Sublethal Toxicity

Scope of Work:

Controlled exposure studies allow scientists to assess cause and effect relationships between stressors and responses of organisms. Lack of understanding of such relationships can limit the effectiveness of management and conservation decisions. Using CROSERF (Chemical Response to Oil Spills: Ecological Research Forum) protocols (adopted for the Deepwater Horizon NRDA), we will expose juvenile chum salmon (Oncorhynchus keta) to several Alaskan crude oils and Corexit 9500 dispersant concentrations under acute spiked exposure regimes. To assess significant sub-lethal responses of exposed fishes, we will conduct biomarker assays designed to measure genotoxicity, lipid composition, and cytokine levels (immune function), and then develop DNA expression and cytokine protein microarrays to assess changes in expression of genes regulating immunity. We will assess morphometrics, standard blood chemistry, and contaminant levels in tissues for exposed and unexposed fishes. Assessments will occur immediately after exposure and be repeated to assess delayed impacts. Results of these studies will document how exposures to oil and/or a dispersant in the field could affect the sustainability of salmon and by extension other Alaskan fish stocks of commercial, subsistence, and ecological importance. Finally, the project facilitates the creation of a regional center of excellence for controlled exposure studies using a range of life stages for other Arctic marine fishes and invertebrates of concern in Alaska and the Pacific Northwest. The proposed study is inclusive of all four strategic goals of the Oil Spill Recovery Institute (OSRI), namely to:

1. Understand: evaluate both short-and long-term effects of oil and dispersant exposure to nearshore species for determining their possible impacts on economics and the environment for future emergency response planning;
2. Respond: through careful assessment of effects of oil and dispersant exposures on key Alaskan species, information regarding a range of responses will be rigorously evaluated for judging the most prudent mitigation scenarios;
3. Inform: a combination of scientific presentations, publications, local community meetings, and educational outreach will alert stakeholders and other interested parties to current scientific techniques and interpretations of exposure responses leading to important social, economic, and environmental outcomes; and
4. Partner: some of the most notable accomplishments of this proposed work will be to help build local capacity for enhanced toxicity research in Alaska, form strong partnerships with the oil industry, and create productive common interest research program collaborations with partners in the Arctic and Sub-Arctic regions of Alaska for a statewide integrated oil spill response coordination.