Lingering Oil: Extending the Tracking of Oil Levels and Weathering (PAH Composition) in PWS through Time. Exxon Valdez Oil Spill Restoration Project Final Report (Restoration Project 12120014-S)
Carls MG, Lindeberg M, Maselko J. 2017. Lingering Oil: Extending the Tracking of Oil Levels and Weathering (PAH Composition) in PWS through Time. Exxon Valdez Oil Spill Restoration Project Final Report (Restoration Project 12120014-S). Exxon Valdez Oil Spill Trustee Council. Anchorage, Alaska
Relatively small patches of Exxon Valdez oil have persisted in the spill area for 26 years. Goals for this project were to provide the EVOSTC with an assessment of persistent Exxon Valdez oil in Prince William Sound, describe its chemical characteristics, and initiate a routine for long-term monitoring. These goals were accomplished in two ways: (1) by conducting a retrospective oil chemistry analysis, which included novel pattern matching of petroleum biomarkers, and (2) by conducting a lingering oil survey during the summer of 2015 to revisit a small set of beaches in Prince William Sound known to have persistent Exxon Valdez oil. Results of biomarker pattern matching allowed for definitive identification of 25-year-old Alaska North Slope crude oil, however some biomarkers did show some evidence of weathering. Results from the lingering oil survey indicated that Exxon Valdez oil remained in subsurface sediments for 26 years and there was little evidence of change in oil area or mass over the last 14 years at these beach segments. This suggests the remaining oil is sequestered and not bioavailable unless disturbed by natural process or human activities and likely will persist in the environment on a decadal scale. Recommendations are to continue monitoring lingering oil for changes in chemical composition, bioavailability, and retention in the environment but on a decadal cycle over which change is more likely to be detected.
- Type
- Published Report
- Authors
- Carls, Mark; Lindeberg, Mandy; Maselko, Jacek
- Date of Issue
- 2017-06
- Publisher
- Exxon Valdez Oil Spill Trustee Council
- Units
- KATM , KEFJ , SWAN
- Keywords
- chemical composition, Exxon Valdez, Gulf of Alaska, lingering oil, long-term tracking, PAHs, passive samplers, petroleum biomarkers, polynuclear aromatic hydrocarbons, Prince William Sound, weathering
- Subjects
- Ecological Framework: Water | Water Quality | Toxics , Ecological Framework: Biological Integrity | Focal Species or Communities | Marine Communities