Effects of chemical contaminants on genetic diversity in natural populations: Implications for biomonitoring and ecotoxicology

Department of Wildlife and Fisheries Sciences, Texas A&M University, 77843, College Station, TX 77843, USA.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis (Impact Factor: 3.68). 08/2000; 463(1):33-51. DOI: 10.1016/S1383-5742(00)00004-1
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ABSTRACT The conservation of genetic diversity has emerged as one of the central issues in conservation biology. Although researchers in the areas of evolutionary biology, population management, and conservation biology routinely investigate genetic variability in natural populations, only a handful of studies have addressed the effects of chemical contamination on population genetics. Chemical contamination can cause population reduction by the effects of somatic and heritable mutations, as well as non-genetic modes of toxicity. Stochastic processes in small populations, increased mutation load, and the phenomenon of mutational meltdown are compounding factors that cause reduced fitness and accelerate the process of population extirpation. Although the original damage caused by chemical contaminants is at the molecular level, there are emergent effects at the level of populations, such as the loss of genetic diversity, that are not predictable based solely on knowledge of the mechanism of toxicity of the chemical contaminants. Therefore, the study of evolutionary toxicology, which encompasses the population-genetic effects of environmental contaminants, should be an important focus of ecotoxicology. This paper reviews the issues surrounding the genetic effects of pollution, summarizes the technical approaches that can be used to address these issues, and provides examples of studies that have addressed some of them.

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Available from: John Bickham, Sep 27, 2015
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    • "In fact transgenerational effects of some PFAS at environmental concentrations have been recently demonstrated (Ahrens and Bundschuh, 2014, Stefani et al., 2014). Patterns of altered mutation rates caused by PFOS and PFBS at 10 μg L − 1 has been evidenced in a 10-generations test with Chironomus riparius (Stefani et al., 2014), and it has been hypothesized that long-term effects on population fitness may occur because of mutational load (Bickham et al., 2000; van Straalen and Timmermans, 2002). Among the possible genetic markers suitable for evolutionary ecotoxicology assessment, we explored the application of Amplified Fragment Length Polymorphism analysis (AFLP) (Vos et al., 1995) in this field case study. "
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    ABSTRACT: Effect-based monitoring is a recommended approach suggested in European Guidelines to assess the response of ecosystem affected by a pollution source, considering the effects at community, population, individual but also at suborganism level. A combined chemical, ecological and genetic approach was applied in order to assess the impact of a fluoropolymer plant on the macrobenthic community of the Northern Italian river Bormida (Piedmont region). The macrobenthic community living downstream of the industrial discharge was chronically exposed to a mixture of perfluoroalkyl substances (PFAS), with perfluorooctanoic acid as the main compound, at concentrations up to several μgL(-1). Ecological assessment proved that the downstream community was not substantially different from that living upstream of the pollution source. The impact on community is not quantifiable with the traditional monitoring methods used for ecological classification under European regulation because macrobenthic communities showed only slight differences in their structure. In order to highlight effects on genetic variability of the native population, a subcellular analysis by using the AFLP (Amplified Fragment Length Polymorphism) genetic technique was applied to genotype of individuals of a selected species (Hydropsyche modesta, Trichoptera) collected in the two sampling sites. Percentage of variation between the two populations was 6.8%, a threshold compatible with a genetic drift induced in the downstream population. The genetic study carried out in field identified a significant divergence between exposed and non-exposed populations, but at present it is not possible to associate this divergence to a specific effect induced by PFAS. Copyright © 2015 Elsevier B.V. All rights reserved.
    Science of The Total Environment 12/2015; 538:654-663. DOI:10.1016/j.scitotenv.2015.08.086 · 4.10 Impact Factor
    • "Pollution effects on organisms can imply consequences at the population level to varying degrees, from changes in population dynamics or genetic diversity (Bickham et al., 2000; Belfiore and Anderson, 2001), to the local extinction of a population (Gibbs and Bryan, 1996). Because biological communities are formed by multiple species interacting with each other, such impacts on populations can have implications for whole communities. "
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    ABSTRACT: Borja, A., J. Bremner, I. Muxika, J.G. Rodríguez, 2015. Chapter 14: Biological responses at supraindividual levels. In: Aquatic ecotoxicology: Advancing tools for dealing with emerging risks. Eds. C. Amiard-Triquet, J-C. Amiard, C. Mouneyrac, Academic Press, Elsevier, p. 333-354.
    Aquatic ecotoxicology: Advancing tools for dealing with emerging risks, Edited by C. Amiard-Triquet, J-C. Amiard, C. Mouneyrac, 07/2015: chapter Chapter 14: Biological responses at supraindividual levels: pages 333-354.; Academic Press, Elsevier.
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    • "One of the greatest challenges in evolutionary ecotoxicology lies in the ability to separate genetic diversity created by natural environmental factors that differ between habitats from genetic diversity caused by anthropogenic impacts, such as contamination (Hoffmann and Willi, 2008). In other words, to establish causality between contamination pressure and changes in genetic diversity in field populations (Bickham et al., 2000; DiBattista, 2008; van Straalen and Timmermans, 2002). It is generally argued that diversity within a given population of a species is important to uphold the fitness of the population (van Straalen and Timmermans, 2002), in parallel to biodiversity within communities that contributes to the sustainability and function of ecosystems (Naeem and Li, 1997; Rohr et al., 2006). "
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