title: Chemical and biological assessment of two offshore drilling sites in the Alaskan Arctic.
abstract: A retrospective chemical and biological study was carried out in Camden Bay, Alaskan Beaufort Sea, where single exploratory oil wells were drilled at two sites more than two decades ago. Barium from discharged drilling mud was present in sediments at concentrations as high as 14%, ~200 times above background, with significantly higher concentrations of Ba, but not other metals, within 250 m of the drilling site versus reference stations. Elevated concentrations of Cr, Cu, Hg and Pb were found only at two stations within 25 m of one drilling site. Concentrations of total polycyclic aromatic hydrocarbons (TPAH) were not significantly different at reference versus drilling-site stations; however, TPAH were elevated in Ba-rich layers from naturally occurring perylene in ancient formation cuttings. Infaunal biomass and species abundance were not significantly different at reference versus drilling-site stations; infauna were less diverse at drilling-site stations. Our assessment showed that discharges from single wells within large areas caused minimal long-term, adverse impacts to the benthic ecosystem.
authors.affiliation: Department of Marine & Environmental Systems, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901, USA. jtrefry@fit.edu
authors.forename: John H
authors.initials: JH
authors.lastname: Trefry
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Dunton
authors.forename: Robert P
authors.initials: RP
authors.lastname: Trocine
authors.forename: Susan V
authors.initials: SV
authors.lastname: Schonberg
authors.forename: Nathan D
authors.initials: ND
authors.lastname: McTigue
authors.forename: Eric S
authors.initials: ES
authors.lastname: Hersh
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: McDonald
mesh_terms: D000413:Alaska; D001110:Arctic Regions; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000032:analysis*; D019652:Extraction and Processing Industry / Q000295:instrumentation*; D019015:Geologic Sediments / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis*; D009792:Oceans and Seas; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D012044:Regression Analysis; D012189:Retrospective Studies; D013054:Spectrophotometry, Atomic
chemical_list: D004785:Environmental Pollutants; D019216:Metals, Heavy; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons