title: Hepatic biomarkers of sediment-associated pollution in juvenile turbot, Scophthalmus maximus L.
abstract: Hatchery-reared turbot (Scophthalmus maximus L.) were exposed for 3 weeks, under laboratory conditions, to sediment collected from polluted sites in Cork Harbour and a reference site at Ballymacoda, Co. Cork, Ireland. The potential of surficial sediment for inducing hepatic biomarkers was assessed at two levels of biological organisation: expression of cytochrome P450 [Western blotting analysis and 7-ethoxy-resorufin O-dealkylase (EROD), 7-benzoxy resorufin O-dealkylase (BROD), 7-methoxy resorufin O-dealkylase (MROD), 7-pentoxy-resorufin O-dealkylase (PROD) activities] and DNA integrity (Comet assay). Positive controls were generated, either by exposing turbot to cadmium chloride-spiked seawater (Comet assay) or to beta-naphthaflavone by intraperitoneal injection (cytochrome P450 induction). The induction of cytochrome P450 activity (EROD, MROD and PROD) in animals following a 7-day exposure to contaminated sediments was significantly higher than those exposed to reference site sediment and remained elevated thereafter; BROD was not induced. DNA single-strand breaks were also significantly higher following exposure to contaminated sediments throughout the experiment. Although no direct correlation between induction of alkoxyresorufin O-dealkylase activities and a particular chemical class was established, the induction of MROD and PROD activities in fish exposed to sediments containing complex contaminant mixtures, appeared to be more sensitive than conventional EROD activity assays. We conclude from the present laboratory study that S. maximus is a suitable sentinel species for the assessment of moderately contaminated sediments and therefore allows for the further development of this model for future, ecologically relevant, field studies.
authors.affiliation: Environmental Research Institute, University College Cork, Ireland.
authors.forename: Mark G J
authors.initials: MG
authors.lastname: Hartl
authors.forename: Michael
authors.initials: M
authors.lastname: Kilemade
authors.forename: David
authors.initials: D
authors.lastname: Sheehan
authors.forename: Carmel
authors.initials: C
authors.lastname: Mothersill
authors.forename: John
authors.initials: J
authors.lastname: O'Halloran
authors.forename: Nora M
authors.initials: NM
authors.lastname: O'Brien
authors.forename: Frank N A M
authors.initials: FN
authors.lastname: van Pelt
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D015415:Biomarkers / Q000378:metabolism; D020552:Comet Assay; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004249:DNA Damage; D004784:Environmental Monitoring; D005412:Flatfishes / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D019015:Geologic Sediments / Q000737:chemistry*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D014874:Water Pollutants, Chemical; D003577:Cytochrome P-450 Enzyme System