Publications by authors named "Stephane le Floch"

Plastic products contain complex mixtures of chemical compounds that are incorporated into polymers to improve material properties. Besides the intentional chemical additives, other compounds including residual monomers and non-intentionnaly added substances (NIAS) as well as sorbed pollutants are usually also present in aged plastic. Since most of these substances are only loosely bound to the polymer via non-covalently interactions, i.

View Article and Find Full Text PDF

In recent years, biosurfactants (BS) produced by various bacteria, fungi and yeast strains have attracted much interest because of their unique properties and potential applications in many industries ranging from bioremediation to agriculture and biomedical to cosmetics. Glycolipids are a popular group of BS that include rhamnolipids, sophorolipids, mannosylerythritol, trehalose lipids, xylolipids and cellobiose lipids. Lipopeptides e.

View Article and Find Full Text PDF
Article Synopsis
  • Watersheds and estuaries face various human-related stressors that threaten their biodiversity and ecosystem health, creating a challenge for scientists and stakeholders in evaluating their ecological quality.
  • The study focuses on seven small French estuaries in agricultural watersheds, utilizing a multidisciplinary approach that includes landscape analysis, pollutant chemistry, and fish proteomics to understand the impact of land use on these environments.
  • Results showed significant environmental stress on juvenile European flounder due to factors like pesticides and hypoxia, revealing a complex response in fish proteins linked to detoxification, immunity, and metabolism in densely agricultural areas.
View Article and Find Full Text PDF

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants generally found in complex mixtures. PAHs are known to cause pleiotropic effects on living organisms, including developmental defects, mutagenicity, carcinogenicity and immunotoxicity, and endocrine disruptions. The main goal of this study is to evaluate the toxicity of water-accommodated fractions (WAFs) of oils in two life stages of the Japanese medaka, larvae and juveniles.

View Article and Find Full Text PDF

Rapid, simultaneous detection of organic chemical pollutants in water is an important issue to solve for protecting human health. This study investigated the possibility of developing an reusable optical sensor capable of selective measurements utilizing a chalcogenide transducer supplemented by a hydrophobic polymer membrane with detection based on evanescent waves in the mid-infrared spectrum. In order to optimise a polyisobutylene hydrophobic film deposited on a chalcogenide waveguide, a zinc selenide prism was utilized as a testbed for performing attenuated total reflection with Fourier-transform infrared spectroscopy.

View Article and Find Full Text PDF

Fish are currently used models for the toxicity assessment of chemicals, including polycyclic aromatic hydrocarbons (PAHs). Alternative methods including fish cell lines are currently used to provide fast and reliable results on the toxic properties of chemicals while respecting ethical concerns about animal testing. The Rainbow trout liver cell line RTLW1 was used to analyze the effects of two water-accommodated fractions from two crude oils: Arabian Light crude oil (LO) and refined oil from Erika (HO).

View Article and Find Full Text PDF

On September 26th 2019, a major fire occurred in the Lubrizol factory located near the Seine estuary, in Rouen-France. Juvenile flounders were captured in the Canche estuary (a reference system) and caged one month in the Canche and in the Seine downstream the accident site. No significant increases of PAHs, PCBs and PFAS was detected in Seine vs Canche sediments after the accident, but a significant increase of dioxins and furans was observed in water and sewage sludge in the Rouen wastewater treatment plant.

View Article and Find Full Text PDF

There is increasing evidence that sunscreen, more specifically the organic ultra-violet filters (O-UVFs), are toxic for aquatic organisms. In the present study, we simulated an environmental sunscreen exposure on the teleost fish, Chelon auratus. The first objective was to assess their spatial avoidance of environmental concentrations of sunscreen products (i.

View Article and Find Full Text PDF

Biomarkers involved in detoxification process (GST), oxidative stress (SOD and MDA), immune response (Laccase) and neurotoxic disorders (AChE) were analysed in Pacific oysters and blue mussels collected from 4 locations within the Pertuis sea (France). Seasonal variations of total pesticide mean concentrations were found in seawater with metolachlor being the main pesticide measured (up to 32 ng/L). The majority of pesticide concentrations in sediment were below the LOD.

View Article and Find Full Text PDF
Article Synopsis
  • This study developed a multidisciplinary framework to evaluate the ecological health of six French estuaries by collecting various data types, including geography, hydrobiology, pollution chemistry, and fish biology.
  • European flounder were collected to analyze their responses to environmental stressors through classical biomarkers and modern molecular techniques like transcriptomics and proteomics, revealing significant changes in protein levels related to detoxification and stress.
  • The findings highlighted specific human impacts on each estuary, such as industrial activity and agricultural runoff, which led to issues like hypoxia and potential endocrine disruption in fish populations.
View Article and Find Full Text PDF

Port areas are socio-ecosystems impacted by chronic mixture pollution. Some marine species benefit from living there and may be studied to define the ecological state of such environments. In this study, the risks of chronic chemical contamination and its consequences on three marine molluscs were evaluated in North Corsica (France) port areas.

View Article and Find Full Text PDF

Aims: To investigate fungal diversity and biosurfactant-producing fungi in four oil-contaminated sites.

Methods And Results: Water and sediment samples were collected from four sites in Brittany (France), over two periods, in winter/spring and summer. Fungal diversity was investigated using a metagenetic approach targeting the ITS2 region.

