DISTRIBUTION OF OIL FROM THE GULF WAR SPILL WITHIN INTERTIDAL HABITATS—ONE YEAR LATER

Autor: Abdul Halim Al-Momen, Ahmed M. Al-Mansi, Jacqueline Michel, Todd M. Montello, Don V. Aurand, Gordon W. Thayer, Miles O. Hayes, Sunil Narumalani, John R. Jensen
Rok vydání: 1993
Předmět:
Zdroj: International Oil Spill Conference Proceedings. 1993:373-381
ISSN: 2169-3358
2169-3366
DOI: 10.7901/2169-3358-1993-1-373
Popis: Results of a land-based intertidal survey of the impacts of the Gulf War oil spill on the Saudi Arabian coast, carried out from 1 March to 4 April 1992 in conjunction with Leg II of the NOAA ship Mt. Mitchell's ROPME Sea cruise, show that there is a striking correlation between the nearshore geomorphology and the persistence of intertidal oil. Significant quantities of oil (measured in millions of gallons) remained in the sediments of the sheltered tidal flat/marsh areas, and significant erosion of oiled sediments has occurred along many of the outer exposed areas. A massive asphalt pavement, tens of meters wide and over 20 kilometers long, which is believed to have formed as a result of the Nowruz spill of 1983, occurs along the outer coast of the Abu Ali headland. Along certain other exposed outer sand beaches, conditions are conducive to the formation and preservation of a similar asphalt pavement as a result of the Gulf War spill. The most severely impacted areas studied were several halophyte marsh/algal mat complexes and mudflats at the heads of sheltered bays, where all the halophytes were dead and there was no sign of living epibiota in the mid to upper intertidal areas. Before the spill, burrowing infauna, such as crabs and polychaetes, occurred in large numbers in these sheltered areas. The previously occupied burrows were heavily oiled, with some containing liquid black oil to depths of over 40 cm. The deep penetration of oil into the burrows and probable slow weathering rates of the oil could result in many years of pollution of these sheltered habitats. The development of “bubble sand,” a sponge-like sand deposit with porosities probably as high as ± 50 percent, is a common phenomenon in the sheltered coarse-grained beaches and intertidal sand flats of the bays, covering hundreds of acres of intertidal area. The high porosity results from entrapment of air between the water table, which is lowered during low tide, and water flooding the sediment surface during rising tides. Depths of penetration of the oil into bubble sand exceeding 40 cm were found at several localities. This deep oil will also remain in the sediment for many years, because of the slow erosion rates that occur in these sheltered environments. In most places, the oiling extended all the way to the low-tide line (the tidal range is 0.5 to 1.5 m), but, one year later, the oil in the lower intertidal areas was generally restricted to the tops of intertidal sand bars. Many of the unoiled topographic lows between the bars and other unoiled portions of the lower flats were rich in epifaunal and infaunal populations of invertebrates and plants. Shorebirds were observed feeding in these unoiled areas.
Databáze: OpenAIRE
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