Ecotoxicological biomarker development and validation

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The overall objective of this research program is to develop, validate and apply a suite of non-lethal biomarkers of exposure to, and effects of, environmental contaminants in fish. This will be achieved by the undertaking the following tasks: Develop a species specific protocol for applying the innovative and new non-lethal biomarker technique, bioeletrical impedance analysis (BIA), to determining a rapid assessment of fish proximate body composition, specifically lipid and energy density. The BIA technique, which was developed for human health applications, instantaneously measures the resistance and reactance (or capacitance) along the body of the fish, which is then used to quantify body lipid and energy levels. Initial work will focus on creating calibration equations for rainbow trout (Oncorhynchus mykiss), Japanese medaka (Oryzias latipes) and Florida flagfish (Jordanella floridae). Validation will involve lipid and calorimetric measurements to be made using lethal sampling to develop appropriate mathematical models for each species. Application of non-lethal biomarker techniques will then be undertaken to assess the biochemical and bioenergetic impacts of toxicant exposure to fish in the laboratory. Correlations between altered blood enzyme biomarkers and bioenergetics will be made in relation to specific doses and time following exposure. Field biomonitoring using caged-fish populations held in regions of varying contaminant levels will be done to measure the bioenergetic costs of detoxification and acclimation over time. This novel information will result in increased understanding of the impacts of contaminants on the physiology and health of fish populations. Finally, calibration equations for a wider range of local freshwater fish species will be created to permit fish community bioenergetic studies to be undertaken. Thus, this research program will enhance efforts to rapidly assess condition of fish species in the wild as well as in laboratory situtations, and to permit more precise understanding of the bioenergetics of contaminant exposure on different spatial and temporal scales. Development and validation of this non-lethal BIA technique will increase our ability to manage important fish populaions for the benefit of all Canadians.