 1991 samples of nearshore sediments, bivalves and fish were collected from Kuwait, Saudi Arabia, Bahrain, UAE and Oman. Analyses revealed that the highest levels of contamination were along the heavily-impacted coast of Saudi Arabia between Ras Al Khafji and Ras Al Ghar, where concentrations of total petroleum hydrocarbons (expressed as Kuwait crude oil equivalents) ranged from 62-1400 mu g/g dry wt in surface sediments, 570-2600 mu g/g dry wt in clams and 9.6-31 mu g/g dry wt in fish muscle. Gas chromatographic analyses indicated that much of the oil in the intertidal zone had substantially degraded within a few months of the spill. Concentrations of the oil-related metals Ni and V were slightly elevated in oil-contaminated sediments from Saudi Arabia but elsewhere in the Gulf were similar to levels measured in earlier years at those sites. This initial regional survey demonstrated that hydrocarbon contamination originating from the war-related pollution events was restricted to approximately 400 km from the source, that levels of combustion derived PAHs in the marine environment at that time (e.g. 1-450 ng/g dry wt for pyrene in sediments) were of the same order as those which have been measured in several coastal areas of the eastern United States and northern Europe, and that outside the immediate area of impact, petroleum hydrocarbon and trace metal levels in sediment and bivalves were generally as low as, or lower than, those concentrations measured at the same sites before the war.