title: Biomarkers of effects of hypoxia and oil-shale contaminated sediments in laboratory-exposed gibel carp (Carassius auratus gibelio).
abstract: In North-East Estonia, considerable amounts of toxicants (e.g. polycyclic aromatic hydrocarbons (PAHs), phenols, heavy metals) leach into water bodies through discharges from the oil-shale industry. In addition, natural and anthropogenic hypoxic events in water bodies affect the health of aquatic organisms. Here we report a study on the combined effects of contaminated sediment and hypoxia on the physiology of gibel carp (Carssius auratus gibelio). We conducted a laboratory exposure study that involved exposure to polluted sediments from oil-shale industries (River Purtse) and sediments from a relatively clean environment (River Selja), together with sediments spiked with PAHs. The oxygen content (saturation vs. hypoxia (< 2 mg/L)) was changed to reflect hypoxia. A multi-biomarker approach was chosen to enable the combined effects to be assessed comprehensively and integratively. We used HPLC to measure the PAH concentration in sediment and fish muscle, fixed wavelength fluorescence (FF) analyses to indicate the presence of PAH metabolites in fish bile, and nuclear abnormalities in erythrocytes as markers of geno- and cyto-toxicity; and we monitored the change in body condition and measured EROD activity to indicate CYP1A induction. High levels of PAH conjugates in fish bile were found in the group exposed to the Purtse River sediment under hypoxia. The results suggested that induction of the CYP1A gene was modulated by hypoxia as well as by heavy metals. We found a correlation between several erythrocyte abnormalities (8-shaped nuclei and blebbed nuclei) and PAH metabolite content in fish. In conclusion, a measurable effect of pollution from the oil-shale industry on fish health parameters was clear under different oxygen levels.
authors.affiliation: Centre for Limnology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Rannu, 61117 Tartu County, Estonia; Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51020 Tartu, Estonia. Electronic address: randel.kreitsberg@ut.ee.
authors.forename: Randel
authors.initials: R
authors.lastname: Kreitsberg
authors.forename: Janina
authors.initials: J
authors.lastname: Baršienė
authors.forename: Rene
authors.initials: R
authors.lastname: Freiberg
authors.forename: Laura
authors.initials: L
authors.lastname: Andreikėnaitė
authors.forename: Toomas
authors.initials: T
authors.lastname: Tammaru
authors.forename: Kateriina
authors.initials: K
authors.lastname: Rumvolt
authors.forename: Arvo
authors.initials: A
authors.lastname: Tuvikene
mesh_terms: D000818:Animals; D001646:Bile / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D004912:Erythrocytes / Q000187:drug effects / Q000648:ultrastructure; D004957:Estonia; D019015:Geologic Sediments / Q000737:chemistry*; D006054:Goldfish / Q000378:metabolism*; D019216:Metals, Heavy / Q000032:analysis / Q000633:toxicity; D009132:Muscles / Q000737:chemistry / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D059392:Petroleum Pollution / Q000009:adverse effects*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D019216:Metals, Heavy; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1; D010100:Oxygen
keywords: Cytotoxicity; Fish bile; Oil-shale; Oxygen; PAH; Purtse River