View Article and Find Full Text PDF

Pollution particularly affects coastal ecosystems due to their proximity to anthropic sources. Among those environments, harbours are subjected to marine traffic but also to accidental and chronic pollution. These areas are thus exposed to complex mixtures of contaminants such as trace elements and organic contaminants which can impact marine species, habitats, and ecosystem services.

View Article and Find Full Text PDF

The main objective of this study was to improve our knowledge on the responses of fish populations to multistress (diffuse pollution and warming waters) in estuaries. Adult flounders were caught in two estuaries in the Eastern English Channel: the heavily polluted Seine estuary vs the moderately contaminated Canche estuary. Fish samplings were conducted in January just before the reproduction period, and in July when gonads were at rest.

View Article and Find Full Text PDF

The present pilot study aimed to provide an overview of organic contaminant concentration levels in the littoral ecosystems of the Pertuis seas. The study determined the concentrations of twenty-nine pesticides, six nonylphenols and seven polybrominated diphenyl ethers (PBDEs) in sediments, seawater, Pacific oysters and blue mussels. Oysters accumulated a higher number of pesticides than blue mussels.

View Article and Find Full Text PDF
Article Synopsis
  • Pesticides and microplastics are prevalent in coastal waters and can negatively affect marine organisms like the Pacific oyster.
  • This study investigated the impact of a herbicide and microparticles on juvenile oysters over 24 days, examining factors like valve activity and shell growth.
  • Results showed that exposure to these pollutants altered valve micro-closures and opened durations, and significantly reduced shell growth, indicating harmful effects on oyster physiology.
View Article and Find Full Text PDF

In the early 1970s, studies of marine litter first appeared in the scientific literature. Fifty years later, knowledge of several coastal areas of the Atlantic, the driving forces of oyster farmers and aquaculture, is lacking. This work documents a pilot study on an Atlantic coastal area (France).

View Article and Find Full Text PDF

The objective of this study was to develop an integrative approach in ecotoxicology (from biomarkers to population genetics) to assess the ecological status of fish populations. Flounders () collected after the spawning season in the heavily polluted Seine estuary were compared with the moderately polluted Bay of Douarnenez. The muscle energetic reserves were highly depleted in Seine vs.

View Article and Find Full Text PDF

Accidental spills are pervasive pollution in aquatic ecosystems. Resorting to chemical dispersant is one of the most implemented strategies in response to oil spills, but it results in an increase in the bio-availability of oil compounds known to disturb fish neurosensory capacities and hence fish habitat use. While it has become well established that acute oil exposure can cause a range of physiological defects, sub-lethal consequences on animal behaviour have only received recent attention.

View Article and Find Full Text PDF

This study investigated the sensitivity of two deepsea species using mortality of northern shrimp (Pandalus borealis) and polyp activity of stony coral (Lophelia pertusa) to dispersant, Corexit 9500 and aromatic hydrocarbons (toluene, 2-methylnaphthalene, phenanthrene) in 96-h tests. Resulting hydrocarbon toxicity data were fit to the Target Lipid Model to generate predictive models and determine species sensitivity. Toxicity of chemically enhanced water accommodated fractions of Alaskan North Slope crude oil (ANS-oil) was also investigated with shrimp using nominal loading, total petroleum hydrocarbons and biomimetic extraction (BE) as oil exposure metrics.

View Article and Find Full Text PDF

Hypoxia and petrogenic hydrocarbon contamination are two anthropogenic stressors that coexist in coastal environments. Although studies have estimated the impact of each stressor separately, few investigations have assessed the effects of these stressors in interaction. We therefore investigated the impact of these combined stressors on sea bass, (Dicentrarchus labrax) physiology.

View Article and Find Full Text PDF
Article Synopsis
  • The study explores how high hydrostatic pressure (10.1 MPa) affects turbot liver cells exposed to different types of oil and dispersants, highlighting the importance of ecotoxicological research after the DeepWater Horizon oil spill.
  • It was found that oil exposure led to increased cell viability despite no notable changes in overall cell mortality, suggesting that stress responses differ under these conditions.
  • The research also indicates that while oil exposure under pressure raises cellular oxygen consumption, the presence of dispersant prevents this increase, hinting at complex interactions that require further investigation.
View Article and Find Full Text PDF

In the context of new oil exploration/production areas, knowledge of the biological impact of dispersed oil in the deep-sea environment is essential. Hence, the aim of this study was to perform a comparison, at atmospheric pressure (0.1 MPa) and at a high hydrostatic pressure corresponding to 1000 m depth (10.

View Article and Find Full Text PDF

We studied how exposure to oil spill response technologies affect marine microorganisms during Arctic winter and spring. Microorganisms were exposed to chemically dispersed oil (DISP), in situ burnt oil (ISB), and natural attenuated oil (NATT) in mesocosms from February to May. We subsampled the mesocosms and studied the effects of oil in laboratory incubations as changes in biomass of the major functional groups: bacteria, heterotrophic-nanoflagellates, dinoflagellates, ciliates, pico- and nanophytoplankton, and diatoms over two 14-day periods.

View Article and Find Full Text PDF

Aquatic ecosystems are now chronically polluted by a cocktail of many chemical substances. There is now clear evidence of associations between exposure to pollutants and greater susceptibility to pathogens. The aim of the present study was to characterize the defense capacities of rainbow trout (Oncorhynchus mykiss), chronically exposed to pendimethalin (PD), to subsequent experimental challenge with the infectious hematopoietic necrosis virus (IHNV).

View Article and Find Full Text PDF