Is metallothionein in Mimachlamys varia a suitable biomarker of trace elements in the waters of the French Atlantic coast?

The development of human activities along the Atlantic coast is responsible for the chronic pollution of the environment with organic and inorganic contaminants. In recent years, environmental regulations such as the MSFD (2008/56/EC) and the OSPAR commission have been developed to preserve coastal environments, giving rise to studies in aquatic biomonitoring. One of them is to use biomarkers to observe the pollutants impact on coastal species such as the bivalve Mimachlamys varia.

Biomonitoring of Mimachlamys varia transplanted to areas impacted by human activities (La Rochelle Marina, France).

The development of human activities on French Atlantic coastlines (La Rochelle) lead to chronic pollution of the environment by organic (pesticides, hydrocarbons, agrochemicals) and inorganic (heavy metals) contaminants. These past years, several regulations have been implemented to preserve coastal environments. The purpose of this study was to perform biomonitoring of bivalve species using an outdoor caging technique.

Metabolomics based on UHPLC-QToF- and APGC-QToF-MS reveals metabolic pathways reprogramming in response to tidal cycles in the sub-littoral species Mimachlamys varia exposed to aerial emergence.

Mimachlamys varia is a sub-littoral bivalve encountered from Norway to the Mediterranean Sea, which lives mostly byssally attached to rocks. During the low tide period, M. varia individuals, located highest on the shore, may experience short time of aerial exposure and face a low availability of oxygen.

Assessment of the biological quality of port areas: A case study on the three harbours of La Rochelle: The marina, the fishing harbour and the seaport.

This work was designed to investigate biological impacts at 3 dates (day 0, day 7 and day 21) on black scallops (Mimachlamys varia) in the three ports areas of La Rochelle town in winter 2017. In order to assess the biological effects on the wild population of black scallops, bivalves were place in four different locations: in the three ports (semi-closed areas), and in a marshland uncontaminated site (closed area). Biomarkers of effects (heavy metals) and exposure (oxidative stress and immunological effects) were assessed in the digestive glands of specimens in order to compare two techniques of sampling: "pool" technique and "inter-subject" technique.

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.

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.

Spatial and temporal impacts of the Skjervøy harbour diesel spill on native population of blue mussels: A sub-Arctic case study.

This work was designed to investigate biological impacts on blue mussels (Mytilus edulis spp) after being exposed to diesel spill. On December 2013, an 180,000-litre accidental acute diesel spill was reported in a small harbour of northern Norway (Skjervøy). In order to assess the biological effects on the wild population of blue mussels, bivalves were collected at three different locations: at the oil-spill spot, at the other side of the harbour (opposite the oil-spill area), and in an uncontaminated site.

Recent findings on phenoloxidases in bivalves.

The production of melanin is a complex process involving biochemical cascades, such as the pro-phenoloxidase (proPO) system, and enzymes, such as phenoloxidases (POs). Different studies have shown a strong correlation between the decrease in PO activities and the occurrence of diseases in bivalve invertebrates, leading to mortalities in the host. Results of these studies suggest that POs could play a fundamental role in defense mechanisms in bivalves.

First data on three bivalve species exposed to an intra-harbour polymetallic contamination (La Rochelle, France).

Evaluating diffuse sediment contamination in the environment is a major concern with the aim of reaching a good chemical and ecological state of the littoral zone. In this study the risks of chronic chemical contamination and consequences in the bivalves Crassostrea gigas, Mytilus sp. and Mimachlamys varia were evaluated in coastal environments.