What is the relationship between the bioaccumulation of chemical contaminants in the variegated scallop Mimachlamys varia and its health status? A study carried out on the French Atlantic coast using the Path ComDim model

• Published in: The Science of the total environment 2018-11, Vol.640-641, p.662-670
• Main Authors: Breitwieser, Marine, Vigneau, Evelyne, Viricel, Amélia, Becquet, Vanessa, Lacroix, Camille, Erb, Marina, Huet, Valérie, Churlaud, Carine, Le Floch, Stéphane, Guillot, Benoit, Graber, Marianne, Thomas, Hélène
• Format: Article
• Language: English
• Subjects: Animals; Atlantic coast; Biochemical assays; Biomarkers - metabolism; Chronic chemical contamination; Environmental Monitoring; Environmental Sciences; Genetic diversity; Health Status; Mimachlamys varia; Path-ComDim model; Pectinidae - metabolism; Polycyclic Aromatic Hydrocarbons - metabolism; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2018.05.317

Increasing activity along the French Atlantic coast has led to chronic pollution with, in particular, mixtures of contaminants such as hydrocarbons, phytosanitary products, PCBs and heavy metals. Based on previous research, pollution biomarkers were used in this study as they can indicate health status when monitoring the impact of pollutants on coastal species such as the marine bivalve Mimachlamys varia. Mollusc bivalves were sampled in March 2016, in open and semi-open areas (a harbour zone), from thirteen sites which differed in terms of their level of pollution, and were located along the Atlantic coast from Brittany down to the Nouvelle-Aquitaine region. First, analyses of heavy metals and organic contaminants (e.g. pesticides, polycyclic aromatic hydrocarbons, polychlorobiphenyl) in the digestive gland of bivalves were performed. Second, biochemical assays were used to study defence biomarkers: oxidative stress with Superoxide Dismutase (SOD), detoxification of organic compounds with Glutathione-S Transferase (GST), lipid peroxidation with Malondialdehyde (MDA), and immune processes with Laccase. In addition to the biochemical assays, a genetic approach was used to measure genetic diversity (haplotype and nucleotide diversity) at each site. Biomarker assays and genetic diversity were correlated with the chemical contaminants in bivalves using the Path-ComDim statistical model. Our results showed specific correlations between biochemical assays in the digestive glands with heavy metal contaminants, and between genetic diversity and organic pollution. Blocks of responses were analysed for correlations in order to develop standardized tools and guidelines that could improve our understanding of the short-term and long-term impact of contaminants on physiological parameters. Integrative approach undertaken in this study to assess effects of a chronic chemical contamination on natural populations of the marine bivalve Mimachlamys varia. Photo credit: Thierry Guyot. [Display omitted] •Mimachlamys varia was shown to be a useful bioindicator for environment quality assessment•Scallops were collected from 13 areas along the French Atlantic coast, contaminated to different degrees•Relationships between blocks of variables were demonstrated with the Path-ComDim model•The health of marine bivalves is modulated by polymetallic pollution•Genetic diversity was negatively correlated to organic contamination