title: A multiple endpoint analysis of the effects of chronic exposure to sediment contaminated with Deepwater Horizon oil on juvenile Southern flounder and their associated microbiomes.
abstract: Exposure to oiled sediments can negatively impact the health of fish species. Here, we examine the effects of chronic exposure of juvenile southern flounder, Paralichthys lethostigma, to a sediment-oil mixture. Oil:sediment mixtures are persistent over time and can become bioavailable following sediment perturbation or resuspension. Juvenile flounder were exposed for 32 days under controlled laboratory conditions to five concentrations of naturally weathered Macondo MC252 oil mixed into uncontaminated, field-collected sediments. The percent composition of individual polycyclic aromatic hydrocarbons (PAHs) of the weathered oil did not change after mixing with the sediment. Spiked exposure sediments contained 0.04-395mg/kg tPAH50 (sum of 50 individual PAH concentration measurements). Mortality increased with both exposure duration and concentration of sediment-associated PAHs, and flounder exposed to concentrations above 8mg/kg tPAH50 showed significantly reduced growth over the course of the experiment. Evident histopathologic changes were observed in liver and gill tissues of fish exposed to more than 8mg/kg tPAH50. All fish at these concentrations showed hepatic intravascular congestion, macrovesicular hepatic vacoulation, telangiectasia of secondary lamellae, and lamellar epithelial proliferation in gill tissues. Dose-dependent upregulation of Cyp1a expression in liver tissues was observed. Taxonomic analysis of gill and intestinal commensal bacterial assemblages showed that exposure to oiled sediments led to distinct shifts in commensal bacterial population structures. These data show that chronic exposure to environmentally-relevant concentrations of oiled sediments produces adverse effects in flounder at multiple biological levels.
authors.affiliation: Department of Coastal Sciences, The University of Southern Mississippi, 703 East Beach Dr., Ocean Springs, MS 39564, United States. Electronic address: nancy.brown-peterson@usm.edu.
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Brown-Peterson
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, Colorado 80302, United States. Electronic address: MKrasnec@stratusconsulting.com.
authors.forename: Michelle
authors.initials: M
authors.lastname: Krasnec
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, Colorado 80302, United States. Electronic address: RTakeshita@stratusconsulting.com.
authors.forename: Ryan
authors.initials: R
authors.lastname: Takeshita
authors.affiliation: The Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409, United States. Electronic address: Caitlin.ryan@ttu.edu.
authors.forename: Caitlin N
authors.initials: CN
authors.lastname: Ryan
authors.affiliation: Department of Coastal Sciences, The University of Southern Mississippi, 703 East Beach Dr., Ocean Springs, MS 39564, United States. Electronic address: kim.griffitt@gmail.com.
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Griffitt
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, Colorado 80302, United States. Electronic address: claymsc@stratusconsulting.com.
authors.forename: Claire
authors.initials: C
authors.lastname: Lay
authors.affiliation: The Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409, United States. Electronic address: greg.mayer@ttu.edu.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Mayer
authors.affiliation: Department of Coastal Sciences, The University of Southern Mississippi, 703 East Beach Dr., Ocean Springs, MS 39564, United States. Electronic address: kmbayha@gmail.com.
authors.forename: Keith M
authors.initials: KM
authors.lastname: Bayha
authors.affiliation: Department of Coastal Sciences, The University of Southern Mississippi, 703 East Beach Dr., Ocean Springs, MS 39564, United States. Electronic address: william.hawkins@usm.edu.
authors.forename: William E
authors.initials: WE
authors.lastname: Hawkins
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, Colorado 80302, United States. Electronic address: ianlipton@stratusconsulting.com.
authors.forename: Ian
authors.initials: I
authors.lastname: Lipton
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, Colorado 80302, United States. Electronic address: JMorrisMSCanyon252@stratusconsulting.com.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Morris
authors.affiliation: Department of Coastal Sciences, The University of Southern Mississippi, 703 East Beach Dr., Ocean Springs, MS 39564, United States. Electronic address: joe.griffitt@usm.edu.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Griffitt
mesh_terms: D000818:Animals; D004781:Environmental Exposure; D005432:Flounder / Q000502:physiology*; D019015:Geologic Sediments / Q000737:chemistry*; D005880:Gills / Q000187:drug effects*; D008099:Liver / Q000187:drug effects*; D064307:Microbiota / Q000187:drug effects*; D010578:Petroleum / Q000633:toxicity*; D059392:Petroleum Pollution; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D010578:Petroleum; D014874:Water Pollutants, Chemical
keywords: Deepwater Horizon; Ecotoxicology; Gene expression; Histopathology; Microbiome; Paralichthys