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FIELD VALIDATION OF SEDIMENT TOXCITY IDENTIFCATION AND EVALUATION METHODS
Citation:
Ho, K T., M. L. Gielazyn, R M. Burgess, M Pelletier, J R. Serbst, S Ryba, M. M. Perron, M Cantwell, R L. Johnson, AND K T. Perez. FIELD VALIDATION OF SEDIMENT TOXCITY IDENTIFCATION AND EVALUATION METHODS. Presented at Society of Environmental Toxicology and Chemistry Annual Meeting, Austin, TX, November 9-13, 2003.
Description:
Sediment Toxicity Identification and Evaluation (TIE) methods have been developed for both porewaters and whole sediments. These relatively simple laboratory methods are designed to identify specific toxicants or classes of toxicants in sediments; however, the question of whether the same toxicant identified in the laboratory is causing effects in the field remains. We report on an approach to field validate TIE methods. The field site (Elizabeth River,VA) was chosen because of high concentrations of PAHs and documented effects on indigenous fish populations. Benthic community analyses was performed to ensure that an ecological impact had occurred at the site. Results from the Euclidean distance similarity index indicated that the benthic community in Elizabeth River differed from that in a nearby reference site. Using TIE procedures on sediments collected from the Elizabeth River, we identified PAHs as the major toxicant. Concentrations of PAHs in Elizabeth River sediment were also elevated relative to a nearby reference site. To determine if additional adverse effects were occurring in field organisms, we used the Comet assay, which measures DNA damage and is sensitive to PAHs. Evidence of DNA damage in caged bivalves, Mercenaria merceneria, from the Elizabeth River was observed using the Comet Assay. Based on the presence of high PAH concentrations in the sediments and observed effects in field organisms using the COMET assay and benthic community analyses, we believe that the TIE process identified the toxicants responsible for field effects.