Short-Term and Long-Term Biological Effects of Chronic Chemical Contamination on Natural Populations of a Marine Bivalve

PLoS One. 2016 Mar 3;11(3):e0150184. doi: 10.1371/journal.pone.0150184. eCollection 2016.

Abstract

Understanding the effects of chronic chemical contamination on natural populations of marine organisms is complex due to the combined effects of different types of pollutants and environmental parameters that can modulate the physiological responses to stress. Here, we present the effects of a chronic contamination in a marine bivalve by combining multiple approaches that provide information on individual and population health. We sampled variegated scallops (Mimachlamys varia) at sites characterized by different contaminants and contamination levels to study the short and long-term (intergenerational) responses of this species to physiological stress. We used biomarkers (SOD, MDA, GST, laccase, citrate synthase and phosphatases) as indicators of oxidative stress, immune system alteration, mitochondrial respiration and general metabolism, and measured population genetic diversity at each site. In parallel, concentration of 14 trace metals and 45 organic contaminants (PAHs, PCBs, pesticides) in tissues were measured. Scallops were collected outside and during their reproductive season to investigate temporal variability in contaminant and biomarker levels. Our analyses revealed that the levels of two biomarkers (Laccase-type phenoloxidase and malondialdehyde) were significantly correlated with Cd concentration. Additionally, we observed significant seasonal differences for four of the five biomarkers, which is likely due to the scallop reproductive status at time of sampling. As a source of concern, a location that was identified as a reference site on the basis of inorganic contaminant levels presented the same level of some persistent organic pollutants (DDT and its metabolites) than more impacted sites. Finally, potential long-term effects of heavy metal contamination were observed for variegated scallops as genetic diversity was depressed in the most polluted sites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Citrate (si)-Synthase
  • Gastrointestinal Tract / metabolism
  • Genetic Variation
  • Glutathione Transferase / metabolism
  • Malondialdehyde / metabolism
  • Metals, Heavy / metabolism
  • Metals, Heavy / pharmacology*
  • Pectinidae / drug effects*
  • Pectinidae / genetics
  • Pectinidae / metabolism
  • Pesticides / metabolism
  • Pesticides / pharmacology*
  • Polychlorinated Biphenyls / metabolism
  • Polychlorinated Biphenyls / pharmacology*
  • Polycyclic Aromatic Hydrocarbons / metabolism
  • Polycyclic Aromatic Hydrocarbons / pharmacology*
  • Stress, Physiological
  • Superoxide Dismutase / metabolism
  • Water Pollutants, Chemical / metabolism
  • Water Pollutants, Chemical / pharmacology*

Substances

  • Metals, Heavy
  • Pesticides
  • Polycyclic Aromatic Hydrocarbons
  • Water Pollutants, Chemical
  • Malondialdehyde
  • Polychlorinated Biphenyls
  • Superoxide Dismutase
  • Citrate (si)-Synthase
  • Glutathione Transferase

Grant support

This study was supported by a Master grant from the Port de Plaisance de La Rochelle and an ATER grant from Université de la Rochelle for Marine Breitwieser and Amelia Viricel, respectively. Additional funding was provided by the Ministère des Affaires étrangères—Royal Norwegian Embassy, the Centre National pour la Recherche Scientifique, the Port de Plaisance de La Rochelle. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.