Gene expression in caged juvenile Coho Salmon (Oncorhynchys kisutch) exposed to the waters of Prince William Sound, Alaska

The 1989 Exxon Valdez oil spill (EVOS) resulted in the release of 258,000 barrels of crude oil into the waters of Prince William Sound (PWS), Alaska. The current study, conducted in 2004, sought to use juvenile Coho salmon (Oncorhynchus kisutch) caged in situ to determine whether biomarker induction differed at sites where the adjacent shoreline contained buried residues from the 1989 oil spill compared to sites that were never oiled. Juvenile Coho salmon were caged at five sites; three oiled during the 1989 EVOS and two that were not oiled. Tissue samples were collected from organisms caged at each site as well as a control group housed onboard the research vessel. Analysis of CYP1A, superoxide dismutase (SOD), and glutathione peroxidase (GPO) gene expression was conducted using real time reverse transcriptase polymerase chain reaction (rtRT-PCR). Statistically significant levels of CYP1A expression were observed at some sites indicating increased hydrocarbon exposure. No patterns were observed regarding sites that were originally oiled or not oiled by the 1989 EVOS, indicating that sources of PAHs other than EVOS oil occur in PWS.