title: Biodegradation of dispersed oil in Arctic seawater at -1°C.
abstract: As offshore oil and gas exploration expands in the Arctic, it is important to expand the scientific understanding of arctic ecology and environmental impact to mitigate operational risks. Understanding the fate of oil in arctic seawater is a key factor for consideration. Here we report the chemical loss due to the biodegradation of Alaska North Slope (ANS) crude oil that would occur in the water column following the successful dispersion of a surface oil slick. Primary biodegradation and mineralization were measured in mesocosms containing Arctic seawater collected from the Chukchi Sea, Alaska, incubated at -1°C. Indigenous microorganisms degraded both fresh and weathered oil, in both the presence and absence of Corexit 9500, with oil losses ranging from 46-61% and up to 11% mineralization over 60 days. When tested alone, 14% of 50 ppm Corexit 9500 was mineralized within 60 days. Our study reveals that microorganisms indigenous to Arctic seawater are capable of performing extensive biodegradation of chemically and physically dispersed oil at an environmentally relevant temperature (-1°C) without any additional nutrients.
authors.affiliation: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: McFarlin
authors.affiliation: ExxonMobil Biomedical Sciences, Inc., Annandale, New Jersey, United States of America.
authors.forename: Roger C
authors.initials: RC
authors.lastname: Prince
authors.affiliation: Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America.
authors.forename: Robert
authors.initials: R
authors.lastname: Perkins
authors.affiliation: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America.
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Leigh
mesh_terms: D000413:Alaska; D001110:Arctic Regions; D001673:Biodegradation, Environmental / Q000187:drug effects; D003080:Cold Temperature; D008401:Gas Chromatography-Mass Spectrometry; D006838:Hydrocarbons / Q000032:analysis; D008055:Lipids / Q000494:pharmacology; D008903:Minerals / Q000032:analysis; D010578:Petroleum / Q000032:analysis*; D059392:Petroleum Pollution / Q000032:analysis*; D012623:Seawater / Q000737:chemistry*
chemical_list: D006838:Hydrocarbons; D008055:Lipids; D008903:Minerals; D010578:Petroleum; C470995:corexit 9500