Water Resources Research Act Program

Details for Project ID 2007WA210B

Assessment of contaminated sediments using a rainbow trout (Oncorhynchus mykiss) as an embryonic exposure assay

Institute: Washington
Year Established: 2007 Start Date: 2007-03-01 End Date: 2008-02-28
Total Federal Funds: $24,000 Total Non-Federal Funds: $48,077

Principal Investigators: Jeffrey Ullman

Project Summary: Despite contaminated sediments presenting an environmental health hazard, ecological risk assessments remain largely impeded by a lack of data and guidance. The state of Washington has adopted a robust system of standards to handle marine sediments, but freshwater sediment evaluation remains on a case-by-case basis. Since sediments display temporal variability and bioavailability can not be directly linked to total contaminant load, more information on the effects of direct contact exposure to sediments by benthic organisms is needed. Rainbow trout (Oncorhynchus mykiss) have been used extensively as a toxicological model for assessing water quality due to low husbandry costs, sensitivity to pollutants and easily quantified physiological responses to contaminants. Due to inadequacies of LD50 values (dose response that results in 50% lethality), use of early life stage (ELS) toxicity analysis has increased as a tool to characterize risk in aquatic ecosystems. However, no published studies were found addressing the use of rainbow trout embryos to evaluate toxicity associated with direct contact with sediments. This project hypothesizes that sub-lethal concentrations of organic contaminants associated with sediments will yield quantifiable health impacts using a variety of indices. Two classes of chemicals, polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PDBEs), will be used separately and together to determine synergistic effects. Survival, fluctuating asymmetry, sex reversal, vitellogenin production and embryonic uptake will be examined using all-male clonal lines. This novel approach will provide insight into the toxicological and physiological effects of these compounds, as well as assess the feasibility of using this strategy as an alternative bioassay to determine sediment toxicity. Corresponding examination of sorption behavior of the organic compounds will provide further insight into the bioavailability of sediment-bound pollutants.