Biomarker Response of Feral Fish after the Hebei Spirit oil spill

Abstract

To clarify the impact on fish physiological response by oil spill, hepatic biomarker responses were measured in several fish species from Euhang-ri, one of heavily oiled areas. Biomarkers were selected in order to evaluate the toxic effects on hepatic detoxification system exposed to PAHs. Level of ethoxyresorufin-O-deethylase (EROD), cytochrome P4501A (CYP1A) mRNA and protein were measured on a weekly or monthly basis from four days after the oil spill. The uptake of PAHs by fish was indirectly measured by pyrene metabolite, 1-OH-pyrene, using synchronous fluorescence spectrometry. Fish bile showed highly increased 1-OH-pyrene levels four days after the oil spill and then decreased to the reference level according to time. A significant induction in EROD and CYP1A mRNA and protein expression were observed from five days after the oil spill, and then decreased to reference level, too. Acetylcholine esterase activity was also slightly inhibited in initial fish samples compared to the reference site. Enzymatic biomarker levels increased rapidly in flatfish (marbled sole) caught at Euhang-ri on 23, July 2008. These results correlated well with bile 1-OH-pyrene levels. This episodic increase of bile 1-OH-pyrene level and biomarker response reflects secondary pollution from removal of oiled aquaculture facilities near the sampling site.