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An Estuarine Fish Bioassay for Sensitive Biomonitoring of Oil-related Contamination
Citation:
NACCI, D. E., D. M. CHAMPLIN, D. Proestou, AND M. G. CANTWELL. An Estuarine Fish Bioassay for Sensitive Biomonitoring of Oil-related Contamination. Presented at SETAC North America 31st Annual Meeting, Portland, OR, November 07 - 11, 2010.
Impact/Purpose:
In this abstract we describe a sensitive embryonic and larval bioassay using the estuarine fish, Fundulus heteroclitus, which includes an endpoint that is diagnostic of certain organic pollutants, including some oil-related contaminants.
Description:
An embryonic and larval bioassay using the estuarine fish, Fundulus heteroclitus, was modified for the rapid detection of bioavailable compounds that act through the aryl hydrocarbon receptor (AhR). The early development of fishes is particularly sensitive to AhR agonists, such as some poly-halogenated dioxins/furans, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs), including oil-related contaminants. Exposure to these contaminants activates the AhR pathway, signaled by the induction of cytochrome P4501A, often measured as ethoxyresorufin-o-deethylase (EROD) activity. Here, embryonic EROD was measured non-invasively following a 2 day exposure during mid-embryonic development and a 7 day early embryonic exposure, both of which were complemented with traditional toxicity endpoints assessed at 28 days post-fertilization. We compared results using oil spill-related environmental samples including some prototypical AhR-agonists, and No. 2 Fuel oil water soluble fraction, made with and without an oil dispersant. In 2- and 7-day exposures, embryonic EROD fluorescence was increased at concentrations 1 – 3 orders of magnitude lower than concentrations producing adverse health effects. These results suggest the usefulness of this approach to sensitively detect bioavailable contamination by compounds that act through the AhR, rank toxic potency of environmental media, reveal mechanisms of toxicity for compounds and environmental mixtures, and inform species-specific population models used to project ecological effects of contamination.