BOTTOM SEDIMENTS OF THE ARABIAN GULF .2. TPH AND TOC CONTENTS AS INDICATORS OF OIL POLLUTION AND IMPLICATIONS FOR THE EFFECT AND FATE OF THE KUWAIT OIL-SLICK

Measurements of total petroleum hydrocarbon (TPH) concentrations in 77 core samples collected in 1992 from the bottom sediments of the Arabi an Gulf were used to delineate oil pollution levels and their distribu tion in the region. Seven chronic moderately (TPH 50-89 mu g g(-1)) an d heavily (TPH 266-1448 mu g g(-1)) polluted areas were identified; th ree in the northern part of the region and four in the southern part. Oil pollution in these areas was attributed to natural oil seepage, ac cidental damage to pipelines, accidental spillage front rankers, the N owruz oil slick, and tanker deballasting. Present-day intermediate (TP H 50-114 mu g g(-1)) and high (TPH 200-1122 mu g g(-1)) pollution leve ls were identified in 10 areas. Of these, three polluted areas iii the northeastern corner, offshore Saudi Arabia and offshore Bahrain, Qata r and United Arab Emirates are probably directly affected bf the Kuwai t oil slick. A new scenario is suggested for the movement and fate of the oil slick, in which additional large oil discharges from northern sources, as well as substantial quantities of eroded oiled sediments m id oil floating from heavily impacted tidal flats along the Saudi Arab ian coastline, serve as sources of oil pollution. A definite relations hip exists between the grain-size distribution and the TPH content of bottom sediments, with the highest TPH concentrations in the muddy sed iments, suggesting chat adsorption onto muds is the primary mechanism of oil pollutant accumulation in the Arabian Gulf. Total organic carbo n measurements do not correlate positively with the grain-size distrib ution and TPH contents of the sediments, and hence cannot be used as i ndicators for petroleum hydrocarbon pollution in the Arabian Gulf. Cop yright (C) 1996 Elsevier Science Ltd