title: Effects of diluted bitumen exposure on juvenile sockeye salmon: From cells to performance.
abstract: Diluted bitumen (dilbit; the product of oil sands extraction) is transported through freshwater ecosystems critical to Pacific salmon. This is concerning, because crude oil disrupts cardiac development, morphology, and function in embryonic fish, and cardiac impairment in salmon can have major consequences on migratory success and fitness. The sensitivity of early life-stage salmon to dilbit and its specific cardiotoxic effects are unknown. Sockeye salmon parr were exposed to environmentally relevant concentrations of the water-soluble fraction (WSF) of dilbit for 1 wk and 4 wk, followed by an examination of molecular, morphological, and organismal endpoints related to cardiotoxicity. We show that parr are sensitive to WSF of dilbit, with total polycyclic aromatic hydrocarbon (PAH) concentrations of 3.5 µg/L sufficient to induce a liver biomarker of PAH exposure, and total PAH of 16.4 µg/L and 66.7 µg/L inducing PAH biomarkers in the heart. Furthermore, WSF of dilbit induces concentration-dependent cardiac remodeling coincident with performance effects: fish exposed to 66.7 µg/L total PAH have relatively fewer myocytes and more collagen in the compact myocardium and impaired swimming performance at 4 wk, whereas the opposite changes occur in fish exposed to 3.5 µg/L total PAH. The results demonstrate cardiac sensitivity to dilbit exposure that could directly impact sockeye migratory success. Environ Toxicol Chem 2017;36:354-360. © 2016 SETAC.
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Alderman
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
authors.affiliation: Department of Zoology and Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Farrell
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Kennedy
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Todd E
authors.initials: TE
authors.lastname: Gillis
mesh_terms: D025041:Animal Migration / Q000187:drug effects*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D017753:Ecosystem; D004625:Embryo, Nonmammalian / Q000187:drug effects; D005618:Fresh Water; D006321:Heart / Q000187:drug effects* / Q000196:embryology; D006838:Hydrocarbons / Q000737:chemistry / Q000633:toxicity*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D061329:Oil and Gas Fields; D010578:Petroleum / Q000633:toxicity; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity; D012474:Salmon / Q000196:embryology / Q000378:metabolism / Q000502:physiology*; D012995:Solubility; D013550:Swimming; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D006838:Hydrocarbons; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; C006647:asphalt
keywords: Bitumen; Crude oil; Fish; Heart; Polycyclic aromatic hydrocarbon