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.

A protocol for identifying suitable biomarkers to assess fish health: A systematic review

“…The changes in CYP1A activity, however, did not necessarily correlate with metals levels in the water column or metals accumulated in fish tissue [86], as shown by the mixed response observed in some studies [97, 98]. The absence of a relationship between CYP1A activity and metal concentrations is possibly due to the sediments also being contaminated with organic contaminants which are known to induce the CYP1A enzyme due to its role in detoxification of PAHs [96, 97, 99]. …”

Biomonitoring of Genotoxicity of Shallow Waters Around the Brazilian Antarctic Station Comandante Ferraz (Eacf), Admiralty Bay, King George Island, Antarctica, Using Amphipod Crustaceans

“…DNA damage is a primary concern for the assessment of pollution-related stress in living organisms (Klobučar et al, 2003). Comet assay have been applied to assess the effects of genotoxicity in different forms of marine organisms (Hartl et al, 2007;Taban et al, 2004), including crustaceans (Rocha et al, 2012).…”

Environmental contaminant effects on juvenile striped bass in the San Francisco Estuary, California, USA

“…Although CYP1A and other cytochrome P450 enzymes have been shown to be differentially involved in EROD and BROD activity in mammalian species, the significance of BROD induction is not fully understood in aquatic species. Exposure of fish to crude oil aqueous extracts induced both EROD and BROD activity [33], whereas other chemical exposures differentially induced either EROD or BROD activity [34].…”