Identification of hydrocarbon sources in the benthic sediments of Prince William Sound and the Gulf of Alaska following the Exxon Valdez oil spill
- Bowdoin Coll., Brunswick, ME (United States)
- Arthur D. Little, Cambridge, MA (United States)
- Exxon Production Research Co., Houston, TX (United States)
Advanced hydrocarbon fingerprinting methods and improved analytical methods make possible the quantitative discrimination of the multiple sources of hydrocarbons in the benthic sediments of Prince William Sound (PWS) and the Gulf of Alaska. These methods measure an extensive range of polycyclic aromatic hydrocarbons (PAH) at detection levels that are as much as two orders of magnitude lower than those obtained by standard Environmental Protection Agency methods. Nineteen hundred thirty six subtidal sediment samples collected in the sound and the eastern Gulf of Alaska in 1989, 1990, and 1991 were analyzed. Fingerprint analyses of gas chromatography-mass spectrometry data reveal a natural background of petrogenic and biogenic PAH. Exxon Valdez crude, its weathering products, and diesel fuel refined from Alaska North Slope crude are readily distinguished from the natural seep petroleum background and from each other because of their distinctive PAH distributions. Mixing models were developed to calculate the PAH contributions from each source to each sediment sample. These calculations show that most of the seafloor in PWS contains no detectable hydrocarbons from the Exxon Valdez spill, although elevated concentrations of PAH from seep sources are widespread. In those areas where they were detected, spill hydrocarbons were generally a small increment to the natural petroleum hydrocarbon background. Low levels of Exxon Valdez crude residue were present in 1989 and again in 1990 in nearshore subtidal sediments off some shorelines that had been heavily oiled. By 1991 these crude residues were heavily degraded and even more sporadically distributed. 58 refs., 18 figs., 5 tabs.
- OSTI ID:
- 382754
- Report Number(s):
- CONF-930442-; ISBN 0-8031-1896-1; TRN: 96:025713
- Resource Relation:
- Conference: 3. symposium on environmental toxicology and risk assessment, Atlanta, GA (United States), 25-28 Apr 1993; Other Information: PBD: 1995; Related Information: Is Part Of Exxon Valdez oil spill: Fate and effects in Alaskan waters; Wells, P.G.; Butler, J.N.; Hughes, J.S. [eds.]; PB: 961 p.; ASTM special technical publication, 1219
- Country of Publication:
- United States
- Language:
- English
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