EFFECTS OF DISPERSED CRUDE OIL TO FISH: BIOMARKER APPROCH

Abstract

Oil dispersants are valuable tool for minimizing the impact of marine oil spills. This paper reports whether fish will be exposed to more polycyclic aromatic hydrocarbon (PAHs) in dispersed oil relative to equivalent amount of the water-accomodated, WAFs. Measurements were made on CYP1A induction in Rockfish exposed to chemically enhanced WAF (dispersant) (Corexit 9500, and X product made in Korea) of oil. To evaluate expression of hepatic detoxification enzyme, we have constructed the cDNA library after exposing the b-NF to rockfish. CYP1A primers designed to a conserved region in GenBank were used. The deduced amino acid sequences of the CYP1A submitted to Genbank (Genbank no. AY568556). Level of CYP1A and EROD activity in rockfish exposed to CEWAF (Corexit 9500) increased in response to Concentration of 0.1 %(v/v) at after 48 h. After 72 h of exposure, Level of CYP1A and EROD activity were increased at 0.1% and 0.01% CEWAF (Corexit 9500 and X product made in Korea) significantly. The uptake of Polycyclic aromatic hydrocarbones (PAHs) by fish can be determined by screening the gall bladder bile for PAH metabolites. In the study, a bile sample exposed CEWAF showed 350 nm peak, which is attributed to 1-OH-py. But samples exposed to WAF were showed low fluorescence at 350 nm. Fish in both Corexit 9500 and X product CEWAF showed highly increased the 1-OH-py. than fish exposed to WAF and control fish after 72 h of exposure. These experiments suggest that the use of oil dispersants will increase the exposure of fish to hydrocarbons in oil. Therefore risk of PAH toxicity from dispersant oil will be greatest in coastal water aqua farm. The monitoring tools could be useful for the evaluation of risk assessment of oil spill and could be good for screening of PAHs exposure.