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Resolving mechanisms of toxicity while pursuing ecotoxicological relevance?

Laboratory of Molecular Aquatic Toxicology, Division of Environmental Sciences and Policy, Nicholas School of the Environment and Earth Sciences, Duke University Durham, NC 277-8-0328, USA.
Marine Pollution Bulletin (Impact Factor: 2.79). 02/2005; 51(8-12):635-48. DOI: 10.1016/j.marpolbul.2005.07.020
Source: PubMed

ABSTRACT In this age of modern biology, aquatic toxicological research has pursued mechanisms of action of toxicants. This has provided potential tools for ecotoxicologic investigations. However, problems of biocomplexity and issues at higher levels of biological organization remain a challenge. In the 1980s and 1990s and continuing to a lesser extent today, organisms residing in highly contaminated field sites or exposed in the laboratory to calibrated concentrations of individual compounds were carefully analyzed for their responses to priority pollutants. Correlation of biochemical and structural analyses in cultured cells and tissues, as well as the in vivo exposures led to the production and application of biomarkers of exposure and effect and to our awareness of genotoxicity and its chronic manifestations, such as neoplasms, in wild fishes. To gain acceptance of these findings in the greater environmental toxicology community, "validation of the model" versus other, better-established often rodent models, was necessary and became a major focus. Resultant biomarkers were applied to heavily contaminated and reference field sites as part of effects assessment and with investigations following large-scale disasters such as oil spills or industrial accidents. Over the past 15 years, in the laboratory, small aquarium fish models such as medaka (Oryzias latipes), zebrafish (Danio rerio), platyfish (Xiphophorus species), fathead minnow (Pimephales promelas), and sheepshead minnow (Cyprinodon variegatus) were increasingly used establishing mechanisms of toxicants. Today, the same organisms provide reliable information at higher levels of biological organization relevant to ecotoxicology. We review studies resolving mechanisms of toxicity and discuss ways to address biocomplexity, mixtures of contaminants, and the need to relate individual level responses to populations and communities.

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    • "Recently, small fishes are increasingly taken as model species for physiological and biochemical studies (Hinton et al., 2005). The marine medaka Oryzias melastigma, which is a counterpart of the freshwater medaka O. latipes with genome data available, has been advocated to be a saltwater fish model for marine environmental research and ecotoxicological studies (Fang et al., 2012; Wu et al., 2012). "
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    • "Substantial advances have been made in recent years regarding the complex molecular and cellular mechanisms involved in physiological responses to pollutants. Still, determining the broad population-and community-level consequences is necessary to establish the ecological relevance of pollution (Hinton et al. 2005). In the aftermath of the Macondo blowout, the most comprehensive ecotoxicological studies must consider both broad and focused perspectives (Fodrie et al. 2014). "
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    • "In the recent decade, there is a trend of using small size freshwater fish as the model animals for ecotoxicology research, such as zebrafish, Japanese medaka, and fathead minnow (Pimephales promelas) (Hinton et al., 2005; Ankley et al., 2009; Chen et al., 2011a). However, these commonly used freshwater fish models are not suitable for assessing the environmental stress in the estuarine/marine environment. "
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